5
$\begingroup$

From NASA September 16 Hubble studies a spectacular spiral:

enter image description here

There are 4 really bright blue stars in this photo of galaxy NGC 1961. For those who can't see them very clearly, you can focus on the furthest top right one.

Is it a type O star as its blue? They seem much brighter than any other stars and are further away from the galaxy too.

Improve this question
$\endgroup$

1 Answer 1

Reset to default
6
$\begingroup$

This is almost certainly a foreground star.

It appears in the Gaia database as source 485036192954347136 and is given a parallax of 0.49 milliarcseconds, corresponding to a distance of 2000 parsecs (6500 light years). A long way, but still firmly in the milkyway.

It is not part of the NGC 1961

I can't find a spectral type for this object, but in the DSS images it is brighter in the red filter than in the blue one, suggesting it is a more likely to be a (perhaps) F or A type dwarf than a very powerful O type star. That would be consistent with its apparent magnitude and distance too. (2Mass gives a magnitude of about 13.5, suggesting an absolute magnitude of about 2)

Improve this answer
$\endgroup$
2
  • $\begingroup$ "This is almost certainly a foreground star", how about the other similar looking stars closer to the galaxy? $\endgroup$
    – DialFrost
    Sep 25, 2022 at 7:22
  • 1
    $\begingroup$ Yes, those too, for the same reasons. You can check on Aladin for the parallax of each source. $\endgroup$
    – James K
    Sep 25, 2022 at 7:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .