| Program Number | Principal Investigator | Program Title |
|---|---|---|
| 14163 | Mickael Rigault, Humboldt Universitat zu Berlin | Honing Type Ia Supernovae as Distance Indicators, Exploiting Environmental Bias for H0 and w. |
| 14181 | S Thomas Megeath, University of Toledo | A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds |
| 14216 | Robert P. Kirshner, Harvard University | RAISIN2: Tracers of cosmic expansion with SN IA in the IR |
| 14608 | Nadia L Zakamska, The Johns Hopkins University | Host galaxies of high-redshift quasars with extreme outflows |
| 14616 | Simon Porter, Southwest Research Institute | Primordial Triplicity: A Census of Hierarchical Triples in the Cold Classical Kuiper Belt |
| 14640 | John Sebastian Pineda, University of Colorado at Boulder | Investigating the FUV Emission of Young M dwarfs with FUMES: the Far Ultraviolet M-dwarf Evolution Survey |
| 14700 | Ben E. K. Sugerman, Goucher College | Light Echoes and the Environments of SNe 2014J and 2016adj |
| 14704 | Charlie Conroy, Harvard University | A Year in the Whirlpool |
| 14707 | Philip Louis Massey, Lowell Observatory | Searching for the Most Massive Stars in M31 and M33 |
| 14760 | Zheng Cai, University of California - Santa Cruz | Imaging a Massive Galaxy Overdensity at z=2.3: The Morphology-Density Relation at High Redshift |
| 14765 | Ian U. Roederer, University of Michigan | The Unexplored Domains of the s-Process |
| 14767 | David Kent Sing, University of Exeter | The Panchromatic Comparative Exoplanetary Treasury Program |
| 14779 | Melissa Lynn Graham, University of Washington | A NUV Imaging Survey for Circumstellar Material in Type Ia Supernovae |
| 14788 | Thomas R. Ayres, University of Colorado at Boulder | Alpha Centauri at a Crossroads |
| 14795 | Frank Crary, University of Colorado at Boulder | Observing an artificial meteor: Cassini's entry into the atmosphere of Saturn |
| 14912 | Boris T. Gaensicke, The University of Warwick | High-precision asteroseismology of the accreting white dwarf in GW Lib through simultaneous HST and K2 observations |
| 14938 | Avani Gowardhan, Cornell University | Impact of the most extreme AGN-driven molecular outflow on its host galaxy |
| 15077 | Tucker Jones, University of California - Davis | Accurate Emission Line Diagnostics at High Redshift |
| 15082 | Andrew Robinson, Rochester Institute of Technology | Monsters on the move: Confirming gravitational wave recoiling supermassive black hole candidates |
| 15140 | Ragnhild Lunnan, Stockholm University | Resolving the Connection Between Superluminous Supernovae and Star Formation in Dwarf Galaxies |
| 15145 | Adam Riess, The Johns Hopkins University | The Hubble Constant to 1%: Physics beyond LambdaCDM |
| 15282 | Simon J. Lilly, Eidgenossiche Technische Hochschule (ETH) | Transport of magnetic fields into the circumgalactic medium |
| 15304 | Julien de Wit, Massachusetts Institute of Technology | Collecting the Puzzle Pieces: Completing HST's UV+NIR Survey of the TRAPPIST-1 System ahead of JWST |
| 15311 | Chris S. Kochanek, The Ohio State University | Confirming the Formation of a Black Hole |
| 15320 | Tommaso L. Treu, University of California - Los Angeles | Probing the dark universe with quadruply imaged quasars |
| 15323 | Jonelle L. Walsh, Texas A & M University | Addressing a Bias in the Galaxies with Black Hole Mass Measurements |
GO 14216: RAISIN2: Tracers of cosmic expansion with SN IA in the IR
The first supernova discovered by the Pan-STARRs survey |
Supernovae are the most spectacular form of stellar obituary. In recent years, these celestial explosions have acquired even more significance through the use of Type Ia supernovae as distance indicators in mapping the `dark energy' acceleration term of cosmic expansion. However, while there are well-established models for the two main types of supernovae (runaway fusion on the surface of a white dwarf in a binary system for Type Ia, or detonation of the core in Type II), some uncertainties remain as to the uniformity of the events. Moreover, as the sample of known supernova has grown, so has the range of photometric systems and the methods used to fit the light curve and account for the ever-present uncertainites inroduced by dust absorption. Consequently, the potential remains for systematic bias in distance estimates due both to intrinsic differences and to measurement errors. The present program builds on a Cycle 21 program, and aims to minimise these systematics by compiling standard sequences of observations, primarily in the Y, J, and H filters, of supernovae at redshifts between z~0.3 and 0.5. Focusing on those wavelengths minises the effects, and hence the uncertainties, due to dust absorption. The supernovae themselves are drawn from the Pan-STARRS survey, with the WFC3-IR camera on HST employed to obtain the photometry. |
GO 14640: Investigating the FUV Emission of Young M dwarfs with FUMES: the Far Ultraviolet M-dwarf Evolution Survey
