aas notes day 2

severe connection/audio problems during the exoplanets III oral session.

Main-Sequence Reinflation of Giant Planets
-the Hot Jupiter Radius Problem
-audio is falling apart, extremely frustrating.
-I can't listen in at all.
-reconnected, but i missed a lot of this one.
-main sequence stars brighten over their lifetime aaaaaaand the audio is still failing.
-planets could reinflate by a detectable amount over their main sequence lifetime. They may or may not show this inflation
-requires statistical testing.
-fractional age of a star is correlated with its radius.
-the radii are keeping up with the flux.
-

The evolutionary track of H/He envelope in the observed population of sub-Neptunes and Super-Earths planets
-there is a gap between sizes in small short period planets, between rocky and subneptunes.
-are super-earths the remnants of subneptune cores, or are they big venus/earths.
-two families, t1 and t2. t1 observes same density/radius family as solar system bodies.
-They can be EITHER! (venus/earths or subneptune cores)
-could photoevaporation imply formation of t2 family objects
-what were the t2 populations like at 100my, timescale of photoevaporation
-assume different core masses between superearths and subneptunes.
-subneptunes have 4% envelope mass.
-superrocky core mass is the whole mass (core in this case means the whole rocky planet, not the iron core)
-t2 lose all of their envelope mass.
-subneptunes have higher mass, bc larger cores.
-T2 are bare cores who have lost their entire envelope. let's look at their secondary atmosphere with JWST.
-T1/T2 separated by higher insolation levels (S/S_earth > 10) while T1 has lower insolation.

The Spitzer-Kepler Survey (SpiKeS): Precision Warm Spitzer Photometry of the Kepler Field
-adding precision photometry to the data on kepler targets.
-used for 400hr of spitzer time
-search for infered excesses (look for faint companions or dust), improve exoplanet characterization.
-3 observations per star, unusually bright stars for spitzer.
-good agreement between models and observations
-there are a few infrared excesses detected in the survey.
-red clump stars could be standard candles due to their fairly constant magnitude.
-improvement over WISE.
-test 1/10,000 stars should have lots of ir excess.
-long wavelengths: mitigate reddening due to extinction.

Old Dog, Old Tricks, Old Data - A Mass for Proxima Cen c
-COMIC SANS TEXT!
-before 1st exoplanets, in 1992-1999, astronomers started looking for planets and substellar companions for proxima and barnard's, starting a long term study for these stars.
-Prox Cen c: found in early 2020.
-original Proxima Cen c suggests 18 mEarth, agrees with gaia.
-difficult measurement results in a good orbit.
-audio cut out (streamer side, not viewer side error, this time)
-Prox Cen c results using HST+FGS+radial velocity: 7+/-2 Mearth.
-very good proxima mass: 0.097+/-0.007 Sol Masses. Pushes proxima closer to mass/luminosity relationship.
-way too visible for a planet of that mass, "would have to be made out of nerf or something"
-maybe a dust cloud or large ring system around the planet.

Pixel Level Decorrelation in Service of the Spitzer Microlens Parallax Survey
-investigating your detector systematics is really important. a systematic error can result in a spurious planet observation.
-spoiler alert: detected planet w/ microlensing! oh wait no it's a systematic error. how did we get here?
-when two unrelated objects come in alignment, a source and a lens. the source will be magnified by the gravity lens. no flux needed from the lens. timescale of event tells lens mass for a kn0own distance.
-lens will have a deviation if lens has a planet--planetary anomaly.
-microlensing can find very distant planets. looking for planets in the core of galaxy.
-spitzer and earth observe slightly different viewing geomtry, slightly different distance from different light curves.
-residual systematic error would also be consistent with a saturn-mass planet.
-would be nice to model correlated noise that looks like a planet but isn't.
-challenges: crowded field, dithered observation, nonuniform sensitivity, a bit of field rotation.
-pixel-level decorrelation used to look at individual stellar pixels surrounding a star.
-no obvious planet seen in a known m-dwarf's jovian planet with a single-lens model, but it does appear with decorrelation and a 2 lens model.
-pixel-level decorrelation does not absorb real planetary signals.
-PLD is useful for lots of microlensing surveys (Roman ST)

Analysis of exoplanets TrES-5b and WASP-43b using the EXOplanet Transit Interpretation Code (EXOTIC)
-this talk feels more public-facing than the others.
-freshining transit midpoint is done by looking at repeat transits.
-short period, large transit depths for the two planets
-deal with meridian flip! watching transit while telescope rotates 180 degrees! Use two separate flux files rather than one.
-must realign images after meridian flip.
-TrES-5b. transit occurred after meridian flip.
-WASP-43b used three light curves with three different reference stars.
-may have missed the transit for WASP-43b. Phase difference very large. incorrect data correction by the observatory.
-TrES_5b freshened by 12 minutes.
-my question: what's the use in diff ref stars. Need a reference star to look at relative brightness without worrying about atmospheric problems. multiple references fix for star variability.
-meridian flip program sharing? being implemented more into codebases for lightcurves, something more normal for transit science.

