Special Notice #179: Request for observations of TT Ari in support of GALEX observations

AAVSO Special Notice #179

Request for observations of TT Ari in support of GALEX observations
November 16, 2009

Further to Alert Notice 408 (2009 October 13), we are updating the initial request for observations of the cataclysmic variable TT Arietis to obtain time-series photometry in conjunction with ultraviolet observations by the GALEX satellite.  These observations were initiated by Dr. Joseph Patterson (Columbia U. and Center for Backyard Astrophysics) and are scheduled to continue through 2009 November 27.  These observations will occur daily on the schedule listed below.  Time-series observations are strongly encouraged during the expected times of the spacecraft observations. 

TT Ari remains in its low state, and is still exhibiting very large amplitude oscillations with timescales of minutes to hours.  The star varies between roughly V=16.5 and V=14.5, and the oscillations are rapid. Good signal-to-noise with high time-resolution are the key requirements; filters should only used if you have sufficient aperture to obtain good signal to noise with exposures of 5 minutes or less.

The scheduled GALEX observations are as follows.  GALEX exposures are approximately 30 minutes long starting at the UT indicated; please observe for at least 30 minutes on either side of the window if possible.

        2009 November 17 05:32:26.8 UT (JD 2455152.7309)
        2009 November 17 07:11:00.9 UT (JD 2455152.7993)
        2009 November 18 04:32:25.0 UT (JD 2455153.6892)
        2009 November 18 06:10:59.2 UT (JD 2455153.7576)
        2009 November 19 05:10:58.8 UT (JD 2455154.7160)
        2009 November 19 06:49:33.1 UT (JD 2455154.7844)
        2009 November 20 05:49:34.5 UT (JD 2455155.7428)
        2009 November 20 07:28:09.0 UT (JD 2455155.8112)

Additional observations have not yet been scheduled.

For more information on these observations, please see the CBA website: http://cbastro.org/communications/news/messages/0683.html

The AAVSO is also maintaining a web page on TT Ari's current activity: http://www.aavso.org/news/ttari_campaign.shtml

TT Ari is located at the following (J2000) coordinates:

RA: 02:06:53.10 , Dec: +15:17:42.0

Charts for TT Ari may be plotted with AAVSO VSP: http://www.aavso.org/observing/charts/vsp/index.html?pickname=TT%20Ari

Please promptly submit all observations to the AAVSO with the name "TT ARI".

This AAVSO Special Notice was prepared by M. Templeton.

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