Alert Notice 376: Request to monitor SDSS J151413.72+454911.9 for HST Observations [PP Boo]

April 23, 2008: Dr. Paula Szkody (University of Washington) and collaborators have requested our help in monitoring the cataclysmic variable SDSS151445 (SDSS J151413.72+454911.9) [PP Boo] for upcoming Hubble Space Telescope observations.  Dr. Szkody requests nightly monitoring of this source beginning immediately, and continuing through 2008 May 10 UT at least. A follow-up AAVSO Special Notice will be issued when the HST observing window has been set.

SDSS J151413.72+454911.9 is located at RA 15:14:13.720,Dec +45:49:11.80 (J2000)

This star is a cataclysmic variable not previously seen in outburst, and is being observed as part of a larger study of pulsating white dwarf primaries in cataclysmic variables. In particular, Szkody and collaborators are investigating the effects that higher temperatures and larger rotation velocities caused by accretion have on the pulsation behavior.

This object is extremely faint at quiescence, with V=19.5. AAVSO observations are requested to ensure that the object remains in quiescence when observed with HST, as it could damage the instrument if it were to go into outburst. AAVSO observations will be used to make a "go"/"no go" decision prior to the opening of the HST observing window, and will also be used in the analysis of the resulting data. Observations are requested to continue through the end of the science observing window, likely to be the second week in May 2008.

Observers are asked to monitor SDSS J151413.72+454911.9 beginning immediately (2008 April 23 UT). Visual observers please observe as normal, and report any "fainter than" estimates using the faintest comparison star magnitude you can reach if unable to detect the CV itself. CCD observers are asked to use filters during observations if available; V filter is preferred, but B,Rc, and Ic may also be used. Detection of the variable itself is not required; please use sufficient exposure time to detect at least the V=15.023 comparison star (RA 15:14:17.96 , Dec +45:50:23.9 , J2000) with a S/N of 10, and report the observation as a "fainter-than" measure.  Please go as faint as possible in reasonable time, preferably to the faintest comparison star as you can.

Please submit all data to the AAVSO via WebObs as promptly as possible. In the event of an outburst, please contact the AAVSO immediately. 

Please submit data to the AAVSO using the name "SDSS J151413.72+454911.9" or the AUID "000-BDB-386".

A sequence has been prepared and will be uploaded to VSP shortly. Charts for SDSS J151413.72+454911.9 are available at this URL:

For more information on this campaign, visit the following URL:

This campaign is being organized at AAVSO HQ by Dr. Matthew Templeton.



Information on submitting observations to the AAVSO may be found at‭:‬


An Alert Notice archive is available at the following URL‭:‬

Subscribing and Unsubscribing may be done at the following URL‭:‬

Please support the AAVSO and its mission -- join or donate today: