DPS meeting to be broadcasted live.

Is anyone going to watch to Exoplanet-related stuff? I might be able to Saturday, hopefully someone here can as well. If possible, I'll try to type everything being said and post it here.

http://dps08.astro.cornell.edu/

I posted some of the presentations below.

Saturday (I may be able to watch and write this stuff as it happens):

Direct Spectroscopy of Non-Transiting Exoplanets

Abstract wrote:

We are using ground-based infrared spectroscopy to directly characterize the atmospheric properties of the close-in exoplanet population. These planets, discovered through indirect means such as precision radial velocity surveys, are strongly irradiated by their parent stars, resulting in exotic atmospheric conditions. Recent direct measurements of transiting exoplanets using space-based facilities have provided information about a variety of atmospheric processes, including energy transfer from the day-side to the night-side, atmospheric structure and temperature at depth, and cloud cover. However, the sample of transiting planets that can be measured with these techniques is very small; to understand the close-in planets as a population, measurements of non-transiting planets are necessary.
The temperature of a close-in exoplanet atmosphere determines whether CH4 or CO is the dominant carbon bearing species, so the measurement of either species probes the equilibrium temperature of the atmosphere. We are observing close-in exoplanet systems with the NIRSPEC spectrometer on the Keck II telescope, obtaining blended star-planet spectra at the 3.3 micron CH4 fundamental and at the 4.6 micron CO fundamental. Our observations achieve a signal-to-noise of several thousand with a spectral resolution of R~25000. We use a correlation analysis to search for the contribution from the planet, with a predicted planet-star flux of one part in 104 - 105. Here, we will present preliminary results from our search for CH4 absorption from the exoplanet 55Cnc b, using spectra obtained in December 2007 and March 2008. We will also describe the techniques that are yielding high signal-to-noise spectra in the thermal infrared, and our detailed terrestrial absorption correction using line-by-line atmospheric synthesis of the transmission function.
CB is supported by an NRC Research Associateship at NRL; basic research in infrared astronomy at NRL is supported by 6.1 base funding.

Multiple-Exoplanet Systems

Abstract wrote:

Today there at least 27 well-characterized multiple exoplanet systems, and although that composes only ~15% of the known planet-bearing stars, residual radial velocity trends and periodicities suggest that planet multiplicity is probably quite common, with at least 1 in 4 planetary systems hosting multiple planets. The continuing detection of ever-smaller "super-Earths" and long-period planets continues to enlarge the sample. I will discuss some of the opportunities clues multiple-planet systems offer to study the nature of planet formation and dynamical evolution. For instance, the orbital distance and eccentricity distributions of apparently single planets and those in multiple-planet systems appear inconsistent, offering a clue into the origins of eccentricities and constraints on planetary migration theories.

Secondary Eclipse Photometry of GJ 436b in Six Spitzer Channels

Abstract wrote:

The nearby exoplanet GJ 436b is a hot Neptune with an equilibrium temperature of approximately 700K, assuming uniform redistribution and 0.3 Bond albedo. This eccentric exoplanet is the only known transiting hot Neptune and the only known transiting M dwarf companion. The Spitzer Exoplanet Target of Opportunity program observes secondary eclipses, where the planet passes behind the star, to provide direct measurements of emitted planetary flux, thus constraining atmospheric models. The observations took place in January and February of 2008 for the 3.6, 4.5, 5.8, 16 and 24-micron events, while GJ 436b was observed at 8.0 microns in June of the previous year. Of the channels that yielded eclipse detections, we will present estimates of infrared brightness temperatures and discuss how they can provide insight into atmospheric composition using current models. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA, which provided support for this work.

