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Questions tagged [star]

Questions regarding large spheres of plasma undergoing fusion.

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7 votes
1 answer
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Are spectral subtypes a logarithmic scale, or a linear one?

Are spectral subclasses logarithmic? I can't seem to find any source on whether they're linear or logarithmic. For reference, by spectral subtypes I mean, for example, G2 vs G3 stars.
Astrovis's user avatar
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-4 votes
0 answers
74 views

What is wrong with this star

What is wrong with this star? It was spinning and moving rapidly while changing colors.
Amy's user avatar
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1 vote
1 answer
64 views

python question-discrepancy between number of stars found

Ok,I get that this is a long question but it's ok if you don't know just thought I'd give this a try anyway.I get that it's a long shot.Basically I'm trying to replicate a methodology used in the ...
Rjs2312's user avatar
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7 votes
3 answers
1k views

When a star enters a red giant phase, does the pressure in its core increase or decrease?

When a star becomes a red giant, does the pressure in its core increase or decrease? From one side, the only source of pressure in a star is gravity. A red giant is much larger than an ordinary star, ...
cuckoo's user avatar
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1 vote
1 answer
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What was the first nebulae of the first class?

On Wikipedia, it describes the Tarantula nebula as the second of the "Nebulae of the First Class", Wikipedia says that a Nebulae of the First Class is a Nebula with no other stars visible ...
Astrovis's user avatar
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8 votes
1 answer
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Why do larger mass stars form quicker?

I understand that larger mass stars form faster than lower mass stars. After doing research, I found it was because they got heated faster. But wouldn't this slow down the process as the higher ...
Astrovis's user avatar
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-5 votes
1 answer
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Is it possible that some "stars" or "black holes" have "wormholes" in their center? [closed]

Seems like if the mass of a "star" or "black hole" changed without absorbing or expelling anything, then that would be an indicator that there is a "wormhole" inside. ...
Bryan Grace's user avatar
1 vote
2 answers
981 views

Why does Helix Nebula look like an eye?

The infrared lights, the material clumps that radiate and the whole view resembling a celestial firework or giant eye
Helix Nebula's user avatar
1 vote
0 answers
36 views

Comprehensive Stellar Evolution Article

Is there an article that comprehensively covers stellar evolution, from start to finish. I've found articles on this, one in an introduction to a stellar evolution model, and I am searching for more. ...
Astrovis's user avatar
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2 votes
0 answers
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Single, binary, triple, .. fraction of star systems in our galaxy by mass

What is the fraction of single, binary, triple and so on systems as a function of one of the stars masses (or their sum)? This can be either derived from simulation or measurement. I feel like I have ...
SpaceCore's user avatar
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0 votes
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What direction do Herbig Haro outflows go from?

After doing some research about Herbig Haro objects, I found that the outflows are formed perpendicular to the circumstellar disk. Is that the same direction as the star's rotation, or is it the ...
Astrovis's user avatar
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What element drives pulsations in T Tauri Stars?

What element drives pulsations on T Tauri stars? I understand that T Tauri stars are variable and pulsate, and I also know that other stars pulsate as well. My thinking is that a T Tauri star would ...
Astrovis's user avatar
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2 votes
1 answer
60 views

Tracking variable stars?

Is there a website or application I can use do track the brightness of variable stars and notify of any unusual or particularly spectacular changes. I am particularly interested in tracking the blaze ...
Harrychink's user avatar
10 votes
2 answers
5k views

Why does nuclear fusion generate heat?

I understand that nuclear fusion generates energy in the form of gamma-rays (as in the pp chain), but how does that translate into heat in the star's core? Or is the heat just generated by ...
Astrovis's user avatar
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0 answers
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What do you call a protostar with more than 10 solar masses?

PMS Stars with less than 3 solar masses are T Tauri stars, and PMS stars between 3 and 10 solar masses are herbig ae/be stars, so what do you call a star with more than 10 solar masses? Is there ...
Astrovis's user avatar
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1 vote
0 answers
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Hayashi Track vs Red Giant branch

Are the red Giant branch and the Hayashi track the same thing? After doing some research, I found some similarities between the two, such as both aree fully convective. However, the T Tauri phase does ...
Astrovis's user avatar
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10 votes
2 answers
1k views

Where in a star are the spectral absorption lines formed?

This question was inspired by a recent Cool Worlds video "The Star That Shouldn't Exist", in which one of the speculative solutions to Przybylski’s Star's strange spectrum is aliens "...
asgallant's user avatar
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7 votes
2 answers
550 views

Why do red dwarf (M-type) stars give off such violent flares and CMEs, out of proportion to their size and temperature?

