| Program Number | Principal Investigator | Program Title |
|---|---|---|
| 14077 | Boris T. Gaensicke, The University of Warwick | The frequency and chemical composition of rocky planetary debris around young white dwarfs: Plugging the last gaps |
| 14141 | Guy Worthey, Washington State University | NGSL Extension 1. Hot Stars and Evolved Stars |
| 14181 | S Thomas Megeath, University of Toledo | A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds |
| 14212 | Karl Stapelfeldt, Jet Propulsion Laboratory | A Snapshot Imaging Survey of Spitzer-selected Young Stellar Objects in Nearby Star Formation Regions*.t23 |
| 14610 | Julianne Dalcanton, University of Washington | A Legacy Imaging Survey of M33. |
| 14629 | Marc W. Buie, Southwest Research Institute | Astrometry of 2014MU69 for New Horizons encounter |
| 14633 | Kevin France, University of Colorado at Boulder | A SNAP UV Spectroscopic Study of Star-Planet Interactions |
| 14654 | Peter Milne, University of Arizona | A Second Ladder: Testing for Bias in the Type Ia Distance Scale with SBF |
| 14662 | Luigi R. Bedin, Osservatorio Astronomico di Padova | The end of the White Dwarf Cooling Sequences of Omega Centauri |
| 14666 | Stefano Casertano, Space Telescope Science Institute | Astrometric Light Deflection Test of General Relativity for Non-spherical Bodies: Close Approach to Jupiter |
| 14672 | Ruth C. Peterson, SETI Institute | Tracing the Earliest Nucleosynthesis from Elements Just Past the Iron Peak in Extremely Metal-Poor Dwarfs |
| 14683 | Jean-Claude Bouret, CNRS, Laboratoire d'Astrophysique de Marseille | Before the Burst: The Properties of Rapidly Rotating, Massive Supergiants |
| 14700 | Ben E. K. Sugerman, Space Science Institute | Light Echoes and the Environments of SNe 2014J and 2016adj |
| 14704 | Charlie Conroy, Harvard University | A Year in the Whirlpool |
| 14719 | Philip N. Best, Royal Observatory Edinburgh | The detailed properties of star-forming regions at high redshift: a matched-resolution HST-Halpha-ALMA study |
| 14762 | Justyn Robert Maund, University of Sheffield | A UV census of the sites of core-collapse supernovae |
| 14767 | David Kent Sing, University of Exeter | The Panchromatic Comparative Exoplanetary Treasury Program |
| 14784 | Evgenya L. Shkolnik, Arizona State University | HAZMAT: Habitable Zones and M dwarf Activity across Time |
| 14791 | Martin Barstow, University of Leicester | Assessing the dependency of the fine structure constant on gravity using hot DA white dwarfs |
| 14796 | Denija Crnojevic, Texas Tech University | An extremely asymmetric dwarf satellite distribution around M101 |
| 14807 | Elena Sabbi, Space Telescope Science Institute | The primordial binary fraction in the young massive cluster Westerlund 2 |
| 14811 | Laurent Lamy, Observatoire de Paris - Section de Meudon | The Grand Finale : probing the origin of Saturn s aurorae with HST observations simultaneous to Cassini polar measurements |
| 14840 | Andrea Bellini, Space Telescope Science Institute | Schedule Gap Pilot |
| 14888 | Jason A. Dittmann, Massachusetts Institute of Technology | Initial Reconaissance of a Transiting Rocky Planet in a Nearby M-Dwarf's Habitable Zone |
| 15282 | Simon J. Lilly, Eidgenossiche Technische Hochschule (ETH) | Transport of magnetic fields into the circumgalactic medium |
| 15371 | John W. MacKenty, Space Telescope Science Institute | Jupiter stray light background measurements for future Europa STIS observations |
GO 14181: A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds
An image of the Orion Nebula superimposed on the 13CO map of Orion A (from this link ). |
Giant molecular cloud complexes serve as nurseries for star formation. Deeply embedded in dust and gas, young stars are generally extremely difficult to detect at optical wavelengths. Consequently, these complexes have been subject to extensive scrutiny at near- and mid-infrared wavelengths, initially through ground-based observing campaigns and more recently by the Spitzer and Herschel space missions. Those observations have resulted in the identification of numerous embedded sources, young stellar objects (YSOs) that are still accreting from the surrounding molecular gas .he present proposal aims to follow up on those discoveries by obtaining WFC3-IR SNAPs of candidate protostars in several molecular cloud complexes. These observations will provide an excellent complement to Spitzer and Herschel since, while HST cannot offer either the same areal coverage or sensitivity at mid-infrared wavelegths, the imaging has a resolution close to 0.1 arcsecond, an order of magnitude higher than the Spitzer images. The observations are therefore capable of detecting very faint companions, with luminosities consistent with sub-stellar masses, as well as identifying jets and outflows associated with the star formation process. The present program is using the F160W filter to obtain H-band images and determine the true nature of these objects. |
