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: http://www.stsci.edu/~inr/thisweek1/2009/thisweek110.html
Дата изменения: Mon Apr 20 21:53:02 2009 Дата индексирования: Tue Aug 18 11:52:23 2009 Кодировка: Поисковые слова: guide 8.0 |
Program Number | Principal Investigator | Program Title | Links |
11113 | Keith S. Noll, Space Telescope Science Institute | Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution | Abstract |
11704 | Brian Chaboyer, Dartmouth College | The Ages of Globular Clusters and the Population II Distance Scale | Abstract |
11788 | George Fritz Benedict, University of Texas at Austin | The Architecture of Exoplanetary Systems | Abstract |
11790 | John Wisniewski, NASA Goddard Space Flight Center | HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic | Abstract |
11943 | Douglas R. Gies, Georgia State University Research Foundation | Binaries at the Extremes of the H-R Diagram | Abstract |
11944 | Douglas R. Gies, Georgia State University Research Foundation | Binaries at the Extremes of the H-R Diagram | Abstract |
11974 | Sahar S. Allam, Fermi National Accelerator Laboratory | High-resolution imaging for 9 very bright, spectroscopically confirmed, group-scale lenses | Abstract |
11975 | Francesco R. Ferraro, Universita de Bologna | UV light from old stellar populations: a census of UV sources in Galactic Globular Clusters | Abstract |
11978 | Tommaso L. Treu, University of California - Santa Barbara | Luminous and dark matter in disk galaxies from strong lensing and stellar kinematics | Abstract |
11979 | Paul Kalas, University of California - Berkeley | WFPC2 Imaging of Fomalhaut b: Determining its orbit and testing for H-alpha emission | Abstract |
11981 | Jesus Maiz Apellaniz, Instituto de Astrofisica de Andalucia | FUV imaging survey of Galactic open clusters | Abstract |
11982 | Scott F. Anderson, University of Washington | Spanning the Reionization History of IGM Helium: a Large and Efficient HST Spectral Survey of Far-UV-Bright Quasars | Abstract |
11983 | Massimo Robberto, Space Telescope Science Institute | An Imaging Survey of Protoplanetary Disks and Brown Dwarfs in the Chamaeleon I region | Abstract |
11987 | Michael W. Regan, Space Telescope Science Institute | The Recent Star Formation History of SINGS Galaxies | Abstract |
11993 | Tod R. Lauer, National Optical Astronomy Observatories | High Resolution Imaging of a Binary Supermassive Black Hole Candidate | Abstract |
GO 11704: The Ages of Globular Clusters and the Population II Distance Scale
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Globular clusters are the oldest structures within the Milky Way that are directly accessible to observation. They are relatively simple systems, with relatively simple colour-magnitude diagrams (albeit with some complexities adduced from recent HST observations, see GO 11233 ). Matching those CMDs against theoretical models allows us to set constraints on the age of the oldest stars in the Galaxy, and hence on the age of the Milky Way and the epoch of galaxy formation. However, the accuracy of those age determinations rest crucially on the accuracy of the cluster distance determinations. The clusters themselves lie at distances of several kpc at best, and tens of kpc at worst; thus, direct trigonometric parallax measurements must await microacrsecond astrometric missions. The classical method of deriving distances is main sequence fitting - using nearby stars, with similar chemical abundances and accurate parallax measurements, to map out the main sequence in absolute units, and then scaling the cluster data to fit. The problem with this method is that metal-poor subdwarfs are rare, so even Hipparcos was only able to obtain accurate distances to a handful of stars. The present program aims to improve the distance measurements by using the Fine Guidance Sensors on HST to determine sub-millarcsecond trigonometric parallaxes to 9 subdwarfs, almost doubling the sample available for MS fitting. |
GO 11974: High-resolution imaging for 9 very bright, spectroscopically confirmed, group-scale lenses
GO 11979: WFPC2 Imaging of Fomalhaut b: Determining its orbit and testing for H-alpha emission
GO 11987: The Recent Star Formation History of SINGS Galaxies