Questions regarding large spheres of gas undergoing fusion.

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1answer
43 views

What's an order-of-magnitude main sequence star look like?

I'm looking for a very rough, order-of-magnitude approach to the main sequence. What I mean is, I have a spherically-symmetric hydrogen distribution. I'm looking to get a rough approximation for ...
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2answers
21 views

Can solar luminosity & activity be predicted?

Can a star's luminosity and its activity, solar flares and sunspots, be predicted? If so, with what accuracy & precision?
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1answer
32 views

how to measure temperature of the distant star [duplicate]

As part of small project i want to measure temperature of the distant star on basis of optical observations. so by what exact method i can do it? which instruments will be necessary? what is the ...
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2answers
101 views

Accurate way to programmatically generate a main sequence star?

I am working on a (personal) programming project, part of which involves generating random stars and their parameters. In order to create a procedurally generated star, I want to randomly select as ...
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1answer
27 views

Naive star filter visible at night in certain country

I have a HYG catalogue and I'd like to filter out stars visible at night and in Europe. Doesn't have to be exact. I was assuming that it'll be all stars with positive declination, but I wasn't sure ...
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2answers
157 views

Are there a lot of collisions between stars in the core of the galaxy?

I'm reading on Wikipedia about Halo Stars that orbit the center of the galaxy at a high inclination away from the plane of the Milky Way. It seems that at some point, these stars must dive back into ...
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4answers
134 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 ...
1
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1answer
48 views

What is the physics of a gas mass subject to gravity in space?

There are many formulas for atmospheric pressure on earth, but how does gas behave in free space? I am thinking about why stars form. I am guessing that the gas density will influence pressure, as ...
3
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1answer
76 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. ...
3
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1answer
59 views

Formation of stars

How are stars formed? I read somewhere that when dust, gas, rocks etc come close to each other due to gravity, slowly and gradually build up a lot of pressure and form stars. If what I read is ...
1
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1answer
82 views

Statistically, what would the average distance of the closest black hole be?

The closest confirmed black hole is several thousand light years away from earth. Our galaxy has about 100 billion stars. I didn't find any reliable information on the black hole count of ratio versus ...
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2answers
47 views

Stars in star clusters in SMC and LMC

Is there any catalog or any paper published in any journal that enlists the stars discovered under which ever star-cluster of Small Magellanic Cloud (SMC) they belong to? There is one for Large ...
2
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2answers
48 views

How many stars are visible to naked eyes around Equator area?

In the best sky conditions, we can see about 44,000 stars in the sky. But what if I am located around Equator area? How many stars I can see? From what I know, the number of stars I can see should ...
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1answer
35 views

Distance of extra-galactic Classical Cepheids

There have been many questions and answers about finding the distance of a star from the earth. But as I did some research on the net, I found that we have specific approaches for finding the ...
7
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1answer
87 views

Is it safer to be near a star or a black hole?

If a star or black hole neared the solar system, which would do the least damage? For the sake of a good comparison, lets assume the candidate star is an "average" 5 solar mass star, and the black ...
2
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3answers
101 views

Where can I find a catalog of all stars in the Milky Way?

Is there a catalog of all known stars or brightest stars in our galaxy? Preferably with some sort of galactic coordinates instead of just night sky coordinates (right ascension, etc.) I'm trying to ...
2
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2answers
98 views

Is the Sun homogeneous?

Does the Sun have the same composition and density everywhee within it? How does it vary in other stars?
4
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1answer
105 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 ...
2
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1answer
52 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 ...
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2answers
44 views

What is the difference between LMC and SMC?

Apart from the obvious difference as suggested by their names that the Large Magellanic Cloud is 'larger' than the Small Magellanic Cloud, what are the other differences between them? Do give all the ...
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2answers
86 views

Why do we think that there is no two-solar-mass black hole?

We think that the mass boundary between neutron stars and stellar mass black holes is around three solar masses. The maximum mass of the neutron stars now is two solar masses and we may find a 2.6 ...
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1answer
24 views

How can pre-main sequence stars radiate more energy than main-sequence stars?

How can a pre-main sequence star radiate more energy by gravitational contraction than a main-sequence star can by hydrogen fusion?
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2answers
66 views

Metallicity of Celestial Objects: Why “Metal = Non-metal”?

Metallicity of objects refers to the amount of chemical elements present in it other than Hydrogen and Helium. Note: The other elements may or may not be actual ...
2
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3answers
84 views

Pulsation Modes of Cepheids

There are various modes of Cepheids like single modes: fundamental (F), first overtone (1O), and likewise. And then we have double modes: F/1O, 1O/2O etc. triple modes: 1O/2O/3O etc. ...
2
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1answer
35 views

how to know the nature of the companion in a neutron star binary?

The companion could be a main sequence star, white dwarf, neutron star or black hole. We detected pulsar-pulsar binaryhere several decades ago. But if one of the pulsar does not radiate towards us, ...
3
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1answer
79 views

Sun from SuperNova

I have read that our sun was created from older star(s) which had exploded in a supernova. If all the matter is travelling away from the central point of explosion, how does it coalesce back into a ...
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0answers
31 views

Triangular Asterism Trigonometry

Using the SIMBAD database for Alnitak, Saiph, and Sirius -- i.e.: Alnitak: FK5 coord. (J2000): RA = 05 40 45.527 DEC = -01 56 33.26; Saiph; FK5 coord. (J2000): RA = 05 47 45.389 DEC = -09 40 10.58; ...
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1answer
76 views

Why planet's orbit is not perpendicular or random ?

