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The Pulsating White Dwarf Stars
Fontaine, G.; Brassard, P.
We present a summary of what is currently known about the three distinct families of isolated pulsating white dwarfs. These are the GW Vir stars (He/C/O-atmosphere stars with Teff ≃ 120,000 K), the V777 Her stars (He-atmosphere, Teff ≃ 25,000 K), and the ZZ Ceti stars (H-atmosphere, Teff ≃ 12,000 K), all showing mu…
Revised Bolometric Corrections and Interstellar Extinction Coefficients for the ACS and WFPC2 Photometric Systems
Girardi, Léo; Seth, Anil C.; Holtzman, Jon A. +9 more
We present extensive tables of bolometric corrections and interstellar extinction coefficients for the WFPC2 and ACS (both WFC and HRC) photometric systems. They are derived from synthetic photometry applied to a database of spectral energy distributions covering a large range of effective temperatures, surface gravity, and metal content. Carbon s…
Calibrated griz Magnitudes of Tycho Stars: All-Sky Photometric Calibration Using Bright Stars
Ofek, Eran O.
Photometric calibration to ∼5% level is frequently needed at arbitrary celestial location. However, existing all-sky astronomical catalogs do not reach this accuracy, and time consuming photometric calibration procedures are required. I fitted the Hipparcos BT and VT magnitudes, along with the 2MASS J, H, and K magnitudes of …
NGC 602 Environment, Kinematics and Origins
Sabbi, E.; Nota, A.; Gallagher, J. S. +3 more
The young star cluster NGC 602 and its associated HII region, N90, formed in a relatively isolated and diffuse environment in the Wing of the Small Magellanic Cloud. Its isolation from other regions of massive star formation and the relatively simple surrounding HI shell structure allows us to constrain the processes that may have led to its forma…
The Identification of New Stellar Groupings in the M81 Debris Field
Davidge, T. J.
The stellar content of the debris field around M81 is investigated using deep images obtained with MegaCam on the Canada-France-Hawaii Telescope. Three new concentrations of bright main-sequence stars and red supergiants are identified within ∼20 kpc of M81. These systems have integrated brightnesses MV ∼ -11 and surface brightnesses &m…
An Upper Mass Limit on a Red Supergiant Progenitor for the Type II-Plateau Supernova SN 2006my
Leonard, Douglas C.; Kraus, Adam L.; Gal-Yam, Avishay +5 more
We analyze two pre-supernova (SN) and three post-SN high-resolution images of the site of the Type II-Plateau supernova SN 2006my in an effort to either detect the progenitor star or to constrain its properties. Following image registration, we find that an isolated stellar object is not detected at the location of SN 2006my in either of the two p…
Using Resolved Galaxies in Hubble Space Telescope Images to Measure Absolute Proper Motions
Anderson, Jay; Mahmud, Naved
We explore the possibility of using resolved background galaxies to measure accurate absolute proper motions with the Hubble Space Telescope. Because galaxies are not point sources, we cannot use stellar point-spread functions (PSFs) to measure their positions. Rather, we must develop a template for each galaxy that can be used to measure a consis…
A Hubble Space Telescope Survey of the Disk Cluster Population of M31. II. Advanced Camera for Surveys Pointings
Hodge, P. W.; Krienke, O. K.
This paper reports on a survey of star clusters in M31 based on archival images from the Hubble Space Telescope. Paper I reported results from images obtained with the Wide Field Planetary Camera 2 (WFPC2) and this paper reports results from the Advanced Camera for Surveys (ACS). The ACS survey has yielded a total of 339 star clusters, 52 of which…
The Spatial Orientation of Planetary Nebulae within the Milky Way
Weidmann, Walter A.; Díaz, Rubén J.
We analyze the spatial orientation of a homogenous sample of 440 elongated Planetary Nebulae (PNe) in order to determine the orientation of their apparent major axis with respect to the Milky Way plane. We present some important geometrical and statistical considerations that have been overlooked by previous works on the subject. The global distri…
OMCat: Catalog of Serendipitous Sources Detected with the XMM-Newton Optical Monitor
Snowden, Steven L.; Kuntz, K. D.; Mushotzky, Richard F. +2 more
The Optical Monitor Catalog of serendipitous sources (OMCat) contains entries for every source detected in the publicly available XMM-Newton Optical Monitor (OM) images taken in either the imaging or “fast” modes. Since the OM is coaligned and records data simultaneously with the X-ray telescopes on XMM-Newton, it typically produces images in one …