Like the Unfinished Souls in da Vinci’s Adoration

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Many of Michael’s poems are obviously autobiographical, if not about actual events or people then about real places in his life. That has let me use them to riff on elements of his biography and character.

The twelfth poem in Cape Cod LightLike the Unfinished Souls in da Vinci’s Adoration, is not one of those poems. It is more modern than his other poems, with a shifting, dream-like quality. The full title of the da Vinci work it references is Adoration of the Magi, an unfinished painting in the Uffizi.

The paining uses true perspective, with a vanishing point on the horizon, and combines many scenes in a single work, including a battle in the background. It is extraordinary in its presaging of many elements of modern art, including the Escher-esque staircases in the background and the unnatural coloring (blue trees!).

I presume Michael saw Adoration on one of his visits to Italy. The poem seems to be a walk through the painting: wandering the “back alleys,” witnessing the luminescent veneer lain down, visiting the “hunched pedestrians” and “cornices.” This journey has metaphorical significance: you are guided, your course “charted like the future we reject”; “strategy is required,”, until finally nightfall surprises you.  Perhaps it is you, the reader, that are like da Vinci’s unfinished souls, trying to discern meaning and plan your future amid beauty, complexity, and fate.

Michael at the Colosseum in Rome

[Note: I made one alteration to the poem: The word alleys in the first stanza rendered allies in the book, which I think must be a typographical error. “Back allies” does not make sense in context, and although I suppose he could be using the very rare variant of the plural of alley intentionally, that’s not really his style, and he uses the conventional spelling in the second stanza.]

Like the Unfinished Souls in da Vinci’s Adoration

The reverie guided you
Across the fields, into the back alleys, and among
The first low houses, violating that clean line
Between a village and its apron of countryside,
Curious that no resistance must be crushed,
Refreshed by the receding infinity of precisions.

Alleys unfold into avenues, and that
Has been charted like the future we reject,
But lingering here allows
A yielding gesture in the face of confusion
Any simple idea could clarify.

Dust lifts and settles on the pavement.
Here and there a shade is drawn over the light.
A streetlamp flickers, then the whole block
Is illuminated. This is no revelation,
The veneer spread luminescently over everything,
No plan of action that could make life easier, hence
The one state in which you could turn to it,
Become salt, shifting, indistinguishable from sand.

Some strategy is required, some evaluation
In a calculus to be learned from the following course.
No ceremonial motions can be exacted, no
Public denunciations of the self, rare
Collection of external phenomena, as various
As cornices or hunched pedestrians. There it is
Again, nightfall has surprised you.

The next poem is here.

The Loved One

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Breaking up is hard to do, and many of us look back on old relationships and grimace at how we behaved, how we were treated, and so on. The silver lining, for those who grow emotionally, is that we learn from our past mistakes and become better partners, and learn to partner with more compatible people in the future.

Michael had a rough childhood, as an army brat moving around the world, then later as a cerebral and gay teenager. His mother raised him to be proper and not complain—stiff British upper lip and all that—and that rearing ultimately served him well and shaped a lot of what made him so special.

He grew to understand that successful relationships require sacrifice and nurturing and growth, and not to feel entitled to other people’s good behavior, even a lover’s.

Michael with his mother, Valerie

Michael had a poet’s knack for perfectly articulating, in a few words, nebulous feelings you could never quite articulate, or even think about clearly, especially about love.

The eleventh poem in Cape Cod Light is The Loved One, about a certain sort of lover.

The Loved One

I know if I’m wrong you won’t defend me.
You’ll call your mother and tell her how wrong.
If I’m bitchy
Everyone will hear about it at once.
You weren’t raised the way I was
To say everything’s just fine,
To wake up as a child,
Eat breakfast, and walk out
To face the angry bullies on the schoolbus.
You never needed to explain.
You grew up convinced it didn’t make sense.
When you found love, you took it,
Something that was happening, like weather.

The next poem is here.

Disco Dancing

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael loved music, and enjoyed dancing (though truth be told he wasn’t very good at it.)

Michael dancing in the living room with Michael Carl. (I think they’re dancing? ;)

Michael’s haunt in Provincetown was the Little Bar at the A House, the slightly quieter one with less club-y music that was well-lit, and where he could get a table and smoke. And also (Michael was sure to note to those he would introduce the bar to): it was the spot where Tennessee Williams liked to sit and write when he lived in Provincetown. (!)

All night there would a steady stream of people from the A House Dance Club and the Macho Bar around and through the Little Bar, and thus Michael got to sit at the social hub of town, and enjoy its characters, while listening to the music. Later, after indoor smoking was banned in Massachusetts (and after Cape Cod Light was published), he favored the Porch Bar at the Gifford House as his preferred spot to “hold court” (as Richard Schneider put it).

The tenth poem in Cape Cod Light is Disco Dancing. It captures quite well I think the experience of eavesdropping on the random conversations of people at the bar and taking a break from the Dance Club—after a few years, I guess they all start to sound the same.

Disco Dancing

I don’t know if you’re what I want, he said.
We do things totally differently in New York.
She said it was coming on over a generation
Like sunrise sliding down the slope of the Rockies:
Even her dentist smoked pot on his vacations,
And her brother was reading Autobiography of a Yogi.
Someone said the seagulls were diseased,
Whole populations being annihilated right now.
And the jetty was dotted with corpses
Swirling slowly in the scummy brine.
He said it was time to shift inside
With the dancers, away from the hustlers by the pool
With the music, where the words were all the same
Circling back, predictable, on beat.

The next poem is here.


[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael’s father’s name was actually Elwood.

He met his soon-to-be wife, Valerie at a mixer in England while he was stationed there shortly after VE day. Her name was Enid Elkins, but she went by her middle name Valerie because she hated “Enid.” The story I heard (certainly condensed and probably apocryphal) is that their first conversation went like this:

Valerie: Hello, I’m Valerie. What’s your name?
Elwood: Elwood.
Valerie: [pauses] Do you have another name?
Elwood: My middle name is Van Ness.
Valerie: Hello, Van.
Van: Hello, Valerie.

He took up painting late in life. That story goes that he would occasionally complain that he could do a better job than many of the painters he saw. Valerie got tired of hearing it and challenged him to prove it, so he did.

We have lots of Van’s paintings at our houses now. His genre was “copies of famous paintings.” Or no-so-famous paintings by request—I asked for a painting of the pulsar planets illustrated in Astronomy Magazine when I was young, and his reproduction hangs in my office now. Another not-so-famous reproduction is on the cover of Cape Cod Light.

