Page 1 of 1

NGC 6284 13.3 Billion Years Old

Posted: Tue Nov 07, 2023 6:24 pm
by Graeme1858
A new study has found Globular Cluster NGC 6284 to be 13.3 billion years old!


https://phys.org/news/2023-11-globular- ... omers.html


Graeme

Re: NGC 6284 13.3 Billion Years Old

Posted: Tue Nov 07, 2023 7:12 pm
by helicon
That's amazingly old! Must have really low metallicity....

Re: NGC 6284 13.3 Billion Years Old

Posted: Tue Nov 07, 2023 8:26 pm
by Graeme1858
helicon wrote: Tue Nov 07, 2023 7:12 pm That's amazingly old! Must have really low metallicity....

The article says:

The metallicity of this cluster was found to be at a level of -1.36

Which I don't really understand because I was taught that the level of metallicity is calculated from and shown as a mass fraction: Hydrogen + Helium + Metals = 1

Maybe it's so old the stars are Population 3 and the maths is different?

Anyone know what a metallicity level of -1.36 means?

Graeme

Re: NGC 6284 13.3 Billion Years Old

Posted: Tue Nov 07, 2023 11:53 pm
by messier 111
I don't know if this can be useful ,
https://en.wikipedia.org/wiki/Metallicity