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Questions tagged [star]

Questions regarding large spheres of plasma undergoing fusion.

17
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3answers
3k views

Can I sense a bright star pointing an eight foot antenna towards it?

If I connect an eight foot Yagi or other comparable sized antenna to my oscilloscope and point the antenna at a bright star will I see a voltage on my oscilloscope? I am not interested in turning the ...
1
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0answers
15 views

Fast moving bright star with eliptic course, instant stop [duplicate]

Around 13 years ago I saw fast moving bright star with eliptic course which crossed half a sky in 1-2 sec and stopped instantly like it was a smashed like a bug, and didn't move for a while few ...
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2answers
71 views

Are there any stars that one day we could collide with?

I'm not talking about tomorrow but in the far far future could we say our Sun could collide with another star or otherwise within our current detectable range?
3
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1answer
46 views

Will comet 21P that just passed Earth on Sept 10 produce Draconid storm on Oct 9?

Comet 21P/Giaccobini-Zinner just made its closest pass to Earth and also made its Solar perihelion on the same day (Sept 10) which is roughly one month ahead of the annual Draconids meteor shower (Oct ...
0
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3answers
56 views

Hypothetically, if our sun was yellow would we still see “white” colours?

Hypothetically,if our sun was yellow would we still be able to see white colour on objects like snow,cotton etc.? Would we have the phenomenon of rainbow?
3
votes
1answer
60 views

Why does the adiabatic exponent decrease at the ionization zones?

The context is the ionization zones in stellar atmospheres or interiors, the Sun, for instance. The adiabatic exponent is the heat capacity ratio: $$\gamma = \frac{c_P}{c_V} = \frac{C_P}{C_V}$$ And,...
4
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1answer
55 views

Stellar core mass as a function of metallicity

Using Hurley's 2000 paper on Single Stellar Evolution, I have graphed the core mass of a star at three stages as a function of metallicity, Z, for a chosen ZAMS mass: at the beginning of the HG (MS), ...
4
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2answers
64 views

Classification and discovery of stars

How do astronomers find the difference between a 'Cephid Variable Star' and distinct normal stars with opaque objects blocking it's light, like stars with planets revolving around them while both ...
2
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1answer
35 views

How to find star location knowing latitude and LST

Newbie learning Astronomy and was curious how to locate a star giving a Latitude and LST. For example if my LST is 4:00 and my latitude is 20*N, how would I find where the Horsehead Nebula appears in ...
0
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3answers
97 views

Is there any definitive proof of stars being “born” in nebula formations?

Is there any absolute evidence of star formation inside of nebulae (AKA stellar nurseries) as is suggested and even stated as fact by many textbooks?
5
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2answers
75 views

Temperature gradient in stars

It is a well known fact that in stars, there exists a temperature gradiënt. The observational reason is because we perceived spectral lines in the otherwise continuous spectrum of a star. If this ...
3
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4answers
110 views

Why there are less massive stars than low mass stars?

What factor determines the selection of star mass? And how we know that the number of massive stars is less than the number of low mass stars?
6
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1answer
78 views

Were all first generation stars of same mass and size?

If the density of the matter from which the first generation stars were made was homogeneous, so during the star formation nuclear fusion would have started around when they all reached to same ...
2
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1answer
46 views

What are these objects near Mirach

Night sky objects always interested me, nowadays Im trying to observe and photograph some of these objects. My phone is iPhone 6S, i used SkyGuide app to find positions, NightCap to photograph. Im ...
1
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1answer
49 views

Eccentricity and Inclination of a Star

I understand Planetary Eccentricity and Inclination. However when it applies to a star, does the centre or ecliptic plane refer to the Sun or the Galactic Centre? The star Sirius for example, 136....
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3answers
44 views

Ratios of magnitudes instead of differences

The color index in the photometric system is defined by the differences in magnitudes between two wavelength filters, which gives the ratio of intensities. For example, to determine the B-V index, you'...
3
votes
1answer
61 views

Orange light that rises quickly and moves of to the righ [duplicate]

I have recently noticed an orange "star" (or what I presume to be a star), rise above the hill line behind my home. It rises later than every other star and rises within a few hours while the other ...
3
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2answers
48 views

Dataset containing list of known globular clusters

Does anybody know if there is an existing dataset that consists of all known star clusters, their name, and their apparent dimensions or similar? Is it possible to make a query to, or download all ...
4
votes
1answer
98 views

We are in Green Lake, WI, 8/12/18, seeing bright orange “planet”/“star” almost due South, perhaps 20 degrees above horizon, what is it?