As far as I know he painted only two originals; you can see part of one one of them at the top of the picture in the last post, made in the style of Rothko, but in the colors of Michael’s collegiate homes (Swarthmore, Yale, Harvard).

Van with Michael, Vanessa (right) and Victoria (my mother, front) at the beach.

So I suspect Michael got much of his artistic sensibilities from him father (though to be fair, Michael’s uncle, Frances Elkins, was also a painter, so he had influences on both sides).

The ninth poem in Cape Cod Light is Illustration. It as about how art reflects life.


The painted representation flowers away
Leaving us with these mounds of earth and eloquent grids
On which we can stretch experience.
As if we didn’t know the hero
Is exposed at the end as reflection. Here
The high wire artist is caught in slow motion,
Tumbling, and we wait for the next episode
To see him recover, trotting on with élan.
Or will he? Any time it could be for real
And the other rings in this circus include
The horses, for instance, who surprise you
By dancing. We are coming over the hill
Into a glare of sunlight that distorts
And clarifies: on the right
An orchard ready for harvest;
On the left, a village trembling
On its overhang of rock. What is ahead
Is too much in the light,
But not so unlike ourselves as it first appeared.

The next poem is here.

False Clues

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael was the consummate host. He loved to entertain, to cook giant meals, to show off the house and the view, to keep the music going.

Christmastime was an endless string of family and friends; us kids on couches and mattresses on the floors of every spare room; hors d’oeuvres and drinks for everyone who stopped by or came to stay; Grandpa’s recipe for artillery punch chilling in the snow on the deck.

Thanksgivings were epic, with tables lined up from one end of the house to another, place settings crammed as close as possible, and extra chairs borrowed from the theater company or the AIDS support group.

When we invited ourselves up, when we wanted a place to stay while we showed friends the Cape, Michael never said ‘no.’  Everyone was welcome at Michael and David’s house, within walking distance of downtown and the beach.

Michael in his living room in Provincetown with good friends Ron (left) and Robert (right) at Christmastime.

But things are different when a loved one gets really sick, or after you’ve lost someone. You need space, you lose bandwidth, you can’t hold the smile quite as long. You forget things, you flake, sometimes you don’t even send regrets.

People tend to be nice about it. You and they know this is temporary, that eventually you’ll have the capacity to entertain and to laugh again. But that’s hard to think about.

False Clues is the eighth poem in Cape Cod Light. It first appeared in SQUiD, a “semi-defunct and apocryphal Provincetown publication“.

False Clues

Ordinarily, I’d invite you to arrive
With your knapsack, cigarettes, and kisses.
At times like these,
Amid the neatly paid bills and curls of dead lettuce,
What I await shifts a little,
One thing replacing another, as Orion exiles Hercules.

But this is an apology.
I’ve stood you up before with a worse excuse.
You understand, but it’s not all the same to me.
Everyone has his dawdling angel, everyone knows
How to put it all back in its place
Just as the sky does, every year, with its stars.

The next poem is here.

Death Watch

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael was a cat person. (Myself, I don’t take sides. I grew up with both cats and dogs and both have their charms—and their allergens).

Michael and his pet kitten.

He was also a gardener. The garden on Miller Hill was his annual project, filled with deliberately chosen climate- and soil-appropriate flowers to keep the walk up to the front door beautiful.

Getting to the house, it being tall and at the very top of the hill, required quite a hike. The driveway was very steep, leading to the basement of the house. The first floor of the house was a mother-in-law apartment (his sister Vanessa lived there for a long while). So to get to the main house, one climbed the garden stairs, then the exterior stairs up to the main balcony on the west side of the house, where the front door opened into the dining and living rooms, with their cathedral ceiling.

One of the housecats on the wall of Michael’s garden. 

The seventh poem in Cape Cod Light, Death Watch, is compact and concrete, like an extended haiku, with straightforward symbolism. A bat is killed and buried in the garden; the cats play their natural role of hungry predators.

The unavoidable backdrop to this poem is that around 1990 (the time we arrived to live in their apartment in Brookline) his partner of 5 years, David Harkins, was diagnosed with AIDS. Shortly thereafter, Michael and David relocated to the Cape house full time so they could make the most of their time together. Both the incubation period and the time David lived with AIDS were on the long side at the time, and so for many more years we knew Uncle David and his family every holiday on the Cape.

Cape Cod Light was published the year after David’s death. This poem foretells what is, for those of us who knew Michael and David, the emotional heart of the book to come.

Michael’s dear friend Richard Schneider wrote in Michael’s obituary of “his fatalism, his wholly unsentimental view of life as an arbitrary moment in time—a great privilege to be sure, an opportunity to learn and learn; but don’t get too attached to these borrowed atoms that must be returned, whether sooner or later.”

Death Watch first appeared in Poet and Critic.

Death Watch

A bat died this morning
Under the shovel
On the third step up from the kitchen.

On the first blow
It arched its wings
Shrieking outrage
In mouse cries.
The cats murmured like water.

Under a careful spade
The bat folded into the mulch
And the maw of April:
The cats leapt to the aroma.

Death was bracing;
They smelled it every day.
They guard the mound like Sphinxes.

The next poem is here.

The Angel in the Streets

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael wrote three published books: a textbook for business students called Management Communication: Principles and Practice that grew out of his work at Harvard Business school (which is still in print), Cape Cod Light, of course, and a third called Socrates and Jesus: The Argument That Shaped Western Civilization.

Micheal’s mother was a proper British Anglican. She met my grandfather during the war while he had some R&R time in England. They were married after a whirlwind courtship and Michael grew up an army brat at army bases around the world, until they settled in my grandfather’s home state of Connecticut. My mother was born after my grandfather stopped touring, and they became a nuclear family of five.

Michael was not religious—the closest he came was his nonbeliever’s appreciation for the spectacle of the midnight Christmas Eve High Mass, which we attended once or twice at grandmum’s request, and the poetry of the King James Bible. But his childhood religious education stuck with him, and he wrote with authority about the Gospels’ place in literature and Jesus’s place in history.

Toward the end of his life, he consolidated much of his thoughts about the tension between the Enlightenment and Christianity into a single book, and had it published at a small press with essentially no marketing. I know he hoped it would gain more traction than it ever did; it’s still in print, though and you can find it on Amazon. It’s a good book!

