Festschrift — A publication or conference honoring a respected academic during their lifetime, typically published on the occasion of the honoree’s retirement, sixtieth or sixty-fifth birthday, or other notable career anniversary.
Today and Tuesday stellar and exoplanet astronomers gather in Cambridge, MA, at the Phillips Auditorium at the Harvard/Smithsonian Center for Astrophysics to honor David Latham’s 50 years of contributions to astrophysics. The title was at one point “Exoplanets in the Post-Kepler Era”, but given Kepler’s recent crippling, it was changed to “From Binaries to Exoplanets”, presumably to avoid the feeling of a wake.
The first speaker is Michel Mayor, who gives a history of radial velocities, most especially work by Latham and Stepfanik with moderate precision, including their 1989 discovery of HD 114762 b (in retrospect, the first exoplanet), which they wrote “…is probably a brown dwarf, and may even be a giant planet.”
He notes that from 1990 to 2013, RV precision has improved by a factor of 103. (250 – 500 m/s to 0.3 – 0.5 m/s). He also provides a description of the HARPS program including the latest low mass planets.
Describing the metal-poor sample of Santos, Michel tells us that only the most metal-rich of the metal-poor stars ([Fe/H]~-0.4) host giant planets. Describing Pepe’s intensive search of 10 Sun-like stars (at least 50 points per season each), he describes the super-Earths they have detected (including HD 85512 b which he says is in the Habitable Zone. And, of course, α Centauri B b.
The next speaker is Jon Jenkins “not here to bury Kepler, but to praise it.” Six super-Earths in the Habitable Zone so far. Bill Borucki, the PI of Kepler, is sanguine about the Kepler news. “He asked for four years, and that’s exactly what he got.” Still lots of work to do to understand the Kepler database: learn about the stars, the selection biases, and the pipeline. Automatic detection of instrumental junk vs. astrophysical sources is >99%, distinguishing planets from other sources is around 96%. New data validation and other pipeline goodies are coming soon, proven through pixel-level signal injection.
Andrew Howard is third, describing planet overall exoplanet occurrence rates from Doppler and Kepler. The “two key plots” are the mass and radius histograms, both of which increase towards smaller planets.
But he starts with a description of his first night on a telescope with David Latham on the 61″ Wyeth Telescope, which retired in 2005 after a 72 year lifespan. He describes Oak Ridge Observatory and its various components. He recognizes Robert Stefanik and Joe Zajac as the workhorses of the observatory that kept it going.Dave’s farm is across the street from the observatory, and Dave observed every Sunday night. He has pictures of Dave with a chainsaw taking care of the trees that have grown up around the observatory over the decades. Andrew points out that the 61″ discovered the first exoplanet. Andrew describes his optical SETI detector (searching for optical nanosecond laser pulses) and working with Dave on that.
Andrew tells us that Kepler-11 tells us most of what you need to know about low-mass planetary systems: they are numerous, commonly multiple, have low eccentricities, and are flat (low mutual inclinations). Andrew describes Eric Petigura’s independent “TERRA” pipeline for processing Kepler data. Looking only at the quietest stars (to simplify the problem), they recover all of the known Kepler planets plus 37 more low-radius exoplanets, and find that the radius histogram has a plateau at low radii, consistent with Fressin’s work.