Blazar CTA 102 Reaches Historic Optical Maximum During Current Extended Period of Activity

ATel #9732; Thomas J. Balonek, Saiyang Zhang, Katie J. Chapman, Ryan W. Stahlin, Alina Sabyr (Colgate Univ., Hamilton, NY, USA), Daria Morozova, Valeri M. Larionov (St. Petersburg Univ., St. Petersburg, Russia); Svetlana Jorstad (BU, Boston, MA, USA: St. Petersburg Univ.)
on 8 Nov 2016; 08:42 UT
Credential Certification: Thomas J. Balonek (tbalonek@colgate.edu)

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We report optical observations showing the blazar CTA 102 in an unprecedented bright state (R~13.4) on two consecutive nights, 2016 November 07 and 08 (UT). To our knowledge, this is the brightest level reported in over 40 years of optical monitoring by several groups, including the well-documented optical outburst in 2012. We also report additional observations associated with the outburst reported by Jorstad et al. (ATel #9676) on 2016 October 26/27.

On 2016 November 7 (UT) continuous observations at the Colgate University Foggy Bottom Observatory (FBO) consisting of seventy-two two-minute images showed CTA 102 varying by 0.2 magnitudes in four hours. The blazar steadily increased in brightness from about 13.6 (R) at 00:30 UT to about 13.4 (R) at 04:00 UT followed by a slower dimming by about 0.02 magnitudes when we concluded observations at 05:30 UT. There is no evidence of microvariability with amplitude greater than two percent during this linear rise in magnitude. Eight to six hours prior to these observations, CTA 102 was observed at St. Petersburg University within 0.05 magnitude of the brightness observed at the beginning of our sequence.

On the subsequent evening, preliminary reductions indicate CTA 102 was slightly brighter, fluctuating by about 0.05 magnitude around an average of R~13.4. One hundred fifteen images were obtained at FBO between 23 UT on 2016 November 7 and 05 UT on 2016 November 8.

CTA 102 was observed to be at a comparable brightness (R~13.5 - 13.6) ten days earlier on 2016 October 29 (UT) at Lowell Observatory (Flagstaff, AZ) and FBO. This event was part of the outburst reported by Jorstad et. al. (ATel #9676).

Both the October 29 and November 7-8 outburst peaks were part of a long term rise from R~15.7 in mid-September 2016, which in itself is part of the extended period of activity which began in late 2015. Previous outbursts have been reported by Balonek (ATel #8598), and Larionov and Kopatskaya et. al. (ATel #9130).

Observations at Colgate University's Foggy Bottom University in Hamilton, NY were obtained using the Ferson 0.4-m telescope equipped with a FLI PL1001 CCD camera. Observations at St. Petersburg were obtained using the LX-200 0.4-m telescope with ST7-XME camera. Observations at Lowell Observatory in Flagstaff, Arizona were obtained using the 1.8-m Perkins telescope.

Student research participation at Colgate University is supported by the NASA / New York Space Grant, and Colgate University Schlichting fellowships and a Research Council grant.

Further observations at multiple wavelengths are encouraged as this source is exhibiting significant optical intra-day variability.