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Special Notice #221: Infrequent Outburst of the SU UMa Variable HT Cas

November 2, 2010: As reported by Tim Parson (Circle Pines, Minnesota, USA) and confirmed by Pavol Dubovsky (Kolonica, Slovakia), the infrequently-outbursting dwarf nova HT Cas is in outburst.  Parson observed HT Cas in outburst at m(vis)=12.9 on JD 2455502.93 (2010 November 2.43), and the outburst was confirmed by Dubovsky at m(vis)=12.4 on JD 2455503.3 (2010 November 2.8).  The last confirmed well-observed outburst of this star occurred on 2008 January 10.  Observations of this variable are strongly encouraged at this time.  Both visual and CCD observations are encouraged, and CCD time-series data are particularly encouraged if possible.

HT Cas is classified as a UGSU-type dwarf nova with eclipses, having an orbital period of approximately 0.0736 days (106 minutes).  We ask all observers to contribute whatever observations they can throughout the outburst.  CCD observers are asked to perform time series observations if possible, keeping the best balance between short integration times and good signal to noise.

HT Cas is located at the following (J2000) coordinates:

        RA: 01 10 12.96 , Dec: +60 04 36.3

Charts for HT Cas may be plotted using AAVSO VSP:

There is a m(vis)=13.9 comparison star approximately 30 arcseconds south of this star, HT Cas is easily separated and the identification should be clear.

Please promptly submit all observations to the AAVSO using the name "HT CAS".

This AAVSO Special Notice was prepared by Matthew Templeton.


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