Questions regarding large spheres of gas undergoing fusion.

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0
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3answers
49 views

Does the Sun turn around a big star?

The moon turns around the Earth. The Earth turns around the Sun. Does the Sun turn around a big star? If so, does this big star turn around a very big star? ... etc ... What are all the intermediate ...
3
votes
3answers
102 views

Is gravitational energy released when a body contracts?

Kelvin stated that gravitational energy released due to contraction was responsible for the energy radiated in the stars. Although the theory was wrong, was the assumption practically right? If it's ...
2
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1answer
135 views

How bright was Scholz when is passed near the Sun 70,000 years ago?

I just read that a star called Scholz passed only 0.8 years-light away from us 70,000 years ago. It is a red dwarf. I don´t know how bright it was in the night sky. Does someone know how bright it ...
1
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1answer
182 views

What happens to a white dwarf past the Chandrasekhar limit?

This is a multiple choice question I had trouble with on an exam. Will a white dwarf that has had too much mass piled on top of it a) undergo a thermonuclear flash and explode in a type IA supernova ...
1
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1answer
75 views

Could a close passing star be captured by the Sun's gravity?

Earlier I read an article here stating that a binary pair of stars passed within 0.8 light years from the sun. That made we wonder why the stars weren't captured by the Sun's gravity since the sun's ...
-1
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1answer
48 views

What is the acceleration of the stars' speed in the Universe? Positive or negative? [closed]

I have read quite different opinions about that, so can someone tell me what is the sign of the acceleration of the stars in the Universe if we accept that the center of the Universe is the beginning ...
4
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3answers
142 views

Is there a flaw with the newer purposes and correlations attributed to the HR diagram? (And would a third axis of mass correct the enclosed flaw?)

When I was younger, I was looking at HR diagrams, and began to experiment with the HR diagram. I was looking at plotting different groups of stars on the HR diagram when I found RV Tauri stars. ...
5
votes
2answers
338 views

Where do the heavier elements come from?

Partly inspired by this question, the end result of stellar fusion is Iron-56 (eventually, after some decay). Then it explodes. How/where then to the heavier elements come from. The answer here ...
4
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1answer
90 views

Estimating the angle covered by the star trails and deducing how long the exposure lasted

How would you estimate the angle covered by the star trails and deduce how long the exposure lasted in the following image? Here is the photo's caption: Star trails beyond the Gemini ...
2
votes
6answers
345 views

Why are stars so far apart?

So, this is mere musing, but it seems that stars are quite extremely far apart. I tried to determine the mean distance between nearest neighbors for stars (in just our galaxy) but I'm not sure what it ...
2
votes
3answers
156 views

What would the night sky look like if Earth orbited an intergalactic star?

If the Earth and its host star were located exactly in-between the Milky Way and Andromeda would the night sky be completely void of light? Would stars be visible to the unaided eye? So there could ...
5
votes
2answers
154 views

Find distance from star to star?

How do you find the distance from a star/planet/black hole to another? I know people can calculate the distance from Earth to a star, but what about from one to another?
6
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4answers
225 views

Burning Out Stars

In the book "A Really Short History Of Nearly Everything", I read that the larger the star is, the faster it burns itself. Whys that? Wouldn't there be more energy to burn if it's larger, and just be ...
4
votes
1answer
106 views

Entropy of black hole

A line from one of the answers on a different question got me thinking: The simplest way to see this is probably that a black hole has a much higher entropy than a star or even another type of ...
0
votes
1answer
49 views

Find the height of the shooting star from the Earth's ground

One night, you and your friend were talking to each other. Your friend far about 20 km. from you. You told your friend that you see the shooting star pass through the sky at altitude of 75 degrees. ...
-2
votes
1answer
62 views

Mass, Radius, Colour, Size, Type of a Star from the Hipparcos Catalog

Using data from the Hipparcos Catalog download file, is there a way to determine the Visual or Apparent Magnitude from the data within? Can I obtain the Mass, Radius, colour, temperature, type ...
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0answers
25 views

Can you suggest telescope for beginners? [duplicate]

I am interested in astronomy and want to look deep into the awesome sky . So, suggest me an economic telescope or the specifications that are to be considered. I am from India.
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2answers
72 views

How to complete the Hipparcos Catalog?

I've downloaded hipparcos catalog from the Strasbourg Universe but whilst there is a lot of information, I can't find the names of the stars that the HipID relates to. There is the wikipedia page ...
0
votes
1answer
229 views

Is there any planet/star bigger than VY Canis Majoris?

Compared to VY Canis Majoris, our Sun is more like a speck of space dust. Is there any planet or star which is known to us that is bigger than the VY Canis Majoris?
2
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2answers
97 views

How do stars or galaxies get their spin?

It is my understanding that when a star, a planetary disk, or a galaxy forms, the rotational momentum of the whole system is conserved. Due to the smaller size of the resulting object, it will spin ...
9
votes
4answers
946 views

How do scientists determine the age of stars?

I was Googling about the oldest galaxies in the Universe. Everywhere is written that their age is known by the light. Referring to this line "Since light travels at a set speed, if you look at a star ...
1
vote
1answer
53 views

Instrumental magnitude to “real” magnitude - Photometry with not enough data?

I have a lot of data taken in R, B, V, Luminance and Halpha-bands which I want to analyse photometrically (one target in the frame). The frames are already reduced (with flats, darks etc.) and have a ...
7
votes
1answer
68 views

How would the pocket cellular clock work?

In a museum in Lviv, I saw a pocket cellular clock. I don't have a photo, but it was a small disc that had 2 or 3 filaments in it which were pointed at the stars (one of them was Andromeda, I think). ...
2
votes
1answer
96 views

Why stars are named Gliese?

There are exoplanets called Gliese 581c, Gliese 581d etc. I assume their star is Gliese 581. So where does this Gliese come from?
2
votes
1answer
103 views

Mechanism for Brown Dwarf Fusion

I've read (at here, among other places) that during the Degenerate Era, star formation will end and the last stars will go out. But it was noted that there is still the possibility of star birth, ...
0
votes
1answer
95 views

Photos from galaxy

So, I hear people say blah blah blah is 3 light years away, and here's a photo. So does that mean the photo that we see are actually at least 3 years ago since that's how long it takes that light to ...
2
votes
2answers
68 views

Quantum death of stars

This comes from a comment on this question, to quote: The death of (large mass) stars is also based on quantum events with probabilities technically not 1 (and is very fast), so it is technically ...
3
votes
1answer
51 views

What does designation VY, NML, UU in star names stand for?

I've read the a IAU page on the subject but i am no closer to understanding how this works. Also did search the already asked question, but didn't see anything on the subject. What does bolded item ...
0
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4answers
187 views

Is it possible for a star to orbit a planet?

Is it possible for a red dwarf to orbit a gas giant? OR Has this happened and it is just assumed that the gas giant is orbiting the star?
-4
votes
2answers
114 views

Could we actually freeze a star?

I read an article recently that said NASA has discovered a brown dwarf that has frozen. If we had the technology, resources, and supplies, could we actually freeze a star and stop it from burning its ...
1
vote
0answers
26 views

Is Nomad data heliocentric or geocentric?

I'm wondering if the data in star catalogues are heliocentric equatorial coordinates or geocentric equatorial coordinates. Also given the distance between stars compared to the distance between the ...
1
vote
1answer
125 views

Why can't the surfaces of stars be observed?

If I'm correctly informed, only three stars: Sol, Betelgeuse and Altair have surfaces which have been resolved by telescopes. All other stars are only point sources of light, even in the greatest of ...
1
vote
2answers
123 views

How did Bradley arrive at the +/- correct speed of light when he calculated it?

