Questions tagged [age]
Questions about the temporal duration of a celestrial object.
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What would evidence of stars and galaxies significantly older than 13.8 billion years old look like? In what parts of space has it not been found?
The September 19, 2023 podcast with transcript Why the earliest galaxies are sparking drama and controversy among astronomers includes the following:
An article published earlier this year in the ...
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Why is Earth 1/3 the age of the universe?
The Earth is 4.6 billion years old
The universe is 13.8 billion years old.
3 times the age of the Earth
Are there other planets with ages that are close to say 1/4 1/5 etc the age of the universe? Why ...
user48394
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Cosmic microwave background the same as the first visible light at 379,000 yrs after the Big Bang? How do these measure the age of the universe?
Was the CMB emitted at the same time as visible light at 379,000 yrs after the BB ? Was this a one time event ? If headed away from us, how does it measure the age of the universe?
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What is mass-weighted age?
This seems to be a common term used in the field of stellar populations and galaxy evolution, but I can't find a good definition besides the fact that it is different from light-weighted age (a term I ...
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Does "Angular Diameter Turnaround Point" solve the Great Wall Problem?
According to Wikipedia,
The Hercules–Corona Borealis Great Wall is the largest known structure in the observable universe, measuring approximately 10 billion light-years in length.
But since it's ...
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How did Hubble know the red shift difference between "moving away" and "old"?
My 9yo daughter is very into space at the moment and asked a question that my physics knowledge (6th form college, 20 years ago) is way too poor to answer.
Her space book tells us that as stars age, ...
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How slow would you age on a double gravity planet?
How slow would you age on a double gravity planet?
Gravity of the planet A is 10 units. If you are taken from planet A to planet B where gravity is double that of A, i.e. 20 units. How slowly would ...
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Do black holes have "age" when they form?
I was thinking about black holes, and I know that they form by the death of massive stars. I was wondering, though, do they technically have an "age" when they're born? Do they begin at 0 ...
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Why is there a discrepancy with calculated and given age of nebula
In the book "Horizons: exploring the universe-Cengage learning (2018)", page 206, it states that:
Simple observations tell astronomers about the nature of planetary nebulae. Their angular ...
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Seeming conflict between most distant objects and age of universe (both estimated)
There was a recent article on bbc.com for laypeople like me titled "The mystery of how big our Universe really is", which prompted me to post the following question in their comments section ...
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Long-lived supernova remnants?
We cannot see the supernova remnant of the star that triggered the formation of the Sun and the Solar System, as the remnant dispersed and became mixed into the interstellar medium. So I am wondering, ...
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How to determine the age of a star using asteroseismology?
I keep reading that a standard way to determine the age of a star is asteroseismology, and I tried to learn more about it. I am wondering if somebody could help me to describe the method in simple ...
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How can a very old star be formed among Population III stars?
After looking at some articles about old stars, (this, that, and this Wikipedia article), I thought about how such an old and small star could have formed. As the early universe had very massive, ...
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Absolute model ages of lunar craters
I have been looking at several articles on the dating methods of craters, but I am wondering how exactly the "absoluteness" creeps into it. I came across several methods that link crater &...
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Is a star with 2/3 solar masses and 9/10 solar radii still in the main sequence?
As far as I know, K-type and G-type stars (among others) grow in radius as they age, eventually leading to red giant phases.
My question is, would a star that is about 0.66 solar masses and 0.94 solar ...
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Is the age of the Universe really 13.8 billion years?
Ok, I know this has been asked by a lot of people, but my reason for asking this question is a bit different. Please read further.
I was watching a video by Fermilab (Start at 6:30, at 8:30 he ...
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Is it be correct to say that we live in a young (only 14 billion years old) universe?
From what I have read, it seems that our universe is expected to function more or less as it does now for some $10^{12}$ years, possibly more. If that is correct, our universe's current age of $14$ ...
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How do we measure the age of the universe?
As mentioned in wiki/Age_of_the_universe,
The current measurement of the age of the universe is around 13.8 billion years (as of 2015) – 13.799±0.021 billion years
When my friend who is not from ...
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Stellar age determination - code
I'm trying to determine the age of some stars. I have many parameters that characterize these stars: $T_{eff}$ ,log ${g}$ ,$[Fe/H]$, $V$... I've tried to use the isochrones package but so far no ...
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Are photons aged?
If a star is at a distance of one lightyear, how old are its photons when they reach earth (from the photons’ perspective)? If time dilation is near zero at light speed, can we assume that the light ...
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Is there a stellar database that indicates how long ago stars in our Galaxy formed?
There are several ways of determining the age of a star: its position in the HR diagram, the presence of a protoplanetary disk, it belonging to a cluster...
When did the stars in our Galaxy form? Do ...
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Age of earth relative to other planets
Relative to the average age of other known planets, is the earth young, old or in the middle? Does it make a difference if you compare the earth against nearby planets (say < 500 LY), or other ...
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How to evaluate the fit of an isochrone to a stellar population?
Consider that I know the extinction, distance modulus, reddening, and metallicity for a particular star cluster.
I need to determine it's age from isochrone fitting.
After generating the required ...
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Relationship between IMF and time spent during an evolutionary phase
I was reading a little about stellar evolution and was wondering whether there was any relationship between the lifetime of an evolutionary phase and the IMF, I searched on google but all I found were ...
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Could a star closely orbit a black hole long enough for the star to have lost 0.5B+ years to time dilation?
I was wondering how stable a close star-black hole system could plausibly be, and thus how much time a star could plausibly miss out on (from an outside observer's perspective) due to being in an ...
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Can someone calculate the age of the KOI-4878 star?
The star’s low metallicity and fairly high space velocity suggest that KOI-4878 is older than the Sun.
But I don't know how to calculate an estimation for the age.
KOI-4878 data on Simbad
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Could the Universe really be 12.5-13 billion years old?
My initial reaction is that "this must be wrong" and apparently that's a lot of people's initial reaction according to the article.
https://www.nbcnews.com/mach/science/universe-may-be-billion-years-...
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How far would EGSY8p7 be away now?
Apparently EGSY8p7 is the object with the longest light travel distance, 13.2 gly or a redshift of z = 8.68 (Wikipedia).
So the light took 13.2 billion years to travel to us from that object, but we ...
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Do we know how old the matter that makes us is?
Last weekend, I had the pleasure of visiting an observatory where there was a series of lectures to cover up the fact that there was too much cloud cover to actually observe much at all.
One of these ...
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How to derive the equation for the age of a flat universe with a positive cosmological term?
Can anyone show the steps involved in deriving this equation from the friedmann equation with the cosmological constant involved
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