Questions tagged [age]
Questions about the temporal duration of a celestrial object.
46
questions
6
votes
2
answers
882
views
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 ...
- 189
3
votes
2
answers
233
views
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 $14$ ...
- 133
7
votes
2
answers
766
views
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 ...
- 1,007
1
vote
1
answer
93
views
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 ...
- 381
43
votes
5
answers
11k
views
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 ...
- 439
6
votes
3
answers
350
views
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 ...
- 17.6k
0
votes
1
answer
590
views
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 ...
- 103
5
votes
1
answer
2k
views
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 ...
- 333
0
votes
0
answers
30
views
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 ...
- 333
11
votes
2
answers
521
views
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 ...
- 387
6
votes
1
answer
499
views
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
user30548
3
votes
1
answer
208
views
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-...
- 24.1k
8
votes
1
answer
216
views
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 ...
- 183
6
votes
1
answer
267
views
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 ...
user20278
2
votes
0
answers
179
views
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
- 61