Alessandro Sozetti chairs the day's final session, on "The Small Star Opportunity."

Says "If you are a current or former student of Dave Latham, please raise your hands."  A very good showing.  "If you are a long or short term collaborator, raise your hands" (most of the room has their hands up now).  

"The few who have not raised hands, please pay your registration fee."

Now, the first speaker is (close AstroWright friend) John Johnson. 

He says that his experiences with Dave, mostly after having given a talk, is that Dave has been "extraordinarily kind to other scientist"  Dave looks incredulous until John continues  "...especially to younger scientists.  I've seen him be cranky with older scientists."  Thanks Dave for that and says being kind to younger scientists really sets a good tone for science.  This gets applause.

Problem: it's difficult to characterize M dwarfs.  John is describing the work of several Jamie Lloyd students and postdocs, Barbara Rojas-Ayala, Phil Muirhead, and Kevin Covey.   This gives radii of the M dwarfs, lets us get good radii for the planets.

KOI 961 is a near twin of Barnard's Star, which is very well characterized, which really helped.  The KOI 961 triple system has all 3 planets smaller than the Earth, and the best figure "for scale" is not 51 Peg, but Jupiter and the Galilean Satellites.  

"I love that I can say that and nobody gasps.  It's just 'yeah, we've seen that.' What a great era this is."

Two undergraduate students found a strange M dwarf transit around KOI 256 -- the flat bottomed, very sharp ingress/egress.  RV work at Palomar revealed that the "transit" was at the wrong phase, is actually the secondary eclipse.  The true transit is at the wrong depth because of lensing effects.   Kepler does general relativity!

Next up, John Swift's work on Kepler-32, a 5 planet system with the innermost planet in a 0.01 AU, 0.7 day orbit, and the next two out participate in a 3:2:1 period commensurability.    Might be very typical of M dwarf systems, which dominate planets in the Galaxy.

Next, Morton & Swift's work on a period-normalized non-parametric radius function with a modified kernel density estimator.  Most common size planet around M dwarfs so far: 1 Earth radius.  Statistically significant bump near 2.2 Earth radius, maybe.  See a real deficit in distribution at less than 1 Earth radius.  Shows that MEarth will have great success with just a bit more precision (distribution falls off above 3 Earth radii = GJ 1214).

Cites Dressing's work that there are 0.15 Habitable Zone planets per star.  Nearest Earth-size planet in the HZ is 21 pc away.

Next up Suvrath Mahadevan about the "challenges and opportunities" of near infrared precise radial velocities ("another tool in our toolbox in finding planets around M stars").  

Starts with a detour about APOGEE: 300 fibers on the Sloan telescope doing H band velocities.  

At one point, the APOGEE team said "we think we've found a planet" and sent him an RV curve that got sent to him; APOGEE was very excited because they saw a 80-day period signal around a 7th magnitude star.  This sounded very familiar.  [At this point Dave Latham is looking at the 2MASS ID, which has the coordinates, and says "hey, wait a minute" and the audience starts to catch on].  Suvrath^* looked the star up in the literature, and it turned out to be HD 114762!  They were using this as a telluric standard, and the RV pipeline had seen variation.  This is the first NIR exoplanet detection!  Suvrath declares that NIR can now clearly detect exoplanets.

NIR information content isn't as high as optical, but more flux means you win in Z, Y, J.  Habitable Zone Planet Finder (HPF) has R~50,000, with requirement of < 3 m/s precision and goal of 1 m/s on best stars.  Heritage comes from Larry Ramsey's Pathfinder tested at Hobby-Eberly Telescope.  Pathfinder retired a lot of risk and concern about NIR spectrographs, including detector issues (persistence, inter-pixel capacitance) and calibration sources.  

Shows actual on-sky laser fiber comb velocities, showing stability of carbon dioxide telluric lines (only stable to 5-10 m/s) and stars.  Also shows Fabry-Pérot interferometer comb tested at APOGEE, which looks great.

Hand agitation of fibers seems to reduce modal noise, but this is "not practical for a five-year survey."  Commercial device solves the problem: "OptoTune laser speckle remover" which does exactly what it sounds like, and combines with an integrating sphere to solve modal noise of bright calibration sources.  