GO 14629: Astrometric Follow-up of 2014MU69U for the New Horizons Mission
Hubble Space Telescope images of the Pluto system, including the recently discovered moons, P4 and P5 |
The Kuiper Belt lies beyond the orbit of Neptune, extending from ~30 AU to ~50 AU from the Sun, and includes at least 70,000 objects with diameters exceeding 100 km. Setting aside Pluto, the first trans-Neptunian objects were discovered in the early 1990s. Most are relatively modest in size, with diameters of a few hundred km and photometric properties that suggest an icy composition, similar to Pluto and its main satellite, Charon. In recent years, a handful of substantially larger bodies have been discovered, with diameters of more than 1000 km; indeed, one object, Eris (2003 UB13), is slightly larger than Pluto (2320 km) and 25% more massive. We know the mass for Eris because it has a much lower mass companion, Dysnomia, which orbits Eris with a period of 16 days (see this recent press release ). Pluto itself has at least 5 companions: Charon, which is about 1/7th the mass of Pluto, and the much smaller bodies, Hydra, Nix, P4 and P5 discovered through HST observations within the last few years. The New Horizons Mission was launched on January 19th 2006 with the prime purpose of providing the first detailed examination of Pluto. Following the Pluto fly-by on Bastille day 2015, the program aims to redirect the probe towards one or more smaller members of the Kuiper Belt, with the goal of providing a closer look at these icy bodies. Based on Hubble imaging, a suitable prime target has been identified: 2014 MU69, a ~30 km KBO lying ~44 AU from the Sun. In addition, New Horizons is expected to take longer-range, monochromatic images of up to 10 other KBOs. The present observations aim to refine the orbital parameters for the prime target to optimize the New Horizon encounter. |
GO 14662: The end of the White Dwarf Cooling Sequences of Omega Centauri
ACS imaging of the central regions of Omega Cen |
Globular clusters are members of the Galactic halo population, which formed during the first extensive period of star formation in the Milky Way. As such, the properties of the 106 to 107 stellar constituents can provide crucial insight into the earliest stages of galaxy formation. Hubble has conducted a significant number of observing programs targeting these systems, with the majority designed to obtain moderately deep, multicolour imaging data of a range of clusters. Those programs probe evolved stars, on the red giant and horizontal branch, and generally extend only a few magnitudes below the main-sequence turnoff. Noetheless, the exqusite photometric precision offered by HST's camera has revealed that the majority of these systems have multiple stellar populations, rather than conforming to traditional single-burst formation models. A few clusters have been studied in detail - specifically, the two nearest clusters, NGC 6397, an extremely metal-poor cluster, and M4, a moderately metal-rich systems; Omega Centauri, one of the most massive clusters, perhaps even the remnant core of a dwarf galaxy; and 47 Tucanae, one of the higher metallicity systems, lying in the foreground of the Small Magellanic Cloud. Deep imaging of all four clusters has succeeded in clear detecion of the white dwarf cooling sequence in those clusters, and those data have been used to derive age estimates. The present program builds on past observations in aiming to probe the multiple white dwarf cooling sequences in Omega Cen. The WFC3/UVIS and ACS/WFC cameras will be used to obtain multi-colour imaging of the cluster. Those observations should enable measurement over the full extent of the white dwarf cooling sequences, offering the potential of resolving the nature and origin(s) of the distinct stellar populations. |
GO 14791: Assessing the dependency of the fine structure constant on gravity using hot DA white dwarfs
|
The fine-structure constant is a fundamental physical constant that characterises the strength of interactions between charged particles. Such quantities are usually more amenable to tests within physics laboratories than in the astronomical regime. However, astronomy has the advantage that we can observe environments radically different than anything that can be simulated on earth. Thus, white dwarf stars offer surface gravities that are 104 to several times 105 greater than Earth's. The present program aims to obtain UV spectra of four hot white dwarfs that span a range of masses, as determined from the Balmer line profiles. Changes in the fine structure constant would lead to variations in the measured wavelengths of the UV spectral lines. Thus, this program will set constraints on potential variations in alpha wthin the high gravity regime. |