Questions regarding large spheres of plasma undergoing fusion.
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1answer
28 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 ...
0
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1answer
32 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....
1
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3answers
40 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
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1answer
47 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
36 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
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1answer
86 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
25 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
129 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
356 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
292 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
48 views
Almost unseeable light moving over nightsky. What is it?
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 ...
0
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0answers
26 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
98 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?
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1answer
62 views
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 ...
-6
votes
1answer
65 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
111 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 ...
1
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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
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1answer
103 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
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1answer
88 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
24 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 ...
0
votes
1answer
40 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
194 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
vote
3answers
139 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
5k 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
46 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
56 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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votes
2answers
95 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
51 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
votes
1answer
98 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
votes
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 ...
1
vote
2answers
96 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
102 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
54 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
126 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
78 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 ...
2
votes
3answers
133 views
Our Sun already a White dwarf?
I watch the discovery science channel a lot & enjoy the material about space, stars, planets, etc. In one episode the narrator states our Sun will one day become a white dwarf star. The size of ...
3
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1answer
130 views
How to calculate observer's latitude from declination and culmination of a star?
From gcseastronomy.co.uk:
A star culminates at 50°. It has a declination of +20°. What is the latitude from where it is observed?
What is the relationship between a culmination, declination, and ...
3
votes
0answers
27 views
How to fit lorentzian to lyman alpha cross section?
This is my data and purpose of this assignment is to fit a lorentzian to this data.
And.. i dont know how to do that....:(
First, there is sharply lowered region.
Couple of hours of googling isn't ...
4
votes
3answers
132 views
Is star a necessary phase in black hole lifecycle?
It now seems general fact that when a massive star core collapses at the end of its lifecycle it forms a black hole, can a black hole be formed skipping the star phase altogether?
2
votes
2answers
963 views
Fate of Jupiter when our sun dies
Five billion years from now, the sun will have grown into a red giant star, more than a hundred times larger than its current size.
While this metamorphosis into the giant star will change the solar ...
3
votes
1answer
49 views
Is it possible for a solar flare in one star to influence the chances of a solar flare in another star?
Can a solar flare reach far enough to travel from one ordinary star to another? If so, how can that solar flare affect the following star?
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2answers
87 views
Can Two Stars of One Same Type Orbit Each Other?
This is a simple, textbook definition of a binary star orbit. One low-mass star orbits a higher-mass star in a narrow but definitive center. For example, the high-mass star would be our own sun--a G-...
4
votes
2answers
365 views
Detecting habitable planets
From my understanding we detect planets by measuring dips in light intensity from the star the habitable planet is orbiting when it passes by it.
There are 2 things I don’t understand about this ...
3
votes
2answers
55 views
Observing eclipsing binaries
In a matter of weeks, I will be performing my first observation using a 25-cm Newton telescope (+CCD camera) and would be grateful for advice regarding an otherwise basic research that I have decided ...
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3answers
66 views
How do I obtain the brightness of a star in the night sky?
I am planning to conduct a research which involves observing the brightness of a star. So far, I haven't been able to obtain much information as to how I may go forward with the observation process. I'...
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3answers
70 views
What would happen if a star passed through the barycenter of two binary stars?
I was doing some research on Alpha Centauri A and B, and thought to myself: 'What would happen if something passed directly through the barycenter of these two stars?' I may theorise that a passing ...
2
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2answers
61 views
What does this figure imply about the luminosity of pre-main-sequence stars?
Check out Figure 1 in http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1955PASP...67..154H&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf .
It seems to ...
7
votes
2answers
162 views
Why the track of the subgiant stage is almost horizontal on the HR diagram?
It is stated that:
After the main sequence, as fusion weakens or stops in the core, outward radiation weakens. The helium core contracts and heats up. Gravitational energy is converted to thermal ...
