Agreed terms - what subject would you like next?

Catastrophe

The devil is in the detail
"Population I includes stars with a wide range of ages. While some are as old as 10 billion years, others are still forming today. For example, the Sun, which is about 5 billion years old, is a population I star. But so are the massive young stars in the Orion Nebula that have formed in the last few million years.!! Google.

How about Population I II III stars as a whole, to include, of course, ages?

Cat :)
 
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"Population I includes stars with a wide range of ages. While some are as old as 10 billion years, others are still forming today. For example, the Sun, which is about 5 billion years old, is a population I star. But so are the massive young stars in the Orion Nebula that have formed in the last few million years.!! Google.

How about Population I II III stars as a whole, to include, of course, ages?

Cat :)
I wasn't aware of cat one stars being that old. They must be dwarf stars otherwise they would have left the main sequence eons ago. If what you're saying is true, then that means the universe has been capable of supporting sentient, intelligent, alien life for almost 10 billion years!! That's astounding!
 
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Catastrophe

The devil is in the detail
Patrick, I try to be most careful Here was my source. I will look into it, in case my source contained an error. Many thanks for pointing it out. Cat :) :) :)



25.5 Stellar Populations in the Galaxy – Astronomy
https://pressbooks.online.ucf.edu › chapter › 25-5-stella...


Population I includes stars with a wide range of ages. While some are as old as 10 billion years, others are still forming today. For example, the Sun, which is about 5 billion years old, is a population I star. But so are the massive young stars in the Orion Nebula that have formed in the last few million years. Population II, on ...
 

Catastrophe

The devil is in the detail
Patrick. I just found this in Astronomynotes.com (I don't know them?)
"he Population I stars are in the disk component of the Galaxy. They have a wide range of ages, from 0 to 10 billion years old. The youngest ones are in the spiral arms. Population I star orbits are orderly: roughly circular orbits close to the mid-plane of the galactic disk. Young star clusters made of Population I stars are called open clusters because the stars are loosely bound together, in contrast to the old, concentrated globular clusters."
My emphasis.

I found another at 10 billion years, but their 'metals' content was only 10% Sun, which seems on the low side. Cat :)
 
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Patrick. I just found this in Astronomynotes.com (I don't know them?)
"he Population I stars are in the disk component of the Galaxy. They have a wide range of ages, from 0 to 10 billion years old. The youngest ones are in the spiral arms. Population I star orbits are orderly: roughly circular orbits close to the mid-plane of the galactic disk. Young star clusters made of Population I stars are called open clusters because the stars are loosely bound together, in contrast to the old, concentrated globular clusters."
My emphasis.

I found another at 10 billion years, but their 'metals' content was only 10% Sun, which seems on the low side. Cat :)
Indeed, if your source is correct, then the oldest cat one stars could very easily have been born in globular clusters, since galactic stellar nurseries would have been rare to non-existent so long ago.
 
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Another worthwhile topic is to delineate between what is metaphysics and physics, or even pseudoscience. This would be especially helpful whenever the BBT is discussed. It is very common to see people talk as if science is able to address singularities for BBT, etc.
 
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Another worthwhile topic is to delineate between what is metaphysics and physics, or even pseudoscience. This would be especially helpful whenever the BBT is discussed. It is very common to see people talk as if science is able to address singularities for BBT, etc.
That would be very interesting. It's ironic that you brought up metaphysics along with pseudoscience, since it is known that cosmology is one of the pillars of metaphysics. Just thought I'd throw that one in.
 
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I would guess that the distinction between populations is tied to metallicity. It is the metals that makes one star different than another, for the same mass.
It had me thinking about the apparent discrepancy between the age of the Universe and Methuselah's star. Extremely low metallicity, along with the age contraversy. I wonder if there might be some indirect method of determining whether or not Methuselah star was created after the first population 3 stars went supernova. We know that the first population three stars came into existence approximately two hundred million years after the big bang. Since the overall volume of the universe back in that era, was microscopically smaller than it is today, the Dynamics of Stellar evolution must have been strikingly different.
 
Jun 1, 2020
1,750
1,475
3,560
It had me thinking about the apparent discrepancy between the age of the Universe and Methuselah's star. Extremely low metallicity, along with the age contraversy. I wonder if there might be some indirect method of determining whether or not Methuselah star was created after the first population 3 stars went supernova. We know that the first population three stars came into existence approximately two hundred million years after the big bang. Since the overall volume of the universe back in that era, was microscopically smaller than it is today, the Dynamics of Stellar evolution must have been strikingly different.
Yes, things were indeed different when the first stars formed. The elements were only hydrogen and helium. [There was a tiny amount of deuterium and even less lithium.]

These early stars may have all been very massive, which was great for nucleosynthesis because the more massive the star, the more heavier elements are formed, both in quantities and in atomic number.

Perhaps we can someday see some of these stars directly thanks to gravitational lensing, but that will be a huge challenge given their distance and redshift.
 

Catastrophe

The devil is in the detail
Yes, things were indeed different when the first stars formed. The elements were only hydrogen and helium. [There was a tiny amount of deuterium and even less lithium.]

These early stars may have all been very massive, which was great for nucleosynthesis because the more massive the star, the more heavier elements are formed, both in quantities and in atomic number.

Perhaps we can someday see some of these stars directly thanks to gravitational lensing, but that will be a huge challenge given their distance and redshift.
Strangely metallicity came up as:
Metallicity [Fe/H]−2.40±0.10[1] dex

whereas the scale iirc goes down to -4 etcetera.

Cat :)

 
Jul 4, 2021
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Yes, things were indeed different when the first stars formed. The elements were only hydrogen and helium. [There was a tiny amount of deuterium and even less lithium.]

These early stars may have all been very massive, which was great for nucleosynthesis because the more massive the star, the more heavier elements are formed, both in quantities and in atomic number.

Perhaps we can someday see some of these stars directly thanks to gravitational lensing, but that will be a huge challenge given their distance and redshift.
Alternative abiogenesis, panspermia route
 

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