Discovery of a Giant Planet Candidate Transiting a White Dwarf
-doen't tweeet.
-what happens to planets when stars die? when they become red giants, then white dwarfs.
-we've seen planets orbiting white dwarfs. discovered by direct imaging, with huge separation using spitzer.
-circumbinary planets around a binary white dwarf.
-small bodies scattered close to wd's. wd have high metal spectrums, which should not happen on the white dwarf itself, only if a planet was tidally disrupted.
-can large planets migrate inwards and survive?
-7 minute transit, very short. very deep transit. could be even deeper, but TESS observes light from nearby stars too.
-1.4 day orbital period! too short to be there before red giant.
-transit is grazing, it can not be a complete coverage. Planet is a jupiter, but what's the mass?
-this is one of the most exciting talks!
-jupiter-radius objects have lots of possible masses.
-DC-continum-dominated spectrum for white dwarf. no radial velocity allowed.
-spitzer looks at object, sees that it's not lighter in the ir, so must not be very massive. very low mass brown dwarf or super-jupiter.
-earth mass planets could migrate too, and if so, they could enter the white dwarf habitable zone.
-about half a solar mass white dwarf. <0.6 or so, not sure because it's a cool dwarf.
-0.02 au sma.
-what is a microjansky? some kind of brightness unit?

Discovery of the Earth-Sized Habitable-Zone Planet Kepler-1649 c: What Other Treasures Remain to Be Unearthed in Kepler and K2 Data?
-most similar planet to earth by size and insolation.
-within error bars same size of earth.
-orbits a late-M star. also a venusian planet known.
-all we know right now: size and insolation. habitable zone!
-why was it found 11 years after launch?
-K1649c not part of kepler target search. GO target for high proper motion lensing study.
-automated kepler pipeline. robot gave it a fail, but a weak fail so someone looked at it and found it was not a false positive, it was a false negative. people just highlighting KOIs by eye find these planets.
-planet b was already well studied in 2017 to make data easier to gather.
-P 8.69 and 19.54 days for b and c.
-help constrain occurence rate of habitable zone planets: only earthlike world known around late-mid M dwarfs.
-K2 planet candidates, lots to look at. firehose of data, especially with TESS.
-hundreds of K2 planets left to find. Kepler(K1) predicts lots more planets than have yet been confirmed for K2 data.
-need more user friendly engineering data which can be used for more precise photometry.

Random Forests for Systematics Removal in Spitzer IRAC Light Curves
-or uh... machine learning as a tool for reducing spitzer light curves.
-goals: reduce systematic error/noise. 50% transit depths are lucky, most samples are not so lucky.
-machine learning approach can be applied quickly.
-reduce entire IRAC archive, a gigantic 2 year database.
-also using PLD-like model.
-many models make pretty light curves but underestimated the eclipse depths, all literature models need to be rechecked, and new telescopes should be thinking about fiducial datasets where we can agree on what the signal actually is. removing systematics and the signal is not ideal.
-broadly applicable to other scopes.

fun fact: the solar system is the closest of all planetary systems.
(paraphrased from David Schultz while introducing the solar system oral session)

Mixing of Condensible Constituents with H/He During Formation of Jupiter
-scenario of core-nucleated accretion, where planetecismals grow into planetary cores, where H/He starts small and grows much faster after it exceeds the mass of the solids (i assume this means rock and ice both). This occurred for J & S but not U & N.
-screen sharing problems!
-he's leaving to get some local tech support oh god oh frick.
-gradual change in mean molecular weight with distance from center, trapping a large amount of heat, keeping the planet much hotter than otherwise. Gradual change in mean molecular weight = rock and ices mixed with h/he
-broad region with about 10% heavy elements mixed in with H/He. This keeps a lot of heat in the entire planet. inner parts stay at 50,000 K and stay that way until present.
-planet is evenly mixed as it forms. solids accretion ends at about 10-13 million years, it begins to shrink, but structure remains very similar.
-at end of gas accretion (3 myr): very little gas in the inner core. outer core is half rock, half ice. rock drops off less rapidly with distance from center than ice. rock does not vaporize until it gets very deep.
-most shrinking happens in the first 100 Myr.
-most ice and rock remains in envelope. constituents remain mixed for billions of years -- no sharp core/envelope boundary.
-doesn't fit juno constaints, although closer than traditional models.
-this implies that Jupiter is still relatively mixed together today. much of the bulk of heavy elements are outside the core of the planet.

Addressing Comet Threats to Our Planet Security
-solar orbiting threats, mostly comets.
-comets are unpredictable during their close pass, but once they go out they're predictable, until they come back again.
-comets are far longer than asteroids, they change their orbits, they're very massive, they're faster than asteroids.
-the danger of comets is from inbound comets. Most comets are not returnees on human timescales.
-watching comets outbound is difficult due to the sun. Use telescopes?
-there might be decades of warning for an outbound orbit aimed at earth. inbound it might be a surprise.
-asteroids are easier to track.
-comets arrive at odd angles where they're not being observed.
-skywatchers should not ignore comets.
-use telescopes on mercury and/or jupiter?
-jupiter: asses threat from inbound comet. Only provide short warnings due to nature of inbound comets. mercury: outbound. provide decades or centuries of warning.
-must change the lack of hardware specifically built for space defense.

question asked: should there be slides?
response: Hi Dr. Brannon, I am very sorry for my mistake earlier. There are no slides for this presentation.

