The Mystery Star: HAT-P-22B/ISC 50750

[ProtoJeb21]

If you may recall, my first official IRVEES observations targeted the star HAT-P-22 and its Hot Jupiter exoplanet. Those observations showed something I wasn't aware of before: a binary companion to HAT-P-22. Or so it seems. This star has very little information about it. In fact, I can't find anything relating to it! So for now, I've given it an IRVEES Star Catalog designation of ISC 50750. The digits to the designation come from the star's declination of about 50* 07' 50".

If this is an actual binary companion to HAT-P-22, then it will be renamed HAT-P-22B. But if this is an optical binary, it will keep its current ISC designation. 

I plan on doing some SCIENCE! with this star. One of the keys to figuring out if this is a true binary system is to see if ISC 50750 has a smaller spectral type than HAT-P-22. The primary has a spectral type of about G5V. If ISC 50750 has an ST of G9V/K0V or lower, then it may be a companion to HAT-P-22. Distance to this star will also have to be found.

Regular analysis of ISC 50750 is not all I'm planning. I might want to search for planets around this star, since it is such a convenient target. ISC 50750 is about magnitude 10 and is not too hard to separate from HAT-P-22. Also, if HAT-P-22b is't transiting, then it poses no issues to my observations of ISC 50750.

So what do you guys think? Do you know anything else about ISC 50750, or do you want me to search for transiting exoplanets around it?

Also, here's a picture of the system so you guys know what I'm talking about (HAT-P-22 is the larger star):

Edited June 18, 2016 by ProtoJeb21
I had to rename the star, because I got its declination wrong

[insert_name]

Do you get naming rights? If so name it after something from KSP.

[rudi1291]

Im actually surprised that theres nothing about it on the internet. HAT-P-22 has at least one confirmed exoplanet, it looks like (http://exoplanets.org/detail/HAT-P-22) so it should be safe to assume that it has been looked at before.

Edited June 17, 2016 by rudi1291

[cubinator]

If it's a gas giant orbiting really close, chances are the solar wind will be stripping away its atmosphere and giving it a huge, comet-like tail which would glow very brightly. Can you measure the movement of the star and potential companion to estimate its mass?

Edited June 17, 2016 by cubinator

[LordFerret]

11 hours ago, ProtoJeb21 said:

This star has very little information about it. In fact, I can't find anything relating to it!

You'll find an entry for it in Simbad. You'll also find 100+ references in various catalogs via a VizieR search ... so I'd say there's quite a bit of information out there on it.

[ProtoJeb21]

18 hours ago, insert_name said:

Do you get naming rights? If so name it after something from KSP.

Nope! It's just a temporary designation until I find out more. I do want to give HAT-P-22 and its planet actual names. Same thing with ISC 50742. However, I want to confirm if they are a binary system before naming. I just found out that HAT-P-1 is in a similar situation, with a star very near it. That star is cataloged and is confirmed to be a binary companion - the primary member at that. Why isn't that the case for ISC 50742?

11 hours ago, rudi1291 said:

Im actually surprised that theres nothing about it on the internet. HAT-P-22 has at least one confirmed exoplanet, it looks like (http://exoplanets.org/detail/HAT-P-22) so it should be safe to assume that it has been looked at before.

There's an image of it on the Exoplanet Transit Database with ISC 50742. That means that people know it exists, but I can't find anything about it.

6 hours ago, cubinator said:

If it's a gas giant orbiting really close, chances are the solar wind will be stripping away its atmosphere and giving it a huge, comet-like tail which would glow very brightly. Can you measure the movement of the star and potential companion to estimate its mass?

Radial velocity is not for the faint of heart, especially since I just started using the transit method. However, HAT-P-22b has a mass confirmed to be about 2.1 times that of Jupiter. If I do find a companion to ISC 50742, I will try to find its mass.

6 hours ago, LordFerret said:

You'll find an entry for it in Simbad. You'll also find 100+ references in various catalogs via a VizieR search ... so I'd say there's quite a bit of information out there on it.

The website isn't working for me. It might be because of the computer I'm using at the moment. I'll try on a different device. Either way, I still can't find anything about ISC 50742.

[LordFerret]

19 hours ago, ProtoJeb21 said:

IRVEES Star Catalog

Where is this catalog? I find no such animal titled as such, unless you're meaning this.

What is the source of that image you've posted? Could it be you, or whomever, gave an incorrect identifier (ISC 50742)?... I know you said it's temporary, but I find nothing, absolutely nothing on this, not even in the various databases with HAT-P-22 identified.

Have you seen Aladin's (Lite) SDSS9 color image of that same object?!? **
http://aladin.u-strasbg.fr/AladinLite/?target=HD 233731&fov=0.04&survey=P%2FSDSS9%2Fcolor

** Edit: You may have to click on the SDSS9 option in the Survey panel on the left to get the color image to load up.

Edited June 17, 2016 by LordFerret

[ProtoJeb21]

@LordFerret This is a catalogue I'm using both for stars observed for IRVEES that seem to have planes, and for uncataloged stars I want to observe with IRVEES.

I took the image myself. It was a copy of the image of HAT-P-22b during the middle of its transit (I posted the original image on "IRVEES Scientific Achievements"). I used GIMP to cut out the part with HAT-P-22 and ISC 50750, and Google Drive (specifically, Google Drawings) to label it.

I've now looked at the ALADIN images for the two stars, and they're odd. The SDSS9 image shows ISC 50750 as an orange star, but some infrared images show both stars as the same temperatures. All those images just seem to confuse me. 

[LordFerret]

Some things I've found:

Quote

"HAT-P-22b orbits the bright V = 9.732 G5 dwarf star HD 233731 on a circular orbit, with a period P = 3.212220 ± 0.000009 days, transit epoch T_c = 2454930.22001 ± 0.00025, and transit duration 0.1196 ± 0.0014 days. The host star has a mass of 0.92 ± 0.03 M _☉, radius of 1.04 ± 0.04 R _☉, effective temperature 5302 ± 80 K, and metallicity [Fe/H] = +0.24 ± 0.08. The planet has a mass of 2.147 ± 0.061 M _J and a compact radius of 1.080 ± 0.058 R _J yielding a mean density of 2.11^+0.40_{– 0.29} g cm^–3. The host star also harbors an M-dwarf companion at a wide separation." - http://iopscience.iop.org/article/10.1088/0004-637X/742/2/116/meta

 

Quote

"HAT-P-22b orbits a fairly metal-rich ([Fe/H]  =  + 0.24  ±  0.08), bright (V = 9.732), and close-by (82  ±  3 pc) star. Similar to HAT-P-20, the host star has a faint and red neighbor at 9'' separation that is co-moving with HAT-P-22 (based on the POSS plates and recent Keck/HIRES snapshots), thus they are likely to form a physical pair." - http://iopscience.iop.org/article/10.1088/0004-637X/742/2/116/meta

See also - http://iopscience.iop.org/article/10.1088/0004-637X/785/2/126/meta

Mention made here as well - http://real.mtak.hu/16367/1/Affordable spectroscopy for 1m.....pdf

In another (unrelated) article, I saw mention of a "HAT-P-22c".

 

I'll assume you've seen all this already?