photometry

Special Notice #233: Bright outburst of the cataclysmic variable SDSS J133941.11+484727.5

February 7, 2011: The star SDSS J133941.11+484727.5 has been reported in outburst by Jeremy Shears (Bunbury, UK).  Shears reports this star at magnitude 10.4 on 2011 February 7.919 (JD 2455600.419).  This is approximately 7 magnitudes above quiescence, which suggests a superoutburst of an SU UMa star or a WZ Sge-like outburst.  Gary Poyner (Birmingham, UK) confirms this outburst, estimating the star at 10.5 on February 7.959 (2455600.459).

Alert Notice 425: Monitoring of HBC 722 and VSX J205126.1+440523 Requested

October 1, 2010: Dr. Colin Aspin (U. Hawai'i) has requested the help of AAVSO observers in performing long-term photometric monitoring of the two new young stellar objects (YSOs) in Cygnus, HBC 722 and VSX J205126.1+440523 (see AAVSO Special Notice #216).  

Bibliography: visual magnitude estimates and photometry

A number of papers have been written discussing visual magnitude estimates in comparison to photometry.  Multiple studies have shown that visual magnitude estimates compare very favorably with instrumental photometry in terms of sensitivity and consistency.  As with all data, care must be taken to understand what visual magnitude estimates represent, what their bandpass is, and when their use is appropriate.