After Bradley discovered stellar aberration and the corresponding constant of aberration he was able to calculate the speed of light, since he knew the speed of the Earth around the Sun. As far as I ...
6
votes
0answers
167 views

Magnetic fields of peculiar HgMn A type stars

Do HgMn (peculiar A type) stars really possess global magnetic fields? See, for example, this paper by Hubrig et al. from 2012.
6
votes
4answers
396 views

Are the stars in constellation located in a plane or they are in different distances

Are the stars in constellation located in a plane or they are in different distances from each other and when we observe them from the Earth we think they are all in a plane?
4
votes
2answers
69 views

Is there anywhere I can find some kind of database on all known stars and their properties (mass, surface temperature, radius, and luminosity)?

I have been looking for some kind of collection of all known stars and their individual respective mass/radius/temperature/and luminosity, can you link me to one if it exists? My goal is to write an ...
11
votes
4answers
175 views

Are there ways other than the collapse of a star which have been observed to form black holes?

Every time I hear about a black hole, it's always in conjunction with the collapse of a star. Have any other processes been observed to create a black hole?
10
votes
2answers
346 views

How often do stars pass close (~1ly) to the Sun?

Interstellar exchange of massive objects is difficult across several light years. But as the stars orbit the galaxy the distances between them change. I don't find data for neighbor star distances ...
4
votes
2answers
86 views

Does Tobler's First Law of Geography Apply to Star Composition?

There is a principle in Geography called Tobler's First Law of Geography which states that "Everything is related to everything else, but near things are more related than distant things." Does this ...
10
votes
3answers
216 views

Calculate Distance To Stars

I was just watching a lecture from Carl Sagan. He talked about figuring out the distance to the stars; it got me interested in learning more about the subject. As far as I know, the Inverse square ...
0
votes
2answers
148 views

Why don't small stars end up as a black holes?

I've recently done some research about black holes, and I realized that big stars form black holes and small ones don't. Is it because the gravity isn't strong enough for it to fall in on itself, or ...
3
votes
4answers
206 views

What is the most oblate astronomical object known?

There are some very vast spinning objects out there. How high can the eccentricity get, or, which I think is easier to understand, how small can the ratio between the polar and equatorial diameter ...
3
votes
3answers
155 views

Absolute magnitudes of stars

Where to find comprehensive list of absolute magnitudes for stars of different spectral types? I need published paper or web page with data and reference to the source.
4
votes
4answers
137 views

Without using absolute magnitudes or isochrones, how might we tell a star's age and evolutionary status?

Usual methods of estimating stellar ages involve isochrone approximations. It can also help to estimate a star's radius by correlating its absolute magnitude with effective temperature and apparent ...
1
vote
1answer
69 views

What is “Median Stellar Mass”?

Could someone explain what is "median stellar mass" and how is it calculated? I have seen it written as: $$\log(M)$$ or as: $$\log\left(\frac{M_*}{M_{\text{Sun}}}\right) $$ but I do not ...
4
votes
5answers
520 views

Very bright star in the east at northern hemisphere. What is it?

From some time now (few weeks as far as I can remember), there is a very bright star in the eastern sky. I first thought it was Venus, but according to this link, Venus is in the western sky and ...
8
votes
1answer
109 views

Appearance (frequency) ranking of stars?

Is there some ranking / statistics that shows how common given type of celestial objects is? A table that would allow the answers to questions like: What type of star is most common per volume of our ...
0
votes
1answer
36 views

Yellow object between δ Ori and η Ori

Can someone perhaps assist me in identifying the yellow object between δ Ori and η Ori? I took an image of this object, but I can't identify it. It can be seen on the image below, hosted on the Eagle ...
4
votes
3answers
187 views

Is there enough hydrogen left after a star dies so another star will have enough to light up?

A star consumes quite a lot of hydrogen in its life, and is pretty much "vacuuming" everything in its vicinity. After it dies (eventually by supernova which will spread all its composition over light ...
4
votes
1answer
167 views

At what density does helium burning start in a star?

I have seen several references that say that helium burning begins in a star once the core temperature reaches $10^8$K (such as here) but nowhere that says what density that corresponds to. Does ...