Why planet's orbit is not perpendicular or random ? It always seems each planet is revolving on the same geometric-plane around the star.
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1answer
46 views

How often do stars form?

There are many more stars in the universe than the years that the universe has been in existence, so wouldn't this mean that stars were/are forming at an astounding rate?
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1answer
76 views

How do we find the exact temperature of a star/galaxy?

This is a very basic question, but I am a little confused. As far as I know, the temperature of a star is analyzed based on the color of the light it emits. So, if a star is moving away from us, then ...
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1answer
86 views

Cooling of stars

If all stars suddenly stopped producing heat (or heating up) which stars would cool to absolute zero first and how long would it take?
3
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1answer
44 views

which or what kind of star has a very stable luminosity?

I mean those kind of stars should be very stable and barely have activity. Their light curves should be very very flat. Our sun, as a G type star, are not so stable. At lest there are lots of ...
2
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1answer
99 views

In the end what is the ultimate matter/element in the universe, due to fusion process in stars?

We know that, in stars, hydrogen is used by the stars and due to the fusion in two hydrogen elements we get helium -> Carbon -> Oxygen ->Other elements -> Iron -> then Super/Hypernova. If everywhere ...
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1answer
29 views

is pan-starrs' data available to public users?

Anybody knows that? The data products are all images or star catalogs? This is the link: http://pan-starrs.ifa.hawaii.edu/public/
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1answer
46 views

What is visible light colour output of different stars?

I know the colours of the stars relate to their heat, however if I were standing on a different planet identical to Earth, but orbiting a blue Bright Giant or a Red Giant, or perhaps even a Red Dwarf, ...
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1answer
42 views

“Chain reaction” supernovae?

I know not all stars can "go nova", and that of those that do there are different types of novae, among which are some that aren't even explosions (at least not as we think of them), and that even the ...
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3answers
123 views

Does the Sun have hard radiation?

Does the Sun spread hard radiation waves around the Solar System? If so, why are we safe here (or are we even safe)?
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1answer
63 views

Relation between position of stars and locations of gemstones? [closed]

A theory has been said that the patterns and positions help identify where valuable gemstones are hidden. I am wondering if this has any truth in it.
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2answers
56 views

Putting mass-luminosity relation and HS diagrams together leads us to a mass-age relation; so how do stars lose their mass over time?

I think that the title is completely clear, but here's an expansion: I was just reading about Mass-luminosity relation that says massive stars are more luminous than tiny ones. Well, let's talk about ...
3
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2answers
74 views

Does the earth's atmosphere act as a spherical lens and refract light from space?

If so by how much does it "spoil" the view of stars and galaxies etc. Is this error noticable, when compared to pictures taken from outer space.
3
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2answers
100 views

What is the term for a star swallowing another star?

A star A goes through the body of another star B, or is swallowed by B. There is no tidal disruption. It sounds like kerzan. Does anybody recognise this pronunciation?
2
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3answers
257 views

First night on a telescope questions

So I recently got into astronomy and I am using my fathers old Meade EQ1-B reflector telescope. This is my first night using it and I have come across a few questions. To begin, the telescope was left ...
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1answer
204 views

Best telescope for the viewing of Nebulae, Stars and Planets

So, I am a 15 year old interested into astronomy. My father used to have a reflector telescope, but was never so serious about it that he could recommend me a good telescope. I am looking to buy a ...
1
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1answer
67 views

Position and velocity vectors of nearby stars?

One of my favorite tools for modeling the solar system is the Horizons Ephemeris generator where I can get position and velocity vectors of various bodies. Is there something similar for neighboring ...
1
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1answer
76 views

3D Positions of Nearby Stars

I have come across a number of star catalogs that list stars by right ascension and declination, along with other data such as magnitude. Is there a star catalog that lists the 3-D position of stars ...
1
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1answer
80 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 ...
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0answers
120 views

How can I calculate what star was above my head when I was born? [closed]

Almost everybody knows the concept of Zodiac. But there are others. And, AFAIK, even Zodiac classification is wrong for nowadays - since the classification of the people's Zodiac Sign was developed ...
2
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1answer
76 views

why are galaxies different in color?

whether its in movies,television,real-life or some planetarium different galaxies are shown in different color. For ex:- Milky way is always seen in Blue where as Andromeda gives out a bit reddish ...
2
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0answers
24 views

need data-point: actual counts per second with APD (avalanche photodiode) detector

I'm designing a sensor system to perform specialized [astronomy and space-sciences] experiments, and need a "reality check" to support or adjust my theoretical calculations. What I need is the ...
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0answers
25 views

local stellar mapping data

I've been playing around with Near Star Map, and I think I kind of want something more sophisticated, so for all stars within 100ly/30pc, is the following known? velocity (it would be nice to have a ...