eclipsing binary

Note: Text and forum links edited per request of Dr. Howell.  -  Elizabeth O. Waagen, April 21, 2023

April 13, 2023

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
 - Campaigns and Observing Reports: https://www.aavso.org/xx-oph-v5569-sgr-campaign
 - Eclipsing Binaries: https://www.aavso.org/xx-oph-v5569-sgr-campaign-01

The 2022 Eclipsing Binary Ephemeris and 2022 RR Lyrae Ephemeris are now available.

Many thanks to Gerry Samolyk for all his hard work putting these two valuable documents together!

Note: Please continue to observe ASASSN-21co to help build a long-term light curve.  -  Elizabeth O. Waagen, January 3, 2023

March 2, 2021

Note:  Please continue observations at a cadence of 1 observation per week until further notice. - Elizabeth O. Waagen, July 6, 2021

Please continue observations at a cadence of 1 observation per week at least through 2021 June 15. See the post by Principal Investigator Dariusz Kubicki in the forum threads for this campaign (URLs below).  -  Elizabeth O. Waagen, 2020 June 29

The eclipse of EE Cep has occurred but continued monitoring is requested to establish post-eclipse behavior.  - Elizabeth O. Waagen, 2020 May 21

August 17, 2017: In AAVSO Alert Notice 593 we announced a campaign on the very long period VV Cep M2Iabe+B0/2Ve binary. The amplitude of the eclipse was wrongly given as slightly under a magnitude in the V band when it is actually around 0.1 mag. This means that the VV Cep eclipse is largely undetectable visually,  and is not a good candidate for visual observations. CCD and DSLR photometry, however, are still encouraged.

Edit: The information given in this alert notice has been updated to correct eclipse depth values. Please see AAVSO Alert Notice 594

August 16, 2017: The AAVSO is requesting monitoring of the eclipse of the very bright Algol-type eclipsing binary variable VV Cep, predicted to have begun in June 2017 and to conclude in November 2019.

June 30, 2017: Dr. Octavi Fors (University of North Carolina at Chapel Hill) and colleagues have requested AAVSO observers' assistance in following up on some targets from the Evryscope survey.

June 8, 2017:  Dr. Milena Ratajczak (University of Wrocław) has requested AAVSO observers' assistance in monitoring the very bright (V = 4.23) and very unusual eclipsing binary HD 148703 (HR 6143, N Sco) during its infrequent primary and secondary eclipses scheduled for 2017 June 11 and June 14, respectively.