Special Notice #311: HST COS to observe CW Mon 2012 November 30 - December 1

November 20, 2012:  The HST COS far ultraviolet observations of the dwarf nova CW Mon will be taking place 2012 November 30 20:54:49 through 2012 December 1 02:26:15 UT (AAVSO Special Notice #309, www.aavso.org/aaso-special-notice-309).

***Your observations beginning now, and particularly on November 28 and 29, are crucial to confirm whether the target is at minimum (which it must be for HST to observe it). The HST scheduling team will make a final decision on the morning of November 30. Of course, observing while the satellite observations are taking place and for a few days afterwards are also crucial.***

As instructed in AAVSO Alert Notice 471 (www.aavso.org/aavso-alert-notice-471), for CCD observers, simultaneous photometry [shortly before, during, and after the HST observations] would be ideal. B filter would be best for a light curve, although for the magnitude estimates, a V measurement would be best. An uninterrupted light curve would be better than cycling between filters. This target is most likely too faint for positive visual observations (16.8V at minimum, unknown at maximum), but if possible they are welcome, as are visual fainter-than observations fainter than magnitude 15.0.

Coordinates for CW Mon: R.A. 06 36 54.58  Dec. +00 02 17.3 (2000.0)

Charts for CW Mon may be created using VSP (www.aavso.org/vsp).

Please report observations promptly to the AAVSO International Database using the name CW MON. If you see the target in outburst, please contact the AAVSO immediately and post a message to the Observations and Campaigns & Observations Reports forum (www.aavso.org/forum).

Thank you for your contributions and good observing.

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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