It’s a home day for me with the flu, so to recover from a long day of videoconferencing meetings, and because a headache won’t let me concentrate on important stuff, I played around with an idea I wrote up as a high school English project.

Milton wrote the epic Paradise Lost, in which he presents his own cosmology of Heaven, Hell, and Earth. This was an ambitious task, since Dante’s Divine Comedy had set a pretty high standard here.

The geometry of Creation in the Divine Comedy (not to scale) with Hell inside the Earth and heaven outside the final sphere in a Ptolemaic universe.

Milton actually met Galileo in person—he visited Galileo’s estate as a boy when the astronomer was there in his later years under house arrest.

The visit may have left an impression. Milton avoids any reference to where the center of the Solar System is in his cosmology—it’s pretty nebulous exactly how everything is arranged—but in Book 4 the angel Uriel needs to get back to his station in the Sun from Earth. He slid down to Earth on a sunbeam, but fortunately for him the Sun has now set, so the tip of his sunbeam is now up in the air. He just jumps on and slides down:

 …and Uriel to his charge
Returnd on that bright beam, whose point now rais’d 
Bore him slope downward to the Sun now fall’n
Beneath th’ Azores

but how did the Sun get so low? It is “beneath th’ Azores” far to the West:

whither the prime Orb,
Incredible how swift, had thither rowl’d
Diurnal, or this less volubil Earth
By shorter flight to th’ East, had left him there

The “prime Orb” is Ptolemy’s name for the Sun, which had (“incredible how swift”) there “rowl’d Dirunal”—rolled down there over the course of the day.  But Milton did not choose his words lightly.  “Incredible” literally means “beyond credibility”.  He doesn’t buy that it really goes so fast.

Is there an alternative?  Milton dithers.  “Or” he writes “this less volubil Earth” (meaning “less apt to roll” according to the OED) went a much shorter distance the other way and the Sun just stayed where “he” was.  That’s Copernicus’s model for the days!

So he clearly prefers Copernicus’s model, and offers it as an alternative, but opens with the more familiar and established terminology and cosmology of Ptolemy (and Dante).

It’s interesting he didn’t commit.  Perhaps he didn’t want to tie his work to a model that might be wrong, or perhaps he didn’t want to alienate his Ptolemist readership.

I wonder, though, if heliocentrism had been widely accepted a century before, if Paradise Lost would have had a well defined geometry of the universe, like the Divine Comedy famously does, but with Heaven and Hell having distinct places in a heliocentric Solar System?

For a long time after sunspots were discovered telescopically by Galileo, there weren’t any to see. John Eddy has a nice paper on the history of sunspot measurements, showing conclusively that there was an 80-year period, now called the “Maunder Minumum”, in which the Sun just didn’t have any sunspots.

Why not? We’d love to know.  The Solar dynamo is a bit of a mystery, and it just apparently turning off for 80 years is kind of important—it may have even had an effect on climate on Earth, although that case is often overstated (it’s not glaringly obvious from the global temperature anomaly record).

Shivani Shah, Penn State undergrad now applying to a graduate program near you!

Finding another star undergoing such a period would be great. We could study its corona and chromosphere it answer questions like: Is it still undergoing its magnetic cycle, just without sunspots? Is it just an extended minimum that lasts many cycle periods? Or did the dynamo turn off entirely? If we had a sample of them we could ask: is this typical behavior of Sun-like stars? All cycling stars? Just stars of the Sun’s age?

For a while, people looked for extremely inactive “sun-like” stars to find “Maunder minimum stars”, but I showed in my thesis that these stars are in fact not Sun-like (they’re subgiants).

People looked in M67, a cluster filled with Sun-like stars, to find extremely inactive stars there, but Jason Curtis showed that these stars were not actually all that inactive (the ISM got in the way).

For a long time Steve Saar has advocated using time series to see a star do what the Sun apparently did: go from a cycling state to a quiet state (or the reverse).  This means using the 50+ year baseline of activity measurements we have of stars to find a cycling star that transitions into or out of a cycling state to a “flat activity state”.  That would make for a pretty convincing candidate, I think.

Well, now we have one! Shivani Shah has written up the strange case of HD 4915, a Sun-like star that seems to have had its cycle peter out to almost nothing.  Here’s the killer plot:

Activity history of HD 4915. Larger “S-Value”s mean (presumably) more starspots. Note that the star came down from a (presumed) maximum, came up to a second, weaker maximum, then had a very slow rise to what seems to be a very weak maximum. Is the magnetic cycle of this star dying out?

It’s cool to see something that looks a lot like what we’ve been expecting to see for a while.  For comparison, here are the “grand magnetic minima” the Sun has experienced, measured with sunspots:

Sunspot number vs. time for three magnetic state transitions on the Sun, from the Hoyt & Schatten 1998 historical reconstructions. Note that we have reversed the x-axis on the bottom panel.

Black dots above are the parts of the Solar record we are suggesting to be analogous to the HD 4915 time series.  The red points are our projections of its future behavior if the analogy is perfect.  So, if this is analogous to the “Dalton Minimum” (no, not that Dalton Minimum) then the next cycle should be rather strong; if it’s truly going into a Maunder Minimum-like state we may not see any activity for another 80 years! So only time will tell if this is right, but I think it’s the best candidate I’ve seen so far.  I hope that by studying this star we can finally crack the nut of what the Sun was doing without sunspots for all those decades!

The paper is on the arXiv here.  Comments welcome!

No, this isn’t a post about METI.  This is about an interesting sociological phenomenon about one of the ways in which SETI is marginalized in astronomy.

SETI tends to get media attention, at an amount disproportionate to the amount of SETI work actually done. There are many reasons for this. One is that it is a topic of genuine interest to much of the lay public.  Another is that it is easily sensationalized and conflated with UFOlogy and science fiction by the yellow press.

I’ve had my share of both sides. Take Ross Andersen’s excellent article on Tabby’s Star (which was a scoop; we did not put out a press release or publish anything that triggered it). This story got huge amounts of global media attention, to the point that it appeared on Saturday Night Live and the Tonight Show. This second wave of stories led to the perception that Tabby herself “jumped to aliens” as an explanation, when in fact her paper and press release made no mention of aliens, and the press release announced “comets” as the cause.

The Daily Mail is a sensationalist rag in the UK that seems to have decided I’m their go-to name for all things alien. Sort of like the way that they find a way to shoehorn Stephen Hawking into the headlines of any article they write about space, but to a much smaller degree, they seem to love to claim I’ve found aliens (or that I think I have) when I write the opposite in a public space.  For instance:

1. I had a press release titled “Search for Advanced Civilizations Beyond Earth Finds Nothing Obvious“.  The Mail Online’s lede was that I had “found 50 galaxies that may contain intelligent alien races.”
2. I wrote a paper whose premise was that the question of extraterrestrial life (of any kind) in the Solar System is an “open question”, and in particular that the Solar System apparently lacks any alien artifacts.  The Mail Online article’s subheads claimed that I believe that intelligent “aliens either lived on Earth, Venus or Mars billions of years ago.”
3. And when I wrote a couple of blog posts about how I didn’t think ‘Oumuamua was a great SETI target (but that it should get us thinking about Solar System SETI), they again reversed my meaning and wrote that I claimed ‘Oumuamua “could be an alien spacecraft with broken engines.”

It’s pretty embarrassing to see your work so brazenly sensationalized in the media, but given the Daily Mail’s reputation I’m not sure there’s anything I could have done to prevent it except not talk about SETI at all where it might be overheard. I’ve developed a thick skin about it, but it still smarts to see my name next to pictures of bug-eyed aliens.  I know that colleagues of mine that don’t know the whole story will think less of me because of these false portrayals of me working on “fringe” science or shouting “aliens” at every astronomical anomaly.

