PSN J12355230+2755559 was discovered by L. Elenin in 2012.
It was reported as a possible supernova in the faint galaxy SDSSCGB 754.2.
It was then better described as a supernova impostor, an outburst from an LBV:
https://www.astronomerstelegram.org/?read=3865
Also in CBET 2976
http://www.cbat.eps.harvard.edu/iau/cbet/002900/CBET002976.txt
Another similar outburst was reported in June 22, 2014:
https://www.astronomerstelegram.org/?read=6303
A previous outburst is mentioned in the same ATel as having occured around February 24, 2014.
They also report SDSS J123551.86+275556.9 as the likely host galaxy.
Another outburst was detected on August 3, 2014 by Gaia.
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia16ada/
Am I the only one not understanding why these outbursts with rather fast fadings and lasting only a few days are being interpreted as LBV outbursts?
Isn't it possible that the spectroscopic features are contaminated by the background galaxy?
In 2016, Gaia detected another similar and fast outburst:
https://www.astronomerstelegram.org/?read=8755
The authors of the above ATel compared PSN J12355230+2755559 with SN 2000ch.
It is present in Pan-STARRS1 (g= 19.0; r= 19.4).
And in SDSS (g= 18.2; r= 18.1).
Gaia shows ~1 mag. variability around G= 20.
ZTF also shows rapid brightenings:
https://lasair.roe.ac.uk/object/ZTF17aaapufz/
So, can it be a foreground dwarf nova? (Gaia shows a negative parallax, but I have seen completely spurious parallax when objects are embedded in nebulosity).
Can an LBV actually show these rapid large amplitude brightenings?
Cheers,
Sebastian