Questions tagged [star]
Questions regarding large spheres of plasma undergoing fusion.
1,312 questions
1 vote
2 answers
191 views
Assuming they exist, what would be the strongest observational evidence of quark stars?
I know that the theoretical side of quark stars is still lacking an equation of state and their existence is, for the time being, hypothetical, but I'm curious to know what would be most likely way we ...
- 21
8 votes
3 answers
2k views
How do we keep track of the positions of stars that are light years away?
We are moving constantly through space. The universe itself is expanding and therefor moving things around. Now, I always wondered how we keep track of those unbelievably far objects that are on a ...
- 97
11 votes
1 answer
582 views
What do lithium abundance numbers mean in catalogs like Hypatia?
I totally understand the meaning of the chemical abundances given for most elements (e.g., [Fe/H], [C/H], [O/H], [C/Fe], [O/Fe], etc.), but values given for lithium don't make sense to me. For ...
- 3,182
-1 votes
2 answers
127 views
Consequences of higher stellar density for the development and maintenance of life on planets
Assume that all astronomical objects retain their current sizes, but the distances between any two stars is only 1/10 of what they actually are, e.g. Sirius is not 8.8 l.y.s away but only 0.88 l.y. ...
- 107
-1 votes
2 answers
125 views
Main sequence stars vs black holes mass-radius relationship crossover
At what mass should we expect the main sequence star radius to equal its Schwarzschild radius? The Schwarzschild radius increases linearly with mass, so the mass to radius ratio of black holes is ...
- 131
10 votes
1 answer
1k views
Which two stars of the Pleiades appear as a single star?
Which two stars of the Pleiades are so close to one another from Earth's viewpoint that they appear as a single star? The Pleiades is Taurus' cluster containing the "Seven Sisters". And yet: ...
- 235
0 votes
1 answer
142 views
Can stars be less wasteful of their nuclear fuel?
When a star dies (either in a nova, supernova, or any other end of its evolution), it always leaves behind residual unfused hydrogen, helium or any other unfused product that was not available in a ...
- 878
24 votes
1 answer
3k views
Could a Dyson sphere trap enough radiation to shift a star off the main sequence?
A Dyson sphere captures most or all of a star’s emitted energy. But if such a structure also traps and reflects radiation back toward the star, could it alter the energy balance at the star’s surface ...
- 781
12 votes
1 answer
733 views
Why is Deneb brighter than Mu Cephei?
If my facts are correct, Mu Cephei is 2,840 light years from earth and Deneb is 2,600 light years from Earth. While the difference of 240 light years is not insignificant, it seems that it is not ...
- 223
-1 votes
2 answers
236 views
Will the universe end up without stars?
Except for those stars that will turn into black holes, we can intuitively think that every star undergoing a supernova should produce some planets (giant planets, dwarf planets, and other small ...
user71936
-1 votes
1 answer
195 views
How many stars are found in milky way [duplicate]
How many stars are found in milky way ? How many large stars and how many small stars are there in the Milky Way?
12 votes
1 answer
2k views
Why is estimating the age of an individual star so complicated?
I have several books on stellar evolution (where one comes from the American Astronomical Society's IOP Astronomy textbook: Understanding Stellar Evolution, by Henry J. G. L. M. Lamers and Emily M. ...
- 878
2 votes
1 answer
97 views
Why is Lomb Scargle detect a stronger peak at a harmonic of the true period?
As you can see there is a strong peak at 1.44 days. There is another peak at 3.05 days (which is the close to the actual period (2.89 days) from the literature). My question is why the harmonic of the ...
0 votes
1 answer
106 views
What is the smallest an Ultradwarf Galaxy can be?
Ultradwarf Galaxies (More commonly known as Ultra-faint Dwarf Galaxies, or UFD's), put simply, are EXTREMELY small and faint Galaxies containing very few stars compared to their more sizable ...
- 183
14 votes
4 answers
2k views
How do astronomers know that two objects appearing near one another are in fact close?
This is something I've been wondering since I started photographing stars at night a month ago. To observers from Earth other stars appear close to each other if they have similar position on the ...
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