A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM)

Details A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM) A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM)

2000-11-09

arxiv.org/abs/astro-ph/0011190v1

Astronomy and Astrophysics

Astrophysics

LaTeX, 21 pages, 8 figures, accepted by PASP (February 2001 issue). Also available at http://beehive.ucsd.edu/ftp/pub/grid/kgi

Scientific paper

10.1086/318610

We present a strategy to identify several thousand stars that are astrometrically stable at the micro-arcsecond level for use in the SIM (Space Interferometry Mission) astrometric grid. The requirements on the grid stars make this a rather challenging task. Taking a variety of considerations into account we argue for K giants as the best type of stars for the grid, mainly because they can be located at much larger distances than any other type of star due to their intrinsic brightness. We show that it is possible to identify suitable candidate grid K giants from existing astrometric catalogs. However, double stars have to be eliminated from these candidate grid samples, since they generally produce much larger astrometric jitter than tolerable for the grid. The most efficient way to achieve this is probably by means of a radial velocity survey. To demonstrate the feasibility of this approach, we repeatedly measured the radial velocities for a pre-selected sample of 86 nearby Hipparcos K giants with precisions of 5-8 m/s. The distribution of the intrinsic radial velocity variations for the bona-fide single K giants shows a maximum around 20 m/s, which is small enough not to severely affect the identification of stellar companions around other K giants. We use the results of our observations as input parameters for Monte-Carlo simulations on the possible design of a radial velocity survey of all grid stars. Our favored scenario would result in a grid which consists to 68% of true single stars and to 32% of double or multiple stars with periods mostly larger than 200 years, but only 3.6% of all grid stars would display astrometric jitter larger than 1 microarcsecond. This contamination level is probably tolerable.

Affiliated with

Also associated with

No associations

Rating

A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Strategy for Identifying the Grid Stars for the Space Interferometry Mission (SIM) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-608249