The sixth poem in Cape Cod Light is less concrete than the others, about a lover walking the streets of a city, and his interactions with an angel (that is, perhaps, the city itself?) I’m not actually sure what inspired it or what Michael had in mind, but there are echoes here of lyrics from his all-time favorite album, Graceland:

A man walks down the street
It’s a street in a strange world
Maybe it’s the third world
Maybe it’s his first time around
Doesn’t speak the language
He holds no currency
He is a foreign man
He is surrounded by the sound, the sound
Cattle in the marketplace
Scatterings and orphanages
He looks around, around
He sees angels in the architecture
Spinning in infinity
He says, “Amen and Hallelujah!”

It perhaps also contains allusions to Angels in America, which I have not seen.

[The Angel in the Streets first appeared in the Spring 1995 issue of The Harvard Gay and Lesbian Review.]

The Angel in the Streets

As you walk past, the music behind a door
Draws you, like a lover
Who isn’t sure it’s time to go. The sky
Prepares a background of stars, and behind it
An angel trembles at the approach of a possible god
And numbers his imperfections. The mindless vibration
Rumbles off to another part of the heavens, and the angel
Reflects how divine action is arbitrary,
Without consciousness except in its effects,
Fatal. His attention turns
To the lover, who tells his imagined errors. The angel
Throws his face into his hands and weeps.
He changes nothing.
Would not if he could. But his radiance
Penetrates the lover, and he sings, and the song
Blares from a radio into the street. Children
Plot the outlines of their games, every pedestrian
Watches where he walks, and under a new moon
The loved one walks the city, thinking of love,
Of how it must be earned. And the face, tone, gesture,
The unexpected patch of bloom in the pavement
That moves the heart up or down,
The bronze door, pigeons, colliding crowds
Unfold themselves, like the ragged fragments of an angel.

The next poem is here.

Key West in July With a Nod

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Provincetown is a seasonal town. In the summer, it is filled with GBOVs* in their pink shorts and muscle shirts, tourist families there for the whale watching and seafood (some of whom clearly did not get the memo), and the laborers that follow tourists: the bartenders, restaurant servers, and entertainers (not that any of these categories are mutually exclusive, of course).

In winter, only the year-rounders remain; many of the rest flee south to warmer climes to keep the party going: Puerto Vallarta, Sydney, Rio, Key West. Provincetown’s sibling city is Key West; poised at the west end of the Florida keys in wonderful point symmetry with its counterpart at the East end of Cape Cod, far to the north.

Michael and David Harkins

Michael loved gay culture and was a student of it. He introduced us to Rocky Horror and John Waters at probably too-young ages (not being a parent himself, he often misgauged these things). He adored Camille Paglia and her analysis of the camp of it all (his interview of her was a personal high point in his scholarship for the Gay and Lesbian Review). He openly fretted about what the mainstreaming and acceptance of gay people in America would do to gay culture. When gay marriage came to Massachusetts he was thrilled but equivocal: he joked that it broke up half of all the male couples in Provincetown, suddenly forced to have “the talk” about their long-term expectations. He wanted no part of it himself: he half-joked “Why would I want to take part in that failed heterosexual institution?”

Which is not to say he was queeny or fringe; he was mostly a paragon of the straight-laced Harvard professor. Yes, he wore a mop in the 60’s, but he was ultimately his British mother and army-officer father’s son, monogamous and conventional (I’m sure it helped that they accepted his sexuality as soon as he came out, around college). Michael was in awe of the heroes of Stonewall, but made sure I knew that it was suit-and-tie-wearing Frank Kameny that radicalized them (I did not learn Kameny was an astronomer until much later in life).

The fifth poem in Cape Cod Light is about Key West in summer, about the beach, and of course, about the humans that walk upon it.

*GBOVs=gay boys on vacation; not sure if this is a common term or a Michael-ism.

Key West in July With a Nod

Wait here by this palm tree with its
Feathered arms pinned back like dog’s ears
For your enemies to make themselves clear.
In a few hours, the moon will rise
Between this and the next tree.

On the beach a man is walking,
Clutching a stick, dazed slightly by the sun:
He delights in the arrangement of things,
What he hears, what you lose in the breeze.
He strides and strides but never goes near the water.

Over here is where the lovers come.
They seek each other only in darkness,
And what they do doesn’t look much like love.
Appearance is false. The practical man
Allows: this making and the sea are the same.

Coral reefs have flattened out the water
With their toothy mouths; it prepares for tenderness,
How you can kiss a breast so many ways
In the sloppy arc of lust. Without a wind
The orderly catamarans are smug as clams.

The next poem is here.

The Edge

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley.  The other parts of this series are here.]

Race Point is the end of Cape Cod. Yes, you can keep following it back around, south towards the much calmer Herring Cove and into Cape Cod Bay towards Wood End, but at Race Point the winds and the surf are strong, and you really get the feeling of being at the end of the world, where the land meets the sea. Herring Cove is the edge of the Cape, a long beach you can drive right up to.

Geography of Provincetown. Race Point is in the upper left. Miller Hill is the red marker at upper right, walking distance from downtown. The breakwater runs north-south from the southernmost part of Provincetown to Wood End.

Further back down the cape, is Cape Cod Light (“Highland Light” is its formal name) in the next town down, Truro. On the drive to Provincetown through Truro you pass long rows of white beach houses for rent.

Life is different out on Race Point and Herring Cove, and gives it you a different perspective on life than you have even in Truro or Downtown Provincetown. The fishermen have a different relationship with the sea and the town than the other Provincetown residents; the tourists tend to prefer the beaches downtown; but the “year-rounders” like Michael are stuck somewhere in between. They remain there through the winter for their own reasons, many of them to escape.

I’m pretty sure the fourth poem in Cape Cod Light is about Race Point or Herring Cove (or maybe not—the fishermen he mentions tend to be found at the wharfs downtown). Either way, it’s certainly about the shores of Provincetown, and about those in-betweener year-rounders like Michael who get to define themselves as they like.

Michael on the beach, I would guess Race Point.

[The Edge first appeared as Citizenship in Several Worlds in Poetry Northwest.]

The Edge

At the edge, you can look back over it all
And take things into account. The sea will help you
If you choose your angle right: foldings and foldings,
The hands
Sealing a package never to be opened again.
All the connections that seemed so organic inland
Grow accidental; you can have your way with the sea
Where life is the constant victim, dismissing
The footprints down the track to the beach, except
You grow less certain. They remind you
As the seawater violence in your blood reminds you.
The parade of strangers
Pins you against the curt acknowledgements
From fishermen who have seen your face before,
And between them you float free, capable of anything,
Of producing a new self at cafe tables.
Creatures float by who have lost their reality at the edge.
They have stayed too long
Without any firm connections to the sea.
They should have wives or lovers
In white cottages. But ghosts are the unlived lines.
Our silhouettes are unlived lines
When strangers walk by our windows. Then they look
At watches, or adjust their clothes. We are looking
At lovers who are thinking of strangers.
They are easier to resist
Where the foghorns will sound after dark.

