WZ Sge-type dwarf nova VSX J213806.5+261957 in outburst

PTS

Carey Chiselbrook (Georgia, United States; AAVSO observercode CCY) observed the WZ Sge-type dwarf nova VSX J213806.5+261957 in outburstat a visual magnitude of 9.7 on 2014 October 22.0590 (JD 2456952.55903).  Prior to the outburst detection,  the last observation (also by CCY) indicatedthe star was not in outburst less than 24 hours prior (mvis < 13.8 at JD2456951.6326.

This star was first discovered in May 2010, and both EddyMuyllaert and Gary Poyner (via the BAAVSS mailing list) note that its recurrencetime of less than five years makes it notable among stars of this class.  

Gary Poyner also notes that this object is on the BAARecurrent Objects Programme, with the name 1RXS J213807.1+261958.  Both visual and time-series instrumentalobservations of VSX J213806.5+261957 are strongly encouraged.

CCD time-series observers may notice superhumposcillations appear within the next few days, having a period near 0.06 days (~1.5 hours).

Observers should note that the variable lies within a fewarcseconds of a 15th magnitude star, and it may not be possible to separate thetwo once the variable falls below 15th magnitude.  Please indicate in the comments field of yourobservations whether you are able to split the two stars.

VSX J213806.5+261957 is located at the following (J2000)coordinates:

               RA:21 38 06.68 , Dec: +26 19 56.6

Please report all observations of this star via theWebObs feature of the AAVSO website, and using the name "VSXJ213806.5+261957".

This AAVSO Special Notice was prepared by M. Templeton.