[vsnet-alert 25633] ZTF21aaoiaer (= ASASSN-21cv) second rebrightening (Apr. 2)

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

 ZTF21aaoiaer = ASASSN-21cv (UGWZ:/UGSU:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=2215599
 
ZTF light curve, data, and images (via Lasair):
https://lasair.roe.ac.uk/object/ZTF21aaoiaer/
 
Recent ASAS-SN Sky Patrol light curve and data ("contaminated"):
https://asas-sn.osu.edu/sky-patrol/coordinate/0cee2b8e-26ae-4627-86d6-4f84bc9b610a
 
The first rebrightening was observed on 2021 March 28
(also noticed in ATLAS Forced Photometry data).
 
Follow-up observations are encouraged (no time-resolved
photometry results have yet been reported).

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
Asteroid Terrestrial-impact Last Alert System (ATLAS):
- Tonry et al., 2018PASP..130f4505T
- Heinze et al., 2018AJ....156..241H
Lasair:
- Smith et al., 2019RNAAS...3...26S
Zwicky Transient Facility (ZTF):
- Masci et al., 2019PASP..131a8003M
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     Am Sonntag, 28. März 2021, 10:38:50 MESZ hat Patrick Schmeer pasc1312-aavso at yahoo.de via vsnet-alert <vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp> Folgendes geschrieben:  
 
  ZTF21aaoiaer = ASASSN-21cv (UGWZ:/UGSU:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=2215599
 
ZTF light curve, data, and images (via Lasair):
https://lasair.roe.ac.uk/object/ZTF21aaoiaer/
 
Recent ASAS-SN Sky Patrol light curve and data ("contaminated"):
https://asas-sn.osu.edu/sky-patrol/coordinate/6f722cad-2b14-4ec2-886d-dcb61233be4f
 
The long outburst (superoutburst?) started on 2021 March 3 or 4.
The possible rebrightening began on March 27 or 28.
 
Follow-up observations are encouraged (no time-resolved
photometry results have yet been reported).
 
Clear skies,
Patrick
-------
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
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    Am Sonntag, 7. März 2021, 07:52:31 MEZ hat Kenta TAGUCHI <kentagch at kusastro.kyoto-u.ac.jp> Folgendes geschrieben:  
 
  From the public ZTF data, I've just found ZTF21aaoiaer out as a CV 
candidate being in a large-amplitude (> ~7 mag) outburst.
Its position is (RA, Dec) = (07:28:18.595, -04:51:5.209).
Lasair: https://lasair.roe.ac.uk/object/ZTF21aaoiaer/
Alerce: https://alerce.online/object/ZTF21aaoiaer

There are no counterpart and no detections by PS1 (limiting mag ~ 23).
No known minor planets are found by the Minor Planet Checker 
(https://www.minorplanetcenter.net/cgi-bin/checkmp.cgi).

Last non-detections by ZTF:
g > 20.5 on 2021-03-03.21 UT
r > 19.6 on 2021-03-03.29 UT

First detections by ZTF:
r = 15.6 on 2021-03-07.15
g = 15.4 on 2021-03-07.19

This is the result of ASAS-SN Sky Patrol: 
https://asas-sn.osu.edu/sky-patrol/coordinate/573a3f4d-789c-4a46-9dbb-b2574f7b2ec2
Please be careful that it has been contaminated by another star (g ~ 15) 
nearby.
However, the result says g = 14.2 on 2021-03-04.27, which is a bit 
brighter for the contaminating star.
(ZTF21aaoiaer may have already outbursted then, and the sky patrol might 
report the magnitude summing up the flux of it and its contaminating star).

Best Regards,
Kenta
________________________________________________________________
  田口 健太　(TAGUCHI, Kenta)
  京都大学大学院理学研究科宇宙物理学教室
  (Department of Astronomy, Graduate School of Science, Kyoto University)
kentagch at kusastro.kyoto-u.ac.jp <mailto:kentagch at kusastro.kyoto-u.ac.jp>
  09090536980