Reverence, a sculpture by Jim Sardonis
Whale Tales, a photo by David Atkinson

The next poem is here.

Stepping Across the Bay

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael loved Cape Cod, and shortly after my mother and brothers moved into his Brookline apartment he and David Harkins finished their house at the top of Miller Hill in Provincetown and he began spending weekends there. After retiring, he moved there full time, becoming a “year-rounder” (the population is highly seasonal). The view from his first floor deck is pictured above; the views from the top floor bedroom balconies are the best on the Cape, bar none:

Michael and Bret DuBack on the upper balcony at Miller Hill

Provincetown is a gay mecca, an art colony, and an old Portuguese fishing village. Michael loved all of its characters (in every sense) and became a central figure in the art scene, hosting festivals and helping run the amateur theater company in town.

Provincetown is known for its beaches, and one of the amazing attractions is the breakwater that runs from “P-town” to nearby Wood End and Long Point, the end of Cape Cod. During low tide, you can walk along it or upon it all the way across. It’s an arduous mile, and you have to watch every step lest you slip or twist your ankle, but worth the trip.

The third poem in Cape Cod Light is about a walk across Cape Cod Bay to Truro, the return home to Miller Hill, and about the youthful experiences that made him fall in love with Provincetown in the first place. I suspect it’s a metaphorical journey, a mix of the breakwater walk and an imaginary journey into the past.

It’s also about the Cape’s ghosts—the memories of the terrible loss and devastation gay men that lived through the 80’s and 90’s carry.

Michael on the beach in his youth

Stepping Across The Bay

Today I walked across the water from Provincetown to Truro.
Sinking wasn’t a problem, it was
Making sure I got all the colors right, skipping
Over the cracks and respecting with my feet
The lines between pale green and white, deep blue and seaweed purple.
When I got to Truro, nuzzling the beach, I met
All the old friends who used to live there in the seventies.
We did great drugs, and cooked, and laid on the lawn.
Only a handful of these people will be alive
When I take a boat back, and climb to the top of the hill.

The next poem is here.

Body Knowledge

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael taught me about etymology. He taught me how many words in English have synonyms of different origin, from the Germanic and from the Latin. Veal and lambcardic and heartcerebrum and brain. The Latin often feels flowery and poetic, the Germanic feels forthright and staccato; but he also taught me how English’s fusion of the two traditions allows its poets to transition between the two modes for rhythmic effect, as with Eliot:

Streets that follow like a tedious argument
Of insidious intent
To lead you to an overwhelming question …
Oh, do not ask, “What is it?”
Let us go and make our visit.

Michael presenting the rings at my wedding.

Michael had a PhD in English literature; his dissertation was on difficult poetry (Poets of Light: Ezra Pound, William Carlos Williams, and Wallace Stevens), but he loved the popular forms, too. He was obsessed with music, especially folk, pop, and rock; he was a huge fan of The Beatles, Squeeze, Michael Jackson, and (above all) Paul Simon; he listened to their albums over and over, studying the lyrics.

He loved poring over the historical Billboard charts and arguing about who deserved to be there. He never understood our appreciation for Billy Joel. He always insisted Bob Dylan deserved the Nobel Prize, but never thought it would actually happen (oh the triumph he would have gloated with if he had only known!).

Poetry and pop music for Michael was no escapist diversion. The second poem in Cape Cod Light is dedicated to the great American poet John Ashbury, and is about the ways that poetry defines and humanizes us.

In Body Knowledge Michael muses how, from their accidental origins millennia ago to their pleasing groupings as they pour off the pop charts, words shape who we are as a species, a culture, and individuals.

The process is not neat: they smack into our senses, our interiors are stung by their hard cores and ragged edges, vestiges of the natural selection of etymology. But that’s how they get through to us, if we are willing to let them, and how they slowly mold us, heal us, and prepare us the for what the future folds.

[Body Knowledge first appeared in Poetry: A Magazine in Verse.]

Body Knowledge

(to John Ashbery)

These chose to be passed on
Because of how they sounded in the ear
And how practical they proved in daily life
Before they were frozen into print.
Now we’re stuck with them,
And their fragments fly about us, all
Hard cores and ragged edges. Because their teeth
Remind us of jigsaw puzzles doesn’t mean they fit,
Although ultimately, no doubt, they do, and even now,
Words from the latest song about failed love
Snap together with what some shepherd chanted
Near the Mediterranean, some forgotten summer,
To reveal the root of last week’s feelings. Then, I wondered
About your body while you were out of my sight,
And reviewed the boy whose T-shirt pictured a galaxy
With an arrow labeled: You Are Here. It was not so true
As sound passing from without to within,
With its body knowledge of distance and echoing space.

Stung by words and tunes,
Our interiors shower crystals of sentiment, their paths
Leave traces against the black, and the debris
Drifts, piles up in corners like snow. We fill up
Until we die in the extravagance of experience
That has been lavished upon us. If they can be deceived,
The senses cannot lie; they have been shaped
By what smacks against them. They give what they get.
The necessary delusion: this clean line between life and death.
The danger: that we will recognize the stones are doing their part
And lie down among them. These old songs
Feature the landscape and vanish. If we can remain
Vulnerable to each tone as it passes,
The hollow in our heart
That feels now like an avoidable sadness
Will grow vaster and vaster, until it contains
Every seed of tomorrow’s arrival.

The next poem is here.

Thanks But I’m

Last month marked the 20th anniversary of the publication of Cape Cod Light, a book of poetry by Michael Hattersley, who was my uncle. The cover is a painting by his father, Van, after a painting of Cape Cod Bay.


You’ve probably never heard of it. It had a small run, and it’s not in print, so you can’t get a copy even in today’s age on on-demand printing (perhaps someone knows how to change that?).

But in my family we all have a copy, and when one of us quotes a favorite passage the others usually recognize it.

Michael would have been 70 for most of this year, which was an age he had no interest in experiencing. His friend Richard Schneider wrote a piece in memoriam Michael in the Gay and Lesbian Review, where Michael was a frequent contributor. It wonderfully captures what it was like to know Michael. After school in his smoke-filled room in my family’s condo in Boston while the MacNeil Lehrer News Hour droned in the background, and in long discussions over the holidays under the cathedral ceiling in his living room in Provincetown, he taught me what it meant to be an academic, a thinker, and a moral being.

