Skip to main content

Web Publications

AAVSO Alert Notice 366: Request to monitor SDSS133948 for HST Observations AAVSO HOME > publications > alert notice

AAVSO Alert Notice 366

Request to monitor SDSS133948 for HST Observations
January 18, 2008

Dr. Paula Szkody (University of Washington) and collaborators have
requested our help in monitoring the cataclysmic variable SDSS133948
(SDSS J133941.11+484727.5) for upcoming Hubble Space Telescope
observations. The HST observations are scheduled to be made starting
2008 January 24, 21:30 UT (JD 2454490.3958) through
the afternoon of 2008 January 25, ending at approximately 15:15 UT 
(JD 2454491.1354).  Dr. Szkody requests monitoring
of this object beginning immediately (2008 January 18 UT), and
intensive monitoring during the 24-48 hour period surrounding the
scheduled time of observations.

SDSS133948 (AAVSO Designation 1335+49) is located at RA 13:39:41.12 ,
Dec +48:47:27.5 (J2000)

SDSS133948 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

This object is faint at quiescence, with V=17.7.  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 at 21:41 UT on January 24 (JD 2454490.4035), 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.  Science
observations will begin at approximately 06:15 UT on January 25 
(JD 2454490.7604) and end at approximately 15:15 UT (JD 2454491.1354).

Observers are asked to monitor SDSS133948 nightly beginning immediately
(2007 November 07 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 SDSS133948 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 unless you can reach V=17.7 in
reasonable time, but please use sufficient exposure to detect at least
the V=15.045 comparison star (AUID 000-BFR-715; RA 13:39:09.21 Dec
+48:50:10.1) with a S/N of 10 and report the observation as a
"fainter-than" measure.

Please observe this object as often as possible for the duration of the
week using the observing procedure outlined above, and submit data as
soon as is possible via WebObs. In the event of an outburst, please
contact the AAVSO immediately. 

Please submit data to the AAVSO using the name "SDSS133948" (AAVSO
Designation 1335+49).

Charts for SDSS133948 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:

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484