[vsnet-alert 18934] MASTER OT J185651.32-721019.9 = NSV 11478

[Sebastian Otero]

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