The first poem in the book was written the Christmas before the book was published, and is about turning 50 (a birthday less than a decade in my own future.) His cranky impatience with the ritual commemoration of the passage of time is interrupted by one of his cats—a metaphor, perhaps, for his impulse to write the poem, or the book. It ends in haiku-like meditation on the ambience of winter on the Cape.

Thanks But I’m

Just as happy being left alone here
Believing all dates on the calendar
Haven’t been labeled yet. Today is:
Inventing your birthday again for the fiftieth time
Unless it can be resolved by stealth.
But wait. A large animal
Has entered the picture, intent
On bearing witness by its presence.
It composes itself like a cat,
Means: late in the year,
Evening. Final quarrelsome squibs of sun.
Make something permanent of, say,
The heat cranking up,
A snowplow grating by in the dusk.

The next poem is here.

Planet-Planet Tides in TRAPPIST-1

Tides are complicated and hard.  When a planet orbits a star, the star raises a bulge on the planet’s surface.  As the planet rotates, this bulge moves across the surface, and because rocks and oceans and atmospheres are viscous this dissipates energy.  The energy comes out of the planet’s rotation, which spins it down.  This is likely why Venus and Mercury rotate so slowly.

Diagram from wikipedia

The planet can also raise tides on the star (as can a moon on its planet), and that tidal bulge gets carried around by the central object’s rotation.  This spins down the central object, and can make the planet (or moon) move inward or outward in its orbit.

Finally, if the planet is in an eccentric orbit, then the magnitude of the tides change.  This dissipates energy, which ultimately comes from the planet’s orbit. This makes the planet slowly circularize its orbit.

Put it all together, and this is why the moon is synchronously rotating around the Earth, moving in a (nearly) circular orbit, slowly moving away from the Earth, and why the Earth’s rotation is slowly slowing down.

Things can get really complicated if you have lots of moons.  The moons of Saturn and Jupiter tug on each other gravitationally, exciting eccentricities that drive tides and keep the bodies warm inside, leading to liquid oceans and volcanism despite the very cold temperatures they would have if they were only heated by sunlight.  Solving all of the resonances and tidal effects in these systems is still an active area of research.

TRAPPIST-1 is a system of at seven close-in planets tightly packed in orbital resonances, much like the moons of Jupiter.  In fact, they have more in common in terms of scale with the Galilean satellites than the Solar System planets:

Comparison of the TRAPPIST-1 system with the inner Solar System and the Galilean Moons of Jupiter

From European Southern Observatory

I think that the TRAPPIST-1 system is exhibiting yet another effect that we haven’t seen before: planet-planet tides. The planets in this system are very tightly packed, and quite massive (much more than the Solar System moons are).  It’s likely that eccentricity tides have made their orbits circular (they have very low eccentricity) and that they are synchronously rotating (always keeping the same face towards the star, or else stuck in a spin-orbit resonance of some kind, like Mercury is).

But if that’s true, then when neighboring planets lap each other, the strain caused by their mutual tides are actually of similar magnitude to the strain caused by the eccentricity tides with the star. In fact, if our estimates of the planet masses and eccentricities are right (they’re pretty uncertain, so this is not necessarily a safe assumption) then planet f causes significant tides on planet g that are actually more important than the very small variations in that planet’s tides raised by the star.

This isn’t the case for any moons I know of in the Solar System: although they are more tightly packed than the TRAPPIST-1 system, the Galilean satellites are so much less massive that their tides just can’t compete with that of Jupiter.  The mass ratio for the TRAPPIST-1 system is much more favorable, so the tides may matter.

Now, planet-planet tides can’t matter too much.  If they did, the planets would not be synchronously rotating with their orbits, which would make the stellar tides orders of magnitude stronger, and then the planet-planet tides would be a minor effect.  But if the planets are in a synchronous rotation state, then I think the planet-planet tides at the very least have to be included in the calculations.

After doing some rough reality checks with Eric Ford and Andrew Shannon, I fired up the old RNAAS template at Overleaf and shot another Research Note on the topic off.  You can find it here.

I hope this is right!  This is way outside my training so I’m worried I missed something obvious…


The Cosmic Haystack

I taught the first Penn State graduate course in SETI last spring, and I thought it went really well. We read a lot of papers, had great discussions about Schelling Points and all the different ways to search, and got to visit Green Bank to conduct original SETI observations. You can read all about the course at the class website here, along with student reactions to the papers (tweeted out by Sofia Sheikh here).

One of the cuter terms in the syllabus was that any student whose final project got published in a refereed paper would get a retroactive ‘A’. Well, the first automatic ‘A’ has arrived!  Shubham Kanodia and Emily Lubar, following a suggestion by Jill Tarter, calculated rigorous volumes of the Cosmic Haystack, and the paper is now on the arXiv.

Some highlights:

The first instance of the term “Cosmic Haystack” to mean the space through which SETI searches to find alien technology is apparently from this article in the Christian Science Monitor in 1977, as tracked down by @spacearcheology:

It appears in a paper 4 years later in Wolfe et al. (1981) in a NASA report, which includes this figure (drafted by Jill Tarter):

The Cosmic Haystack here is 3 dimensional, “compressed” down from many more for clarity. The rectangles inside the haystack represent relatively narrowband searches that were either sensitive or included many targets (it’s hard to do both).

Today, wide-field instruments and broadband receivers and backends can search the haystack for alien “needles” much faster. The question is: how much have we searched? Some have gotten the wrong idea about the whole endeavor, as we explain in our abstract:

Many articulations of the Fermi Paradox have as a premise, implicitly or explicitly, that humanity has searched for signs of extraterrestrial radio transmissions and concluded that there are few or no obvious ones to be found. Tarter et al. (2010) and others have argued strongly to the contrary: bright and obvious radio beacons might be quite common in the sky, but we would not know it yet because our search completeness to date is so low, akin to having searched a drinking glass’s worth of seawater for evidence of fish in all of Earth’s oceans.

