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26 Carbon stars in Andromeda

3 weeks 6 days ago #107582 by flt158
26 Carbon stars in Andromeda was created by flt158
Hello everyone.
I reckon it is about time I listed the 26 carbon stars I have observed within the confines of Andromeda over the last 2 and a bit years.
All but one is fainter than 12.5 in magnitude.
As you all probably know I do own a William Optics 158 mm f/7 apochromatic refractor.
I do have a certain amount of light pollution in my back yard but it is not too bad.
From left to right I start with the star's designation, followed by its magnitude, the date I first observed it, the minimum magnification and the colour.

1. SU Andromedae: 8.0, 1/10/16, 40X, good orange.
2. VX Andromedae: 8.0, 10/10/16, 40X, strong red.
3. AQ Andromedae: 10.0, 29/12/16, 40X, fine orange.
4. HIP 4252: 8.6, 29/12/16, 40X, very slight orange.
5. UY Andromedae: 10.0, 13/01/17, 40X, strong red.
6. ST Andromedae: 10.0, 20/01/17, 40X, orange / red.
7. VY Andromedae: 9.8, 25/11/17, 40X, orange.
8. EW Andromedae: 10.0, 8/12/17, 40X, decent orange.
9. HD 218851: 9.9, 6/01/18, 112X, fairly decent red.
10. EU Andromedae: 10.4, 18/01/18, 112X, dim and red.
11. EV Andromedae: 10.6, 1/02/18, 40X, dim rich orange.
12. TYC 3639-2155-1: 11.2, 6/02/18, 225X, dim and red.
13. HO Andromedae: 9.7, 9/02/18, 40X, good orange.
14. TYC 2262-936-1: 10.2, 20/02/18, 140X, orange.
15. KL Andromedae: 10.8, 6/03/18, 112X, good dim orange.
16. TYC 3302-332-1: 10.7, 8/03/18, 112X, rich orange.
17. V0421 Andromedae: 11.3, 8/03/18, 167X, extremely dim red.
18. TYC 3303-1082-1: 10.2, 19/03/18, 112X, lovely dim orange.
19. LEE 356: 9.6, 16/10/18, 112X, dim but good orange.
20. TYC 3636-1782,: 12.1, 26/10/18, 167X, orange.
22. NC 4: 9.6, 26/10/18, 225X, good strong orange
23. TYC 3281-2203: 11.3, 29/10/18, 167X, dim and orange.
24. C* 3227: 12.5, 10/11/18, 225X, very dim red.
25. C* 95: 10.4, 3/12/18, 112X, good orange.
26. Case 717: 13.2, 1/02/19, 320X, extremely faint orange (inverted vision only).

That last one (Case 717) is the faintest star I have ever observed. Guide 9.1 thinks its magnitude ought to be 11.7. But it is very clearly far dimmer than that. My 3.5 mm Nagler picked it up for me but only by inverted vision.

By the way, my favourite carbon star in Andromedae is the 2nd one: VX Andromedae. It is so intense in its colour.

And finally, there is a real thrill if any of you observe NC 4.There is an optical companion 3UC 280-021968 whose magnitude is 11.7. The separation is 10" from NC 4. I could see both stars at 225X.

I should also say that if these designations don't make sense to you I can introduce you to some alternatives. Just ask!

Thank you for reading.

Contributions are very welcome.

Clear skies from Aubrey.
The following user(s) said Thank You: lunartic, mariosi

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3 weeks 3 days ago #107595 by Mike
Replied by Mike on topic 26 Carbon stars in Andromeda
Thank you very much Aubrey for a most interesting synopsis of observations of Carbon Stars over the last two years. About two years ago I managed to image VX Andromedae, hope you like the image.

Carbon Star VX Andromedae

Andromedae VX (HD 1546 / HIP 1593) is a variable star in the constellation of
Andromeda. It is located at an approximate distance of 1825 light years from
the Solar System.
The carbon-oxygen ratio of Andromedae VX is remarkably high.
Its surface temperatureis approximately 2510 K Its bolometric luminosity is 4800 times solar
luminosity. The measure of the angular diameter in K band is 6.75 +/- 0.6
milliarcseconds leads to about 400 times larger than the actual diameter of the
Sun, only approximate value given the uncertainty in the distance at which it
is located. VX Andromedae brightness varies between apparent magnitude +7.5 to
+9.7 over a period of 369 days.

R-Bessell PhotometricFilter: 10 seconds x11 exposures, flat fielded, aligned and median combined
G-Bessell PhotometricFilter: 20 seconds x11 exposures, flat fielded, aligned and median combined
B-Bessell PhotometricFilter: 45 seconds x11 exposures, flat fielded, aligned and median combined
B-V-R folder images werethen aligned and stacked to give Master B, V and R images; these were then
colour combined in CCDSoft v5

CCD OperatingTemperature: -37 Degrees Centigrade
Field of View: 46 x 37arcmins
Pixel Array: 1280 x 1024
Pixel Size: 16um x 16 um
Plate Scale: 2.17arcsec/pixel
0.2-m SCT+SBIG STL 1301ECCD
f/ratio: 7.6
Date: 05th March 2016
 
Link:
www.facebook.com/pg/cherryvalleyobservat...m_id=425260794562118

Mike
  

I83 Cherryvalley Observatory

After one look at this planet any visitor from outer space would say; "I WANT TO SEE THE MANAGER".
The following user(s) said Thank You: flt158

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3 weeks 3 days ago - 3 weeks 2 days ago #107597 by flt158
Replied by flt158 on topic 26 Carbon stars in Andromeda
That is amazing, Mike!
Thank you for providing us with all the additional information regarding VX Andromedae.
It is extraordinary that the star is 4800 times more luminous than our Sun.
and that it has a lot more carbon and oxygen than the average star.
Thank you for providing the piece of information that VX And is 400 times the diameter of the Sun.
Imagine approaching it in a spacecraft seeing it grow in size.

Thank you, indeed, for helping us in understanding such a wondrous star.

As I don't have Facebook, I cannot delve deeper into your image.
But I do thank you all the same, Mike. 

Clear skies from Aubrey.

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