Tough eclipsing variable

Affiliation
American Association of Variable Star Observers (AAVSO)
Mon, 04/02/2018 - 14:35

Hi everyone,

I have found a new variable through blue stars survey (B-V <0.15) with data mining. It became very problematic and I'm asking for your help in analysis.

This is the star I'm talking about:

https://asas-sn.osu.edu/light_curves/4d8ceb5a-97ac-4989-b7be-ebe368f1a5…

https://wasp.cerit-sc.cz/komar/?object=1SWASP+J215155.31%2B331941.5

Unfortunately, the star is saturated in ASAS-SN data and not really much can be extracted from there. First of all, it's an eclipsing binary (or maybe trinary?) where a few minima don't look saturated - they can be useful to calculate period more precisely, maybe good enough to shift CV to V values too. Mostly we will need SuperWASP data.

Periodogram failed to find the right period, so I had to find it manually. And the only one I managed to get is 6.029974 days, but this is not perfect. Two shifted minima with different lengths, depths and shapes are overlapping, also we have maximum level measurements during them. I got only the real shape for them. I would say this could be an eccentric eclipsing binary with twice longer period. This always worked. But this time, it does not. With x2 and x4, light curve parts from two eclipses are still overlapping (and keep splitting to 0.25, 0.75 etc.) that means there must be some additional mechanism.

I would like some of your help to determine the real period or find solution of the problem. It's a double variable - this is also a DSCT with a period around 0.09 days, possibly also multiperiodic (I see different amplitudes through time, but I haven't calculated it yet). This is not a problem, because for now I'm trying to figure out what's going on with eclipses. Initially it's EA+DSCT, but who knows - maybe it's an eclipsing trinary. Rather not an EA+EW, because of P=0.09d's amplitude changes.

Here's a direct CSV link for SuperWASP measurements:

https://wasp.cerit-sc.cz/json?type=CSV&object=1SWASP+J215155.31%2B33194…

Regards,

Gabriel Murawski

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Affiliation
American Association of Variable Star Observers (AAVSO)
Got the answer. I had to

Got the answer. I had to multiply the period with factor not 2, not 4, not 8, but 7. It's actually a highly eccentric binary with secondary eclipse at phase of ~0.13.