Shubham and Emily decided to construct a radio Cosmic Haystack that included transmitters anywhere, not just around nearby stars, akin to NASA’s old SETI Sky Survey from the 1980’s. We also tried to capture the way that very broadband signals might be detected, and not just the narrow-band signals considered by some of the earliest searches. This required us to include transmission bandwidth as a haystack dimension, and calculate a rough sensitivity function in terms of it. We also wanted to make sure that our haystack boundaries were well defined, and that we were calculating only search space within a well-defined range of parameters, which led to some interesting integrals with lots of cases to consider:

Sensitivity as a function of transmission bandwidth and central frequency for an idealized broadband instrument, with a “ceiling” set by the haystack boundary.

Case six, for very broadband, very bright transmissions.

The bottom line was that we got to calculate what region of parameter space has been searched for transmitters in the Milky Way.  It’s tiny.  Jill Tarter once estimated it as a glass of water out of all the oceans in the world; we got more like a bathtub (despite a much different haystack construction):

We found that the MWA low frequency searches dominated our haystack search volumes, because of their incredible étendu: a very wide field and very good sensitivity. And they did it in just a couple of hours of searching!

We also construct another one-parameter way to calculate search completeness: what density of uniformly spaced megawatt transmitters in the Milky Way can we rule out?  We get about one per 0.27pc for the latest Breakthrough Listen paper (for L-band transmitters). The Galaxy could be filled with more transmitters than stars, and we wouldn’t have found them yet!

So we haven’t done much searching, and people should not use the “failure” of radio SETI to date as evidence that we should stop looking.

But it’s also important not to let the pendulum swing to far the other way! One might see numbers like -18 in the exponent and declare the entire project hopeless.  On the contrary:

  1. New radio technology allows us to search through haystack volumes much faster than before; the Breakthrough Listen program is quickly catching up to the historical NASA programs by our metric, and MWA needed only 2 hours to dominate our calculation.
  2. If we expect to find transmitters near stars, our completeness is many orders of magnitudes higher, because we have concentrated our efforts there
  3. We don’t need to search the entire haystack unless there is nothing to find.  Another way to look at it: you don’t have to drain the oceans to find marine life, unless they are sterile and you are trying to prove that.  A bathtub’s worth of water is probably not enough to find a fish if you randomly sample the ocean, but if you look in the right places it’s about the right order of magnitude of search required.

Hopefully our paper will be a useful extension of Jill Tarter’s work along these lines (see here and here).

We also had a lot of fun figuring out where the phrase “needle in a haystack” comes from which I detailed here. (it’s not Cervantes!)

Finally, a note on how just as every journey begins with a single step, every search begins with comically weak upper limits.  We quote a critical referee on Bachall & Davis’s first neutrino search paper (an upper limit):

Any experiment such as this, which does not have the requisite sensitivity, really has no bearing on the question of the existence of neutrinos. To illustrate my point, one would not write a scientific paper describing an experiment in which an experimenter stood on a mountain and reached for the moon, and concluded that the moon was more than eight feet from the top of the mountain. (Bahcall & Davis 1982, p. 245)

which I also discussed back here. Waste not want not!



What do SETI terms mean? A committee weighs in.

Inspired by a paper by Iván Almár’s paper on SETI terms:

I wrote down my opinions on the topic and recommended a taxonomy of SETI in this paper, which I describe in my blog post hereSofia Sheikh presented my suggestions at the Decoding Alien Intelligence workshop:

One of my recommendations was to organize SETI in a taxonomy like this:

After the talk, Frank Drake(!) stood up and recommended that there be an ad hoc committee to discuss SETI terms and recommend what they mean (thanks to Michael Oman-Reagan for providing me the audio!). So, in anticipation of the upcoming NASA Workshop of Technosignatures, in Houston next week, I convened such a committee, including Sofia and me, Jill Tarter, Iván Almár, Kathryn Denning, and Steven Dick.

We didn’t agree on everything, but we came up with a lot of good recommendations and clarifications that I hope NASA will find useful. We did not go with “Communication SETI” because the committee thought it was too reminiscent of METI, and we did not recommend against “civilization” or “colonize” (mostly because both are in wide use and we did not want to endorse major changes without very good reason) but we did note the problems with those terms.

Our final report is here:

and Sofia will present it at the workshop on Wednesday!

Measuring Rocky Exoplanet Compositions with Webb

Back in June 2016 I advertised a postdoctoral position between me and Steve Desch at ASU for someone to work on the problem of exoplanet interior compositions.

Normally, the way we determine the interior composition of exoplanets is a combination of inference, measurement, and guesswork.  In the Solar System we can study the surface compositions of planets directly, get the bulk density by dividing masses by radii cubed, and a sense of internal structure by looking at how the surfaces have changed or what a body’s gravitational field says about the interior mass distribution. It’s amazing how much we can determine about, say, the interior of Europa!

Evidence from NASA’s Galileo mission suggested that there might be a liquid water ocean underneath Europa’s icy crust. Image credit: NASA/JPL

On Earth we can also use seismology to directly probe the density and composition of the Earth’s interior.  Some things we still don’t know to great precision (the water content of Earth’s mantle is still pretty uncertain, though it’s small) but in general we have a good sense of what’s down there, despite having a very limited set of actual samples from far below the surface (from volcanos, mostly).

Based on this we have a good sense of how the planets formed, and so we can make good inferences and guesses about the parts we don’t know about yet. For instance, we suspect that Jupiter formed around a rocky core of about ten times the mass of the Earth; one of the purposes of Juno is to see if we can better determine Jupiter’s inner composition and perhaps check this model prediction.

This artist’s concept shows the pole-to-pole orbits of the NASA’s Juno spacecraft at Jupiter. Image credit: NASA/JPL-Caltech/SwRI

Exoplanets are much harder.  We generally can measure their masses from radial velocities and radii if they transit, and for planets for which we have both we have bulk densities. By analogy with Solar System planets we can then guess that they have similar compositions to those, and from the compositions of their host stars we can make inferences about how they might differ. But getting anything like a mantle or surface sample seems impossible.


There is a whole class of planet recently discovered by Kepler (Saul Rappaport and Roberto Sanchis Ojeda did a lot of the pioneering work here) that appears to be evaporating. The transit signatures of these things is amazing; they vary in depth (sometimes disappearing entirely!) and don’t have the usual shape of transiting planets. Apparently, these are small rocky bodies  (which have orbital periods of less than a day and which are too small to see transit at all) have gigantic, variable tails of rock that is condensing from a plume of surface material evaporated by the intense heat of their parent star.

Screen shot 2013-03-09 at 5.24.42 PM.png
Transits of KIC 12557548, from Fig. 2 of Rappaport et al. 2012
Here’s an artist’s impression:

Exoplanet KIC 1255b orbits its parent star followed by a comet-like dust tail. Image credit: Maciej Szyszko.

