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THE ASTRONOMER Electronic Circular No 3689      2022 Mar 17 15.58UT
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
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BRIGHTENING Of MRK 421

Alessandro Marchini (Astronomical Observatory, Department
of Physical Sciences) reports on ATEL #15276 that the nearby blazar Mrk 421 

(RA: 11 04 27.31 Dec: +38 12 31.80 J2000.0)

has been progressively brightening in the opticalband in the last weeks, as
indicated by the monitoring performed in the context of our joint program of
blazar observations. The program is carried on with the 0.3m telescope at
the Astronomical Observatory of the University of Siena (K54) and with the
0.53 m telescope at Montarrenti Observatory (C88), both in Siena (Italy).

The following table reports our last V and R (Johnson-Cousins) measurements:

Civil Date(UT) Mag (dMag) - Observatory </br>
2022 Mar. 04.96  V= 12.89 (0.01) - Montarrenti</br>
2022 Mar. 05.77  V= 12.83 (0.01) - Siena Univ.</br>
2022 Mar. 08.79  V= 12.71 (0.01) - Siena Univ.</br>
2022 Mar. 09.78  V= 12.64 (0.01) - Siena Univ.</br>
2022 Mar. 10.80  V= 12.60 (0.01) - Siena Univ.</br>
2022 Mar. 12.97  V= 12.48 (0.01) - Siena Univ.</br></br> 

These measurements were obtained using the photometric sequence made
available by the WEBT Collaboration

http://www.oato.inaf.it/blazars/webt/gasp/fc/1101fc.html">http://www.oato.in
af.it/blazars/webt/gasp/fc/1101fc.html</A>)

Please send estimates/measures to Chris Jones of TA VS column.

Guy M Hurst

