English

The Stability of BVRI Comparison Stars Near Selected TeV Blazars

Solar and Stellar Astrophysics 2015-06-15 v1 High Energy Astrophysical Phenomena

Abstract

We have measured Johnson BV and Cousins RI magnitudes for comparison stars near five TeV blazars. We compare our values with published values, spanning 25 years in some cases, to identify those stars that are most likely proven stable. To avoid zero-point offsets mimicking long-term variability, we based our analysis on the standard deviation between measurements after a mean offset between data sets was removed. We found most stars to be stable at the 0.04 magnitude level. We confirm two stars as variable and identify two others as possibly being variable. In each of the five fields there are at least two stars, and typically many more, that show no evidence of variability.

Keywords

Cite

@article{arxiv.1303.1380,
  title  = {The Stability of BVRI Comparison Stars Near Selected TeV Blazars},
  author = {Cameron J. Pace and Richard L. Pearson and J. Ward Moody and Michael D. Joner and Bret Little},
  journal= {arXiv preprint arXiv:1303.1380},
  year   = {2015}
}