So it’s especially galling when my colleagues accuse me of sensationalizing my work or, worse, only working in SETI at all because I’m after media attention. This attitude is probably widespread, because a few fed-up people have lost their cool and announced it several times in rants online; I can only imagine how many more have kept their cool or only said it where I haven’t noticed.  Some examples (names and links omitted to protect the guilty):

1. About a short ETI discussion in a longer paper (that did not seek or garner any headlines)
   What does the mention of alien civilizations really add to these topics other than an attempt to grab headlines?
   and
   What’s to be gained by a casual mention in the abstract and end of the paper? … this (along with a growing list of other examples in the literature) is an attempt to grab headlines.
2. Rebutting an argument that there is nothing wrong with seriously discussing SETI angles of astronomical anomalies on social media:
   All fine, but there is another component of this, which is cynical citation of ETI as a simple way of gaining attention. Your discussion assumes earnest and honest motivations. I’m not sure that that is always true.
3. Starting a discussion about how SETI astronomers need to stop sensationalizing their work:
   most SETI-related news seems to be interfering with conventional scientific discoveries, stealing the limelight – without following basic rules of science
4. Piling on to that discussion:
   It’s not just SETI you should be dumping on here, if your overall argument is to stop selling bullshit to the media because it’s fun.

At the risk of making an analogy to an infinitely more serious problem, they’re blaming the victims. Here we are getting misquoted and caricatured in the yellow press, and they’re the ones that are offended and embarrassed at what we have put them through. To them, somehow it’s our fault that the Mail misquotes us, and their attitude is that if we didn’t want to be misquoted, then why were we doing that kind of science in the first place? 

The real bad actors here are the yellow journalists, and that is a problem all of us in science and science communication have to deal with all the time; SETI is just a particularly soft target for them.

So, for the record: this kind of media attention is not “fun,” it’s mortifying, and we are not asking for it when we discuss our work in public. Many of the above accusations were surrounded by claims that the writers respect SETI as science, but you don’t really respect scientists’ work if you think it’s irresponsible of them to talk about it out loud, or if you think the only reason they do it is so that they can get their names in the papers.

SETI astronomers have had to deal with conflation with UFOlogy and fringe psuedoscience for decades; I hope that more of our colleagues will recognize that we share their disdain for sensationalism and are pulling in the same direction on the issue of sober science communication about good science.

And I hope that they won’t cast scorn at every SETI paper or reference to ETIs in the literature (“astro-crap” one astronomer called it on Facebook), and not cast aspersions on the authors for working on an important problem (especially junior researchers, who are both the future lifeblood of the field and the most sensitive to these accusations).

SETI gets enough unjustified grief from Congress, the last thing we need is to have to worry about our colleagues in our flanks piling on.

What follows is my submission to the National Academies of Sciences, Engineering, and Medicine ad hoc Committee on Astrobiology Science Strategy for Life in the Universe, 2018. It is available as a PDF here.

Please also see Jill Tarter’s companion white paper here.

I. SETI is Part of Astrobiology

“Traditional SETI is not part of astrobiology” declares the NASA Astrobiology Strategy 2015 document (p. 150). This is incorrect.¹

Astrobiology is the study of life in the universe, in particular its “origin, evolution, distribution, and future in the universe.” [emphasis mine] Searches for biosignatures are searches for the results of interactions between life and its environment, and could be sensitive to even primitive life on other worlds.  As such, these searches focus on the origin and evolution of life, using past life on Earth as a guide.

But some of the most obvious ways in which Earth is inhabited today are its technosignatures such as radio transmissions, alterations of its atmosphere by industrial pollutants, and probes throughout the Solar System. It seems clear that the future of life on Earth includes the development of ever more obvious technosignatures. Indeed, the NASA Astrobiology Strategy 2015 document acknowledges “the possibility” that such technosignatures exist, but erroneously declares them to be “not part of contemporary SETI,” and mentions them only to declare that we should “be aware of the possibility” and to “be sure to include [technosignatures] as a possible kind of interpretation we should consider as we begin to get data on the exoplanets.”

In other words, while speculation on the nature of biosignatures and the design of multi-billion dollar missions to find those signatures is consistent with NASA’s vision for astrobiology, speculation on the nature of technosignatures and the design of observations to find them is not. The language of the strategy document implies NASA will, at best, tolerate its astrobiologists considering the possibility that anomalies discovered in the hunt for biosignatures might be of technological origin.

But there is no a priori reason to believe that biosignatures should be easier to detect than technosignatures—indeed, we have had the technology to detect strong extraterrestrial radio signals since the first radio SETI searchers were conducted in 1959, and today the scope of possibly detectable technosignatures is much larger than this. Furthermore, intelligent spacefaring life might spread throughout the Galaxy, and so be far more ubiquitous than new sites of abiogenesis. Life might be much easier to find than the NASA strategy assumes.   

Indeed it has been cynically, but not untruthfully, noted that NASA eagerly spends billions of dollars to search for “stupid” life passively waiting to be found, but will spend almost nothing to look for the intelligent life that might, after all, be trying to get our attention. This is especially strange since the discovery of intelligent life would be a much more profound and important scientific discovery than even, say, signs of photosynthesis on Ross 128b.

Further, since technosignatures might be both obvious and obviously artificial SETI also provides a shortcut to establishing that a purported sign of life is not a false positive, a major and pernicious problem in the hunt for biosignatures. SETI thus provides an alternative and possibly more viable path to the discovery of alien life than is reflected in NASA’s astrobiology roadmap. Indeed, this was recognized explicitly in the panel reports of the Astro2010 decadal survey:

Of course, the most certain sign of extraterrestrial life would be a signal indicative of intelligence. [A radio] facility that devoted some time to the search for extraterrestrial intelligence would provide a valuable complement to the efforts suggested by the PSF report on this question. Detecting such a signal is certainly a long shot, but it may prove to be the only definitive evidence for extraterrestrial life. (p.454, Panel Reports—New Worlds, New Horizons in Astronomy & Astrophysics)

II. Why is SETI Neglected in NASA’s Astrobiology Portfolio?

While it is not completely clear why NASA does not include SETI in its astrobiology portfolio, there are several factors that seem likely to be at play.

The first is the risk of public censure: SETI sometimes suffers from a “giggle factor” that leads some to conflate it with “ufology” or campy science fiction. Indeed, such an attitude likely led to the cancelation of the last NASA SETI efforts in the early 1990’s, after grandstanding by US senators denouncing “Martian hunting season at the taxpayer’s expense” (Garber 1999). Such attitudes harm all of science, and the National Academies should be clear that such a “giggle factor” must not be allowed to influence US science priorities.

The second is the erroneous perception that SETI is an all-or-nothing proposition that yields no scientific progress unless and until it succeeds in detecting unambiguous signs of interstellar communication. On the contrary, even with scant funding, SETI has historically been involved in some of the most important discoveries in astrophysics. Not only have the demands of radio SETI led to breakthroughs in radio instrumentation (see, for instance, the new Breakthrough Listen backend at the Green Bank 100-meter telescope, with bandwidth of up to 10 GHz, an ideal Fast Radio Burst detection device; Gajjar et al. 2017), but some of the most famous SETI false positives have proven to be new classes of astrophysical phenomena, including active galactic nuclei (CTA-21 and CTA-102, Kardashev 1964), pulsars (originally, if somewhat facetiously, dubbed “LGM” for “Little Green Men”), and perhaps the still-not-fully-understood “Tabby’s Star” (KIC 8462852, Boyajian et al. 2016, Wright et al. 2016, Wright & Sigurdsson 2017).

