[vsnet-alert 16450] Re: ASASSN-13db

[Denis Denisenko]

More on this interesting object. I wrote:

> Obviously the *blue* star goes into outbursts which
> is 4" North of the red star. See the color-combined finder chart:
> http://master.sai.msu.ru/static/OT/J051011-032826-BRIR5x5.jpg

The two stars are present in SDSS with the following coordinates and magnitudes:

Red dwarf: SDSS J051011.00-032826.2
u=22.61(41) g=20.15(2) r=18.69(1) i=16.85(1) z=15.85(1)
http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237676302413070821

Blue star: SDSS J051011.04-032822.3
u=23.15(65) g=20.98(4) r=20.44(3) i=20.37(4) z=20.11(15)
http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237676302413070822

Previous outburst was serendipitously observed by MASTER-Amur
telescope 2.5 years ago in two filters (!!!) which allowed to measure
the color of the star (V image was obtained 46 minutes before the R
image):

ASASSN-13db = CSS J051011.0-032826
  20110122.521  13.24V  MASTER-Amur
  20110122.553  13.11R  MASTER-Amur

Image in V filter:
http://master.sai.msu.ru/static/OT/J051011-032826-MASTER-20110122.jpg

The precise astrometry of the object is desirable during the fading of
current outburst to make sure it is the blue (northern) component
which went into outburst.

Denis Denisenko
Member of MASTER team at SAI MSU