So by now maybe you’ve spotted the opportunity: that background star is a great lamp to pass light through that material so we can figure out what it’s made of!  Is it mantle material? Is it core material?  It it hydrated?

Studies of white dwarf “pollution” can measure the bulk, relative elemental abundances of material from presumably rocky planets that have crashed into the white dwarf, but here we have the opportunity to study chemical composition of one particular layer of a distant rocky exoplanet—we can’t even do this for the Earth!

But will it work? Are the transits deep enough? Can we distinguish different minerals with spectroscopy? Are there any stars bright enough for this?

Yes to all.  ASU/NExSS postdoc Eva Bodman has all the details in her latest paper. It’s an exciting time!

Eppur si muove

We sometimes read in the history of astronomy that it was Bessel that finally proved the Earth moves around the sun with the measurement of the parallax of 61 Cygni, one of the brightest and closest stars to Earth in the Northern Hemisphere.

This is because people early on realized that if the stars are different brightnesses because they are at different distances, and if the Earth really does move around the Sun, then we should see the nearby ones appear to move with respect to the background ones annually as our light of sight towards them changes.  The effect is quite small, and it was challenging for 18th and 19th century astronomers to measure the tiny effect using only their eyes to make measurements (the biggest parallaxes are like a part in a million).

And so astronomers put a lot of effort into this, and indeed eventually Bessel pulled it off. But the clinching observational proof actually came about 100 years earlier, based on those same observations!

Astronomers were expecting to see a “reflex” motion: when the Earth moved in one direction the nearby stars would appear to slightly move in the opposite direction, so when the Earth was at one extreme of its orbit they would appear to be a bit closer to the center of Earth’s orbit (i.e. the Sun) than they should be.  Instead, astronomers kept measuring a much larger than expected motion (around 20 arcseconds instead of less than 1 arcsecond) in the wrong direction: the stars seemed to move towards a point about 90 degrees away from the Sun, towards the ecliptic.

This is what was actually happening, but it was actually pretty confusing at the time.  One way they were measuring positions was by using the zenith as an absolute direction (you can use a plumb or a liquid to determine which direction is straight up) and a telescope to see how close stars got to the zenith as they passed overhead.  So they could only measure one component of the star’s motion, so all they knew is that it was large and had the wrong phase (90 degrees from what was expected).

What was actually going on is that the stars were suffering from aberration. Imagine you have a trash can an you want to collect as much rain as possible.  If there is no wind, you should just keep the can vertical.  But, if you are on the bed of a pickup truck moving at 10 mph, then some of the rain that would have fallen into the can will hit the side instead.  To maximize rain collection, you have to tip the bucket towards the front of the truck (i.e. in the direction of the truck’s motion) to get the rain to go straight down into the can.

Wikicommons illustration of the aberration of starlight. Original here. By Brews ohare, CC BY-SA 3.0.

Similarly with telescopes: to get starlight to go straight down the optical axis of the telescope, you actually have to “lead” the motion of the Earth slightly by pointing in the direction of Earth’s motion.  This effect is equal in radians to the speed of the Earth’s orbit divided by the speed of light, or about 20″.  This is what was being observed, and this is what Bradley finally figured out in 1727.

You can learn more about this history here. Interestingly, Bradley’s original paper describing the aberration and proving the Earth moves has only one citation in ADS!

So while hunting for the proof of Earth’s motion, astronomers actually discovered a much easier to find proof of Earth’s motion!  But it took decades to understand it.

Today, it’s tricky to repeat these measurements with modern equipment. Finding the zenith to a precision of 1″ is not something most observatories are set up to do; we almost never use high precision, absolute positions with respect the ground in astronomy any more (our instruments tend to change their pointing with temperature, humidity, and other factors, so we calibrate them on actual star positions every now and again to keep our pointing models accurate and precise).

But interestingly, there is a way most college observatories and many amateur ones can find an absolute position: star trails!  By turning off tracking and letting the stars trail, one can identify the center of the trails as the true Celestial Pole.  As the Earth goes around the Sun, one can measure star positions with respect to that and detect the aberration, thus proving the Earth orbits the Sun.

Of course, there are lots of other ways to do this: you could build an R~10,000 spectrograph and feed it light from stars on the ecliptic and measure the Doppler shift caused by Earth’s motion, or you could measure the parallax directly with differential astrometry, like Bessel did. But this is a novel solution that actually doesn’t require special equipment of good seeing, just an ordinary camera.

I was going to try this someday, and even wrote up a whole blog post about it, but finally decided that if I haven’t started by now I probably never will, so I’ve “given the idea away” in the form of a Research Note to the AAS (my sixth!).  One reason I never started is that although the equipment needed isn’t special, there are lots of complications.  One is that the Poles move on their own (due to Earth’s axial precession) so you have to remove that effect first.

As part of my plan to learn Python and Astropy I tried to make a figure showing how the apparent position of the true Celestial North Pole moves with respect to the background stars, showing the precession and the aberration.  It was surprisingly tricky!  Plotting things near coordinate singularities is not something most plotting software does well, so in the end I cheated and just plotted things as a plane chart in ecliptic coordinates and drew the Celestial coordinates in by hand.  I think it came out really well:

Figuring out how to calculate the motion of the Celestial Pole (also affected by nutation) was tricky; it turns out Astropy does not expose those functions to the user so I had to cheat.  In the end, I did it two ways that gave the same answer: I asked for the ICRS (astronomical) coordinates of the zenith at the North Pole of Earth.  Astropy converts from geocentric coordinates to barycentric coordinates by correcting for the orientation of the Earth (the axial motion) and the aberration, so this yields the green curve above.  Almost equivalently, one can ask for the Celestial Pole in CIRS coordinates (the intermediate coordinate system between the Earth and Celestrial Sphere) at many times and then ask Astropy to convert these positions to the ICRS frame.   The latter is faster.

To learn more, you can read my research note describing the experiment here.  And if you try this, please let me know!


A Needle In A Haystack

Where does the old idiom “finding a needle in a haystack” come from?

According to my physical copy of Bartlett’s Familiar Quotations, the phrase originates with Cervantes in Book III Chapter X of Don Quixote, and indeed most searches online state so with authority.

But I just checked my physical copy and the Project Gutenberg version and not only is there no  Book III, the phrase does not appear!

