Kanata optical and near-infrared observations of BL Lacertae in the bright state
ATel #14081; M. Sasada, R. Imazawa, N. Hazama, Y. Fukazawa (Hiroshima University)
on 10 Oct 2020; 09:01 UT
Credential Certification: Mahito Sasada (sasadam@hiroshima-u.ac.jp)
Subjects: Infra-Red, Optical, AGN, Black Hole, Blazar
Since August, BL Lacertae is on an active state in optical (ATel #13930, #13956, #13958 #14065, ), X-ray (ATel #14069), and gamma-ray (ATel #13933, #13963, #13964, #14032, #14072) wavelengths. We have performed optical and near-infrared photometric and polarimetric monitoring to the object using the Hiroshima Optical and Near-InfraRed camera (HONIR; Akitaya et al. 2014, Proc. SPIE, 9147, 91474O) attached to the Kanata 1.5-m telescope at Higashi-Hiroshima Observatory.
The measured magnitudes (Vega system) are:
MJD R J
59123.730 11.93+/-0.02 10.13+/-0.06
59124.431 12.06+/-0.02 10.30+/-0.03
59125.417 12.19+/-0.01 10.34+/-0.09
59127.450 11.73+/-0.01 9.92+/-0.03
59128.528 12.00+/-0.01 10.23+/-0.02
The optical fluxes are calibrated by comparing nearby field stars with Pan-STARRS DR1 (Chambers et al. 2016, arXiv:1612.05560) and color transformation (Tonry et al. 2012, ApJ, 750, 2). The near-infrared fluxes are calibrated by nearby stars with the Two Micron All Sky Survey (2MASS) catalog (Skrutskie et al. 2006, AJ, 131, 2, 1163). We do not correct the Galactic extinction. The object has been brightened both in optical and near-infrared wavelengths compared with the gamma-ray faint state (R=13.26+/-0.01 and J=11.51+/-0.10 on MJD 58707.550).
We will continue to monitor the object.