First Results From The SDSS-III Multi-object APO Radial-velocity Exoplanet Large-area Survey (MARVELS)

Abstract wrote:

We present the first light results from the Multi-object APO Radial-Velocity Exoplanet Large-area Survey (MARVELS). MARVELS is part of the on-going Sloan Digital Sky Survey (SDSS) III survey which started in July 2008 and will end in July 2014. The data are taken with a multi-object fixed delay interferometer coupled to a R=11,000 spectrograph capable of acquiring precision radial velocities (3-20 m/s depending on V magnitudes) for ~60 objects simultaneously in the 3 degree field of view of the SDSS telescope. MARVELS is to monitor a total of 11,000 V=8-12 relatively bright survey stars over ~800 square degrees over the 6 years. The survey stars include about 90% F8 and later type main sequence stars and subgiants, and 10% G and K giants with V=7.6-12. MARVELS will produce the largest statistically well defined sample of giant planets drawn from a large of host stars with a diverse set of masses, compositions, and ages which will be used to study exoplanet diversity and planet formation, migration & dynamical evolution. It will also possibly discover rare planet systems and identify signposts for lower-mass or more distant planets. The first two year survey data will be released to the public in 2011. A new planet in a spectroscopic binary system discovered in the MARVELS pilot program will also be reported.
We would like to thank the W.M. Keck Foundation, Sloan Foundation, NSF, NASA and UF for support.

A Representative Sample of Exoplanetary Secondary Eclipses at 8 Microns

Abstract wrote:

Eclipses observed with the Spitzer Space Telescope provide the highest S/N direct measurements of a given exoplanet, and thus give access to the largest number of planetary atmospheres of any current observing method. To provide direct constraints on models of exoplanetary atmospheres, we are using Spitzer to measure a representative sample of exoplanetary infrared brightness temperatures. We report measurements of GJ 436b, HAT-P-1b, HD149026b, TrES-2, WASP-1b, and WASP-2b in the 8.0-micron channel. We will discuss the constraints placed on planetary atmospheric models by emerging patterns in a plot of predicted vs. observed brightness temperatures.
These observations are part of the Spitzer Exoplanet Target of Opportunity program, which selects transiting exoplanets for observation in a dedicated block of Spitzer time based on predicted S/N, the quality of parameters not in our control (e.g., system distance), and predicted planetary temperatures. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA, which supported this work.

Exoplanet Masses from HST/FGS Astrometry - Progress Report

Abstract wrote:

We present a progress report on our ongoing efforts to produce actual exoplanet masses (as opposed to M sin i). We obtain masses through astrometry of host star perturbations. The Fine Guidance Sensors aboard Hubble Space Telescope provide millisecond of arc per observation precision. Our five targets include HD 38529, HD 47536, HD 136118, HD 145675, and HD 168443. Specific results presented at this meeting will include masses for components of HD 47536 and HD 136118 (Martioli et al. 2008, in preparation). Published radial velocities and high-cadence velocities from the Hobby-Eberly Telescope permit us to characterize the orbits of companions with periods far longer than our roughly 2 year span of HST data. These velocities also occasionally yield previously unknown companions, which, if not properly taken into account, would have introduced noise into our simultaneous astrometry-radial velocity modeling. This project originally had six host star targets. HST astrometry of the first of these, HD 33636 (Bean et al. 2007, AJ, 134, 749), identified the presumed planetary mass companion HD 33636 b as an M dwarf star, HD 33636 B.
This work is supported by NASA through the Space Telescope Science Institute General Observer program grants: GO-09407, -09971, -10103, -10610, -10989, and -11210.

Total Solar Irradiance at the 2006 Transit of Mercury and Application to Transiting-Exoplanet Observations

Abstract wrote:

Following our earlier work on the Total Solar Irradiance (TSI) at the 2004 transit of Venus, in which an 0.4 percent drop in TSI was readily detectable with the ACRIM3 instrument on NASA's ACRIMsat, we report on ACRIM3 observations of the 29 November 2006 transit of Mercury. We also observed the transit from Haleakala and from Sacramento Peak. Mercury's cross-sectional angular area is only 1/30th that of Venus's, so the expected drop in TSI was only 0.01 percent. As expected, this tiny drop was not detected, though detailed statistical analysis continues. Our Venus and Mercury transit observations provide closeup views of phenomena increasingly observed for exoplanets and provide examples by which one can assess the limits at which exoplanet discoveries can be made with the transit method.
Acknowledgments: JMP's planetary occultation work and the POETS instrument (Portable Occultation, Eclipse, and Transit System) were funded in part by NASA Planetary Astronomy grants NNG04GE48G, NNG04GF25G, NNH04ZSS001N, and NNG05GG75G to M.I.T. and Williams College, and continues under NNX08AO50G. Our transit work was funded in part by the Committee for Research and Exploration of the National Geographic Society. ACRIMsat is supported by a grant from NASA to Columbia University.