I am officially a doctor! Hurrah! No need to go to school for years and years!

Inferring a time dependent map of Io's surface from occultations
-when Europa occults Io, it covers up volcanoes, changing the ir light from Io as a point source.
-make a movie of the surface by "inverting" the light curves.
-100 or so light curves going back to the 90s.
-Huge variation in the baseline--total brightness of Io over time.
-expand the map in spherical harmonics.
-Io's surface is changing, so we want a dynamic model.
-each light curve is the sum of some basis light curves.
-model is fully probablistic and uncertainties are accounted for.
-model has 1000 parameters.
-not at the point where real data can be fit.
-simulated data allows for fitting multiple volcanoes.
-applications for time-variable maps of exoplanets.
-this kind of model can be used to map giant planets. Probably could be done for extrasolar direct imaged giant planets.
-signal-to-noise limits extrasolar direct imaging applications. But this can be used for stars.

Dragonfly: NASA's Rotorcraft Lander for Saturn's Moon Titan
-Barnes: Deputy Principle Investigator.
-launching 2026 arriving 2034.
-four places... ANYWHERE we know of for sure, with air and solid surfaces. Venus, Earth, Mars, and Titan. Surfaces which can interact with atmospheres and vice versa.
-Titan has a similar atmo.
-Look for prebiotic chemistry or even extant astrobiology.
-Titan has liquid water and liquid methane. The water ocean is 100km down or so. May errupt onto surface. Water can interact with complex organic compounds.
-impacts can result in 10,000 years of liquid water in a subsurface region.
-complex atmospheric chemistry might progress further.
-Dragonfly is considered a relocatable lander. Most of the science is done on the ground, then the dragonfly lands again.
-8 cameras, atmospheric and siesmic science. sampling w/ mass spectrometer. gammaray/neutron spectrometer.
-scale mockup is "larger than you think."
-not a toy quadcopter from amazon, a real functional landed vehicle which can translate and move across the surface.
-rotors are more energy-efficient than wheels on titan.
-titan is like early earth in a transient sense--in these impact seas.
-what ground based observations should be done before dragonfly arrives?
-Methane rainfall and dust storms? Make sure we're ready before we fly away from the desert.
-dragonfly was impossible w/o huygens.
-how likely is it to flip over? Really heavy. Not blowing over in a breeze. Active systems to prevent this. every landing made is done to prevent landing on a steep slope, after having already flown over it.
-orbiter component? no. direct to orbit communications.
-rain problems? possibility of encountering rain in dessert mostly during equinox. water is dangerous in water because it's polar, but methane is nonpolar. so if it did rain and methane got where it shouldn't, the methane would vaporize bc the spacecraft is warm, but it would also not damage electronics.
-volcanoes would be molten for months, craters for 10,000 years.
-The lakes/seas are near the north pole, and we're landing at the equator.  The idea here is that if you wanted to look for life on Earth, landing in the middle of the Pacific Ocean wouldn't be the best option.  So instead we are looking to land in the organic sand dunes instead to sample concentrated carbon chemistry, as opposed to diluted in the seas.

 Diagnostic Simulations of the Lunar Sodium Tail and Bright Spot
-sodium exosphere discovered 1998.
-sodium is extracted by several processes.
-some portion of sodium is pushed by solar wind into a tail.

Evidence for a Past Martian Ring from the Orbital Inclination of Deimos
-ring forms, moon torques ring, moon spirals out, rings spiral in, then moon spirals in.
-every presentation in this session has had problems with slides!
-cyclic martian moons! every successive moon is smaller. Moons form close to 3:1 with deimos, where the roche limit approximately is. Moon forming affects Deimos' orbit. Deimos can get outward migration for inner moon.
-end state for deimos depends on mass of inner moon. resonance breaks due to resonance overlap. 20x phobos results in deimos' 2 degree inclination. phobos should be cycle three. 3.5 billion years ago.
-Phobos can only move outwards if there's a ring.
-can Mars J2 act like a ring? No. ring dissipation pushes away moon. Equivalent would be tides within mars, not j2.
-ring particles ran into atmosphere and fell onto Mars.
-giant impact requires something very massive to get material out at deimos.
-Deimos formed from a disk that was short lived. Phobos and proto-phoboses formed from a long lived sub-roche-limit disk.
-phobos is very young in this model. deimos is ancient.
-past moons would not make it to the surface, you just get dust.
-ring breakup have something to do with martian atmosphere disintigration? not really sure, speaker isn't qualified. unlikely useful for big picture idea of martian climate.
-impacts on phobos and deimos are planet-centric, not mostly asteroids and comets.
-captured asteroid is something thatr won't go away, but is never realistic. equatorial orbit is a dead giveaway for insitu forming.
-saturn's moons ALSO have local-formation evidence.
-material transfer between the two martian moons? material from same moon hitting again is more common.