1999/05/11 by Andrew Gould, Gould, Andrew
Engineering · Physics and Astronomy · #Advanced Measurement and Metrology Techniques #Advanced optical system design #Calibration and Measurement Techniques #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9905120
16 pages plus 2 figures, submitted to ApJ
arxiv created 1999/05/11 · arxiv updated 2009/12/01
I investigate the prospects for using the Space Interferometry Mission (SIM) to measure the masses of nearby stars from their astrometric deflection of more distant sources, as originally suggested by Paczynski and by Miralda-Escude. I derive an analytic expression for the total observing time Ttot required to measure the masses of a fixed number of stars to a given precision. I find that Ttot ~ rmax-2, where rmax is the maximum radius to which candidates are searched, or Ttot ~ μmin2, where μmin is the minimum proper motion to which candidates are searched. I show that Ttot can be reduced by a factor 4 if source availability is extended from Vs=17 to Vs=19. Increasing rmax and Vs and decreasing μmin all require a significantly more agressive approach to finding candidates. A search for candidates can begin by making use of the Luyton proper motion catalog together with the USNO-A2.0 all-sky astrometric catalog. However, a thorough search would require the all-sky USNO-B proper-motion catalog which is not yet available. The follow-up observations necessary to prepare for the mission will become more difficult the longer they are delayed because the candidate pairs are typically already within 1" and are getting closer.