Alert Notice 702: TCP J21040470+4631129 to be observed with HST

Note: This campaign has been rescheduled. Please see AAVSO Alert Notice 714 for information.  -  Elizabeth O. Waagen, August 6, 2020

Note: The HST observations of  TCP J21040470+4631129 have been postponed due to the target's going into (super)outburst on 2020 March 31. The observations will be rescheduled at a later time and this notice will be updated accordingly; a new Alert Notice may also be issued. However, photometry is still requested (please see AAVSO Alert Notice 703 for details).  -  Elizabeth O. Waagen, April 2, 2020


March 27, 2020

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports:
- Cataclysmic Variables:

Dr. Boris Gaensicke (University of Warwick) has requested AAVSO assistance in monitoring the WZ Sge-type dwarf nova TCP J21040470+4631129 (Cygnus) in support of observations scheduled with the Hubble Space Telecope for 2020 April 10, 17:30:39 - 23:05:48 UT.

AAVSO observations are essential to know the state of TCP J21040470+4631129 in order to ensure that the system is NOT in outburst when observed with HST. AAVSO observations made 24 hours before the HST observing time will be used to make a go/no-go decision; AAVSO data will be used in the analysis of the resulting HST data.

Nightly snapshots in V are requested beginning now and continuing through April 13. Intensive monitoring is requested April 7-10. During the period of intensive observations, prompt submission of observations will be essential. The most critical need for a positive observation is the night of April 9/10 (as early on the morning of April 10 as possible). Visual observations are also welcome.

TCP J21040470+4631129 has a range in V of 8.4-18.1. Its last major outburst occurred in July 2019, when it reached magnitude 8.293 V, and was followed by several re-brightenings, the most recent of which occurred in December 2019. The most recent observation of TCP J21040470+4631129 in the AAVSO International Database shows it at magnitude 15.3 CV on 2020 Feb. 22.20486 UT (K. Wenzel, Grossostheim, Germany).

Coordinates (J2000): R.A. 21 04 04.68  Dec. +46 31 14.5

Charts with comparison stars for TCP J21040470+4631129 may be created using the AAVSO Variable Star Plotter (VSP).

Please report all observations to the AAVSO International Database using the name TCP J21040470+4631129.

This Alert Notice was compiled by Elizabeth O. Waagen.

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