Indeed, exactly because SETI seeks signals of obviously artificial origin, it must deal with and examine the rare and poorly understood astrophysical phenomena that dominate its false positives. Anomalies discovered during searches for pulsed and continuous laser emission (Howard et al. 2007, Wright et al. 2014, Tellis & Marcy 2015, 2017) broadband radio signals, large artificial structures (Dyson 1960, Griffith et al. 2015, Wright et al. 2016), and other astrophysical exotica push astrophysics in new and unexpected directions. If there is a perception that SETI little more than the narrow search for strong radio carrier waves producing a long string of null results it is because historically there has been essentially no funding available for anything else.

Third, there is the erroneous perception that, since radio SETI has been active for decades, its failure to date means there is nothing to find. On the contrary, the lack of SETI funding means that only a tiny fraction of the search space open to radio SETI has been explored (Tarter et al. 2010). Indeed, Robert Gray has estimated that the total integration time on the location of the Wow! Signal (the most famous and credible SETI candidate signal to date) is less than 24 hours (see, for instance, Gray et al. 2002). That is, if there is a powerful, unambiguous beacon in that direction with a duty cycle of around one pulse per day, we would not have detected a second pulse yet. Other parts of the sky have even less coverage. The truth is, we only begun to seriously survey the sky even for radio beacons, and other search methods have even less completeness.

Fourth, there is the erroneous perception that SETI will proceed on its own without NASA support. Indeed, the 2015 NASA Astrobiology Roadmap claims that “traditional SETI is…currently well-funded by private sources.”  Even setting aside the non sequitur of considering the amount of private philanthropic funding when assessing the merits of the components of astrobiology, this is not a fair description of the state of the field. While it is true that the Breakthrough Listen Initiative has pledged to spend up to $100 million over 10 years, in truth its spending has been far below that level, and it is focused on a small number of mature search technologies. Beyond this initiative, private benefactors have supported the SETI Institute’s Allen Telescope Array, but not at the level necessary to complete the array or fund its operations.

Fifth, there is the erroneous perception that the search for technosignatures is somehow a more speculative or risky endeavor than the search for biosignatures. We note that the entire field of astrobiology once faced a similar stigma. Chyba & Hand rebutted that perception in 2005:

Astro-physicists…spent decades studying and searching for black holes before accumulating today’s compelling evidence that they exist. The same can be said for the search for room-temperature superconductors, proton decay, violations of special relativity, or for that matter the Higgs boson. Indeed, much of the most important and exciting research in astronomy and physics is concerned exactly with the study of objects or phenomena whose existence has not been demonstrated—and that may, in fact, turn out not to exist. In this sense astrobiology merely confronts what is a familiar, even commonplace situation in many of its sister sciences.

Their rebuttal holds just as well as SETI today. Indeed, Wright & Oman-Reagan (2017) have articulated a detailed analogy between SETI and the relatively uncontroversial search for dark matter particles via direct detection. They argue that unlike with dark matter searches, with SETI, at least, we have the advantage that we know that the targets of our search (spacefaring technological species) arise naturally (because we are one).

Finally, there is an erroneous perception that SETI is exclusively a ground-based radio telescope project with little for NASA to offer. On the contrary, SETI is an interdisciplinary field (Cabrol 2016) and even beyond the potential for NASA’s Deep Space Network to play an important role in the radio component of SETI, archival data from NASA assets have played an important role in SETI for decades: from Solar System SETI using interplanetary cameras, to waste heat searches using IRAS (Carrigan 2009) WISE, Spitzer, and GALEX (Griffith et al. 2015), to searches for artifacts with Kepler (Wright et al. 2016) and Swift (Meng et al. 2017). Future ground-based projects like LSST and space-borne projects like JWST and WFIRST will undoubtably provide additional opportunities SETI research both as ancillary output of legacy and archival programs and through independent SETI projects in their own right.

III. Reinvigorating SETI as a Subfield of Astrobiology

One difficulty SETI faces is a negative feedback between funding and advocacy.

As it stands, SETI is essentially shut out of NASA funding. SETI is not mentioned at all in most NASA proposal solicitations, making any SETI proposal submitted to such a call unlikely to satisfy the merit review criteria. Worse, the only mentions of SETI in the entire 2015, 2016, and 2017 ROSES announcements are under “exclusions,” in the Exobiology section (“Proposals aimed at identification and characterization of signals and/or properties of extrasolar planets that may harbor intelligent life are not solicited at this time”) and the Exoplanets section (as “not within the scope of this program.”) In other words, SETI is ignored entirely in NASA proposal solicitations, except for those most relevant to it, in which cases it is explicitly excluded.

Meanwhile, other parts of astrobiology have flourished under NASA’s aegis, which has incubated strategies for the detection of life elsewhere in the universe, and produced scientists who can advocate for mature roadmaps to the detection of life in the universe as part of NASA’s astrobiology program. But now, twenty years after the last major NASA SETI program was cancelled, there are only a handful of SETI practitioners and virtually no pipeline to train more.

Thus there are only a few well-developed strategies to advocate for, and only a few scientists to advocate for them. This will doubtless be reflected in the number of white papers advocating SETI (like this one) versus those advocating other kinds of astrobiology responsive to the current call. This disparity should not be seen as indicating a lack of intrinsic merit of the endeavor of SETI, but as a sign of neglect of SETI by national funding agencies.

Since SETI is, quite obviously, part of astrobiology, SETI practitioners should at the very least be expressly encouraged to compete on a level playing field with practitioners of other subfields for NASA astrobiology resources.

Doing so will uncork pent-up SETI efforts that will result in significant progress over the next 10 years and beyond. As a fully recognized and funded component of astrobiology, SETI practitioners will be able to develop new search strategies, discover new astrophysical phenomena and, critically, train a new generation of SETI researchers to guide NASA’s astrobiology portfolio to vigorously pursue the discovery of all kinds of life in the universe—both “stupid” and intelligent.

And if, as many suspect, technosignatures prove to be closer to our grasp than biosignatures, then including of SETI in NASA’s astrobiology portfolio will ultimately lead to one of the most profound discoveries in human history, and a reinvigoration of and relevance for NASA not seen since the Apollo era. In retrospect, we will wonder why we were so reluctant to succeed.

