[vsnet-alert 23055] the black-hole binary ASASSN-18ey: rebrightening

[mkimura]

According to ATEL #12567, the black-hole binary ASASSN-18ey
began rebrightenings at least 2 days ago.
The current magnitude is ~15.5.
This object showed a very bright and long outburst in 2018,
and this rebrightening can be the best opportunity for
observing superhumps in the black-hole binary again.
(Personally I expect large-amplitude variations will appear.)
Further observations are strongly encouraged.


-------- Forwarded Message --------
Subject: 	ATel #12567
From: 	atel at astronomerstelegram.org
To: 	mkimura at kusastro.kyoto-u.ac.jp



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The Astronomer's Telegram http://www.astronomerstelegram.org

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ATEL #12567 ATEL #12567

Title: Rebrightening of ASASSN-18ey = MAXI J1820+070 Author: J. Ulowetz, 
G. Myers, J. Patterson (Center for Backyard Astrophysics)
Queries: jop at astro.columbia.edu
Posted: 12 Mar 2019; 12:11 UT
Subjects:Optical, X-ray, Binary, Black Hole, Transient

The X-ray transient ASASSN-18ey = MAXI J1820+070 (ATel #11423, #11756, 
#12128, #12157, #12534) has experienced a post-outburst "rebrightening" 
or "echo outburst". Our nightly light curves from the

Center for Backyard Astrophysics network show that the transient faded

below V=17.2 - close to quiescence - by JD 2,458,460. Scattered 
observation during JD 2458523-2458540 showed the star near V=17.7. 
During JD 2458552-2458554, the star rose rapidly from V=17.2 to V=15.4.

Such a rebrightening, long after the main outburst, warrants coverage at

all wavelengths.
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Password Certification: Jules Halpern (jules at astro.columbia.edu)
http://www.astronomerstelegram.org/?read=12567
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