Alert Notice 831: V1082 Sgr to be observed with HST this week

August 8, 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 magnetic cataclysmic variable V1082 Sgr have been scheduled with the Hubble Space Telescope for:

2023 11 August 02:23:24 - 07:59:23 UT

Dr. Pala writes: "This is very bright target [for HST], close to the bright limit of COS [Cosmic Origins Spectrograph] and its observation with HST might be difficult. Any photometric data you can obtain in the next night[s], particularly on the night of August 9th and 10th would be extremely helpful to understand if the system is safe for HST.

"Since this is a relatively bright target, if possible, any spectroscopic data would also be helpful to try to model the system and understand its brightness.

"Thanks a lot for your support!"

Your V observations from tonight through August 10/11 are critical; please continue nightly V snapshots through 2023 August 25. V1082 Sgr has a range of 13.4 - 15.6 V. The most recent observations of it in the AAVSO International Database show it at V magnitude 13.942 +/- 0.016 on 2023 Aug. 7.1163 UT (F.-J. Hambsch, Atacama, Chile) and visual magnitude 13.7 on Aug. 8.5944 UT (R. Stubbings, Tetoora Road, Vic, Australia).

Please see Alert Notice 796 for additional details and instructions.

For spectroscopists, Dr. Pala will post more information/instructions in the Campaigns forum thread given above.

Coordinates (J2000):  R.A. 19 07 21.87    Dec. -20 46 50.5    (from VSX entry for V1082 Sgr)

Charts with comparison stars for V1082 Sgr may be created using the AAVSO Variable Star Plotter (VSP).

Please report observations to the AAVSO International Database or AAVSO Spectroscopic Database using the name V1082 SGR. 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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