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THE ASTRONOMER Electronic Circular No 3700      2022 Apr 28 12.45UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.ORG.UK             Backup: guy_hurst@hotmail.com
WORLD WIDE WEB                         http://www.theastronomer.org
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GP COM: HST COVERAGE

AAVSO ALERT:

Further to AAVSO Alert Notice 758, Dr. Anna Francesca Pala (European Space
Agency, ESAC, Spain) informs us that the cataclysmic variable GP Com will be
observed by the Hubble Space Telescope on April 29-30, 2022.
The exact time of the HST observations is:
2022 April 29 23:22:51 UT - April 30 01:54:27 UT
Coverage is requested from now through May 20. Observations from tonight and
tomorrow night are crucial. Please observe GP Com a few times per night
tonight through April 30, then nightly through May 20. 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.
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."
Coordinates for GP Com (2000.0): R.A. 13 05 42.40  Dec. +18 01 03.8 
Range: 15.7 - 16.2 V
Variability Type: IBWD
Charts with comparison stars for GP Com may be created using the AAVSO
Variable Star Plotter (VSP).
 

Guy M Hurst