Search of Exoplanets - Phase I

Abstract wrote:

From the Astronomical Observatory at the University of Nariño-COLOMBIA, we have begun a systematic search for exoplanets. Initially we made differential photometry on variable stars weaker than the tenth magnitude to get enough experience on the establishment of stellar transits, so then we could undertake the work with exoplanets. We have already confirmed the transits of two exoplanets with good photometry data: At the exoplanet HAT-P-5b, discovered by Bakos and other investigators and which turns around the GSC 02634-01087, with an orbital period of 2.788491 days according to measurements of the discoverers, and also at the exoplanet TrES-3, discovered by O’Donovan and other investigators and which turns around the GSC 03089-00929, with an orbital period of 1.30619 days, established by its discoverers. Both exoplanets are quite interesting because they have one of the smallest periods found on exoplanets. The TrES-3 also provides a big opportunity for studying the orbital decay and mass loss due to evaporation, caused by the great closeness to its star. We have captured a lot of data to elaborate the lightcurves so we can estimate physical parameters of the bodies. We are getting data on various dates. Actually we are preparing the equipment to develop observations of radial velocities through spectrometry. In a later phase, we expect to verify the presence of other exoplanets which cause less deep transits, and then we can investigate stars with possible exoplanets around them. Besides we hope to design a mathematical model of the studied systems. The equipment we employed is: 14”LX200 GPS MEADE telescope, ST-7XME SBIG camera, STL-1001 SBIG camera, LHIRES III Spectrograph, and SGS-SBIG Spectrograph. On the poster it is explained at length the methodology followed over the search, the data we obtained and the physical- mathematical analysis that was carried out.

Worlds Beyond: A Strategy for the Detection and Characterization of Exoplanets

Abstract wrote:

We summarize the recent report of the Exoplanet Task Force, which was charged by NASA and NSF through the Astronomy and Astrophysics Advisory Committtee to develop a 15-year scientific strategy for the detection and characterization of exoplanets down to the size of Earth. The raw material for the strategy was provided in the form of invited briefings and 85 white papers received from the community. The time horizon for the strategy is divided into three epochs, 1-5, 6-10 and 11-15 years. A two-pronged effort is recommended, one focused on ultimately detecting and characterizing Earth-size/Earth-mass planets around M-dwarfs using ground-based and space assets in place or under development today, and the second with the ultimate goal of detecting and characterizing Earth-size/Earth-mass planets around stars like our Sun with new capabilities whose technologies are under development today. A pivot point in the strategy is deployment in the second epoch of an astrometric facility in space with the sensitivity to survey at 0.2 microarcsecond accuracy for one Earth-mass planets around 60-100 solar-type stars in our cosmic neighborhood, providing a target list for a direct-detection mission to be deployed in the final epoch. Following this, in the third epoch, a direct-detection mission is deployed capable of doing a spectroscopic examination of Earth-mass planets identified by the astrometric mission. In this paper we explain the importance of obtaining mass and orbital information on potential Earth-sized planets and derive the required accuracies. Because the charter of the DPS now includes the study of exoplanets, it is to be hoped that the DPS membership will consider carefully this strategy as a means to the end of the long search for planets like our own around other suns.

Preliminary Results From The NASA EPOXI Mission

Abstract wrote:

EPOXI (EPOCh + DIXI) is a NASA Discovery Program Mission of Opportunity using the Deep Impact flyby spacecraft. From January through August 2008, the EPOCh (Extrasolar Planet Observation and Characterization) Science Investigation used the HRI camera to gather precise, rapid cadence photometric time series of stars with known exoplanets in edge-on orbits. One of the EPOCh science goals is a search for additional planets at larger orbital radii in these systems. Such planets would be revealed either through the variations they induce on the times of transit of the known exoplanet in front of the parent star, or directly through the photometric transit of the second planet itself. I will describe our techniques for searching for additional planets orbiting the EPOCh targets, and for placing limits on their physical sizes. This search is especially interesting in the case of the GJ 436 system, since the eccentricity of the known Neptune-mass planet may point to the presence of a second planetary companion. Using our EPOCh observations for this system, we have the sensitivity to detect a planet as small as the Earth, even if the planet produces only a single transit event.

