Eclipsing binary?

[firejuggler]

it look like 3 event to me, but maybe i'm too influenced by planethunter.org scale.
The event at 1.0 is the one taking one hour, right?

[xilman]

Originally Posted by firejuggler

it look like 3 event to me, but maybe i'm too influenced by planethunter.org scale.
The "event at 1.0 is the one taking one hour, right?

The phase curve is repeated so that you can follow it through the 1.0 through 0.0 transition after an orbit is complete.

The primary eclipse is at about 0.8 (and so also at 1.8) and the secondary at about 0.3 (and so at 1.3).

[VictordeHolland]

Originally Posted by firejuggler

it look like 3 event to me, but maybe i'm too influenced by planethunter.org scale.
The event at 1.0 is the one taking one hour, right?

There are 3 'events' in a eclipsing binary:
1. Both can be seen side by side (max Mag)
2. Brighter star eclipses the fainter star (small dip in Mag)

3. Fainter start eclipses the brighter star (bigger dip in Mag)


The way I understand the graph is: X-axis 1.0 corresponds to one full period (of 0.2305 days) 2.0 of 2 periods etc. So 0.2 is about an hour.

[Spherical Cow]

Originally Posted by xilman

The phase curve is repeated so that you can follow it through the 1.0 through 0.0 transition after an orbit is complete.

Ah- I misunderstood at first, and was amazed at the repeatability of the measurements in what I thought was the next eclipse cycle. Good way to show this though. Very neat result.

Norm

[fivemack]

Originally Posted by xilman

Looks very much like an eclipsing binary with a primary eclipse of ~ 0.025 mag, a secondary of 0.01 mag and a period of 0.2305 days. The attached image is the phase plot folded at the assumed period and smoothed into bins of size 0.005. Something over 5000 measurements into that plot so each bin is the average of about 25. The secondary minimum is barely visible in the noise of the unsmoothed data.

Nice work! And 25mmag is well under the noise threshold for the all-sky survey people, so I suspect this is a new discovery! Which telescope are you using for the observations?

That's a convenient period (just under six hours), and if you've got it to four significant figures it sounds as if you could predict a good time to watch for the next eclipse.

Do you have any idea what colour the object is, and is there a sign of contaminating light from a third object in the aperture?

[xilman]

Originally Posted by fivemack

Nice work! And 25mmag is well under the noise threshold for the all-sky survey people, so I suspect this is a new discovery! Which telescope are you using for the observations?

That's a convenient period (just under six hours), and if you've got it to four significant figures it sounds as if you could predict a good time to watch for the next eclipse.

Do you have any idea what colour the object is, and is there a sign of contaminating light from a third object in the aperture?

The telescope is a 0.5m Newtonian operated robotically from the UK though it is physically located in my property on La Palma.

We've 46 days of data analyzed now (195 periods) so perhaps four figures is over-egging it but three should be good.

No sign of any contamination from stars brighter than 18th magnitude according to Gaia. I can't find the spectral type of the primary (TYC 444-2670-1) but guess its a late F dwarf based on the Gaia photometry.

[fivemack]

Originally Posted by xilman

The telescope is a 0.5m Newtonian operated robotically from the UK though it is physically located in my property on La Palma.

We've 46 days of data analyzed now (195 periods) so perhaps four figures is over-egging it but three should be good.

No sign of any contamination from stars brighter than 18th magnitude according to Gaia. I can't find the spectral type of the primary (TYC 444-2670-1) but guess its a late F dwarf based on the Gaia photometry.

Ah, so the primary is larger diameter and much brighter per-unit-area than the secondary, so the dip from the secondary blocking out parts of the disc of the primary is deeper than the dip from the primary blocking out the whole secondary. That makes a lot of sense - I had somehow got 'pair of M dwarfs' stuck in my head and couldn't understand why both the eclipses were so shallow without assuming a lot of third light.

[Spherical Cow]

Just curious- Have you been able to acquire any more data on this project? Is it holding up as an eclipse?

Norm

[xilman]

Originally Posted by Spherical Cow

Just curious- Have you been able to acquire any more data on this project? Is it holding up as an eclipse?

Norm

It's in the AAVSO VSX database now and so, TBH, I've rather lost interest.

[Uncwilly]

Originally Posted by xilman

It's in the AAVSO VSX database now and so, TBH, I've rather lost interest.

Is it in there because of your efforts in particular?

[xilman]

Originally Posted by Uncwilly

Is it in there because of your efforts in particular?

Almost entirely my efforts, with contributions from the AAVSO people of course.