Some sleuthing of other phrases that do appear reveals that “Book III” refers to what is normally called “Part II”, and indeed there in Chapter X of my copy it reads:

…tracking Dulcinea up and down El Toboso will be as bad as looking for a needle in a haystack or for a scholar in Salmanca.

just as promised.  So why isn’t it in the Project Gutenberg version? There it reads:

looking for Dulcinea will be looking for Marica in Ravena, or the bachelor in Salamanca.

which is not the same thing at all. Indeed, the Spanish original seems to read:

buscar a Dulcinea por el Toboso como a Marica por Rávena, o al bachiller en Salamanca.

So the phrase is actually not in the original!  It seems to be due to Cervantes’ English translators who used the phrase as a more familiar [to English ears] version of “to find Maria in Ravena”.  Bez Thomas helped me to figure this out on the Twitters:

So where does the phrase “needle in a haystack” originate?  The OED has two attestations that predate Cervantes:

c1530   T. More Let. Impugnynge J. Fryth in Wks. (1557) 837/2   “To seke out one lyne in all hys bookes wer to go looke a nedle in a medow.”
1592   R. Greene Quip for Vpstart Courtier sig. Ev   “He…gropeth in the dark to find a needle in a bottle of hay.”

Where a “bottle” here means “bundle”.  Apparently the translators were using a 100+ year old phrase!   The “haystack” version is from later:

1779   W. Rogers in J. Sullivan Jrnls. Mil. Exped. (1887) 262   “But agreeably to the old adage it was similar to looking for needles in a hay stack.”

And there you have it.  Even an authority as solid as Bartlett’s occasionally gets things wrong, so it’s good to check!


[Update: Apparently Bartlett’s is full of these errors with respect to Don Quixote: see this article here which details the “haystack” mistake and many more.]

Smooth continuum stars and RNAAS

We can tell what stars are made of by the colors missing from their spectra, but that’s not really true for hot, rapidly rotating stars. These stars lack convective envelopes, so they lack magnetic dynamos, so they do not spin down as they age. As a result of their rapid rotation, the Doppler shift blurs out their lines and its hard to get a precise measurement of their abundances (except hydrogen, whose lines are so deep you can’t miss them, even blurred out).

But one astronomer’s trash is another’s treasure. These rapidly rotating stars make great sources of light for calibrating spectrographs because you can be sure that any spectral features you *do* see are due to your instrument, not the star. And these stars can be very bright, so it’s a quick test.

The problem is that not all hot stars rotate quickly enough to be “good” calibrators. For instance, here’s what a small portion of a rapid rotator looks like:
This star’s spectrum is flat (or slightly sloped) in this small region of the blue.  The overall mountain shape is the response of the spectrograph, which this star lets you model.  The “fuzz” is photon noise—by chance some channels get more photons than others.  The spike in the middle is a “cosmic ray” event—a high energy particle from somewhere in the dome struck the detector and caused a spike.  The only thing here that’s due to the star are some barely perceptible wiggles.

Here’s a “bad” calibrator star, that is not spinning fast enough to be a “good” calibrator:

Not smooth at all!  Those “bites” taken out are due to elements in the star’s atmosphere absorbing certain shades of blue light, and the bowl shape is due to the way different parts of the stellar surface are moving towards and away from us as the star rotates.

So which stars are “good” and which are “bad” for calibrating high resolution spectrographs Published values of their rotation speeds turn out to be an unreliable guide for this, so observers over the years make lists of “good” hot star calibrators.  For instance, when I need a “good” hot star, I ask Howard Isaacson at Berkeley, who has a list carefully compiled by Kelsey Clubb.  At Berkeley, Kelsey Club went through the California Planet Survey’s library of hot star spectra and separated the wheat from the chaff, which is really useful!

This sort of list isn’t usually publishable—it’s not the sort of scientific advance or discovery that usually warrants a peer-reviewed paper.  But it is the sort of thing scientists should share and that Kelsey should get credit for.

Now, thanks to the new AAS journal “Research Notes of the American Astronomical Society”, we have a good way to share the list.  This new journal is not peer reviewed, but it is free, curated, and has a science editor who accepts papers. They can only be 1,000 words, have one figure or table, and they do not have to be new or novel or anything—just interesting.

But why not just put it to the arXiv, and skip the 1,000 word limit thing?  Well, Geoff Bower asked the same thing on the Twitter, and I came up with two big reasons: RNAAS will curate machine-readable tables, which is great, and as a AAS journal, if your result is (unlike this one) newsworthy, it might get picked up by AAS Nova.  Editor Chris Lintott points out a third:

Anyway, as a journal that emphasizes utility and curates tables, it is the perfect place for Kelsey’s list, so that’s where we published it.  You can find it here.

I was actually worried this would happen.  When RNAAS came out, and then when Overleaf linked directly to it for submissions, I got worried I’d like it too much:

and (despite my misspelling of RNAAS) I was right.  I’ve now submitted or supervised five of these. Here are the others:

Tabby’s Star Explanations

‘Oumuamua Is Almost Certainly Interstellar

EPRVIII Instruments

Barycentric Corrections in Python

I may have a problem…

Planets in Clusters

As we study more and more exoplanets, one variable that we have not really gotten a great handle on is age.  There are not many planets orbiting stars with very well constrained ages. We’d like to be able to see how, for instance, young planetary systems differ from old ones to study planet-planet scattering, planetary migration, and other effects.

So there have been many studies of planets orbiting stars in star clusters.  Clusters are great laboratories for stars because the stars formed (mostly) at the same time out of the same stuff. The repurposed Kepler mission K2 was great for this because it looked for planets along the Ecliptic Plane, and by a bizarre coincidence almost every important benchmark cluster is in the ecliptic!

Jason Curtis, NSF postdoctoral fellow a Columbia University

Jason Curtis is a Penn State grad now an NSF postdoctoral fellow at Columbia working on the problem of stellar ages and activity, using the topic of his PhD thesis, the nearby open star cluster Ruprecht 147. He campaigned to get NASA to repoint K2 to make sure it would capture the stars of Ruprecht 147 so we could study its properties (and, you know, maybe find some planets).

And it worked! He has now written up the paper, and you can find it on the arXiv, in particular the new hot Neptune K2-231b.

But even more useful, to my mind, than the 231st K2 planet is that this planet has a well constrained age.  If we get a lot more, we can look for those trends we’d like to study about how systems change with age.  Jason helpfully compiled a list of all known planets in clusters, and there put them together in one big table. I imagine that with TESS we’ll end up with so many you won’t be able to fit them on one page, but for now here they are, with references.  For the full thing with working links, be sure to read the paper!