Dr. Becky (Smethurst) just posted a new YouTube video mentioning, as I have heard many times, that it might not be possible for life to form on planets around Red Dwarf (M) stars because they would ...
Kurt Hikes's user avatar
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1 vote
1 answer
91 views

How far away are the two components of the Rigel system?

How far away is Rigel A and B and what is the angular diameter of Rigel B from A?
Stephen's user avatar
  • 383
2 votes
1 answer
211 views

Pure Lithium Star

Suppose by some miracle a large molecular cloud of pure lithium assembled itself in space, then gravitationally collapsed. What would the result look like? Would it be a star of some sort (fusing the ...
volcanrb's user avatar
  • 129
4 votes
0 answers
191 views

'Star' appeared dimmer and dimmer over multiple days before disappearing. What could this have been?

This happened a little while ago but I've just been thinking about it! I was in Wales for a holiday, and over the period of 7 days, a particularly bright 'star'(or at least a bright dot that looked ...
AriaEternal's user avatar
6 votes
1 answer
450 views

What were the specifics of the photos taken by Sir Arthur Eddington during the Eddington expedition that supported Einstein's Theory

I know that Sir Arthur Eddington went to South American to photograph stars around an eclipse to see if they seemed to change position when the light past by the Sun relative to when the light didn't ...
Elliott Cooper's user avatar
6 votes
2 answers
1k views

What are the most up to date, accepted, evolution stages of big stars that end in compact objects or a planetary nebula?

There are numerous charts and diagrams showing the stages of stellar evolution, as: or among many more (you can find several after googling a little), for example. When I studied my B.Sc. on Physics,...
omivela17's user avatar
  • 201
1 vote
1 answer
103 views

Lifespan of neutron stars and black dwarfs in terms of mass in years

Stars have a lifespan scaling as $1/M^{2.5}_\star$ for sunlike stars or more generally $t\sim 1/M^3$ for general stars (more or less), black holes have a lifespan (according to simple Hawking ...
riemannium's user avatar
0 votes
0 answers
44 views

I saw a strange cluster of stars, help! [duplicate]

On January 1, 2024 in the sky above Almaty region, at about 19:05-19:10, I saw a line of stars that flew in one even line that disappeared in the distance, the stars were not very bright, but they ...
Кудрат Кутлуш's user avatar
3 votes
2 answers
552 views

Neutral vs ionized mean molecular weights

I am confused about the calculation of mean molecular weights, especially for ionized particles. From my understanding, the mean molecular weight $\mu$ is the average mass per the number of particles: ...
justauser's user avatar
  • 133
6 votes
2 answers
2k views

Are there stars that orbit other stars, such that the barycenter is inside one of them?

I know binary stars exist but I mean a star which orbits with a barycenter that is inside another star, much like a moon. Why is such a system so rare?
Stephen's user avatar
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2 votes
2 answers
205 views

Are there any bright *main-sequence* K-type stars in the night sky? Or are all of them giants?

It's well known that stars of a higher (i.e. hotter) spectral class have higher luminosities, due to their larger radii and hotter temperatures. Stars of spectral types O through G have no problem ...
user267545's user avatar
13 votes
1 answer
3k views

What star is this?

From this image, can you help me identify the star circled in yellow? This picture was taken mostly above my head, but facing slightly southeast, from the southwestern corner of Virginia.
rclev's user avatar
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21 votes
4 answers
6k views

What would happen if a small black hole fell into a star?

Let's say you created a cannon that can shoot small black holes and you shoot it at some star. Would the star just turn into a black hole silently? Or rather first destabilize and produce a last ...
Filip Sondej's user avatar
0 votes
0 answers
85 views

Question about a White Dwarf formula

I have a question regarding the White Dwarf radius formula given on wikipedia, in terms of what units I am supposed to use and what expected values of one variable would be. https://en.wikipedia.org/...
DanceroftheStars's user avatar
2 votes
2 answers
236 views

How to predict the radius of a Red giant

I am working on a sci-fi that goes over such a large length of time that I will be having stars dying out, and this raises a question that I would need to find an answer to. How can one predict the ...
DanceroftheStars's user avatar
0 votes
2 answers
223 views

Why do we not call black holes black stars or dark stars?

I've never understood why the term black holes are widely used to describe what is actually a black star or dark star. I mean why name something just because of its extreme space curvature effects? In ...
eBookworm's user avatar
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5 votes
1 answer
441 views

Reasonable stellar body stats

I'm working on a video-game (just a hobby) and I'm trying to strike a balance between scientifically accurate enjoyable to explore. I have here a table of the star types I plan to use. (yes some "...
Cameron Critchlow's user avatar
1 vote
1 answer
84 views

Where can I get historical data of tropical longitude of Delta Cancri

I need historical data of tropical longitude of Delta Cancri. Where can I get it. As of now it is approximately 128 Deg from Vernal Equinox. Where can I get it's historical data, say from 5000 BC to ...
codingEnthu's user avatar
0 votes
1 answer
237 views

What is the distance between Stephenson 2-18 and Earth?

