Variability in the 2MASS calibration fields: a search for transient obscuration events

• DOI: 10.1093/mnras/stu732
• Publication Date: 2014-05-28T00:53:18Z
• Authors: A. C. Quillen; M. Ciocca; J. L. Carlin; C. P. M. Bell; Z. Meng
• Keywords: Extinction (optical mineralogy); Ophiuchus; Variable star; Young stellar object; Apparent magnitude

We searched the light curves of over 40 000 stars in Two Micron All Sky Survey (2MASS) calibration data base, spanning approximately 4 yr, for objects that have significant day-long dimming events. also multi-colour red-dimming events could be due to transient extinction. In colour-independent sigma-limited search, we found 46 previously unrecognized eclipsing binaries, 6 periodic variable likely intrinsic pulsators and 21 young stellar ρ Ophiuchus star formation region studied by Parks et al. An additional 11 exhibited events, most these are unclassified. The search primarily reveals a population low-luminosity active galaxies become bluer when they brighter, exhibiting high cross-correlation coefficients between colour brightness. exhibit brightness variations direction interstellar extinction whereas can bowed distribution magnitude with reduced variation object is brightest. Among usually quiescent (not strongly variable), failed find any deeper than 0.2 mag lasting longer day. objects, however, dimmed day without strong variation.