Jump to content

Narrowband

What are these dots in M33


almcl

Recommended Posts

Been revisiting previous targets with my still-new-to-me ASI 2600 MC.

Last night was M33's turn and the extra detail that is becoming apparent compared to images from 5 years ago is throwing up all sorts of questions.

One I'd like some help with from fellow SGLrs is the detail in this heavily cropped, very quickly processed and probably over-sampled snippet.

What are the blue dots in the spirals?  Surely they can't be stars (at 3 million light years)?  And their arrangement, closely following the galaxy's spiral arms, suggests they aren't foreground objects either.  Don't think they're processing artefacts, although they might be.

Can't find any details in my usual sources on-line and wonder if anyone can point me to a good reference?

1196909454_ASbcrop.jpg.a98d85a64ebe566578ba1dc11fa25392.jpg

  • Like 1
Link to comment
Share on other sites

They can actually be stars - very hot, very big, young stars.

Such stars can have luminosity that is up to 1,000,000 times larger than our Sun.

Relative luminosity falls of with square of distance, so this sort of star will have same brightness if it is x1000 further away. Since M33 is 3.2Mly - it is like looking at a G2V star that is 3.2Kly away or 3200Ly away. That is not very far and you can easily image such star.

You can take a look at Hubble images of M33 and M31 and see individual large stars being resolved:

heic1901a.jpg

In fact - you can compare the two:

image.png.725db7b4c43255e05e7b66ce238481b5.png

image.png.3429c86341ffc5e72fd85dccf1adae6d.png

I've marked two yellow stars and in "direction" they are pointing is star forming region.

  • Like 1
Link to comment
Share on other sites

4 minutes ago, almcl said:

Thanks both!

Really blown away by seeing stars in another galaxy  - wanted it to be so but couldn't quite believe it, that's made my imaging month.

Did you image M31 recently?

Maybe you captured V1?

https://esahubble.org/images/opo1115a/

I actually identified it in amateur M31 images few times. Here it is in my M31 image:

image.png.fa00968a5191e527365ddb29700ba23d.png

Here is guide how to find it:

opo1115d.jpg

  • Like 1
Link to comment
Share on other sites

Possibly, Vlaiv.  I last did M31 with a 200 mm Canon lens this time last year.

Here's a quick 'n dirty reprocess just to show there might be something there.

AS1crop.jpg.56fc628d1e490c47742a6bf2640017c0.jpg

and a zoom in.  With strong imagination there's possibly something there:

cropzoom.jpg.48a12e23c7379324672e79e029fe0a07.jpg

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.