[vsnet-alert 18942] Re: MASTER OT J185651.32-721019.9 = NSV 11478

[Nikolai N. Samus]

Thanks, dear Sebastian!

On Tue, 4 Aug 2015, Sebastian Otero wrote:

> Dear colleagues,
>
> MASTER OT J185651.32-721019.9 was reported as a new CV in ATel #7873
>
> It is only 29"away from the current position of NSV 11478 (18 56 52.3 -72 10 
> 49, J2000.0).
>
> NSV 11478 is another one of Luyten's stars. These are usually large amplitude 
> red variables and since the original positions are poor, they may be more 
> than 1 arc minute away from the actual coordinates.
> This one has a published range of 15 - <17.5 p so if it was a red variable, 
> it would reach V ~13 at maximum.
>
> There are no red stars 2 arc minutes around NSV 11478's position. Actually 
> there is no star brighter than mag. 17 in a 1 arc minute radius.
> This makes the identification with the dwarf nova very likely.
> Since it is not a red star but a blue one, the 15 - <17.5 p becomes 
> consistent with the identification. And 29" is like a perfect match when it 
> comes to Luyten's variables.
>
> The dwarf nova also has CRTS data. It is SSS_J185651.6-721019 and shows a 
> range 16.5 - <20.2 CV.
>
> The star can be identified as USNO-A2.0 0150-18758914 = USNO-B1.0 
> 0178-0497976 = GSC2.3 SADN020583 = DENIS J185651.5-721020.
>
> A mag. of 21.3 B is given in GSC2.3.
>
> The best position comes from PPMXL: 18 56 51.52 -72 10 19.8 (J2000.0).
>
> So MASTER OT J185651.32-721019.9 = NSV 11478.
>
> Best wishes,
> Sebastian
>
> ----------------------
> Sebastian Otero
> VSX Team
> American Association of Variable Star Observers