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Special Notice #385: SBS 1108+574 HST/COS observations crucial NOW

May 13, 2014: The HST/COS observations of the cataclysmic variable SBS 1108+574 described in AAVSO Alert Notice 501 and Special Notice #384 are scheduled for 2014 May 16 06:19:04 - 15:16:56 UT.

Your observations TONIGHT AND PARTICULARLY TOMORROW NIGHT ARE CRUCIAL!

The deadline for the go/no-go decision by the scheduling team is 11am EDT on May 15. The HST team has told PI Dr. Peter Garnavich that "photometry needs to be acquired in the window starting after UT 2014-05-15 03:00:00 (i.e. beginning of night May 14 to 15)". Telescopes the PIs have access to are either down for maintenance or expected to be clouded out tomorrow night. Thus, your observations will be _absolutely essential_. Timely reporting is also essential.

Please continue your more frequent (2-3 per night) V observations through the 16th. After the 16th, nightly V snapshots will be helpful through May 25 to provide good context for the HST observations. Simultaneous photometry/time series is not needed. During quiescence SBS 1108+574 is around magnitude V=18-19 and during outburst around V=15.

Coordinates:  R.A. 11 11 26.87  Dec. +57 12 38.9  (2000.0)

Charts for SBS 1108+574 may be created using the AAVSO Variable Star Plotter (VSP) at http://www.aavso.org/vsp. Photometrists should use the data table supplied in VSP.

Please submit your observations to the AAVSO International Database as soon after making them as possible. If you see the variable in outburst, please contact the AAVSO immediately and post a message to the Observations and Campaigns & Observations Reports forum (http://www.aavso.org/forum).

The primary name for this object in VSX is CSS 120422:111127+571239. When submitting your observations, please use either this name or the name SBS 1108+574 [be sure to include the space between the two parts of the name].

Many thanks for your contributions!

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

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