Alert Notice 466: Monitoring of V380 Oph requested in support of HST observations

THIS CAMPAIGN HAS BEEN CANCELLED. SEE AAVSO ALERT NOTICE 468 FOR DETAILS.  August 21, 2012

August 13, 2012: On behalf of a large Hubble Space Telescope consortium of which they are members, Dr. Joseph Patterson (Columbia University, Center for Backyard Astrophysics) (in cba:chat) and Dr. Arne Henden (AAVSO) have requested observations from the amateur astronomer community in support of upcoming HST observations of the novalike VY Scl-type cataclysmic variable V380 Oph. The HST observations will likely take place in September but nightly visual observations are needed beginning immediately and continuing through at least October 2012.

The astronomers plan to observe V380 Oph while it is in its current low state. Observations beginning now are needed to determine the behavior of this system at minimum and to ensure that the system is not in its high state at the time of the HST observations - if the system were bright it could damage the HST equipment.

V380 Oph is very faint in its low state: magnitude 17 to 19 and perhaps even fainter. Nightly snapshot observations, not time series, are requested, as is whatever technique - adding frames, lengthening exposures, etc. - necessary to measure the magnitude. It is not known whether V380 Oph is relatively inactive at minimum or has flares of one to two magnitudes; it is this behavior that is essential to learn in order to safely execute the HST observations.

Coordinates: R.A. 17 50 13.64  Dec. +06 05 29.4 (2000.0)

Charts for V380 Oph may be created using the AAVSO International Variable Star Plotter (VSP) at http://www.aavso.org/vsp

Please report observations to the AAVSO International Database as V380 Oph.

This campaign is being followed on the AAVSO Observing Campaigns page at http://www.aavso.org/observing-campaigns

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

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