Is our sun part of a star cluster?

  • Thread starter Thread starter lilythmagebor
  • Start date Start date
  • Tags Tags
    Star Sun
AI Thread Summary
The Sun is not currently part of any star cluster, despite some claims suggesting otherwise. While there are nearby stars like Alpha Centauri and Barnard's Star, they do not form a gravitationally-bound group with the Sun. Historically, the Sun may have belonged to an open cluster, but such clusters disperse over time, and the Sun is now isolated. The typical lifespan of open clusters is between 150 to 800 million years, while the Sun is 4.6 billion years old, indicating any cluster it was part of has long since dissipated. Therefore, the Sun's current status is that of a solitary star in the galaxy.
lilythmagebor
Messages
8
Reaction score
0
Because I was curious about this, I read here that, "Our own Sun is part of an open cluster than includes other nearby stars such as Alpha Centauri and Barnard's star."
However, I cannot find any other pages claiming this, and the wikipedia entry on star clusters does not mention us being within a cluster, which I would think would be a rather important thing to mention.
Can anyone give me a definitive 'yes' or 'no' on this one?
 
Astronomy news on Phys.org
The Sun is not part of any cluster. Are there stars that are nearby (in galactic terms)? Yes. Are they part of of a gravitationally-bound group? Nope.

If you have access to a small telescope, look at the double cluster. That's what open clusters look like.
 
I think your link is supposed to say that the sun USED to be part of an open cluster. By its own words it says that the stars will disperse due to interactions with other objects over time.
 
"Typical star densities in the centre of a cluster are about 1.5 stars per cubic light year (the stellar density near the sun is about 0.003 star per cubic light year)."

http://en.wikipedia.org/wiki/Open_cluster#Morphology_and_classification

Open clusters tend to be young because gravitational interactions disperse its members over time. According to the same article, the half life of open clusters is 150-800 million years. The Sun is 4.6 billion years old, so if it once belonged to an open cluster, that cluster had plenty of time to dissipate.
 
Last edited:
IIRC, the dispersion rate of 'mid-sized' stars such as our Sun's G8 is important because it would make the difference between sibs being 40~~50 LY apart, so fairly easy to spot, and 100~~200 LY apart, so statistically dubious...

With luck, searching for 'metal rich' stars in our galactic arm may find some plausible candidates...
 
To add to the mix, even if the sun were part of an open cluster, there's no way Barnard's Star would be a member of it.
 
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
Asteroid, Data - 1.2% risk of an impact on December 22, 2032. The estimated diameter is 55 m and an impact would likely release an energy of 8 megatons of TNT equivalent, although these numbers have a large uncertainty - it could also be 1 or 100 megatons. Currently the object has level 3 on the Torino scale, the second-highest ever (after Apophis) and only the third object to exceed level 1. Most likely it will miss, and if it hits then most likely it'll hit an ocean and be harmless, but...
Back
Top