[vsnet-alert 16453] Re: ASASSN-13db

[Brian Skiff]

     I notice that the WISE 'colors' are very red ---
increasingly bright toward the longer wavelengths, which would
not obtain for either a late-M dwarf or an M-giant.  Given this,
and the sky location not too far from the Orion star-forming
region, suggests the star might be a somewhat embedded young
stellar object that is erupting.


\Brian



On Tue, 2013-09-24 at 23:15 +0400, Denis Denisenko wrote:
> On Tue, Sep 24, 2013 at 19:25+0400 I wrote:
> 
> >> ASASSN-13db         05:10:11.08   -03:28:26.3    2013-09-24.5     15.27
> >
> > Interesting case! 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
> 
> I have to admit I was wrong! The outburst is positionally consistent
> with the red star, as Kris Stanek originally reported. I have checked
> MASTER-Amur images of 2011 Jan. 22. Aligning and blinking V-band image
> with DSS or SDSS clearly shows the southern (red) component has
> brightened. Coordinates formally measured by the robot are 05 10 11.00
> -03 28 26.1 from V image and 05 10 11.01 -03 28 26.3 from the Red one,
> identical to the red dwarf SDSS J051011.00-032826.2. That makes the
> case even more intriguing!
> 
> Near-infrared magnitudes of 2MASS 05101100-0328262 J=14.13(3),
> H=13.54(3), K=13.11(3) correspond to M7-M8 red dwarf.
> 
> > Previous outburst was serendipitously observed by MASTER-Amur
> > telescope 2.5 years ago
> >
> > ASASSN-13db = CSS J051011.0-032826
> >   20110122.521  13.24V  MASTER-Amur
> >   20110122.553  13.11R  MASTER-Amur
> 
> Converting the date into Julian Days, 2011 Jan. 22.521 UT corresponds
> to JD 2455584.021. CRTS photometry during the outburst mentioned by
> Kris Stanek is as follows (dates are MJD = JD-2400000.5):
> 
> 55541.31833 15.06
> 55541.33624 15.19
> 55541.34526 15.08
> 55565.32345 15.06
> 55565.33103 15.10
> 55565.33860 15.09
> 55565.34622 15.14
> 
> The last Catalina observation before the outburst was on
> MJD=55508.39045 (17.29m), then there's a half-year long gap until
> MJD=55855.42951 (17.41m). No additional outbursts were detected in 8
> years of Catalina Sky Survey. Also, there were no outbursts in the
> earlier NEAT data from Dec.2000 to Feb. 2003. Truly amazing and
> mysterious object!
> 
> Denis Denisenko