| Program Number | Principal Investigator | Program Title |
|---|---|---|
| 14181 | S Thomas Megeath, University of Toledo | A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds |
| 14604 | Carlo F. Manara, European Space Agency - ESTEC | Connecting the shape of the FUV spectrum with disk morphology: a combined HST and ALMA study of young stellar objects in Lupus |
| 14606 | Brooke Devlin Simmons, University of California - San Diego | Secular Black Hole Growth and Feedback in Merger-Free Galaxies |
| 14610 | Julianne Dalcanton, University of Washington | A Legacy Imaging Survey of M33. |
| 14618 | Michael Shara, American Museum of Natural History | Ultraviolet Flashers in M87: Rapidly Recurring Novae as SNIa Progenitors |
| 14633 | Kevin France, University of Colorado at Boulder | A SNAP UV Spectroscopic Study of Star-Planet Interactions |
| 14649 | Katherine Anne Alatalo, Carnegie Institution of Washington | Opening a New Window into Galaxy Evolution Through the Lens of CO-detected Shocked Poststarburst Galaxies |
| 14654 | Peter Milne, University of Arizona | A Second Ladder: Testing for Bias in the Type Ia Distance Scale with SBF |
| 14658 | Eric W. Peng, Peking University | Massive Star Clusters and the Origin of Ultra-Diffuse Galaxies |
| 14668 | Alex V. Filippenko, University of California - Berkeley | Continuing a Snapshot Survey of the Sites of Recent, Nearby Supernovae: Cycle 24 |
| 14672 | Ruth C. Peterson, SETI Institute | Tracing the Earliest Nucleosynthesis from Elements Just Past the Iron Peak in Extremely Metal-Poor Dwarfs |
| 14681 | Alessandra Aloisi, Space Telescope Science Institute | Tracing Galactic Outflows to the Source: Spatially Resolved Feedback in M83 with COS |
| 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 |
| 14709 | Brian Mazur, University of Toledo | HST/WFC3 Spectroscopy of < 400 AU Companions to Orion Young Stellar Objects |
| 14714 | Glenn Schneider, University of Arizona | An Extinction Probe Through the HD 107146 Debris Ring: Taking Unique Advantage of a Background Galaxy Transit |
| 14725 | Andrea Dieball, Universitat Bonn, Argelander Institute for Astronomy | Hunting for Brown Dwarfs in Globular Clusters: Second Epoch Deep IR observations of the Globular Clusters M4 |
| 14761 | Geoffrey C. Clayton, Louisiana State University and A & M College | Mapping the UV Extinction Properties of PHAT Stars in M31 |
| 14774 | Trent J. Dupuy, University of Texas at Austin | Dynamical Masses for Free-Floating Planetary-Mass Binaries |
| 14794 | Howard E. Bond, The Pennsylvania State University | Planetary Nebulae in the Open Clusters of M31 |
| 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 |
| 14918 | Hannah Ruth Wakeford, Space Telescope Science Institute | Definitive measurement of WASP-17b's water abundance in preparation for JWST |
| 14924 | Anil C. Seth, University of Utah | Increasing Diversity in Galaxies with Black Hole Mass Measurements |
| 14932 | George G. Pavlov, The Pennsylvania State University | Optical counterpart of high-speed ejecta from the gamma-ray binary LS 2883 |
GO 14610: A Legacy Imaging Survey of M33
M33, the Triangulum Galaxy (Subaru imaging) |
Messier 33, or the Triangulum galaxy, is the smallest of the three spiral galaaxies in the Local Group. Lying at a distance of ~800 kpc from the Milky Way, the system may be a satellite of the Andromeda spiral, and certainly appears to have experienced past interactions. With a mass less than half that of the Milky Way, the galaxy has a small, distinct bulge, no bar and extensive star formation regions forming spiral structure. The proximity to the Milky Way means that Hubble can resolve individual stars, albeit limited to relatively high luminosities. The present program aims to build on that capability by mapping aproximately one-third of the system. Wide Field Camnera 3 and the Advanced Camera for Surveys will be used in parallel to image 54 fields, obtaining multi-band data from the near-UV (F275W filter) through the U, B and I bands (F336W, F475W, F814W) to the near-infarred (F110W and F160W). Those data will enable investigations of the initial mass function for luminous stars; trace the detailed star formation and recent history as a function of location within the galaxy; map the dust distribution; and allow for the detection of star clusters. This dataset will complement the extensive survey of the Andromeda spiral conducted via the PHAT survey. |
GO 14633: A SNAP UV Spectroscopic Study of Star-Planet Interactions
SOHO image of an extremely strong solar flare |
