Neptune and .. whats the red one ?

[powerlord]

I took this one at 3.30am on saturday at around 5000mm (C9.25+2.2 barlow).

neptune is the middle one I assume. triton the light nearby dot ? but can someone tell me what is the red one ?

none of my planetariums have anything showing there ? In fact according to say Skyt Safari there are no other stars in the POV with a magnitude more  than 19, which is clearly mince as there are loads here, and this is just a stack of 40 .5 second exposures.

[Nik271]

Stellarium suggests its a 13 magnitude star, B-V index 1.17 so it will show red on images. Strangely the web version of Stellarium gives a magnitude 10 which fits your image as it is much brighter than Triton. Your image seems to be flipped east to west by the way.

 

[Xilman]

43 minutes ago, Nik271 said:

Stellarium suggests its a 13 magnitude star, B-V index 1.17 so it will show red on images. Strangely the web version of Stellarium gives a magnitude 10 which fits your image as it is much brighter than Triton. Your image seems to be flipped east to west by the way.

You have answered this question nicely. I will add my personal experience: Aladin Lite ( https://aladin.u-strasbg.fr/AladinLite/ ) is a superb way of identifying background stars. Easy to use, goes down to magnitude 21 or so and has immediate access to a number of catalogues, including Gaia EDR3.

In particular, that star is IRAS 23389-0336 (J, H, K mags 6.042, 5.141. 4.689 resp  and so very red) and Gaia EDR3 2639366843454632064 (b, g, r mags 13.395341, 10.539508, 9.055428 again confirming its redness). Finding out much more about this star is only a few clicks away.  Incidentally there is a galaxy, LEDA 107073, nearby but at around 17-18th magnitude it is too faint for you to have picked up on this occasion.  Here is a screen shot from Aladin-Lite showing the star in question, LEDA 1070 and a couple of even fainter galaxies.  The purple cross indicates the approximate position of Neptune.

I use Aladin-Lite all the time when chasing faint moving objects and those objects which are new to me.

 

 

Edited August 21, 2022 by Xilman
Change DR3 to EDR3

[Xilman]

1 hour ago, powerlord said:

I took this one at 3.30am on saturday at around 5000mm (C9.25+2.2 barlow).

neptune is the middle one I assume. triton the light nearby dot ? but can someone tell me what is the red one ?

none of my planetariums have anything showing there ? In fact according to say Skyt Safari there are no other stars in the POV with a magnitude more  than 19, which is clearly mince as there are loads here, and this is just a stack of 40 .5 second exposures.

 

If you have more exposures to stack there is a possibility that you may be able discern LEDA 107073

[Laurieast]

Stellarium with Digital Sky Survey on. 

[powerlord]

Thanks all. Pity none of the sources seem to mention a distance.

Stu

[Laurieast]

From http://simbad.u-strasbg.fr/simbad/sim-id?Ident=IRAS 23389-0336

Parallaxes (mas):0.3835 [0.0868] A

https://www.translatorscafe.com/unit-converter/en-US/calculator/parallax-distance/

8.5 light-year? or 37.58 light-year

I am guessing that's how you do it. 

Somebody will know...

Edited August 21, 2022 by Laurieast

[Xilman]

7 hours ago, powerlord said:

Thanks all. Pity none of the sources seem to mention a distance.

Stu

Distance to what?

Gaia EDR3 gives a parallax for the star from which computing the distance is straightforward.

Distance to the galaxy can be computed from its red shift. Left as an exercise for the reader ...

[Xilman]

5 hours ago, Laurieast said:

From http://simbad.u-strasbg.fr/simbad/sim-id?Ident=IRAS 23389-0336

Parallaxes (mas):0.3835 [0.0868] A

https://www.translatorscafe.com/unit-converter/en-US/calculator/parallax-distance/

8.5 light-year? or 37.58 light-year

I am guessing that's how you do it. 

Somebody will know...

Not entirely sure of that. 10 parsec is about 32.6 light years.

Consulting Gaia EDR the parallax is 0.3835 arcsec (as given above).  1/0.3835 is 2.608 parsecs, or 8.505 light years.

Your first number is correct, IOW, but the second?

A nearby red dwarf in any case.

[Laurieast]

37 minutes ago, Xilman said:

Consulting Gaia EDR the parallax is 0.3835 arcsec (as given above).  1/0.3835 is 2.608 parsecs, or 8.505 light years.

Thanks. 

What is the second number? the  [0.0868] ?

[Xilman]

2 hours ago, Laurieast said:

Thanks. 

What is the second number? the  [0.0868] ?

I believe it is the estimated uncertainty in the first quantity.  I may be wrong.

[Ratlet]

I like the fact you imaged one of the solar systems larger planets and one of the smallest class of stars so close together.

[Xilman]

On 21/08/2022 at 10:33, powerlord said:

I took this one at 3.30am on saturday at around 5000mm (C9.25+2.2 barlow).

neptune is the middle one I assume. triton the light nearby dot ? but can someone tell me what is the red one ?

none of my planetariums have anything showing there ? In fact according to say Skyt Safari there are no other stars in the POV with a magnitude more  than 19, which is clearly mince as there are loads here, and this is just a stack of 40 .5 second exposures.

 

One red one, one white one, and one which may be Triton, and ...

 

Sorry, the opportunity was too good to pass up.