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Vend S934: a possible bright (12.5-13.0mag) CV candidate in Cygnus?

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FRF
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Vend S934: a possible bright (12.5-13.0mag) CV candidate in Cygnus?

Update: no bright object at the given position on CCD images made by Vikrant Kumar Agnihotri at March 16.9358 UT.

 

 

Dear Friends,

I've found a possible CV candidate (Vend S934 interim name) on my CH Cyg images made 2018 March 15.2033 UT at the following preliminary position:

19:22:52.13 +53:36:19.8 (J2000.)

The brightness of Vend S934 measured by VaST was 12.4TG (maybe a bit fainter). Unfortunately this object was quite close to the magnitude limit, thus I'm not 100% sure it was a real object. There was nothing visible on my reference images take on 15 September 2017 with a limit around 14.5 (or fainter).

There is a ~18.5 mag blue star only 8.5" from this position:

USNO A2.0 1425-09651911

19 22 51.98 +53 36 11.5 (J2000.0)

Taking into account that the astrometry might be not perfect since Vend S934 lies near the edge of my DSLR images, if it's a real object, it might be an outburst of this 18.5 mag star, which is also a GAIA source.

The ASAS-SN light curve for the position of this blue star show several short outburst:
https://asas-sn.osu.edu/light_curves/7d3ce0f4-4d9d-4749-af2b-79309829b433

There is a question however whether it's a real light curve of a dwarf nova or the "outbursts" are just an artifact caused by a 9th magnitudes star 1.2' from this position.

Unturtunately tonight there was raining both in Hungary and at the iTelescope.net facility in Spain. The sky was cloudy at the site of one of my friends in India, and the roof of New Mexico facility of iTelescope net is closed (probably because of the strong wind), thus I was not able to make confirmatory images.

Therefore I would like to ask anyone to make a follow-up observation in order to confirm whether it was a real outburst of this 18.5 mag blue star.

Thanx for your efforts,

Robert Fidrich
HAA/VSS
Vendégcsillag-kereső (Guest Star Hunter) team

 

FRF
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~10' distance from the galaxy NGC 6798

The star is located ~10' from the galaxy NGC 6798.

Sebastian Otero
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Hi Robert,

Hi Robert,

>>> The ASAS-SN light curve for the position of this blue star show several short outburst:
https://asas-sn.osu.edu/light_curves/7d3ce0f4-4d9d-4749-af2b-79309829b433

There is a question however whether it's a real light curve or a dwarf nova or the "outbursts" are just an artifact caused by a 9th magnitudes star 1.2" from this position. <<<

You meant 1.2 arc minutes, not arcseconds. Anyway, probably light contamination comes from TYC 3921-674-1 which is 31" away and has V= 11.4.

There is another uncatalogued dot at ~19 22 46.6 +53 18 16 in your image.
Another one at ~19 22 22.3 +53 29 56.

Anyway, confirmation by someone else is always welcomed!

Cheers,
Sebastian

FRF
FRF's picture
1.2 arcmin

Hi Sebastian,
Yes, I wanted to write 1.2' (arcmin). Now corrected.

>> TYC 3921-674-1 which is 31" away and has V= 11.4. <<

I assume you wanted to write 31' (arcmin)....

The two other uncatalogued spots you mentioned are hot pixels.

Best,

Robert

Sebastian Otero
Sebastian Otero's picture
31"

> TYC 3921-674-1 which is 31" away and has V= 11.4. <<

>>> I assume you wanted to write 31' (arcmin)....

No, 31 arc seconds.

FRF
FRF's picture
re: 31"

Oh, indeed. For the first look 31" seemed too small distance, but yes, it's half of the distance of the 9th mag star. I hope my friend in India can observe this field tonight.

FRF
FRF's picture
No bright object tonight

On CCD images made by Vikrant Kumar Agnihotri at March 16.9358 UT there is no bright object at the given position.
The blue star USNO A2.0 1425-09651911 seems to be in quiescence near 18-18.5 mag.

Robert

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