A Search for New Variable and Proper Motion Stars in the Galactic Disk

Robert A Benjamin


Mid-infrared observations of sections of the Galactic Plane with the NASA Spitzer Space Telescope at two widely spaced epochs (2004-5) and (2012-13) have opened up the possibility of a large-scale search for variable stars, proper motion stars, and transients. This has required developing a new research infrastructure to merge and compare the two epochs of observations, and has led to the discovery of a surprising number of variable sources (over 100,000) and high proper motion sources (over 400). We quantify the probability that a star observed in the mid-infrared will show variability at a certain amplitude. For stars with apparent infrared magnitude fainter than m=10, stars have a 0.6% probability of varying by more than 0.25 magnitudes, but this probability increases to 14% for stars with m=6. We also describe upcoming observations of the center of the Milky Way Galaxy.


Milky Way Galaxy; Variable Stars; Proper Motion Stars; Spitzer Space Telescope

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Benjamin, R.A. et al 2003, Publications of the Astronomical Society of the Pacific 115, 953.

Benjamin, R.A. et al 2005, Astrophysical Journal Letters, 630, 149.

Benjamin, R.A. 2008, in Astrophysical Society of the Pacific Conference Volume 387, 375.

Brown, W.R. et al 2012, Astrophysical Journal Letters, 754, 2.

Churchwell, E.B. et al 2009, Publications of the Astronomical Society of the Pacific, 121, 213.

Cyganowski, C. J. et al 2008, Astronomical Journal, 136, 2391.

Fritz, T.K. et al 2014, arXiv.org/1406.7568.

Klein, C. R., Richards, J. W. Butler, N. R., Bloom, J. S. 2011, Astrophysical Journal 738, 185.

Lepine, S. & Di Stefano, R. 2012, Astrophysical Journal, 749, 6.

Nidever, D. et al 2012, Astrophysical Journal Supplement, 201, 35.

Peretto, N. & Fuller, G.A. 2009, Astronomy & Astrophysics, 505, 405.

Poleski, R. et al 2012, Astrophysical Journal, 776, 76.

Robitaille, T.P. et al 2008, Astronomical Journal, 136, 2413.

Robitaille, T.P. & Whitney, B.A. 2010, Astrophysical Journal Letters, 710, L11.

Rossi, E.M. et al 2014, Astrophysical Journal, 795, 125.

Sumi, T. et al 2013, Monthly Notices of the Royal Astronomical Society, 432, 124.

DOI: https://doi.org/10.17307/wsc.v0i0.152


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