More on Saturday:

The Planet-Metallicity Correlation

Abstract wrote:

The tendency of planets to be found preferentially around metal-rich stars is now well established. This correlation gives strong support for most planets being formed by a core accretion scenario. The situation for planets around stars with sub-solar metallicity is, however, much less clear. In the metallicity range -0.8<[Fe/H]<-0.2, the overwhelming majority of stars belong to the thin-disk, but most of the planet-hosting stars are members of the thick-disk population. One possible explanation for this is that thick-disk stars have [a-elements/Fe] significantly enhanced over thin-disk stars of the same [Fe/H]. Even among metal-rich thin-disk stars, Robinson et al. (2006) found that planet-hosting stars have show enrichment of Si and Ni over the general population. Thus, we suggest that the real key to planet formation is not the Fe abundance, but rather the total abundance of heavy elements available to form planets. We define a new total metallicity parameter z= log10(Z*/ZSun) (where Z is total stellar heavy element abundance), and reexamine the trends of planet discoveries as a function of z rather than of [Fe/H]. We also describe a new observing program to survey stars in the metallicity region which samples both thick- and thin-disk stars, in order to improve the statistics of this relationship.

What Children Tell Us about Their Parents: From Visible Dust to Invisible Planetesimals in Debris Disks

Abstract wrote:

Various small body families in the solar system, together with dust they produce through mutual collisions and cometary activity, exemplify a non-planetary component of a planetary system, usually referred to as a "debris disk". Debris disks have been found to be a common phenomenon for main-sequence stars and, similar to the solar system, are believed to comprise planetesimal populations that have accreted at early epochs and survived possible planet formation. However, in contrast to the solar system, observations of extrasolar debris disks only show their dusty portion, whereas the dust-producing planetesimals remain invisible. We show how collisional models of debris disks can be used to "climb up" the ladder of the collisional cascade, from dust towards parent bodies, representing the main mass reservoir of the disks. Applying our approach to five sun-like stars known to harbor dust, we find that the observed excess emission in far-IR to sub-mm is compatible with debris disks collisionally sustained by "large Kuiper belts" of 0.2-50 earth masses (in the bodies up to 100 km in size) with radii of 100-200 AU, larger than thought before.
This research has been funded by the Deutsche Forschungsgemeinschaft (DFG), projects Kr 2164/5-1 and Mu 1164/6-1, by the Deutscher Akademischer Austauschdienst (DAAD), project D/0707543, and by the International Space Science Institute (Bern).

EPOXI Empirical Test of Optical Characterization of an Earth-like Planet

Abstract wrote:

The re-purposed Deep Impact spacecraft was used as part of the EPOXI mission-of-opportunity to observe the whole disc of the Earth at 57° phase angle (77% illumination) and 0.18 AU range and at 77° phase angle (62% illumination) and 0.34 AU range on March 19 and June 5, 2008 (respectively), over a range of wavelength from 350 nm to 4.8 µm. These observations sample the Earth's optical properties at the seasonal extremes of an equinox and near-solstice. A third observation was obtained on May 29, including a transit of the Earth by the Moon. These measurements constitute an empirical test of proposed methods for the remote characterization of terrestrial planets in extrasolar planetary systems. The visible-light signal was sampled with 7 filters of approximately 100 nm width at 100 nm spacing over 350-950 nm central wavelength, at 15-minute intervals in 4 selected filters and 1-hour intervals in the remaining 3 filters. Near-IR spectroscopy at 1-4.8 µm was obtained at 2-hour intervals. These data provide a rotationally-averaged optical/IR spectrum of the Earth in a typical presentation at low-to-moderate spectral resolution, and light curves of the Earth reflecting the surface distribution of clouds and terrain. Infrared spectroscopy demonstrates the signatures of H2O, CO2, and other telluric species. The visible light curve demonstrates significant time-variability of the optical spectrum associated with terrestrial terrain types. Of greatest significance to proposed extrasolar terrestrial planet characterization, these data provide a test for the suitability of the "Red Edge" as a signature for the presence of chlorophyllaceous life on an unresolved planetary body.
This work is supported by the NASA Discovery Program.

