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A Spectacular, Unprecedented Optical Flare in the Blazar CTA 102

ATel #9756; Katie J. Chapman, Alina Sabyr, Ryan W. Stahlin, Saiyang Zhang, Thomas J. Balonek (Colgate Univ., Hamilton, NY, USA)
on 13 Nov 2016; 14:29 UT
Credential Certification: Thomas J. Balonek (tbalonek@colgate.edu)

Subjects: Optical, AGN, Blazar, Quasar

Referred to by ATel #: 9776, 9788, 9808, 9821, 9841, 9868, 9869

We report optical observations of a spectacular, unprecedented optical flare in the blazar CTA 102, reaching a new historic optical maximum (R ~ 12.73) on JD 2457705.57 [2016 November 13.07 (UT)], just before clouds interrupted observations. Thirty-four two-minute images over two hours, between 2016 November 12.99 and 13.07, show microvariability of amplitude 0.08 magnitude. When observations resumed three-and-a-half hours later (November 13.22 - 13.24), CTA 102 had faded by 0.5 magnitudes to R~13.25-13.3.

Subsequent to the outburst peak on 2016 November 7 and 8 reported by our group (ATel #9732), when CTA 102 reached a then historic maximum brightness R~13.4, the blazar faded 0.6 magnitudes in two days to R~14.0 on 2016 November 10.2. It brightened by 0.4 magnitudes in one day to a brightness R~13.6 on 2016 November 11.15, and then an additional 0.9 magnitudes in two days to the level reported above.

The blazar CTA 102 is undergoing a period of extended optical activity, exhibiting several peaks of increasing brightness separated by several days: 2016 October 29, R~13.6; November 7-8, R~13.4; and November 13, R~12.7 (Jorstad et al. ATel #9676; Balonek et al. ATel #9732; this Telegram). The blazar has also exhibited increased gamma-ray emission above 100 MeV between 2016 November 8-10 (Minervini et al. ATel #9743).

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. Student research participation at Colgate University is supported by a Colgate Research Council grant, the NASA / New York Space Grant, an NSF grant to the Keck Northeast Astronomy Consortium, and Colgate Schlichting fellowships.

Further observations at multiple wavelengths are encouraged as CTA 102 is exhibiting significant multi-wavelength intra-day variability, and the greatest optical brightness in four decades of observations by several groups.