Historic flare of ASASSN-15bq
ATel #6993; Roberto Nesci
on 26 Jan 2015; 15:35 UT
Credential Certification: Roberto Nesci (Roberto.Nesci@iaps.inaf.it)
Subjects: Optical, Cataclysmic Variable, Transient
The coordinates (J2000) of this CV candidate reported by ASASSN are 07:18:3.39 +64:47:43.5. It is located 15" South of a relatively bright star (g=16.00, r=15.53 mag in the SDSS DR-10).
In the Digitized First Byurakan Survey (Mickaelian et al 2007 A&A 464, 1177) there are 4 spectroscopic objective prism plates covering this star: plate 1160M (1967-02-28), 1828M (1969-02-21),0021 (1969-10-08) and 0148 (1969-12-07). In this last plate the spectrum of the star is clearly detected, largely superposed to the spectrum of the brighter northern star. Therefore it is clear that ASASSN-15bq in NOT the star FBS0713+648 but the faint star 15" South. This star is reported in the GSC2.2 catalog at R=16.97 B=17.68 and is quite blue in the SDSS-DR10 u=18.25, g=18.7, r=18.41.
From the shape and overall length of the combined spectrum of the two sources it is possible to say that the CV candidate spectrum in the December 1969 flare was rather blue and its R magnitude somewhat brighter then FBS0713+648.
The original plates can be retrieved from the DFBS archives at
www.ia2-byurakan.oats.inaf.it or byurakan.phys.uniroma1.it
Digitized First Byurakan Survey
