Skip to main content

Special Notice #350: 1RXS J105010.3-140431 and SDSS J153817.35+512338.0 next HST/COS targets

We recently released a significant update to the backend systems for the AAVSO website. While most of the bugs introduced by this update have been fixed, there may still be problems we haven't fixed. If you run into a problem, please email webmaster@aavso.org

April 30, 2013:  Further to AAVSO Alert Notice 471 (http://www.aavso.org/aavso-alert-notice-471), 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, and observations from the following night will also be essential. Close monitoring of 1RXS J105010.3-140431 through May 11 is requested to be sure it is below the threshold brightness and to have a good magnitude value for correlation with the HST observations. 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 13 UT (time to be announced later)


Giving 1RXS J105010.3-140431 highest priority, please begin covering SDSS J153817.35+512338.0 now; close monitoring through May 14 is essential. SDSS J153817.35+512338.0 is V=18.6 at minimum and its magnitude at maximum is unknown.

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

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. 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:

http://www.aavso.org/webobs

SPECIAL NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION

A Special Notice archive is available at the following URL:
http://www.aavso.org/special-
notice-archive

Subscribing and Unsubscribing may be done at the following URL:
http://www.aavso.org/
observation-notification#specialnotices

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