IV. Bibliography

• Boyajian, T. S. et al. 2016, MNRAS 457, 3988
• Carrigan, R. A, Jr., 2009, The Astrophysical Journal 698, 2075
• Cabrol, N. A. 2016, Astrobiology, 16, 9
• Chyba, C. F. & Hand, K. P. 2005 Annu. Rev. Astron. Astrophys. 43, 31–74.
• Domagal-Goldman S. D. & Wright K. E. Astrobiology. August 2016, 16(8): 561-653. 
• Dyson, F. 1960 Science 131, 1667
• Gajjar, V., et al. 2017, The Astronomer’s Telegram, 10675
• Garber, S.J. 1999. J. Br. Interplanet. Soc. 52, 3–12.
• Gray, R., et al. 2002, The Astrophysical Journal 578, 967
• Griffith, R. et al. 2015, The Astrophysical Journal Supplement Series 217, 25
• Howard, A., et al. 2007, Acta Astronautica 61, 78H
• Kardashev, N. S. 1964, Soviet Astronomy, 8, 217
• Meng, H., et al., 2017 The Astrophysical Journal 847, 131
• Reines, A. E., 2002 Publications of the Astronomical Society of the Pacific 114, 416R
• Tellis, N. K, & Marcy, G. W., 2015 PASP 127, 540T
• Tarter, J., et al., 2010 SPIE 781902 http://dx.doi.org/10.1117/12.863128
• Tellis, N. K, & Marcy, G. W., 2017 The Astronomical Journal 153, 251
• Wright, S., et al, 2014 SPIE 9147E, 0JW
• Wright, J. T., et al. 2016, The Astrophysical Journal 816, 17
• Wright, J. T. & Sigurdsson, S. 2016, The Astrophysical Journal, 829, 3
• Wright, J. T. & Oman-Reagan, M. P. 2017, Int. Jour. of Astrobiology, arXiv:1708.05318

¹ Indeed, broad swaths of the astrobiology community disagree with NASA’s assertion. For instance, SETI was included as a component of astrobiology in The Astrobiology Primer v.2.0 (Domagal-Goldman & Wright 2016), and SETI activities fall under the Carl Sagan Center for astrobiology at the SETI Institute (which, despite the name, conducts a broad range of science, including many sub-fields of astrobiology).

Part I here.

It’s been a huge amount of work, but we finally have some conclusions.

First and foremost, the dips have now been observed by an instrument other than Kepler.  So we can firmly rule out instrumental effects! (This was already clear, but it’s now true beyond all doubt for the dips).

Secondly, the dips are clearly chromatic:

Analysis of LCO data by Eva Bodman.

Eva Bodman has done a lot of work to characterize how much deeper the dips are at blue wavelengths than red ones.  If there were opaque objects blocking our view of the light, the star should get equally dim at all wavelengths. Instead, Eva finds that the blue (B) dips are much deeper—about twice as deep—as they are when we look at infrared wavelengths (i’ band, just beyond human vision).

This is consistent with ordinary astrophysical dust, and a major conclusion of our paper: the dips are not caused by opaque macroscopic objects (like megastructures or planets or stars) but by clouds of very small particles of dust (less than 1 micron in typical size). We can also say that these clouds are mostly transparent (“optically thin” in astrophysics parlance).

Secondly, we have spectra from Keck/HIRES both before and during the dips (in-dip spectra kindly contributed by John O’Meara, Jay Farihi, and Seth Redfield; see the black lines in the above figure for when they were taken.  Pre-dip data taken by Andrew Howard and Howard Isaacson.)  The difference between these spectra should bear the spectral fingerprints of whatever is causing the dips!  So, is there atomic gas?  Let’s check the neutral sodium lines (analysis courtesy of Jason Curtis):

The broad sodium line from the star forms a shallow bowl, the sharp features are due to interstellar clouds containing sodium between us and the star.

The black points and red line in the figure above are from before and during the dips, respectively, and the black line at the bottom is the difference.  As you can see, there is no obvious change in the spectrum at all. This strongly suggests that the dust causing the dips is not accompanied by much neutral sodium.

What about hot gas? If it’s really hot there shouldn’t be much in the way of dust, but if it’s warm there should be ionized calcium.  How do the calcium lines look?

The broad calcium line from the star forms a shallow bowl, the sharp features are due to clouds containing calcium between us and the star.

Again, no change, so it looks like there is no additional ionized gas accompanying the dust. So the dust—if that’s what it is—seems to be by itself with no accompanying gas.

In fact Jason Curtis has gone further, and shown that there does not appear to be any change in the stellar lines, either, during a dip, meaning the star is not moving, so does not have a nearby companion orbiting it.

So where are our 10 possibilities?

As I wrote, instrumental effects (#1) are now firmly ruled out.

The hypotheses I found most plausible involving an interstellar gas and dust cloud (#3 and #4), are not looking great. There should have been atomic gas in that case, and we see none.

My favorite (but “less-plausible”) hypothesis #5, a black hole disk, has not been similarly developed, so I think is still in play because we’re not sure what we would have expected to see for that one yet. A cold disk of dust could easily have had all of its gas frozen out onto grain surfaces, I suspect.

The unlikely hypotheses of an orbiting black hole disk (#6), spherical swarm of megastructures (#9) and pulsations (#12) continue to be unlikely.

But now even the more generic “alien megastructures” hypothesis (of any geometry) takes a severe blow from the chromatic nature of the dips: no opaque objects seem to be causing this.  I suspect this will be the big headline here, so let me reemphasize: if the dips had been the same color at all wavelengths, we would have been scratching our heads and this hypothesis would be looking better than before (though still of unclear likelihood).  The fact that the data came in the other way means that we now have no reason to think alien megastructures have anything to do with the dips of Tabby’s Star (Recall that Meng et al. had already come to a similar conclusion with respect to the long-term dimming, but it was the dips that got us thinking along these lines in the first place).

I still like the Solar System cloud idea (#2) but until it is developed to the point where we know what colors of dimming we would expect for a Solar System cloud, it remains of “unclear” plausibility.

The fact that the stellar lines did not change velocity during a dip helps us rule out pulsations (#12, if the star changed size then its atmosphere would be moving and would have a changing radial velocity) as well as close companions. Tabby had already ruled out the nearby companion hypothesis (which is why it wasn’t even on my list) but we now have independent confirmation.

Hypotheses invoking circumstellar material seem to be doing well. Steinn and I were originally pretty down on this class of solutions because of the lack of infrared excess and their inability to explain the long-term dimming, but Metzger et al. and Wyatt et al. (2017) ‘s models have shown how this could be explained, bringing this class of hypothesis up the plausibility scale to near the top (in my mind). To remind you, Wyatt et al. explain both the long- and short-term dimming with circumstellar material, while Metzger et al. have the long-term dimming being intrinsic and the dips due to exocomet-like debris).

We were also down on the family of solutions involving intrinsic variations, and we still don’t think the polar spots model (#11) and stellar cycle model (#10) have high likelihood. But in addition to the Metzger et al. hypothesis, Peter Foukal has developed a model where the entire star gets cooler, and this model is also consistent with the data (I think the dips seem to be too deep in the blue, but formally it’s consistent at the “2-sigma” level). Indeed, Peter himself finds the dips to be less chromatic than we do and very consistent with his model. So I’m ready to promote this class of solution up, in particular because it predicts no absorption features accompanying dimmings, which is indeed exactly what we see.

As for the circumstellar material solutions (“exocomets”), I’m not personally sure why that model does not predict neutral and ionized gas to accompany the dips, but I don’t think anyone has worked it out in detail yet, so it could be easy to explain.

So to recap:

Wyatt et al. and Metzger at al. have developed models involving circumstellar material like exocomets that seem to be consistent with the data we have. Wyatt et al. and Foukal have developed models where the star itself is getting dimmer that also seem supported.  Both classes of model are now at the top of my list, though I still see major problems with both.

Hypotheses invoking intervening material like an interstellar cloud, seem to have taken a blow, though I still want to understand better if they are really ruled out by the lack of gas in the spectra, and whether circumstellar material like exocomets is similarly ruled out. I’m still fond of this solution, but it has gone down a notch in light of the new data.

I think my black hole disk hypothesis is still a dark horse in this race.

And the instrumental effects and alien megastructures hypotheses have been put to bed.

So that’s where we are.  The next highest priorities (in my mind) are to scrutinize the in-dip spectra for any signature of the occulting material (I’m especially curious if the diffuse interstellar bands change depth), and modelers need to make detailed predictions of the atomic and ionized gas that should accompany dust in the exocomet, interstellar cloud, and black hole disk models to see if they can be made consistent with our in-dip spectra.

Onward!

For those just catching up on Tabby’s Star, read Kimberly Cartier’s article in Scientific American and my series of blog posts here. And don’t read or trust anything the Daily Mail writes on this (or any other topic involving me).

The star exhibits two unique and very difficult to understand behaviors: the short-term”dips” in brightness (of up to 22%) and long-term brightness variations on years-to-centuries timescales.

Since the Kepler mission stopped observing it, it seems to have continued it slow decline in brightness over the past few years, and that dimming does not seem to be due to solid objects.  But we still don’t have any information about what’s responsible for the dips because we hadn’t been able to see one happening in real time.

But now, thanks to the generous support of our Kickstarter backers, Tabby’s team has been able to pay for year-long monitoring of the star with the Las Cumbres Observatory global telescope network to “catch it in the act” of dipping again so we can study what’s going on.

And in May, it finally happened (when by amazing coincidence I just happened to be at the Breakthrough Listen Lab at UC Berkeley during my sabbatical):

Since then, Tabby’s team has been able to collect a huge amount of data not only from our own organized follow-up efforts, but thanks to he amazing generosity and interest of astronomers around the world who volunteered to observe the star during the dips.  We sincerely appreciate their contributions, and they are all authors of our latest paper.

You can follow every twist and turn of this summer’s activity on the Kickstarter project blog here and follow along with the fans of the project on the Reddit page.  Here’s what’s been going on all summer and fall:

In this plot, the different colors represent different LCO sites where data were taken.  The brightness of the star is on the y-axis, and the date (measured in days with an arbitrary offset astronomers like to use ) is on the x-axis.

One of the rewards for our Kickstarter backers was to name the various dips (they need names!).  After the first (“Elsie”, a nod to Las Cumbres Observatory (“LC”) who was one of our most generous backers), the star continued to oblige with a series of dips. The next dip, “Celeste,” was named as a near reversal of “Elsie” when it looked like the two events might be exhibiting time symmetry (it’s also a nod to team member Angelle Tanner’s mother, who sadly died around the time of the event). The subsequent events have started a theme of “lost cities” which it seems the backers would like to maintain going forward.

After all of that, the star exhibited a strange brightening for a couple of months.

To recap, we were hoping that once we finally caught a dip happening in real time we could see if the dips were the same depth at all wavelengths.  If they were nearly the same, this would suggest that the cause was something opaque, like a disk or (whispering) alien megastructures.

The long-term dimming doesn’t seem to be the same at all wavelengths, which suggests it’s being caused by something like ordinary astronomical dust, but that doesn’t tell us what’s causing the dips (which are what got everyone excited in the first place).

So, what have we found!?!  Well, our paper with a huge author list has been accepted by Astrophysical Journal Letters (thanks to a quick and conscientious referee) and we’re ready to reveal what happened in part II.

[note: As I wrote in November, I don’t think ‘Oumuamua is an alien spacecraft. While other astronomers have made that suggestion, and while I’m happy to engage in such speculation in a SETI context, I think ‘Oumuamua is interesting in its own right as an asteroid and because of how it is getting us thinking about how to find alien probes in the Solar System.]

Three updates to the ‘Oumuamua story!

First, it appears to be tumbling:

Why does 1I/ʻOumuamua vary in brightness & colour on uneven timescales? Our model: it is tumbling, & has a redder spot@wtfastro, P. Pravec, @FitzsimmonsAlan, @pedrolacerda, @astrokiwi, @colinsnodgrass, @pseudotrabanthttps://t.co/IH6atFWiVB pic.twitter.com/ZBTkDDPSjb

— Michele Bannister (@astrokiwi) December 1, 2017

This explains a lot about the confusion over its shape and color. The data keep giving different answers because the object is spinning in a complicated way. To understand deeply, you need a quick primer on principal axes (skip to the slo-mo parts, especially the “unstable” axis around 2:00):

The key is that in space, things generally rotate in a very simple way, about the “principal axis” with the largest moment of inertia (smallest radius).  This is because this is the axis for which a given angular momentum has the least energy, and over time objects will lose energy but not angular momentum.  The Earth, for instance, is oblate, and rotates along the shortest axis it has.

But if you just start something spinning arbitrarily (or, say, you knock it around) or if you start it spinning with some motion along its intermediate axis, it will execute a much more complex motion (around 2:00 in the video above) called tumbling.  It will do this in space until the changing distortions of the body from the changing centrifugal forces eventually cause the rotational energy to dissipate away as waste heat and it ends up a principal axis rotator again (that’s why the Discovery One in 2010:Odyssey Two is spinning that way, along its shortest axis).

The Discovery One is spinning when he Alexei Leonov comes to find it because it had angular momentum but no attitude control, so eventually found the lowest energy state, which was a spin about its shortest axis.

So why is ‘Oumuamua tumbling? It’s unclear, but it may be related to its elongated shape: unlike typical Solar System “rubble pile” asteroids and icy comets, it seems to have more rigidity (apparently not uncommon in smaller Solar System objects), and so it dissipates its rotational energy more slowly—so slowly that it can tumble for a long time.

Second, I wrote a AAS Research Note correcting a small point made by Jean Schneider, who showed that ‘Oumuamua could not have been sent into it’s current orbit via gravitational slingshot with any known planet, or the hypothetical Planet Nine.  I pointed out that in fact there is no way any Solar System object could have done it, hypothetical or not (I supect that this point is trivial to people that think about this for a living, but it is nontheless surprising to those of us who don’t).  I think Alt Mars Crater put it best:

.@Astro_Wright on #A2017U1 #ʻOumuamua: Not scattered by Planet X, for all solar system values of X https://t.co/QM0Mxnw7Sv

— Alt Mars Crater☄ (@Comet2013A1) December 7, 2017

Update:

Somehow I completely missed this paper on 'Oumuamua:https://t.co/5NexVK6zkI
They show that even a complex interaction involving binaries doesn't really work to kick #Oumuamua into its current orbit (https://t.co/jSJLzhooYO)

— Jason Wright (@Astro_Wright) December 15, 2017

Third, Breakthrough Listen is taking a look (listen?) to see if it is emitting radio waves as one might expect (?) if it is an alien probe:

Yuri Milner has directed Breakthrough Listen to check 'Oumuamua, the interstellar asteroid, for radio signals https://t.co/SmXqVrO19T

— Marina Koren (@marinakoren) December 11, 2017

This is neat! We should be thinking about what we will do if something that looks (more) like an alien craft comes through the Solar System. Now the Breakthrough Listen team has a protocol for tracking Solar System objects with Green Bank and analyzing the data they collect.

Such a discovery would imply that there are lots of these things in the Solar System at any given moment (even if they are deliberately targeting the Sun, they are hard to spot and we’ll miss most of them), and so lots of opportunities to study them.

Why would there be so many of them? Part of the argument that it is possible to settle the entire Galaxy is that exponential growth is possible, because the only limiting resource is the stars (and the material around them) themselves.  Exponential growth can be achieved via Von Neumann probes: self-replicating spacecraft that go to a system, make lots more of themselves, and then go to more systems.

Now even if these have purposes that don’t involve coming near the Sun, you might expect some fraction to eventually go derelict (space is a harsh environment, and an optimal design will likely have a nonzero failure rate). Such derelict craft would, if they are not traveling so fast that they escape the Galaxy, eventually “thermalize” with the stars and end up drifting around like any other interstellar comet or asteroid.

In fact, since they (presumably) no longer have attitude control, one would expect that they would eventually begin to tumble, and if they are very rigid that tumbling might distinguish them from ordinary interstellar asteroids… and in fact, just because their propulsion is broken doesn’t mean that their radio transmitters would be broken…

No, I don’t think there’s any reason to think it is, but there’s lots of chatter on Twitter that suggest astronomers think it could be:

It seems likely to me that #Oumuamua is an interstellar spacecraft! @Astro_Wright, are you writing a paper on it?

— David W. Hogg (@davidwhogg) November 21, 2017

So what’s going on?

For the first time, astronomers think they have found an interstellar asteroid.  It is clearly on an escape trajectory, and everything about its path is consistent with a free-floating asteroid that was ejected from another star system and is now happening to buzz by the Sun:

There are several things that have astronomers talking “spaceship”:

• Its discovery closely tracks the opening chapter of the book Rendezvous with Rama, by Arthur C. Clarke, about the discovery of an interstellar spaceship on a similar trajectory to ‘Oumuamua.
• We were expecting the first discovered interstellar rocks (we know they must be out there) to be comets, since our own Solar System’s Oort cloud (populated by nearly-ejected Solar System detritus) is mostly comets. The fact that it is not a comet has people scratching their heads.
• One of the recent measurements of its shape finds it to have a 10:1 axis ratio: this is not typical of asteroids, but is not uncommon for ships in science fiction (the 2001 monolith was 1:4:9)
• One of the recent measurements of its color has it very red, similar to metallic asteroids

In many ways, this discovery tracks the excitement around Tabby’s Star: a prediction of how we might discover alien life was made (Clarke for ‘Oumuamua, Luc Arnold for Tabby’s Star); and later an anomalous object was found roughly tracking that prediction but confounding natural explanation.

I’m glad that astronomers are talking about this in a SETI context (and this is SETI), but my personal prior on this is that there is not much reason to get excited about the SETI angle.

That’s because there are several important differences between ‘Oumuamua and Tabby’s Star:

• The data on Tabby’s Star from Kepler are exquisite.  What’s more, only after being convinced that there was no chance of instrumental error did it really get interesting.  The data on ‘Oumuamua is thin: different groups are getting different sizes, rotation periods, axial ratios, and colors for the object, meaning that it hasn’t been well measured yet.  For instance:

Interestingly, it looks to me like the (g-r) color derived for ‘Oumuamua from Meech et al. (in press) are inconsistent with that of Banister et al (submitted) at the 3-sigma level. Full disclosure, I’m a co-author on the Bannister paper.

— Meg Schwamb (@megschwamb) November 20, 2017

• The various values people get for the axial ratio vary from the hard-to-understand 10:1 to the more ordinary 3:1.  In other words, it’s not at all clear that this characteristic of ‘Oumuamua is actually all that anomalous—the 10:1 measurement could be in error.
• Tabby and her team put 2 years of hard work into understanding that star.  Only after all of that work was the “hypothesis of last resort” something worth publishing. ‘Oumuamua was discovered a month ago.
• Tabby’s team’s ruling out of most natural explanations built on decades of stellar astrophysics and understanding of stars and their environments.  ‘Oumuamua is the first interstellar asteroid we’ve seen, so we have very little to go on.

…or of things that have *not* been subject to 4.5 billion years of Solar System processes. How long would #Oumuamua have lasted in that form in the asteroid belt? I don’t know.

— Jason Wright (@Astro_Wright) November 22, 2017

So I’ll need to see a lot more data and hard, critical analysis of the anomalies in ‘Oumuamua before I get interested in the SETI angle at the level I am for Tabby’s Star.

That said, I’m glad that astronomers are, on the informal forum of Twitter anyway, having a SETI discussion about the prospect of discovering interstellar probes passing through the Solar System.  It’s a neat topic, and once worth thinking about.  I hope ‘Oumuamua inspires more real work on it in the peer-reviewed literature, including concrete suggestions of what to look for when future interstellar objects are discovered passing through.

[Update: please see this Twitter thread by Michele Bannister:

1. We do have local examples: the Oort cloud is the <5% capture efficiency of the ejecta, & contains both comets & asteroids ("Manx comets").
2. We have multi-Gyr outside-heliopause-processed (but bigger) objects. `Oumuamua does not share their "ultra-red" colours.

— Michele Bannister (@astrokiwi) November 22, 2017

This article (in German, but Google Translate) by Daniel Fischer:

Interstellarer Gast ʻOumuamua erstaunlich länglich

and the comment by Darin Ragazzine below for more-informed takes on this whole issue. Where they contradict me, you should trust them, because they are actual planetary scientists that work in this field.

My analysis of the problem of deliberately trying to get the attention of extraterrestrial intelligence is up at Ask the Ethicist, a production of the Rock Ethics Institute.

Objects in space are specified by their Right Ascension, Declination, and distance.  The first two are easily measured, usually to better than a part in a million; the last is notoriously tricky to measure, sometimes uncertain to an order of magnitude.

The time derivatives of these quantities are the reverse: proper motions are unmeasured for most objects in the universe, but velocities can usually be measured to a part in a million rather easily.

I noticed this (I’m sure I’m not the first) when writing a review chapter on precise radial velocities as an exoplanet discovery method. I think it’s a good primer on the subject for students just getting started.  In it I briefly trace the origins of the method to the fundamental importance of radial velocities to astronomy in general and spectroscopic binary star work, then work through the high-mass-ratio limit of SB1s, the first exoplanet discoveries, and the future of the method.

There is also a quick section giving what I think is a fair overview of the problem of stellar RV jitter, including the roles of surface gravity, granulation, oscillations, and magnetic cycles.

You can find it here.  Enjoy!

Waaaaay back in 2015 the International Astronomical Union held its General Assembly in Honolulu. I went and gave a review talk on star-planet interactions at a Focus Meeting.

One nice thing (in the long run) about these Focus Meetings is that they generate proceedings that get published. It’s sort of old-fashioned now, but it’s still nice to see these proceedings because they often contain things not in refereed papers: preliminary, unrefereed results that turn out to be important later, and overarching but concise syntheses of lots of work in a way that is useful for understanding but not really appropriate for a refereed article on novel research.

(I write “in the long run” above because having to actually write the proceedings can be a pain, and because they seem to take fooorrrreeevvvveeeerrrr to finally get published.)

Brendan Miller

Well, I was going through my CV for my end-of-sabbatical report (7 more days!) when I remembered that Brendan Miller and I put in a proceedings for the 2015 summer meeting!  Whatever happened to it?  Turns out it was published a while ago and somehow I missed it (which is weird because I have a copy of that book on my shelf…)

Anyway, our contribution is now belatedly on the arXiv.  Here’s what’s in it:

We really want to study the magnetic fields of exoplanets. It seems sort of hopeless—magnetic fields don’t have that much energy and it’s hard enough to figure out a planet’s mass, much less this little detail—but there is hope.

One hope is that close-in exoplanets will have their magnetic fields interact with their host star’s magnetic fields, causing magnetic activity on the star that we can detect in the calcium H&K lines. There had been suggestions in the literature that this was happening, as magnetic “hot-spots” beneath close-in planets rotated in and out of view, but follow up of those systems found the effect to be difficult to reproduce.  I think it was noise.

Another hope was that there was an overall increase in the level of activity in stars with close-in exoplanets.  If you took a sample of stars with and without close-in planets, were the ones with close-in planets more active?  Turns out that’s hard, because there are lots of biases in the way we detect close-in planets (via transit) that might make it more or less likely to find them around active stars in the first place.  Brendan and I wrote a paper where we looked at the evidence (and gathered some ourselves) and concluded there’s no signal to we can dig out of all of the noise.

