Alert Notice 857: SDSS J080846.19+313106.0 being observed this week with HST

April 1, 2024

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
 - Campaigns and Observing Reports: https://www.aavso.org/hst-campaign-dwarf-novae-2023-2024
 - Cataclysmic Variables: https://www.aavso.org/hst-campaign-dwarf-novae-2023-2024-01

Further to AAVSO Alert Notice 838, Dr. Anna Pala (European Space Agency, ESAC, Spain) informs us that observations of the cataclysmic variable SDSS J080846.19+313106.0 (Cnc) have been scheduled with the Hubble Space Telescope for:

2024 April 5 22:41:47 - April 6 04:23:03 UT

Nightly V snapshots are requested from now through April 20.  V observations will be critical in the few days before the HST date; a positive V observation is required 24 hours before the HST observations. Dr Pala writes: "Any data you can collect on the next nights, especially the night of the 4th and early on the 5th, will be extremely useful for the HST team to finally approve the observations of this target."

SDSS J080846.19+313106.0 has a range of 14.1 - 20.4 g. The most recent observations of it in the AAVSO International Database show it at CV magnitude 18.362 +/- 0.097 on 2024 Mar. 30.06949 UT (J. DeYoung, Palmyra, VA).

Please see Alert Notice 838 for additional details and instructions.

Coordinates (J2000):  R.A. 08 08 46.19    Dec. +31 31 06.0    (from VSX entry for SDSS J080846.19+313106.0)

Charts with comparison stars for SDSS J080846.19+313106.0 may be created using the AAVSO Variable Star Plotter (VSP).

Please report observations to the AAVSO International Database using the name SDSS J080846.19+313106.0 and include spacing and punctuation as shown. Reduce and submit observations as soon as possible after making them.

Dr. Pala also communicates: "SDSS J080449.49+161624.8 (Alert Notice 850) was successfully observed by HST in February. Thanks a lot for all your data! Also, the observations of ASASSN-20pv, which were originally planned to happened in March (Alert Notice 838), have been postponed to the end of May."

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

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Information on submitting observations to the AAVSO may be found at:
 - Photometry/visual observations: https://www.aavso.org/webobs
 - Spectroscopy: https://www.aavso.org/apps/avspec/

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