M45 (close up)

[alan4908]

I wasn't entirely sure how a close up of M45 would look but I was interested in seeing if I could maximise the nebula's detail. 

I do like the resultant detail and colours of the smaller stars but I think I prefer a wider field of view. 

The image is an RGB with a synthetic Lum layer and was taken with my Esprit 150. It represents about 3 hours total integration time.

Alan

 

LIGHTS: R:25, G:14,B:49 x 120s, DARKS:30, FLATS:40, BIAS:100

[michael.h.f.wilkinson]

Superb detail!

[Stu]

You've certainly got some nice detail in the Nebula, good to see. Perhaps a mosaic?  

Interesting to see some orange stars in there, I've always thought of M45 as being exclusively hot blue/stars, but I guess these are background stars, not part of the Cluster? Lovely colours showing anyway.

[alan4908]

32 minutes ago, michael.h.f.wilkinson said:

Superb detail!

Thanks for the comment Michael 

31 minutes ago, Stu said:

You've certainly got some nice detail in the Nebula, good to see. Perhaps a mosaic?  

Interesting to see some orange stars in there, I've always thought of M45 as being exclusively hot blue/stars, but I guess these are background stars, not part of the Cluster? Lovely colours showing anyway.

Thanks Stu. Yes, I did think about a mosaic, however, I decided that I'm still in recovery from my M31 mosaic, which took ages.  

On the stars, I'm not sure if all of the non-blue ones are behind the nebula, the bright yellowish one looks like it may be in front, although I'm not sure quite how you work this out ?

[Stu]

11 minutes ago, alan4908 said:

On the stars, I'm not sure if all of the non-blue ones are behind the nebula, the bright yellowish one looks like it may be in front, although I'm not sure quite how you work this out ?

All the bright main stars are part of the cluster, but I checked the orange one HD 23463 and it is 2700 light years away, rather than around 400 for the rest of the cluster so it seems to be in the background. The one right next to it visually, HD 23479 is 'only' 500 light years away so presumably part of the cluster too, despite appearing to be a binary with the distant star. Interesting stuff  

[alan4908]

27 minutes ago, Stu said:

All the bright main stars are part of the cluster, but I checked the orange one HD 23463 and it is 2700 light years away, rather than around 400 for the rest of the cluster so it seems to be in the background. The one right next to it visually, HD 23479 is 'only' 500 light years away so presumably part of the cluster too, despite appearing to be a binary with the distant star. Interesting stuff  

Thanks Stu - yes very interesting. What is the name of the program that you used to identify the star and it's distance from Earth ?

Alan

[Stu]

1 hour ago, alan4908 said:

Thanks Stu - yes very interesting. What is the name of the program that you used to identify the star and it's distance from Earth ?

Alan

My favourite phone app....SkySafari  

[alan4908]

23 hours ago, Stu said:

All the bright main stars are part of the cluster, but I checked the orange one HD 23463 and it is 2700 light years away

Hi Stu

Since measuring star distances is new to me, I did a more investigation since it seemed a little odd, at least to me, that such a bright star (HD 23463) would be so far away (eg 2700 light years). So, I decided to use the SIMBAD database via the Aladin program which I'm informed professional astronomers use.

For the star HD23463, SIMBAD gives the following data:

HD 23463  -- Star      Parallaxes (mas):    7.56 [0.27] A   2016A&A...595A...2G       Apparently, to convert to light years you use the following formula:  d = 3260/p where p is the parallax angle, the first number (7.56).  If you plug in this data you get a distance of 431 light years eg the star is approximately the same distance as the cluster, which is very different to that predicted by SkySafari ! Apparently, the predicted parallax error measurement is contained in the square brackets, so this wouldn't explain the large distance discrepancy. The symbol A after the square brackets indicates that the data is of the highest quality.

The link to the SINBAD database is here: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD++23463&NbIdent=1

Alan

[Stu]

43 minutes ago, alan4908 said:

Hi Stu

Since measuring star distances is new to me, I did a more investigation since it seemed a little odd, at least to me, that such a bright star (HD 23463) would be so far away (eg 2700 light years). So, I decided to use the SIMBAD database via the Aladin program which I'm informed professional astronomers use.

