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Session 78 - Stars - Young and Old, Large and Small.
Display session, Wednesday, January 15
The observational part of the USNO CCD parallax program, which employed a TI800\times800 detector, has recently been completed. The astrometric targets, for which data have not yet been published, include 54 white dwarfs, 34 subdwarfs, and 32 red dwarfs with 14.0 mag < V < 19.5 mag. In order to investigate whether more suitable reference fields could be obtained in the near-infrared, and whether any of these stars have low-mass companions, a survey was initiated in the K bandpass (or 2.2 microns), using the USNO 256\times256 HgCdTe IR camera. 113 fields were examined to a limiting K magnitude between 16.5 and 17.0 mag. Only one field (about Gr567) was found with an improved reference frame in the K-bandpass as compared to the CCD R-bandpass, and red objects were detected near the two white dwarfs Gr567 and PG1241. The significance and implications of these results will be discussed.
Program listing for Wednesday