Coupled Radiative-Dynamical GCM Simulations of Hot Jupiters

Abstract wrote:

The stellar flux incident on hot Jupiters -- gas giants within 0.1 AU of their stars -- is expected to drive an atmospheric circulation that shapes the day-night temperature difference, infrared lightcurves, spectrum, albedo, and atmospheric composition. Although several atmospheric-dynamics models of these objects have been published, all adopt simplified heating/cooling schemes that preclude robust predictions for the 3D temperature patterns, spectra, and lightcurves. Here, we present cloud-free simulations of hot Jupiters from the first 3D general circulation model (GCM) that couples the atmospheric dynamics to a realistic representation of radiative transfer. We emphasize HD189733b and HD209458b, which are the best observationally constrained hot Jupiters and which represent an interesting pair because one (HD209458b) appears to have a dayside stratosphere while the other (HD189733b) does not. Our simulations develop large day-night temperature contrasts and winds reaching speeds of several km/sec. A prograde equatorial jet forms with retrograde flows at higher latitudes, which leads to an eastward displacement of the hottest regions from the substellar point and coldest regions from the antistellar point. For HD189733b, our predicted lightcurves compare favorably with lightcurves observed at 8 and 24 microns with the Spitzer Space Telescope, including the modest day-night flux variation and offset of the flux peak from the time of secondary eclipse. The simulated temperatures decrease with altitude, leading to a spectrum dominated by absorption features. For HD209458b, inclusion of TiO and VO opacity leads to a dayside thermal inversion layer (stratosphere) where temperatures rise above 2000 K, consistent with suggestions offered to explain the observed secondary-eclipse spectrum. Interestingly, however, our 3D models do not match the observed spectrum, which suggests that our simulated stratosphere does not yet have the correct properties (e.g., altitude and thermal gradient). We discuss the implications of these models for our general understanding of hot-Jupiter meteorology.

Monday:


Transit Detections From Space : The Corot Mission

Abstract wrote:

Since its successful launch in December 2006, the CoRoT satellite has been providing long term, high duty cycle light curves of unprecedented precision for thousands of stars of all types. Its first results, among others an inflated giant planet orbiting a very active G type star and the first eclipsing Brown Dwarf like object on short orbit, illustrate that CoRoT is particularly well-suited to make significant breakthroughs in our knowledge of planets with short orbital periods.
I will briefly describe the mission profile, the instrument performances and the battery of ground-based observations which are being performed to complement the light curve analyses, allowing us to fully characterize the detected planets. I will then present some of the latest results from the mission.

Observational Constraints on the Chemistry and Dynamics of Exoplanet Atmospheres

Abstract wrote:

The observational study of the atmospheres of exoplanets is now well underway, despite the fact that astronomers have not yet imaged these bodies directly. These advances are enabled by the discovery of planetary systems that are viewed nearly edge-on to our line-of-sight, such that the star and planet undergo periodic mutual eclipses. When the planet transits in front of the star, starlight passing through the outer scale heights of the atmosphere is attenuated in a wavelength-dependent fashion that encodes information about the atoms, molecules, and condensates that are present. Observations spanning times of secondary eclipse, when the planet passes out of view behind the star, permit the direct study of the planetary thermal emission and estimates of the dayside temperatures. Furthermore, by inverting the time-dependent changes in brightness as features on the planet rotate in and out of view, we have constructed longitudinally-resolved temperature maps. I will review these various rich datasets, which challenge our understanding of the atmospheres of Jovian planets under strong irradiation.

The Theory of Exoplanet Atmospheres and Spectra

Abstract wrote:

Approximately 300 exoplanets, mostly giant planets (EGPs) in the Jovian mass range, have been detected orbiting stars in the solar neighborhood. More than 15% of them are transiting their primaries and these have collectively yielded a wealth of structural and physical information which theorists are scrambling to interpret. In this talk. I will present the current theory of the their atmospheres, compositions, and spectra. Due to stellar irradiation effects and heat redistribution by super-rotational jet streams, we must eventually construct with some fidelity 3D general circulation models (GCMs), with multi-D radiative transfer.
However, simpler planar models with average irradiation boundary conditions and crude day-night heat transport algorithms do a reasonable 1st-order job of reproducing what is observed directly by the Spitzer infrared space telescope. In particular, thermal inversions and stratospheres are inferred for many close-in EGPs.
I will discuss the confrontation of theory with data and summarize what has been learned to date.

Algol: An Early Candidate for a Transiting Exoplanet

Abstract wrote:

Virtually every astronomy text credits John Goodricke (1764-1786) with the discovery of the period of variability of the star Algol (b Per) and with the explanation of its variation (eclipses by an unseen stellar companion). Today, Algol is considered a prototype of an eclipsing binary star. In actuality, John Goodricke worked in collaboration with his neighbor, mentor, and distant relative, Edward Pigott. As observed by Hoskin1, the observing journals2 of the two clearly show that the eclipse explanation originated with Edward. Both originally used the term “planet” to describe the eclipsing body. However, in Goodricke’s 1783 paper describing Algol, he writes: “....I should imagine it could hardly be accounted for otherwise than either by the interposition of a large body revolving round Algol, or some kind of motion of its own, whereby part of its body, covered with spots or such like matter....”3 Goodricke was later to soften his stance still further after the two discovered several other variable stars; his last published work4 mentions only starspots as an explanation for the light variation of Algol. Although the physics of the time would not have allowed Goodricke and Pigott to distinguish between a star and a planet as the unseen companion, the eighteenth-century astronomers showed great prescience in realizing that the eclipses of Algol were just that. Their mental leap, at a time when astronomers were just beginning to think seriously of discovering planets around other stars, should not go unremembered by modern planetary scientists.

Prospecting For Habitable SuperEarth Exoplanets With The MEarth Observatory

Abstract wrote:

When exoplanets are observed to transit their parent stars, we are granted direct estimates of their masses and radii, and we can undertake studies of their atmospheres. As a result, such systems have profoundly impacted our understanding of the physics of exoplanets, yet to date only large exoplanets (akin to Jupiter or Neptune) are known to transit their parent stars. By targeting nearby M-dwarf stars, a transit search using modest equipment is capable of discovering planets as small as 2 Earth radii in the habitable zones of their host stars. The discovery of such planets is important for two reasons: First, they provide fundamental constraints on the physical structure of planets that are primarily rock and ice in composition. Second, by differencing spectra gathered when the planet is in view from those when it is occulted by the star, we can study the atmospheric chemistry of potentially habitable worlds. The MEarth Project will consist of 8 identical, automated 16-inch telescopes in a single enclosure at Mt Hopkins, AZ. Five of these telescopes are currently in operation. We will describe the target sample, survey design, and the current photometric precision, with the goal of demonstrating the feasibility of the ground-based detection of habitable exoplanets. We acknowledge funding from the National Science Froundation and the David and Lucile Packard Fellowship for Science and Engineering.

Exoplanetary Photometry

Abstract wrote:

The Spitzer Space Telescope measured the first photons from exoplanets (Charbonneau et al. 2005, Deming et al. 2005). These secondary eclipses (planet passing behind star) revealed the planet's emitted infrared flux, and under a blackbody assumption provide a brightness temperature in each measured bandpass. Since the initial direct detections, Spitzer has made numerous measurements in the four Infrared Array Camera bandpasses at 3.6, 4.5, 5.7, and 8.0 microns; the Infrared Spectrograph's Blue Peakup Array at 16 microns; and the Multiband Imaging Photometer for Spitzer's 24-micron array. Initial measurements of orbital variation and further photometric study (Harrington et al. 2006, 2007) revealed the extreme day-night variability of some exoplanets, but full orbital phase curves of different planets (Knutson et al. 2007, 2008) demonstrated that not all planets are so variable. This talk will review progress and prospects in exoplanetary photometry.

Will you guys prefer a new topic made for each presentation? Or have it all in this topic?

Addendum: I'm saving the slides to my hard drive, I'll post them later when I have time (not much time at the moment, slides flying past quickly).