Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 06/26/2022 - 15:42

R. Bachev (IA-NAO, BAS, Bulgaria) reported in ATEL #15447 that  blazar (flat spectrum radio quasar, FSRQ)   AU CVN  = B2 1308+326 is in outburst and reached "...R = 14.4 (T. Balonek, priv.comm.) on 2022-06-19, which was probably the highest reported optical level for the last 40 years."  My observations on 25 June and on 26 June show its brightness is still increasing.  The following Ic mean magnitudes were obtained at Burleith Observatory, Washington, DC (0.32-m PlaneWave CDK, STL1001e CCD, Astrodon Cousins I filter, 180-sec exposures).  Ensemble photometry using (Smith, et al.,  AJ, 90, 1184,1985) comparisons A,B,C,F. 

Mean UT                     Mean HJD             Mean Ic  standard error  Number of observations

June 25.1046 2022     2459755.604572   12.860   (0.002)               39

June 26.1027 2022     2459756.602745   12.720    (0.003)              36

 

R. Schmidt (SREB)

Affiliation
American Association of Variable Star Observers (AAVSO)
AU CVn is still on the rise…

AU CVn is still on the rise tonight. The following Ic mean magnitudes were obtained at Burleith Observatory, Washington, DC (0.32-m PlaneWave CDK, STL1001e CCD, Astrodon Cousins I filter, 180-sec exposures).  Ensemble photometry using (Smith, et al.,  AJ, 90, 1184,1985) comparisons A,B,C, check star F. 

Mean UT                     Mean HJD             Mean Ic  standard error  Number of observations

June 28.1021 2022.    2459758.602146   12.341    (0.001).             25

Rich Schmidt (SREB)