March 2, 2012: Dr. Margarita Karovska, Harvard-Smithsonian Center for Astrophysics, has requested visual and photometric observations of the symbiotic variable CH Cyg in preparation for and support of Chandra and HST observations scheduled for later in March 2012. Dr. Karovska's observations will be a followup investigation of the central region of CH Cyg and its jet that was discovered a couple of years ago. AAVSO observations are requested in order to monitor the state of the system and correlate with the satellite observations.
March 3, 2012: Observer S. O'Connor reported late last week that the symbiotic stars V4018 Sgr, CH Cyg, and V2523 Oph all appeared to be in outburst or brighter than normal. He reports: V4018 Sgr at V=11.59 on JD 2455981.021 (2012 Feb 23.521); CH Cyg at V=7.30 on 2455982.976 (Feb 25.476); and V2523 Oph at V=11.67 on 2455981.0 (Feb 23.5). Other more recent visual observations of CH Cyg by G. Holmberg (vis=7.6 on 2455983.4993) and D. Barrett (vis=7.4 on 2455985.6013) confirm the star is well above magnitude 8.0 at this time.
Approximate wavelengths for filters accepted for the AAVSO International Database
The filters listed below are used in the AAVSO International Database. For your reference, the approximate effective wavelength is given as well as the Full Width Half Maximum. These filters may be used when submitting observations to the AAVSO via WebObs.
The following charts and sequences have been revised since the last update September 29, 2011. This batch of updates includes many stars from the YSO Section Observing Program, as well as stars visible only from the southern hemisphere.