Stellar activity, whether through flares and coronal mass ejections, has the potential to affect the ability of life to evolve and survive on otherwise habitable planets in stellar systems. High energy radiation can lead to significant mutations, and particle ejections can actually strip the atmospheres of unfortunate planets. Previous HST programs have focused on low mass M dwarfs, the most populous stars in the galaxy, and systems where the habitable zone lies close to the parent star, with a correspondingly higher vulnerability. Those observations suggest evidence for interactions between the stellar transition region and the planets, with a correlation between the presence of high temperature emission lines (N V, C IV, Si IV) and the planetary mass and orbit i.e. suggestive of planetary interactions driving conditions in the stellar corona. The present SNAP program expand obsevations to higher-mass K dwarfs and solar-type G dwarfs that are known to harbour exoplanets, searching for similar correlations. The Cosmic Origins Spectrograph will be used to obtain UV spectra (1150-1450 Angstroms), providing a broad sampling of the range of activity levels among these dwarfs. |
GO 14774: Dynamical Masses for Free-Floating Planetary-Mass Binaries
Epsilon Indi Bab, the binary brown dwarf companion of the nearby K dwarf |
Brown dwarfs are objects that form like stars, but lack sufficient mass to drive the central temperature above a few million degrees, and therefore never succeed in igniting core hydrogen fusion. Discovered in the mid-1990s, these objects initially have surface temperatures of ~3,500K, but cool rapidly and move through spectral types M, L, T and Y. Following their discovery, considerable theoretical attention has focused on the evolution of their intrinsic properties, particularly the details of the atmospheric changes in the evolution from type L through T to Y and beyond. The initial transition marks the emergence of methane as a dominant absorber at near-infrared wavelengths, while ammonia becomes increasingly apparent in the coolest dwarfs identified by the WISE mission. Current models suggest that the L to T transition occurs at ~1400-1200K, while the T to Y transition occurs around 600K. The spectral changes are at least correlated with, and perhaps driven by, the distribution and properties of dust layers ("clouds"). The overall timescales associated with this process remains unclear. Mass is a crucial factor in mapping those changes, but mass is also the most difficult quantity to measure in a reliable fashion. The present proposal tackles this issue through astrometry of ultracool binary systems, deriving the orbits and hence dynamical masses. The four targets in this multi-year program include two late-T/Y dwarf binaries, whose masses are expected to lie in the range 5 to 15 jupiter masses. |
GO 14807: The primordial binary fraction in the young massive cluster Westerlund 2
|
The massive, reddedened open star cluster, Westerlnd 2 |
Westerlund 2 is a massive, young star cluster that lies approximately 6-7 kpc from the Sun in the constellation Carina in the general direction of the Galactic Centre. The cluster was discovered just over 50 years ago by Bengt Westerlund, but has only been subject to detailed scrutiny in more recent years since interstellar material along the line of sight leads to foreground absorption of around 14 magnitudes at optical wavelengths. Detailed investigations became possible as near-infrare astronomy came of age in the 1990s. These show that Westerlund 2 has an age of 1-2 Myrs and a total mass approaching 7500 MSun. The cluster members include 10 early-type O stars and more than 20 later-type O stars. while several Wolf-Rayet stars are likely to be cluster members. Consequently, the cluster provides an excellent laboratory for examining how the star formation process might be influenced by such an extreme environment. A number of the O stars are known to be binary systems. The present program aims to enlarge ourn understanding of the binary frequency among massive stars through comprehensive photometric monitoring of the system over a three year period, searching for sigantures of eclipsing binares. In Cycle 24, the WFC3-UVIS camera is being used to obtain I-band imaging at 10 epochs over an 8-day period, searching for short-period systems; in Cycle 25, 5 epochs will be obtained within a 16-day timeframe; finally, Cycle 26 will include a further 10 epochs, with 5 measurments over a 32-day span and a further five over a 64-day span. Combined, these observations should proide a comprehensive sampling of periosd up to ~1 year. |