Rapid intranight variability of the blazar S4 0954+65 during its maximum state
ATel #7083; Rumen Bachev (IA-NAO, BAS, Bulgaria)
on 16 Feb 2015; 10:31 UT
Credential Certification: Rumen Bachev (bachevr@astro.bas.bg)
Subjects: Optical, AGN, Blazar, Quasar
Recently it has been reported (ATel #6996; #7001; #7046; #7055; #7057) that the blazar S4 0954+65 is in an exceptionally high optical state. We monitored this object for several nights with the 60cm telescope of Belogradchik observatory, Bulgaria. The object was indeed in its historical (to the best of our knowledge) maximum in the optical. Furthermore, it manifested violent intranight variability, reaching changes of up to 0.2 mag for ~60 min on several occasions. The following summarizes our findings for the corresponding nights (R-band magnitudes, preliminary results with a typical error of 0.03 mag).
11/12.02.15
The object brightened from R=13.45 (UT 20:45) to 13.05 (UT 23:15)
12/13.02.15
Violent changes between R=13.20 and 13.40 from UT 20:15 to UT 01:45
13/14.02.15
The object faded from R=13.20 (UT 20:30) to 13.60 (UT 00:30) with a gradual rebrightening for the next ~2.5 hours.
14/15.02.15
A sharp decline from R=14.15 (UT 20:30) to 14.85 (UT 01:30)
In general, the objects faded with almost 2 mag for about 3 days. Further monitoring is encouraged, however the decline observed in the last night may suggest that this activity phase is going to an end.