AAVSO Special Notice #76: Support for HST observations of SDSS074545, update

We have been informed by Paula Szkody that HST observations
of SDSS074545 have been tentatively scheduled for the night 
of 2007 October 31/Nov 01 UT (approximate JD 2454405.56).  
Observations are pending ground-based confirmation that 
this cataclysmic variable is not in outburst and is thus 
faint enough to safely observe with HST.  This decision 
will be made on the afternoon of Wednesday, 2007 October 
31 UT, and so observations are critically needed during the 
night of 2007 October 30/31 UT (JD 2454404.5).

For those participating in this campaign, please obtain
one or more observations of SDSS074545 such that (a) you
detect the variable with S/N = 10 and can confirm that 
it is faint, or (b) that you detect the m(vis) = 15.8 
(V = 15.764) comparison star with S/N = 10, and can 
confirm that SDSS074545 is "fainter-than" this limit.
Observations prior to the 2007 October 31 HST scheduling
decision are most critical, and please submit all 
observations made before that time as quickly as possible.
Please continue to observe this object through 2007 November
02, so that the full observing window is covered.

SDSS074545 (SDSS J074531.92+453829.5) is located at
RA: 07 45 31.92 , Dec +45 38 29.5 (J2000).

An SDSS F-scale chart for this object may be plotted using
VSP:

http://www.aavso.org/cgi-bin/vsp.pl?action=render&name=&ra=07+45+31.92&dec=%2B45+38+29.5&charttitle=SDSS074545&chartcomment=&aavsoscale=F&fov=15&resolution=100&maglimit=18.5&ccdbox=0&north=up&east=left&dss=on&Submit=Plot+Chart

Please use the RA and Dec to generate charts -- the name
"SDSS074545" may be used to submit data and view recently
submitted observations, but it will not yet resolve in
either VSP or VSX.

Please report all observations to the AAVSO as "SDSS074545"
(AAVSO Designation 0738+45).  Please report all observations
as soon as you are able to do so.

Thank you for participating in this and other AAVSO observing
campaigns!

This AAVSO Special Notice was prepared by Matthew Templeton.



---------------------------------------------------
SUBMIT OBSERVATIONS TO THE AAVSO

Information on submitting observations to the AAVSO may be found at:
http://www.aavso.org/observing/submit/

SPECIAL NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION

A Special Notice archive is available at the following URL:
http://www.aavso.org/publications/specialnotice/

Subscribing and Unsubscribing may be done at the following URL:
http://www.aavso.org/publications/email/