Alert Notice 818: SSS 100511:061754-362655 observations scheduled with HST

March 15, 2023

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Further to AAVSO Alert Notice 796, Dr. Anna Francesca Pala (European Space Agency, ESAC, Spain) informs us that observations of the cataclysmic variable SSS 100511:061754-362655 (Col) have been scheduled with the Hubble Space Telescope for:

2023 March 24 03:08:59 - 07:10:10 UT

On March 9 Dr. Pala wrote: "This object underwent into outburst on February 21st and it is now back to quiescence at V~18.5. This target seems to outburst on short recurrence time but, given the recent outburst, there are high chances that the HST observations will be successful.

"It would be great if you could keep monitoring it, with a few data points per night. As usual, it will be crucial to obtain a positive [V] detection of the target the day before the HST observations, in order for the HST team to finally approve their execution.

"Thanks and good luck with the observations!"

Your observations from tonight through March 24/25 are critical (even more so than usual because of the short outburst interval for this star), and please continue nightly V snapshots through 2023 April 7. This target is faint at minimum; the most recent observations of SSS 100511:061754-362655 in the AAVSO International Database show it at magnitude 17.666 V +/- 0.19 on 2023 Mar. 12.02246 UT and <17.6 V +/- 0.27 on Mar. 15.01498 UT (J. DeYoung, Palmyra, VA).

Please see Alert Notice 796 for additional details and instructions.

Coordinates (J2000):  R.A.  06 17 53.83   Dec.  -36 26 54.5   (from VSX entry for SSS 100511:061754-362655)

Charts with comparison stars for SSS 100511:061754-362655 may be created using the AAVSO Variable Star Plotter (VSP).

Please report observations to the AAVSO International Database using the name SSS 100511:061754-362655 (be sure to include the space after SSS). Reduce and submit observations as soon as possible after making them.

This Alert Notice was compiled by Elizabeth O. Waagen using information provided by Dr. Pala.


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