SOHO image of an extremely strong solar flare |
M dwarfs - at least, the subset of M dwarfs known as flare stars - are renowned for possessing extremely active chromospheres and coronae. Their discovery as highly variable objects happened largely by chance. Willem Luyten had noticed in 1924 that certain M dwarfs showed spectroscopic variability, with the occasional appearance of emission lines, while in the early 1940s van Maanen commented that two late-type dwarfs, Gl 412B (WX UMa) and Gl 285 (YZ CMi), had brightened by over a magnitude on a handful of parallax plates. The crucial observations came in 1948, when E.F Carpenter noticed that the fainter component of a wide binary system had brightened by more than 3 magnitudes in a matter of minutes. In the succeeding 50 years, these stars have been subjected to extensive observations, particularly at optical and X-ray wavelengths, and the underlying physical processes are relatively well understood. However, most attention has focused on the more active flare stars, and we still have relatively uncertain measurements of the average levels of activity in average stars, particularly the time evolution of those systems. This issue has acquired increased importance with the realisation that somewhere between 10 and 50% of M dwarfs host planetary systems. As the most populous stars in the Galaxy, this also makes M dwarfs the premier planet hosts. The habitable zones in those systems lie much closer to the parent star, and planets are correspondingly vulnerable to detrimental effects from enhanced UV radiation, particularly short-wavelength UV-C. This proposal uses the Cosmic Origins Spectrograph to obtain far-UV spectra of nearby, relatively young (12 - 650 Myrs) M dwarfs, providing a broad sampling of the range of activity levels among these low mass dwarfs. |
GO 14704: A Year in the Whirlpool
The Whirlpool galaxy, M51 |
NGC 5194, the Whirlpool galaxy, is a grand design spiral galaxy with an interacting lower-mass companion, NGC 5195, lying at a distaince of ~7 Mpc from the Milky Way. Originally catalogued as the 51st obect in Charles Messier's list of non-comets, its spiral nature was first discerned by visual observations using the Earl of Rosse's Leviathan of Parsontown. With its clearly deefined spiral structure, M 51 is a prime target for star formation investigations. The present program aims to probe the star formation history by mapping the number and distribution of asymptotic giant branch long period variable (AGB LPV) stars. or miras. These LPV have periods ranging from ~150 days to more than 500 days, and there are well determined correlations between the periodicity and the mass (and hence age) of the individual stars. with such long periods, obervations need to be spaced over a correspondingly long time frame, and the present program schedules observations at 34 epochs over a full year. |
GO 15304: Collecting the Puzzle Pieces: Completing HST's UV+NIR Survey of the TRAPPIST-1 System ahead of JWST
An artist's impression of the view from the third planet in the Trappist 1 system |
The first exoplanet, 51 Peg b, was discovered through radial velocity measurements in 1995. Since then, numerous sysytems have ben discovered, notably through the detetcion of transiting planets by the Kepler mission. launched in March 2009, Kepler discovered more than 1280 confrimed planets together with more than 5000 candidates, with the potential for more discoveries through increasingly detailed analysis of the archival data. Ground-based surveys still play a major role, however, as illustrated by the recent discovery by the TRAPPIST (Transiting Planets and Planetesimals Small Telescope) team of at least three terrestrial planets orbiting the nearby ultracool dwarf, 2MASS 2306-0502, also known as TRAPPIST 1. This team is one of several that are using relatively small telescopes to monitor nearby M dwarfs for planetary transits. Lower mass and cooler than solar-type stars, M dwarfs constitute approximately 70% of the stars in the Galaxy, and are therefore likely to host most of the planets near the Sun. Since they have substantially smaller diameters than solar-type stars, terrestial planets have a larger covering factor and are therefore easier to detect. Moreover, the cooler stellar temperatures mean that the Habitable Zone lies closer to the parent star, and the orbits are correspondingly shorter. 2MASS 2306-0502, an M8 dwarf, presents a remarkable system with no fewer than 7 Earth-sized terrestrial planets, including two in the habitable zone; three were discovered through the ground-based observations, with the others discovered from Spitzer dta. The planets have periods between 1,5 and 19 days. The present observation is using the Space Telescope Imagaing Spectrograph (STIS) to monitor transits of each planet to search for absorption by lyman-alpha that mgith indicate the presence of planetary atmospheres. |