[vsnet-alert 25617] V3721 Oph (= ASASSN-18ey, MAXI J1820+070) brightening by 1 magnitude

[Patrick Schmeer pasc1312-aavso@yahoo.de via vsnet-alert]

V3721 Ophiuchi
https://www.aavso.org/vsx/index.php?view=detail.top&oid=608515
 
"XB-NEWS detects a new outburst from the black hole
X-ray binary MAXI J1820+070" (ATel #14492):
https://www.astronomerstelegram.org/?read=14492
A brightening from V=18.82 on 2021 March 7 to
V=17.72 on March 27 is reported.
 
I have been following this variable on the Lasair web page
https://lasair.roe.ac.uk/object/ZTF18abjkrup/
The brightening can be seen in the latest ZTF images, but
unfortunately most of the 'apparent magnitude' data there
are not useful (at least for me).
 
AAVSO data:
https://app.aavso.org/webobs/results/?star=V3721+Oph
 
Gaia Photometric Science Alerts data:
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia18asi/
 
Recent ASAS-SN Sky Patrol data ("contaminated"):
https://asas-sn.osu.edu/sky-patrol/coordinate/3b577456-15bc-4100-95c7-0e06b7fd4c49
 
Clear skies,
Patrick
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References:
All-Sky Automated Survey for Supernovae (ASAS-SN) Sky Patrol:
- Shappee et al., 2014ApJ...788...48S
- Kochanek et al., 2017PASP..129j4502K
Lasair:
- Smith et al., 2019RNAAS...3...26S
Zwicky Transient Facility (ZTF):
- Masci et al., 2019PASP..131a8003M