Unusual ELL or something else?

Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 04/05/2018 - 15:57

Hello everyone,

This is the time when I need your help (again). Here's a newly found variable with spectral type A0, see the attached phase plot. It shows changes of brightness in P=3.28 d. J-K= -0.02; B-V= 0.09. I have already seen something like that before and the change was a quite large. I kept that one as ELL with O'Connell effect. But this one is even more asymetric than that one. In your opinion, is it also an ELL variable or something different? I don't have any other ideas about that, something unusual (for me) like that made me think about other types. I have been trying to search for similar light curves in Google and I found one (https://ieeenitk.org/blog/space-ml/). Unfortunately they don't mention what exactly is it.

Regards,

Gabriel Murawski

EDIT: Yes, if it was ELL, phase 1.0 should be at minimum, not maximum.

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Affiliation
American Association of Variable Star Observers (AAVSO)
Unusual ELL or something else?

One of the solutions could be very unusual eclipsing binary.
Using ASAS data you can see the preliminary parameters of such a binary system.
The photometric data were fitted by Phoebe code (Prsa & Zwitter 2005, Prsa et al. 2011, Prsa
et al. 2016)
Eclipsing binary - overcontact
Epoch: 2457351.729063
Period: 3.280093
Тeff: 9330 K
Spectral type: A1
Inclination: 30 deg (partial eclipses - small delta)
Cool spot to fit distorsion of the LC (O'Connel effect)

Affiliation
American Association of Variable Star Observers (AAVSO)
Thanks! I never heard about

Thanks! I never heard about that program, I will have to take a closer look. Looks like a really good one to analyze unusual binary systems.