Alert Notice 848: HST schedule set for SDSS J080449.49+161624.8

February 2, 2024

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Further to AAVSO Alert Notice 838, Dr. Anna Francesca Pala (European Space Agency, ESAC, Spain) informs us that observations of the cataclysmic variable SDSS J080449.49+161624.8 (Cnc) have been scheduled with the Hubble Space Telescope for:

2024 February 16 UT

When the exact time is announced, it will be reported in the above forum threads.

Beginning immediately, please observe SDSS J080449.49+161624.8 in V one to a few times per night from now through February 16, then nightly through March 1. As with all targets for HST, it will be crucial to have a positive V measurement 24 hours before the scheduled HST time so the HST team can make a go-nogo decision; the nights of February 13-14, 14-15, and 15-16 will be critical.

A minimum SNR~20 is requested. If the target is too faint to obtain the minimum SNR in V, switch to CV. If a target is observed going into outburst, please submit your observation(s) as soon as possible and begin obtaining multiple observations per night.

Dr. Pala writes: "We know that some observers carry out time-series observations and also spectroscopy, and we welcome any additional contributions. Nonetheless the monitoring to assess quiescence should have the highest priority since, without it, there is the risk to lose the allocated orbits.

"In case of time-series observations, an uninterrupted light curve in a single filter (preferably B or V) would be better than alternating with different filters. CV observations can still be useful but V-filter observations should be the priority (whenever possible).

"DSLR observations, particularly if they are transformed to V, will be useful and are welcome. Visual observations will also be very valuable."

SDSS J080449.49+161624.8 has a range of 17.8 - 19.1 r and variability type IBWD. The most recent observations of it in the AAVSO International Database show it at magnitude 18.896 CV  +/- 0.19 on 2024 Jan. 31.418299 UT (R. Stephens, Rancho Cucamonga, CA).

Coordinates: R.A. 08 04 49.49  Dec. +16 16 24.9 (from VSX entry for SDSS J080449.49+161624.8)

Charts with comparison stars for SDSS J080449.49+161624.8 may be created using the AAVSO Variable Star Plotter (VSP).

Please report all photometry observations to the AAVSO International Database using the name SDSS J080449.49+161624.8. 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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