by Ann » Tue Sep 18, 2018 3:23 pm
Scrooge McDuck. Image: Disney (Carl Barks?)
The salt-n-pepper cluster of M37 is the Scrooge McDuck of open clusters in Auriga: Rich and old!
M37 is not terrifically old by any means, not even as open clusters go, but it is old enough that it is sporting a good many bits of ground pepper, the many red giants of the cluster. Clusters, unlike people, don't grow grayer or whiter as they age, but redder (or at least yellower). The white grains of salt are of course main sequence stars, mostly of spectral class A.
And if M37 doesn't have an entire cosmic vault full of stars, it nevertheless has a lot of them. According to
Wikipedia, it contains over 500 identified stars (and almost certainly many unidentified ones). The mass of M37 is about 1,500 M
☉, about
twice that of the Pleiades, and its estimated age is 346.7 to 550 million years. The Pleiades is generally assumed to be about a hundred million years.
The more massive an open cluster is, the longer it can be expected to survive. (Although admittedly, the nature of its environment is very important too.)
Ann
[float=left][img2]http://bf-astro.com/m37/m37.jpg[/img2][c][size=85]M37. Photo: Bob Franke.[/size][/c][/float][float=right][img2]https://pbs.twimg.com/profile_images/875414294971559936/Hp52Cq6U_400x400.jpg[/img2][c][size=85]Scrooge McDuck. Image: Disney (Carl Barks?)[/size][/c][/float]
The salt-n-pepper cluster of M37 is the Scrooge McDuck of open clusters in Auriga: Rich and old!
M37 is not terrifically old by any means, not even as open clusters go, but it is old enough that it is sporting a good many bits of ground pepper, the many red giants of the cluster. Clusters, unlike people, don't grow grayer or whiter as they age, but redder (or at least yellower). The white grains of salt are of course main sequence stars, mostly of spectral class A.
And if M37 doesn't have an entire cosmic vault full of stars, it nevertheless has a lot of them. According to [url=https://en.wikipedia.org/wiki/Messier_37]Wikipedia[/url], it contains over 500 identified stars (and almost certainly many unidentified ones). The mass of M37 is about 1,500 M[sub]☉[/sub], about [url=https://en.wikipedia.org/wiki/Pleiades#Composition]twice that of the Pleiades[/url], and its estimated age is 346.7 to 550 million years. The Pleiades is generally assumed to be about a hundred million years.
The more massive an open cluster is, the longer it can be expected to survive. (Although admittedly, the nature of its environment is very important too.)
Ann