NIR observations of V404 Cyg with PANIC
ATel #7738; A. W. Shaw, C. Knigge (U. Southampton), K. Meisenheimer (MPIA), J. M. Ibanez (IAA-CSIC)
on 1 Jul 2015; 10:38 UT
Credential Certification: Poshak Gandhi (email@example.com)
Subjects: Infra-Red, Black Hole, Nova, Transient
We report on NIR photometry of the black hole X-ray transient, V404 Cyg during its current outburst (GCN #17929). The source was observed between 27 Jun 22:47 UT - 29 Jun UT 02:28 with the PANoramic Near Infrared Camera (PANIC) on the 2.2m telescope at the Centro Astronómico Hispano-Alemán (CAHA) on Calar Alto, Spain. 4x5 min integrations were obtained over two nights in each of the J, H and Ks filters (1.2 - 2.2um).
The source shows a steady decline across all wavelengths, with the J-band magnitude decreasing from 11.68 (27 Jun 22:47 UT) to 12.98 (29 Jun 02:13 UT) and a similar response in the H and Ks filters. This significant decrease in NIR flux mirrors that seen at optical wavelengths (ATel #7729; AAVSO light curves), as well as X-rays (ATel #7731) and Radio (ATel #7733). We note that a similar decrease in flux occurred during the 1989 outburst, followed by a partial recovery and a slower decline (Han & Hjellming 1992, ApJ, 400, 304).
We intend to continue monitoring V404 Cyg across all wavelengths. Further observations are encouraged.