Special Notice #315: HST COS observing SDSS J075507.70+143547.6 December 13-14 and HS 0218+3229 is next target
December 11, 2012: Further to AAVSO Alert Notice 471 (www.aavso.org/aavso-alert-notice-471) and AAVSO Special Notice #309 (www.aavso.org/aavso-special-notice-309), HST COS is observing the WZ Sge-type cataclysmic variable SDSS J075507.70+143547.6 December 13-14:
SDSS J075507.70+143547.6 13 December 2012 23:32:57 through 14 December 04:45:44 UT
PLEASE GIVE SDSS J075507.70+143547.6 TOP PRIORITY NOW - YOUR OBSERVATIONS WILL BE CRUCIAL FOR THE HST SCHEDULING TEAM TO DECIDE TOMORROW whether to carry out the observations. SDSS J075507.70+143547.6 is 18.2V at minimum and unknown at maximum.
Coordinates for SDSS J075507.70+143547.6: R.A. 07 55 07.72 Dec +14 35 47.6 (2000.0)
The next HST COS target is the UG-type dwarf nova HS 0218+3229:
HS 0218+3229 22 December 2012 06:07:48 through 10:17:53 UT
Please focus on HS 0218+3229 after the SDSS J075507.70+143547.6 HST observations are over. Remember that your observations will be crucial for the HST scheduling team to decide around December 20 whether to carry out the observations. HS 0218+3229 is 15.5V at minimum and 12.5V at maximum.
Coordinates for HS 0218+3229: R.A. 02 21 33.48 Dec +32 43 23.9 (2000.0)
As instructed in 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. SDSS J075507.70+143547.6 is most likely too faint for positive visual observations at minimum. HS 0218+3229 is a more reasonable visual target. If positive visual observations of either system are possible they are welcome, as are visual fainter-than observations fainter than magnitude 15.0.
Charts for both targets may be created using VSP (www.aavso.org/vsp).
Please report observations as soon as possible to the AAVSO International Database as SDSS J075507.70+143547.6 and HS 0218+3229, respectively. If an outburst is detected, please report observations immediately. Many thanks!
This AAVSO Special Notice was compiled by Elizabeth O. Waagen.
SUBMIT OBSERVATIONS TO THE AAVSO
Information on submitting observations to the AAVSO may be found at:
SPECIAL NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION
A Special Notice archive is available at the following URL:
Subscribing and Unsubscribing may be done at the following URL: