Optical follow-up observations of the blazar PG 1553+113

ATel #12635; Aditi Agarwal (Indian Institute of Astrophysics, Bangalore, India)
on 7 Apr 2019; 01:23 UT
Credential Certification: Aditi Agarwal (aditiagarwal.phy@gmail.com)

Tweet

Following the recent announcement of optical activity from the blazar PG 1553+113 in ATel #12631, we carried out follow-up observations of the target on April 05, 2019. Optical Observations for the BL Lac object PG 1553+113 (RA: 15h 55m 43.04s, Dec: +11d 11m 24.37s), were carried out in B, V, R, and I passbands on 05, April 2019 from the Vainu Bappu observatory, Kavalur with 1.3m JCB telescope. The CCD used was 2k x 4k with field of view of about 0.299 arcsec/pixel, read noise of about 4.3 electrons and gain 0.745 electrons/ADU. Instrumental magnitudes of the target plus the standard stars were extracted by processing CCD images using concentric circular aperture photometry. These instrumental magnitudes were then calibrated using star 1 of Raiteri et al. (2015). Preliminary results of the analysis for PG 1553+113 indicates that on April 05, 2019, optical magnitudes in B, V, R, and I filters are 14.037 +/- 0.004, 13.612 +/- 0.008, 13.299 +/- 0.007, and 12.818 +/- 0.01, respectively. Considering the ongoing activity of the source, we will continue monitoring the source. We encourage further multi-wavelength observations.