For the star HD23463, SIMBAD gives the following data:

HD 23463  -- Star      Parallaxes (mas):    7.56 [0.27] A   2016A&A...595A...2G       Apparently, to convert to light years you use the following formula:  d = 3260/p where p is the parallax angle, the first number (7.56).  If you plug in this data you get a distance of 431 light years eg the star is approximately the same distance as the cluster, which is very different to that predicted by SkySafari ! Apparently, the predicted parallax error measurement is contained in the square brackets, so this wouldn't explain the large distance discrepancy. The symbol A after the square brackets indicates that the data is of the highest quality.

The link to the SINBAD database is here: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD++23463&NbIdent=1

Alan

 

That's interesting Alan. I don't think it is necessarily correct to question whether 'such a bright star.... would be so far away' Just as a quick example, the Trapezium stars are brighter but still around 1500 light years away. You cannot tell distance from brightness due to the huge variation in luminosity of the stars.

You may well be correct of course. Distances are tricky things to measure accurately. It seems odd to me that there would be an older orange star within a cluster of relatively new stars so I would be interested to know the correct answer.my gut feel is 'line of sight double' rather than actual binary pair.

Interesting the same discrepancy and discussion appears here after I searched  

http://www.science-bbs.com/17-astro-amateur/2551fe10594572db.htm

Does anyone know 'the truth'  

[alan4908]

10 minutes ago, Stu said:

That's interesting Alan. I don't think it is necessarily correct to question whether 'such a bright star.... would be so far away' Just as a quick example, the Trapezium stars are brighter but still around 1500 light years away. You cannot tell distance from brightness due to the huge variation in luminosity of the stars.

You may well be correct of course. Distances are tricky things to measure accurately. It seems odd to me that there would be an older orange star within a cluster of relatively new stars so I would be interested to know the correct answer.my gut feel is 'line of sight double' rather than actual binary pair.

Interesting the same discrepancy and discussion appears here after I searched  

http://www.science-bbs.com/17-astro-amateur/2551fe10594572db.htm

Does anyone know 'the truth'  

Yes, I agree, quite interesting.

Any experts out there ?

Alan

[MikeODay]

Great image and interesting discussion - thanks for sharing.

[alan4908]

9 hours ago, MikeODay said:

Great image and interesting discussion - thanks for sharing.

Thanks for the comment Mike.

Yes an interesting discussion + I have learnt how to use SIMBAD to calculate star distances from parallax measurements !

[Jannis]

Really nice image with loads of details!

Does it just look like it, or do i see loads of small fuzzy galaxies in the background?

[alan4908]

17 hours ago, Jannis said:

Really nice image with loads of details!

Does it just look like it, or do i see loads of small fuzzy galaxies in the background?

Thanks for the comment Jannis.

Well, I see very faint fuzzy's, however, I don't know what they are. If you run the image through Pixinsight's image solver then it does not pick up any confirmed galaxies.

Alan 

[Stu]

Astrometry.net is the same. It indicates IC1990 which is a bright Nebula but with no circle around it, which I guess means it is just off the image??

[alan4908]

Well, not to be defeated by the lack of fuzzy info from either Pixinsight or Astrometry.net I turned to Aladin, which is a free web based portal that allows you to query numerous astronomical databases. 

For my fuzzy hunt, I decided to plate solve the TIFF image in Maxim DL via Pinpoint, convert it to a FITS file and then let Aladin overlay my image with whatever database image I was going to query.  After a bit of clicking, I found a fuzzy match on the NASA/IPAC NED extragalactic database, I also checked the DSS optical database and sure enough it is also there.  

The fuzzy, according to NED, has the catchy name of SSTSL2 J034448.05+242513.3, which an extra galactic infrared source rather than a galaxy (see below).

Alan

Fuzzy to be investigated (crop of the image above)

NED query result