I have a “sky” app on my ipad and expected it to be Mars, but my app shows Mars just below horizon and closer to East. Oh, I should add that we saw this about 10:15 tonight. Hanging out watching ...
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0answers
27 views

Are there simplified M-L, M-R, and lifetime equations for non main sequence stars?

To give some context - I am trying to create a simple program that outputs the stellar properties of a star when given its initial mass and current age. e.g. Input Initial Mass = 2e30kg Age = 4.6 ...
5
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2answers
162 views

The formation of new stars as depicted in Feynman's lectures

I've stumbled upon this curious passage addressing the formation of stars in Feynman's lectures on physics: Whether we have ever seen a star form or not is still debatable. Figure 7–12 shows the ...
7
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1answer
361 views

Why is H_delta prominent in type A stars?

I understand factually that H$\delta$ lines are most prominent in type A stars and less so in more extreme types of stars on the H-R diagram. However I was wondering the reason for why they are not ...
6
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2answers
306 views

Currently proposed ways to distinguish between a really big planet and a really small star

The Next Big Future article Rogue Exoplanet 12.7 times bigger than Jupiter is 20 light years away Astronomers using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) have made ...
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0answers
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Almost unseeable light moving over nightsky. What is it? [duplicate]

Sometimes when I look up at the sky at night, I can see something moving. It’s so small that I barely can see it, but I can’t see it when I look directly at it. I need to look beside it to see it. It ...
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0answers
27 views

What could this have been? [duplicate]

A few weeks ago me and a friend were at my pool. It was night time, and I looked up at the moon. Right beside the moon was this bright orange looking star. It looked really creepy, but I wasn’t sure ...
2
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1answer
162 views

What are the so called clouds of dust and gas made of?

We constantly read about "clouds of dust and gas" surrounding a (or being the initial state of a) star, but what elements constitute such dust and gas?
2
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2answers
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Struggling to use my new telescope

I recently got my first telescope, a Bushnell reflector telescope. I spent a good while setting up my alignment. And I can see the moon perfectly! I went to look at another, Mars. I got it aligned in ...
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1answer
79 views

Black-hole becoming a star again - follow-up question [closed]

Some questions have been posed about black holes becoming stars again once they attract enough hydrogen/atomic matter from another star. Some answers were a forceful NO. Never. However - let's ponder ...
1
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1answer
115 views

At what speed does something have to travel away from us for it to red shift enough that it becomes invisible to the human eye?

Are there stars, galaxies etc that we cannot see because they are traveling too fast and their spectrum is shifted below our visible range? From what I understand, red shift is caused by stars and ...
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0answers
35 views

a star in the sky thay moves back and forth way up in the sky [duplicate]

did anyone watch the sky in the west at 1:15 am.On 7-13-18. a star moving around in the greenup ky UT WOULD go back and forth
2
votes
1answer
112 views

How to construct a sky map

First of all, I have very basic knowledge of astronomy so sorry if I make some mistakes in my terminology. I'd like to plot the Southern Cross. I can find the name of its 5 stars. Also, I have some ...
2
votes
1answer
89 views

How space scientist keeps the track of the stars?

