May 8, 2013: Further to AAVSO Alert Notice 471 (http://www.aavso.org/aavso-alert-notice-471)and AAVSO Special Notice #350 (http://www.aavso.org/aavso-special-notice-350), HST/COS is scheduled to observe the eclipsing WZ Sge-type cataclysmic variable 1RXS J105010.3-140431:
1RXS J105010.3-140431 2013 May 10 07:51:01 through 12:01:57 UT
The HST team will be making a final decision on observing 1RXS J105010.3-140431 based on the observations of May 8/9 (tonight), and observations from the following night will also be essential. Close monitoring of 1RXS J105010.3-140431 through May 11 is requested. 1RXS J105010.3-140431 is V=17 at minimum; its magnitude at maximum is unknown.
After 1RXS J105010.3-140431, the next target will be the dwarf nova SDSS J153817.35+512338.0:
SDSS J153817.35+512338.0 2013 May 16 22:44:06 through May 17 02:14:05 UT
THIS DATE HAS BEEN REVISED FROM THAT GIVEN IN SPECIAL NOTICE #350.
Giving 1RXS J105010.3-140431 highest priority, please begin covering SDSS J153817.35+512338.0 now; close monitoring May 13 through 18 is essential. SDSS J153817.35+512338.0 is V=18.6 at minimum and its magnitude at maximum is unknown.
Upcoming targets include
Star 2013 Date UT Type MinV MaxV
DT Oct May 20 SU 16.5 11.8
GW Lib May 27 WZ 16.5 8
V1108 Her Jun 3 WZ 17.7 10.4
BD Pav Jun 10 UG 15.4 12.4
QZ Ser Jun 17 SU 17.9 12.7
CC Scl Jun 24 SU 17 13.4
ASAS J160048-4846.2 Jul 8 WZ 17.9 12.6
HS2214+2845 Jul 15 DN 16.8 12.5
Dr. Gaensicke has requested AAVSO observers to begin following these targets now, giving priority to the current and next targets.
As instructed in AAVSO Alert Notice 471, for CCD observers, simultaneous photometry [shortly before, during, and after the HST observations] would be ideal. For the magnitude estimates, a nightly V measurement from now through the HST observations and a day beyond would be best. If positive visual observations are possible, they are welcome, as are visual fainter-than observations fainter than magnitude 15.0.
Coordinates (2000.0)
1RXS J105010.3-140431 R.A. 10 50 10.803 Dec. -14 04 36.64
SDSS J153817.35+512338.0 R.A. 15 38 17.31 Dec. +51 23 38.0
DT Oct R.A. 18 40 52.31 Dec. -83 43 10.0
GW Lib R.A. 15 19 55.34 Dec. -25 00 24.58
V1108 Her R.A. 18 39 26.21 Dec. +26 04 08.9
BD Pav R.A. 18 43 11.919 Dec. -57 30 44.85
QZ Ser R.A. 15 56 54.47 Dec. +21 07 19.0
CC Scl R.A. 23 15 31.86 Dec. -30 48 47.6
ASAS J160048-4846.2 R.A. 16 00 47.46 Dec. -48 46 05.07
HS 2214+2845 R.A. 22 16 31.19 Dec. +29 00 19.7
Charts may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp).
Please report observations as soon as possible to the AAVSO International Database using the names 1RXS J105010.3-140431 and SDSS J153817.35+512338.0, respectively, and the names as listed for the upcoming targets. If an outburst is detected, please report observations immediately. Many thanks!
This AAVSO Special Notice was compiled by Elizabeth O. Waagen.
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