Octagonal fibers + double scramblers give sufficient scrambling to get sub-m/s precision.

Last speaker is Jonathan Irwin, talking about MEarth.  We would like to be able to do the sorts of science we do on GJ 1214 to Earth-sized HZ planets.  This makes mid- to late M dwarfs the most important targets.  

MEarth has been running since 2008, original survey sensitive to 2 Earth radii.

The original MEarth building was Cold War era laser ranging station.  It is bomb-proof, roof has never failed.  Also housed Fairborn Observatory before MEarth.

High proper motion of M dwarfs very useful, and MEarth data can generate parallaxes.  MEarth also 

People are always asking "has MEarth found another planet?"  Says answer is "no, and we'd like to understand why." To do this "I have to do something naughty" -- he is extrapolating from early M's in Kepler to the late M's from MEarth.  GJ 1214 looks like an oddball if you do this extrapolation, but if you compare by equilibrium temperature it's not too bad.  Kepler shows the planet frequencies goes up in the same dimensions that MEarth's sensitivities go down, so a bit more precision will yield a lot of new planets.

MEarth South is coming along soon!  

That's a wrap for day 1.  Hopefully blogging will commence for tomorrow's session, but perhaps not by me.  

[^* Update:  Suvrath points out that it was David Nidever and Scott Fleming were the ones that made the identification.  The full story is here.]

Post-lunch session:

[I'm indenting Latham-specific stuff to separate it from the science content here.  Dave has clearly made this a prospective conference, but many participants cannot resist anecdotes and comments about his prolific career.]

First up is Lars Burchave talking about deriving metallicities of the Kepler stars.   Two ingredients needed to extend known relations to lower-mass planets:  huge sample, and metallicities for the stars in it.  Kepler gives us the first; lots of work into getting the second.  Simple cross-correlation of synthetic library spectra to high resolution spectra of KIC stars yields good effective temperatures and metallicities; does not require high SNR.   Yields a homogeneous sample of parameters for 152 host stars.

Average metallicity correlates with detected planet radius with high statistical significance; below 2 Earth radius average metallicity is sub-solar.

Finishes with images from Google searches on "David Latham," including those of a band called "David Latham and the Strangers," and as an actor in "Jesus Christ Superstar".  

More seriously, he showed images of Dave on a bike at Loveland Pass (way up at the Continental Divide) and other places, and closes with "congratulations on being one of the pioneers in the exoplanets field, so all of the rest of us can do such great work."

Now we move on to TESS, from the PI himself, George Ricker.  Chair Josh Winn points out that George was "converted" by David Latham from an X-ray astronomer to "one of us."  George starts with 7 years of "TESS-related proposal covers": HETE-2 (High Energy Transient Explorer-2) turning into "Hot Exoplanet Transit Experiment-Survey by using the star tracker.  In 2008, TESS was proposed from scratch as a SMEX2 and finally a full explorer TESS to launch in 2017.  Will discover the "best" 1,000 small exoplanets.  Whole sky survey from magnitudes 4-12; 500,000 stars.  TESS will find planets around brighter stars than Kepler, although the planets will be bigger on average.   

Shows prototype TESS cameras and a full-scale mockup, and a movie illustrating the 4 camera FOV, (23 degrees square, each), which have 27 day-long stares.  The movie is very slick, and features a nifty lunar gravity assist into a transfer orbit, followed by a burn to go into a 2:1 orbital resonance with the moon, an orbit that is stable over decades (the orbit exploits the Kozai mechanism!).  

George and Dave apparently competed over getting better deals for things when traveling;  George found the cheapest rental cars, but Dave consistently found the cheapest hotel rooms.  In this, "Dave's tolerance for bedbugs beat mine."

In the Q&A, we learn that TESS will point with reaction wheels (like Kepler) but George assures us that it will have 4 of them, and there is a mission that had one last for 6 whole years (the audience is both very amused and very concerned).  

Finally, Josh Winn introduces David Latham to talk about TESS.  

Josh tells us that 7 years ago he started as an exoplanet researcher, and Dave invited him into his office to discuss being part of the the Kepler followup mission.  Josh was surprised because at this point he had only 3 exoplanet papers, one of which nobody cites ("I don't even cite it," he says) and another that was wrong ("but does get cited!" Geoff interjects, to much amusement).  Josh concludes: "I am not the only one in this room that has benefitted from Dave's generosity" and his "childlike enthusiasm" when he has every right to be an old grump.

At this point, Dave approaches the podium to a lengthy standing ovation.  He says that people do occasionally call him "crusty."

Dave says it's in retrospect a good thing that the SMEX version of TESS did not get selected, because lessons learned from Kepler have shown how hard it would have been to have a low duty cycle and low Earth orbit.  Once Kepler launched Dave "got distracted by other things," but eventually got back to TESS.  His admonishment "sleep is for sissies" to the TESS gang made it into the glossary.   

Lessons from Kepler that informs TESS: 

• Small planets are common, so TESS will find hundreds of planets. 
• Multiples are common (and coplanar), so gravitational interactions would be important and measurable.  This also makes continuous coverage very important.  
• Photodynamical analysis is powerful and multitransiting systems are "information rich"
• Followup with HARPS-N will be essential.  
• The pipeline is challenging and critical.  Dave quotes Andrew Howard from earlier, calling the Kepler pipeline one of the great achievements in scientific computing; agrees that "that's not far off."

Dave's talk is gracious and full of praise for his collaborators, especially Jon Jenkins' team.

Josh asks for questions for "the discoverer of Latham's planet."

Session 2

Geoff Marcy is next talking about radial velocity measurements of 52 planets orbiting 22 stars from Kepler, half of which have asteroseismology measurements. The revealed masses and densities of some of these planets appear to be negative, because the team declined to enforce positivity in the MCMC posteriors in order to avoid biasing the overall statistics of the sample.  That is, many of the planets have not been detected in radial velocities.  

Some of the detections are consistent with rocky planets, densities of a few g/cc, others are clearly gaseous (about 1.5 g/cc).  The bigger planets are lower density, consistent with earlier transiting work and the smaller (below 2 Earth radii) planets are "mostly rocky planets" (where the "mostly" is deliberately ambiguously modifying "rocky" and "planets", or possibly both).  Above 100 Earth masses, the trend reverses, as we transition from planets to brown dwarfs.

Geoff says 21 years ago Dave summoned the nascent radial velocity community here, and Geoff has his transparencies for his talk at that meeting with him!  Back in 1992, there were no BDs and no exoplanets.  Shows a an image of the 429 RVs for HD 114762 presented there.  Dave's introductory remarks state that the "conventional wisdom" is that giant planets will only be found in decade-long orbits, so this will be a long-term project.  

Geoff cites, still from that conference, Bill Cochran's First Commandment of Planet Detection: Thou shalt not embarrass thyself and they colleagues by claiming false planets.

  

The following events occurred amid a jocular mood:  "And now a controversial topic": "Who may name a planet?"  Marcy says that anyone may suggest a planet name, and so he solicits nominations from the gallery for names for HD 114762b.  "Latham's planet" is loudly and prominently shouted from many points of the room (and may or may not have come from plants who were sitting next to me prior to the talk).  Marcy quickly closes the nomination and holds a lightning-fast vote ("all in favor" gets hands; a vote for "all opposed" is not taken).  Marcy's next slide:

 "HD 114762b is hereafter known as: Latham's planet*" ("*=pending IAU approval, of course").  

Next up is Leslie Rogers showing how Kepler has filled out the mass-radius diagram below 10 Earth radii and 50 Earth masses, including adding a new dimension of incident flux, allowing us to study retention and survival of atmospheres.  Describes the problem of inverting mass and radius measurements with uncertainties into a probability of being "rocky".  Finds a dividing line around 1.5-2 Earth radii between rocky vs. non-rocky planets, consistent with Geoff's talk.

Leslie finds that the boundary between "rocky" and "non-rocky" can be tightly constrained between 1.7-1.8 Earth radii in a simple, one-parameter model where "rockiness" is a simple function of radius.  In a two-parameter model with a transition region, values up to 2 Earth radii are allowed.

Finishes with a Latham memory, despite not having ever worked with him.  Dave gave many conference highlight talks at many of her first conferences, and she saw him as a "a kind senior authority figure".  It became her aspiration to "make it into one of your summary highlight reels". :)

Next up is Ruth Murray-Clay giving an overview of the physical processes that we have to worry about for these lower mass planet atmospheres. Shows fraction of mass lost over 10 Gyr at 0.05 AU.  HD 209458 loses 1% of its mass, which is not a big deal because it is made entirely of gas.  For a super-Earth, this is a substantial fraction of its atmosphere.

Two kinds of escape: kinetic, and hydrodynamic, regulated by the Jeans escape limit and hydrodynamic escape limits, respectively.  UV photons heat atmospheres through ionization.

3 fates for this energy: radiated away in place, conducted lower in the atmosphere, then radiated, or it could drive an outflow; all of these could be observable.  Ly-α and H₃⁺.  Low-T planets will have molecules that are good radiators, so the energy will come out as radiation.  For hot Jupiters, the result could be an energy-limited outflow.

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.

Holy ****! Yes we need more precision. We are planning on asking for DDT time anyways early next week...

What if its an SB2? Could that cause aliasing of some sort to create this signal?

• Juggling the HET queue, we slowly started knocking down the sidelobes of the power spectrum with "adaptive scheduling" to only observe on nights (and tracks) that would rule out competing aliases of the period consistent with a 3:1 resonance.  Sure enough, every shot we got strengthened our conviction that the 3:1 resonance was the correct solution.  But the resonance was perfect.  Most resonances show period ratios near an integer ratio, but rarely exact, because of dynamical interactions.  This ratio was perfect to within one part in ten thousand.
• Matt Payne's analysis struggled with the sparse data, but we finally got enough points for his code to settle into a favored overall solution, and the stable solutions were very dynamically active (which means, very exciting for a dynamicist to study!)  They also predicted HUGE transit timing variations, if the system was transiting (10 hours!), an order of magnitude larger than anything seen before (this was pre-Kepler).
• The KELT photometry came back totally stable:  this was not some sort of variable star or eclipsing binary.  It was tricky to look for transits, given the large variations expected, but Scott and the others were able to rule out most transiting scenarios, which was disappointing to some extent, but the stable photometry ruled out most false positive scenarios, too.
• The spectral analysis came back clean, with no hint of contamination, again.  But the gravity of the star changed with the new data:  we now had a regular main sequence F star, not a subgiant.  This wasn't a big deal, but it was strange that we couldn't pin it down better.
• Then Justin Crepp found a couple of AO companions, just to make our lives interesting:

Figure 2 from Lee et al., announcing MARVELS-1 b, the brown dwarf companion to MARVELS-1.

Perhaps the best response to laying off the blame for evil to ideology or theology comes from Murray Kempton... [who] tossed off one of the single wisest things I've ever heard said about ideology and evil: "It took me a while to discover this," he said, "but the biggest mistake you can make is to follow your ideas [i.e. act on them according] to their logical conclusions. You can make a lot of other [mistakes], and every now and then you can be right. But when you follow your ideas to their logical conclusions you are always wrong." 

'Deep-seated preferences,'' as Justice Holmes put it, ''cannot be argued about . . . and therefore, when differences are sufficiently far-reaching, we try to kill the other man rather than let him have his way. But that is perfectly consistent with admitting that, so far as it appears, his grounds are just as good as ours.''

Once Justice Holmes and Judge Learned Hand discussed these questions on a long train ride. Learned Hand gave as his view that ''opinions are at best provisional hypotheses, incompletely tested. The more they are tested . . . the more assurance we may assume, but they are never absolutes. So we must be tolerant of opposite opinions.'' Holmes wondered whether Hand might not be carrying his tolerance to dangerous lengths. ''You say,'' Hand wrote Holmes later, ''that I strike at the sacred right to kill the other fellow when he disagrees. The horrible possibility silenced me when you said it. Now, I say, 'Not at all, kill him for the love of Christ and in the name of God, but always remember that he may be the saint and you the devil.' ''