But there are clear cases where there is star-planet interaction, just by another route: close-in, very massive planets seem to be able to spin up their stars, which makes them more magnetically active.  That probably drives the small amount of correlation we do see.

Then Brendan took a look at WASP-18, which should have one of the strongest planet-induced activity levels around if that’s a thing, and found it’s not elevated in X rays.  Bust there, too.

One thing we did not have time or space to touch on in the article was the one way that magnetic fields do seem to have been detected, via bow shocks., which is a shame but was fortunately covered later in the session.

There is one more bit in the paper that has been dribbling out slowly over the past few years, too. One of my earliest interesting papers was announcing the discovery of the first really good Jupiter analog HD 154345 b.  It’s around a G star, has about an 8 year circular orbit, and is around one Jupiter mass.

One gotcha is that the planet has the same orbital period (and phase!) as the star’s magnetic activity cycle. That’s not too surprising: stars’ cycles tend to be around 10 years, and so some will inevitably have planets at similar periods. The phase matchup is a further inevitable coincidence. After all, our stablest stars, like σ Draconis, have big strong magnetic activity cycles and those don’t create phantom planets in our radial velocity measurements.

Or so we argued in the paper. Well, since then, the coincidence between activity and RV has been getting better and better, and as early as seven years ago I had been conceding that this might be a rare, strong activity-RV coincidence.  I mentioned it in at the first EPRV Workshop (you can see it in the slides here) and again at the 20th anniversary of 51 Peg conference in Haute Provence.

Well, here it is again, in our review:

This is one of those cases where I really should get this into a refereed paper, but I’m busy, and more data will make the case stronger, and retractions are hard to get motivated to write.  Anyway, this has been out there for a while in unrefereed form (and actually disputed! though I still think the planet is probably wrong) but I hope to get it properly written up this fall.

Anyway, that’s the news from Lake Wobegon, where all the planets are Earth-like, all the objects are Rosetta Stones, and all the signals are significant.

It looks like my post was based on the old AAS Ethics Statement, not the more recent Code of Ethics.  That’s fine, but it means the language I quoted was not the latest.  The language on who should be an author is the same, so the heart of my posts are unchanged.

But now, the Code says:

As stated in the National Academy of Science document On Being a Scientist, “The list of authors establishes accountability as well as credit,” and “an author who is willing to take credit for a paper must also bear responsibility for its errors or explain why he or she had no professional responsibility for the material in question.”

So this directly addresses one of the most common objections I’m getting (which is not really an objection to my proposal per se, as I’ve said).  Right there, in black and white, it says that authors may: “explain why he or she had no professional responsibility for the material in question.”

So this part of my proposal really isn’t very radial at all; it’s right there in the new Code of Ethics!

Also present is this new bit:

Data provided by others must be cited appropriately, even if obtained from a public database.

Which I think everyone agrees on.  My entire premise was “what if there is no appropriate citation?” and I’m asking “what does appropriate mean?” I argue that if there is nothing to cite that “counts” today, then this clause can’t be followed, so it no longer overrides the earlier co-authorship requirement.

Finally, on the obligations of co-authors it says:

Every coauthor has an obligation to review a manuscript before its submission, and every coauthor should have the opportunity to do so.

Which is a stronger statement than was in the old policy, but doesn’t affect my argument at all.

The other strain of reaction I’ve gotten is suggestions for reforming our citation and credit system, including adding levels of contributions to papers below “authorship.”  I’m all for that; my proposal had to do with what to do with the system we have in the meantime.

Part I is here.  You’ll need to read it and prior entries for context.

Let me start this final(?) part with a formal statement of my suggestion:

In general, researchers writing a paper that uses unpublished or otherwise unciteable data they did not produce should invite the proposers/observers/producers of that data to be co-authors.

Now, there are many situations where following my co-authorship suggestion isn’t practical. Maybe there are not well defined “proposers”. Maybe the data are 30 years old and widely used. Maybe there is a timeliness or competitive issue that precludes letting the proposer know what you’re working on. Maybe the proposing team didn’t actually do a lot of work to make the observations happen. Maybe the proposer is a social pariah or one of your more important co-authors refuses to be on a paper with them. Maybe you’re on a deadline and simply don’t have time. Maybe you’re in a collaboration whose authorship rules preclude adding these people to the paper. Depending on the specifics of a situation, those might be part of completely legitimate reasons to go ahead and publish without them.

Ethics is often a case-by-case subject; broadly written rules can become outdated, or fail to anticipate pathological cases, or obviously fail in corner cases, or just be too vague to apply to edge cases.  Personal ethics also come into play: we do not all share the same values, and do not all take the same approach to collaboration. Ethics also depend on expectations of the community, and those can change.

But I think our community’s expectation and standard that we never need to include the people who took otherwise unciteable data as co-authors is wrong and should change. 

I encourage my colleagues to consider adopting a presumption that the observers/proposers of public but unpublished data should be invited as co-authors, and even taken on as collaborators early in the project. If there are good reasons not to do so, that’s fine, but those reasons should be articulated and considered and weighed against the good reasons to the contrary before a decision is made.

So before rejecting this presumption, astronomers should ask themselves:

• Why not include them?
• What does it really cost me to include them?
• Why not gain a collaborator?  Why not have a longer author list?
• What would I want them to do if the roles were reversed?

In many cases, the answers to these questions might lead authors to conclude that the producers of the data should not be co-authors, and that’s fine.

But let’s ask these questions more often.

Finally, because Josh Peek got me off on this tangent on Twitter, inspired my particular example, and is working on the MAST data policy which will guide this sort of thing, let me suggest a concrete policy for MAST, consistent with my proposal and the AAS Ethics Policy:

1. Propriety only concerns who can see and use data. It is silent on the issues of authorship. Public data are in the public domain and anyone may download them and use them as they see fit.
2. STScI will provide guidance to users of its data products on how to properly credit STScI and its employees for their work. This is probably something like: include the boilerplate acknowledgement, and cite such and such papers describing the instrument and analysis methods.
3. STScI should have an internal policy for how its many scientists accrue credit (citations and authorship) for their work on projects that produce data, especially for papers produced with public data they enabled. This policy should be consistent with community norms and (hopefully) the AAS Ethics Policy (which may need to change).

That’s it!  If authors want to scoop others and not give them co-authorship, that’s not MAST’s problem (indeed, it is part of MAST’s charter to enable such scooping!).  The AAS Committee on Ethics may be interested in that author list, of course, but I see no reason (or mechanism!) for MAST to be telling its users what they can do with public domain data except publish publish publish.

OK, that’s it.  Flame on!  I will probably update this thread with more entries as good ideas roll in.

[Edit: One more post!  I linked to the old Code of Ethics.  The new one actually further supports my position, I think.]

In Part I I suggested a modest apparently radical proposal. In Part II I laid the groundwork for defending it. Now, let the games begin.

To recap my concrete example, Joe and his team took public data from the HST archive as soon as they landed (this is public DDT time) and have written a paper with it.  The proposing team includes PI Candice and departed members Amber and Brie, and Candice has also written (but not submitted) a paper on the data. Should Candice offer Amber and Brie authorship on her paper (yes, I think we all agree). Should Joe offer the proposing team members Amber, and Brie authorship on his paper?

I say “yes,” because they contributed to Joe’s paper just as much as to Candice’s! The whole proposing team should be offered co-authorship. This is not current practice.

The easiest way to defend my proposal is by responding to some objections I saw when I proposed this on Twitter. I won’t link to individual tweets because I’ve rephrased some of these to be easier to rebut (hey, it’s my blog!)

