-------------------------------------------------------------------
THE ASTRONOMER Electronic Circular No 3707      2022 May 22 20.03UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.ORG.UK             Backup: guy_hurst@hotmail.com
WORLD WIDE WEB                         http://www.theastronomer.org
-------------------------------------------------------------------
MRK421 OPTICAL

Roberto Nesci (INAF/IAPS) reports on ATEL #15390:


After the announcement in ATel #15389 of a flaring activity in Gamma rays of
Mrk 421 I observed the source on May 21 2021 with the 30cm telescope of the
Foligno Observatory (K56) in the B and V (Johnson) bands. 

Four nearby comparison stars were taken from the UCAC4 catalog and aperture
photometry was made with IRAF/apphot using a 6 arcsec radius. Mrk412 was
detected at B=13.54 +-0.03 and V=13.10 +-0.04. 

Guy M Hurst

