ATO J055.6444+50.2662 = ZTF J034234.65+501558.8 (BY - 20.14 d.) = ASASSN-V J034234.63+501558.9 (YSO - 20.04 d.)

https://www.aavso.org/vsx/index.php?view=detail.top&oid=683600

What can this be? Large amplitude, certainly not a BY.
Infrared excess. But what type of YSO could have such periodic variability?

https://www.aavso.org/vsx_docs/683600/3635/2MASS%20J03423464%2B5015587%20light%20curve.png
https://www.aavso.org/vsx_docs/683600/3635/2MASS%20J03423464%2B5015587%20phase%20plot.png
http://variables.cn:88/lcz.php?Period=&SourceID=74435
https://asas-sn.osu.edu/variables/AP1617658

(ZTF and ASAS-SN magnitudes contaminated by the 14.4 mag companion).

Cheers,
Sebastian

-- 
Sebastian Otero
VSX Team
American Association of Variable Star Observers

“The mission of the AAVSO is to enable anyone, anywhere,
to participate in scientific discovery through variable star astronomy”

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