The distance between Earth and Stephenson 2-18 is 19,570 light years (1.15×10¹⁷ miles). The thing that makes this reasonable is because the Earth is in the Milky Way Galaxy and Stephenson 2-18 is in ...
Astral's user avatar
  • 11
3 votes
1 answer
2k views

Could the Methuselah star be evidence that there was a universe before this one?

If the Methuselah star proved to be older than the universe could it be from a previous big bang big crunch cycle in which not everything was crunched? What would be the smallest radius the universe ...
user avatar
2 votes
1 answer
332 views

Latest apoastron of Sirius

The only date that I can find for the latest apoastron of Sirius stars is 2019. Is there a more detailed date with at least the month and/or day. Obviously, it happened in 2019 but can't find any ...
Steve8888's user avatar
2 votes
1 answer
113 views

S0-2 (S2) Diameter/Radius

I'm a student, I am doing an investigation about S0-2. My idea was to take the wavelength that emanates from the star. When I saw the data from Science magazine I found a problem that was that the ...
Nicolás Vallejos's user avatar
0 votes
0 answers
49 views

How do the orbits of star systems V871 Centauri (septuple), Gamma Cassiopeiae (octuple), and QZ Carinae (nonuple) work?

Several years ago, I asked the question on here, "How do the orbits of Nu Scorpii and AR Cassiopeiae work?" At the time, these two stellar systems were the most populated (I don't know the ...
Curious Layman's user avatar
3 votes
1 answer
279 views

Can a star have one forbidden line or does it have to have many?

My question is: Can a star have one forbidden line, or does it have to have multiple? Some Examples I'll be using the O ᴠɪɪ line as an example. ζ Puppis is a well studied O4Ief star with the O ᴠɪɪ ...
Neil Iyer's user avatar
  • 133
1 vote
1 answer
89 views

Is there a easy way to read a star map and discover when and where it was seen and recorded?

I'm making puzzles for a game and found out that you can find out what the night sky would have looked like on any particular date, is there any web site or app that can read a star map and tell ...
NzumbeCortez's user avatar
2 votes
2 answers
1k views

Confusion over habitable zone

I am confused over the habitable zone, as I calculated the expected temperature of Earth (minus greenhouse effects), and it would be -17 C. Which is below the freezing point of water. I also made a ...
DanceroftheStars's user avatar
3 votes
0 answers
147 views

When did astronomers accept that fixed stars aren't fixed and are at different distances?

Was it when heliocentric model was spreading in the whole world? I saw a model of the solar system that was made in the 18th century where the sun was in the middle and the planets and comets around ...
Mansur Hasan's user avatar
3 votes
1 answer
110 views

Distribution of Galaxy sizes (star count)

First off, I realize how hard this is to even come close to estimating, but I'm trying to get a "general feel" for the distribution of galaxies by star count. I realize everything from rogue ...
Cameron Critchlow's user avatar
0 votes
2 answers
90 views

Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?

Stars have to be a certain size to initiate fusion to begin with, correct? Isn't this why brown dwarfs are considered 'failed stars'? But wouldn't the Sun (and other stars with sufficient mass, like ...
Kurt Hikes's user avatar
  • 5,097
0 votes
0 answers
44 views

On a theoretical young tidally locked planet and its relationship with temperature

I have a question regarding tidally locked planets, regarding the length it takes to reach a certain temperature. How would one calculate the estimated temperature after a certain amount of time being ...
DanceroftheStars's user avatar
24 votes
3 answers
3k views

Did the Sun's light always peak in the green wavelengths?

So, I know the sun is getting brighter over it's lifespan and I'm wondering how that affects its emission spectrum. The reason I'm asking this is because I find it weird that plants reflect green ...
Elhammo's user avatar
  • 1,107
1 vote
2 answers
107 views

Laser pointers spotter

Can I use a laser spotter as a guidance to a star in the sky? That's if you're by yourself. Here is an example of a spotter on a tripod 10 feet any from my camera! laser pointer
RJ Przybylo's user avatar
7 votes
1 answer
293 views

What did Galileo believe stars were?

Did he believe stars were attached to the sphere of fixed stars, or did he believe they were suns or did he believe stars weren't attached to anything but just points of light?
Mansur Hasan's user avatar

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