But the data are public!  That means I can use the data however I want and I don’t have to include the proposers.
Also: That’s what proprietary periods are for! Once it’s over I no longer owe the proposers co-authorship.

No, data propriety only has to do with who is allowed to look at and use the data. Once the data are public, anyone can look at the data, work on the data, and publish the data. 

But that does not absolve them from their duty to properly acknowledge and credit the producers of the data. This is obvious when the data are already published. Of course you cite the origin of data you use in a paper. So ask yourself: why does the lack of a paper to cite make the procurers of the data any less responsible for their production, or you any less responsible for acknowledging that contribution in a way they get credit for?

But if they never publish their data, that’s effectively an infinite proprietary period.

Again, no: you can use and publish the data. That’s a completely separate issue from whether you have to give credit where it is due.

Why should I give co-authorship to someone that didn’t work on the paper?

Because they effectively did work on the paper as soon as you used their data in it. Since you are using their work you have to give them credit they can use.

But I list the PI’s name and the proposal number in the acknowledgements. That’s credit!

It is credit in a literal sense, but not in any sense relevant to the ethical issue here. ADS will not track it, it won’t appear on their CV or h-index, etc. It would be nice if we had a better way to track this kind of credit than these ways, and I would be very open to an overhaul of how academics give and receive credit.  But until then we need to act ethically in the environment we do live in.

If they wanted co-authorship they should have published sooner.  The fear of getting scooped is what keeps us productive. This would provide a perverse incentive to collect data and never publish it.

These are not ethical arguments. They boil down to: “their sloth justifies my theft.”

But taking on potentially hostile co-authors is not a good idea. Forced collaboration is a terrible idea.

I absolutely agree!

(And let’s put aside the question of why this person would be hostile towards you, and how you’re sure you’re in the right.  After all, as I discussed in Part I, being allowed to do something doesn’t mean you’re not being a jerk for doing it. But let’s assume arguendo you’re in the clear and they’re hostile for some other reason than your misbehavior.)

Here’s what I think the radical part of my suggestion is based on:

co-authorship does not have to mean collaboration

The minimal rights of co-authors are actually set out in the AAS Ethics statement:

All collaborators share responsibility for any paper they coauthor, and every coauthor should have the opportunity to review a manuscript before its submission. It is the responsibility of the first author to ensure these.…All authors are responsible for providing prompt corrections or retractions if errors are found in published works with the first author bearing primary responsibility.

See? No real collaboration beyond the opportunity to review a manuscript. If Candice, Amber, or Brie (all of whom have been offered co-authorship) make demands on the paper that Joe’s team disagrees with, Joe has every right to say “no” and the proposers have every right to stay off of the paper.

But that’s not really a choice. If these teams don’t want to collaborate, then the proposing team shouldn’t be on a paper where they did not get a say in the methods and conclusions. They might even disagree with the conclusions! And if they make a principled stand and decline to be on a paper they disagree with, they don’t get the credit they deserve.

This is true, but this is not a problem with my proposal: it’s a problem with the concept of co-authorship in general, and it comes up all the time. Many co-authors do not agree with papers or in some cases do not even read papers they are on. Regardless of how severe a problem you think this is with our current model, it is not an excuse to keep proposing teams off of your paper.

But it’s also not a general solution: ethically people must refuse authorship if they disagree with a paper. As co-authors they would be “responsible” for it, after all.

Because this is a general problem, and not an objection to my proposal per se, I offer my general solution: I favor requesting that every author provide a one-sentence description of their contribution to the paper. If an author is only on the paper because they took the data, they should state exactly that.

So if an author disagrees with the content of the paper they can add that in, too (it would be reasonable to limit such qualifications to, say, 140 characters in most cases; a bit more if necessary). That way everyone’s contribution and responsibility for the result is clear and unambiguous, and credit lands where it is due. I have done this several times, even though there were no contentious issues to hash out.  In this way authors can state exactly what their responsibility for a paper is, if they like.

I still think it’s wrong to bring on co-authors from competing teams that didn’t even contribute to the text of a paper!

I don’t think this is really at the emotional core of objections to my proposal.

Many of us have had to deal with that that one senior team member that totally slacked off and didn’t even send in comments and may not have even read the manuscript. They probably don’t really deserve to be a co-author, but we still include them with little more than a tinge of annoyance because that’s the community norm: you invited them on at the beginning, and you should presume that they read the manuscript and were happy with it and had nothing to add, and it would be rude and awkward to take them off. Yes, sticklers should insist will that they contribute or take their name off, but this situation does not arouse the sort of reflexive opposition that my proposal does.

Whereas the thought of adding members of a competing team as similarly “silent” co-authors makes us uncomfortable, even tough they unequivocally contributed much more than the slacker to the science and an equal amount to the manuscript.

Why do we feel so differently about these situations? Not because the proposing team is less deserving of authorship than the slacker, clearly. It’s partly because they are “the competition” perhaps, but mostly, I think, because it’s the community norm that we don’t invite strangers onto our papers.

I assert that this norm is unethical and we should change it.

In the next part: some practical issues and final thoughts, including a skeleton data policy proposal for MAST (for Josh).

In Part I I argued that if you use other peoples’ data in your own paper, you should offer them co-authorship on your paper.  In this part, let me make flesh out the theory behind my proposal, in particular why the policy exists, so that we can apply it where appropriate.

I had a math professor in college who made an analogy that has stuck with my all my career: the product of the Academy is ideas and research output and the currency we use to trade in this product is credit.  We cite, we co-author, we acknowledge. This is at the heart of the AAS Ethics Statement’s rule: if someone did work that made your paper possible, you pay them back with credit in the form of a co-authorship.

Now, the policy is clearly too broad. Sometimes the appropriate currency is a citation, not co-authorship.  In particular, if data have already been published then the norm in our profession is that you don’t need to include them as a co-author; you can just cite the publication.

In many cases, successful proposals are citable and appear on ADS. This provides another way to give credit for using other people’s data, although it is imperfect because proposals are rarely cited, so it’s not really a good way to accrue credit. It’s not a currency that is generally recognized by, say, promotion and tenure committees. If we could change that (make the citations worth more and make them common) it would solve the problem, but that seems more radical to me than my proposal.

Also, the AAS Policy does not define its scope. Which enablers of science deserve authorship?  The AAS guidelines are no help here.  What about the armies of PhD astronomers at STScI and IPAC that enable and reduce NASA space telescope data? The engineers who built the telescopes? The telescope operators? The staff that cleans the dorm rooms at the observatories?

There are professional norms here, but it’s surprisingly hard to articulate them. Note that I’m not defending those norms, just trying to figure out exactly what they are.

Going back to the currency analogy helps a bit here: in the norms of our profession, who needs and appreciates citations and co-authorship as professional currency that advances their careers? Not the cleaning and cooking staff at the dormitories. Many telescope operators do not, but many telescope staff astronomers do.  Many people who write data pipelines and archiving software do.  Certainly instrument designers and builders to, as do some members of the shops that construct the instruments. An imperfect shorthand for this might be “anyone eligible for membership in the AAS” (or their country’s equivalent).

Here I think there is an ethical obligation on observatories and science centers that produce data to offer guidance to users on how their staff that accrues and values citations to get them. This means that data pipelines and instruments need to have papers that can be cited, and staff astronomers that assist with observations in any way need a clear path to getting credit for the science they enable. These centers also need to communicate with their users about what these policies are and what appropriate citation and authorship practices for their employees entail.

OK, having laid the groundwork here, in Part III I’ll defend my proposal from Part I.