April 24, 2018: Drs. Jaroslav Merc and Rudolf Gális (both of the Pavel Jozef Šafárik University (Slovakia)), on behalf of their scientific team, have requested AAVSO assistance in observing the symbiotic variable AG Dra as a follow-up to spectroscopic observations and in order to monitor the system in its current outburst, which began in early April.
April 11, 2018: Dr. Gregory Sivakoff (University of Alberta), on behalf of a large number of collaborators, has requested AAVSO observers' assistance in monitoring the outbursting black hole X-ray binary ASASSN-18ey = MAXI J1820+070 in support of a multiwavelength "blitz" campaign taking place tonight and into tomorrow.
Event: Nova in Sagittarius - N Sgr 2018 = PNV J18040967-1803581
Discovered independently by:
- Tadashi Kojima (Tsumagoi, Gunma-ken, Japan; reported to CBAT by S. Nakano)
- Hideo Nishimura (Kakegawa, Shizuoka-ken, Japan; reported to CBAT by S. Nakano)
- Yuji Nakamura (Kameyama, Mie, Japan; reported to CBAT by M. Soma)
AAVSO Newsletter Number 76 (April 2018) has been published and is online. AAVSO members may download a high- or low-resolution version from here. This issue will be available to non-members when the next issue (Number 77, July 2018) is published.
S Cas is an interesting Mira star that has been observed by AAVSO observers and members since 1865. Over 21,000 observations are in the AID from over 700 different observers as can be seen in the light curve shown below which displays all observations in the AID. It is one of the Legacy LPV Program stars. It is a star with good observational coverage, being visible almost year round with minimal seasonal gaps.
March 29, 2018: Further to AAVSO Alert Notice 618, Anna Pala (Ph.D. candidate, University of Warwick) informs us that the date and time of the HST observations planned for the faint polar cataclysmic variable SDSS J153817.35+512338.0 have been set for
The AAVSO Annual Report for 2016-2017 has been published and is online. Both a high-resolution and a low-resolution version are available at https://www.aavso.org/annual-report.
Thanks to observer and volunteer, Alexandre Amorim from Brazil, we now have available a Portuguese translation of the AAVSO Solar Observing Guide available for download (free-of-charge). This helpful Guide explains how to observe and report sunspot counts in a safe and scientifically useful manner.