In billions of stars, how space scientist keeps the track of the stars ? There is a star called KIC 8462852, I saw that picture, star is so small from the earth. It has higher chance to miss that ...
0
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0answers
25 views

Bright light moving across sky heading north [duplicate]

This morning I saw a very bright light move towards the north. It looked as if a piece broke off. I was wondering if this may be a comet, or a rocket? This light was much brighter than surrounding ...
1
vote
1answer
61 views

Stellar Classification and Star RNG

I found a table that was based on data from 2003 for Stellar Classification, and I can't get to the given data source. I plan on using the table as a basis for a program that spits out random star ...
4
votes
3answers
223 views

Why do photos of Earth always have a black background?

if we are in the milky way, and people are able to take photographs from Earth that look like this: Then how come almost all of Earth's photos look like this? In the first photo, we are seeing what ...
1
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3answers
142 views

What are the possible star fuels?

I always thought the only fuel for a star was hydrogen, which is fused into helium. But while reading some questions and answers here in ASO, I saw phrases like "This balance stays relatively stable ...
21
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2answers
6k views

Is our sun in a star cluster?

Sorry for the absolute begginer question here, but is our sun a part of some globular cluster? It is something related to Virgo supercluster?
14
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2answers
1k views

When a star reaches the red giant phase, why does it become more opaque?

Please refer to this answer from Quora: ... a star will become a red giant before it begins burning helium. In fact, it will bloat into a red giant while still burning hydrogen in a shell on the ...
1
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1answer
50 views

What factors makes a star big in size(Physically)?Is the size of the nebula a relevant factor?

(Our sun compared to some of the known stars) I know that the star is born in a nebula.Do only a extremely gigantic nebula give rise to large-radius star or is there any other factors related?
2
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1answer
57 views

What types of star do we know are hostile to life (like ours)?

Certainly all stars have enough energy for a planet to host life. But a more magnetically active star is not preferred because solar ejection could strip planets of their atmosphere. What's the right ...
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2answers
96 views

What sun-like star is closest to earth/sun? [closed]

This list says that Tau Ceti is very like the Sun (spectrally). Others are predominantly red dwarfs. Is Tau Ceti closest star which is quite like the sun according to some criteria?
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2answers
57 views

Can life on earth be supported by only a Red Dwarf star or a White Dwarf(state still hot not cooled enough yet)?(Provided it is near to the star)

Can a red dwarf star or a white dwarf have enough energy to support life on earth? How it will change the climate and the seasons of earth if it is our only star? (energy source)(Expecting it to ...
4
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1answer
101 views

Do narrow lines in the spectra of O- and B- type stars always indicate magnetic fields?

I was reading a paper on the differential emission measures of a set of hot O- and B- type stars. As the authors discuss in Section 3 (page 959), two stars, $\tau$ Sco and $\theta^1$ Ori C, have ...
2
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1answer
29 views

Relationship between galactic rotation and stellar lifetime

I have read that the lifetime of stars is much less than the period of rotation for a spiral galaxy. For example https://www.coursera.org/learn/evolvinguniverse/lecture/wlYhz/the-origin-of-spiral-arms ...
2
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3answers
117 views

Position of specific stars in the sky as a function of time

I'm a beginner in astronomy and I'm trying to figure out how to model the positions of stars in the night sky mathematically (ie a function which spits out azimuth and altitude as a function of time). ...
3
votes
1answer
105 views

Why planets and stars are always round/oval in size? [duplicate]

What kind of stability it provides to each and every celestial body that each one them are round in shape?
4
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1answer
55 views

Is there any difference among exoplanets in composition due to host star?

Simply put, would, say, rocky planets orbiting red dwarfs have a noticably different chemical makeup than rocky planets orbiting B-type main sequence stars? Mutatis mutandis gas giants and the other ...
5
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1answer
280 views

Black Dwarf Capabilities

Can a black dwarf be suitable for manned exploration, once it cools down? And potentially used for space mining?
4
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1answer
128 views

What makes an exoplanet to orbit around its star backwards?And why did we consider our orbital movement to be forward?

I read somewhere that an exoplanet in the name of HAT-P-7B orbits its star backwards.Why? And why did we consider our orbital movement to be forward?Is there some scientific reason to consider the ...
4
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1answer
80 views

Is the age of the solar system equal to the age of meteorites?

I've read articles that state the age of the solar system has been determined by measuring the amount of decay of isotopes in some meteorite, which has demonstrated that the lead isotopes in the ...