Questions tagged [star]
Questions regarding large spheres of plasma undergoing fusion.
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Is there a star over my head?
Say I'm standing up straight, and I draw a straight line from my core through the top of my head (perpendicular to the ground). What is the probability that that line intersects with a star?
EDIT: I'...
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Is there a better explanation of this picture showing the very distant star "Earendel"?
"Close-up of the tiny region where Earendel happened to fall right on top of the narrow line where the magnification increases by (tens of) thousands of times. A cluster of many stars is seen ...
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How can 'HD 140283' be older than the universe?
Scientists have known about the star HD 140283, informally nicknamed the Methuselah star, for more than 100 years, since it cruises across the sky at a relatively rapid clip. The star moves at about ...
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Why does gas form a star instead of a black hole?
When a space gas gets pulled together a star is formed. On the other hand, when a massive star dies, it collapses to a black hole.
You would think that the initial mass of the gas would be bigger ...
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How did Hubble know the red shift difference between "moving away" and "old"?
My 9yo daughter is very into space at the moment and asked a question that my physics knowledge (6th form college, 20 years ago) is way too poor to answer.
Her space book tells us that as stars age, ...
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Are there any stars that orbit perpendicular to the Milky Way's galactic plane?
Most stars orbit in the Milky Way's galactic disc. But is it possible for one to orbit perpendicular to it?
Here on Earth since we're inside the galactic plane we can't get a good view of what the ...
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Why is one picture of this star blue with red, and the other red with blue?
Someone just retweeted a NASA tweet onto my timeline, and it includes two images, allegedly from the same star that was in the process of dying, taken by the new space telescope, side by side:
I don'...
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What is this web on the surface of the Sun?
I was going through my Social Media Feed and found the attached post too frequent. The caption reads this is the best image of our Sun. Just as an example, the Universe Today's This is the Highest ...
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What are the odds that the Sun hits another star?
The Sun moves around the Milky Way disk in the same direction as most of the other stars in our galaxy (prograde). But there are a number of older stars in the galactic halo that move in retrograde ...
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How many stars and galaxies can be seen by the naked eye?
How many of the luminous dots that we see naked are galaxies and not stars from our galaxy?
I imagine that the majority of the luminous points that we see naked eye during the night, are actually ...
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Are we really star-stuff from the interior of collapsing stars?
Carl Sagan has said several times that we are "star-stuff".
One instance can be found in Good Reads' Carl Sagan > Quotes > Quotable Quote:
The nitrogen in our DNA, the calcium in our teeth, the ...
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Is there a theoretical maximum size limit for a star?
Some stars are simply huge. Eventually, though, wouldn't there be simply too much pressure or mass for the star to sustain itself? Wouldn't it eventually collapse into a black hole?
Is there a ...
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What causes a star to become a pulsar?
What processes does a star undergo to become a pulsar? Does it take a very specific star with a certain set of qualities such as "Just the right mass, diameter, and composition," or is it a freak ...
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Why don't (or can't) stars be more than 325 or so times the mass of the sun? What limits their size?
Is there a particular reason why stars cannot grow as massive as they want to?
And why doesn't this limit apply to supermassive black holes?
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Is there any planet bigger than a star?
Or a star smaller than a planet?
Which star and planet would be an example of this?
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Is the light we see from stars extremely old?
Our nearest star Proxima Centauri is 4.243 light years away from Earth.
Does that mean we are seeing light that is 4.243 years old everyday?
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Was Galileo expecting to see so many stars?
Beginner amateur here. I see mentioned many times that Galileo was surprised to see the moons of Jupiter and all that their existence proved, i.e. the Earth not necessarily being the center of ...
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How often do stars pass within 1 light year of 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 ...
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Why do stars explode?
I always hear the narrator of documentaries say that a star explodes because it ran out of fuel.
Usually things explode when they have too much fuel, not when they run out of fuel.
Please explain...
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Why are there no green stars?
There are red stars, and orange stars, and yellow stars, and blue stars, and they are all understandable save the fact that there is a 'gap': There are no green stars.
Is this because of hydrogen's ...
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How else can a star form, other than gravitational collapse?
I read this paragraph on the Sun's page on Wikipedia:
[The Sun] formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most ...
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Are we made of the stuff of one star or more stars?
[T]his coincidence enabled stars in the late stages of their lives to turn helium into carbon, oxygen and most of the other atoms that you and I are made of. [...] [W]e're made of star stuff.
Max ...
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What exactly is the "paradox" in Olber's Paradox?
To the extent of my understanding, Olber’s paradox states that if the universe was static and homogeneous, we should see a star at every point in the night sky and therefore the night sky should be ...
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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?
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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 ...
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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 ...
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What's the brightness of Alpha Centauri from Proxima Centauri?
Self-explanatory, but I would like a comparison as well. Is the light enough to see by? How disrupted will the pitch darkness on the spot opposite of the 'solar pole' be?
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So, what exactly is an 'ultra-cool' dwarf star?
The TRAPPIST-1 system is around an ultra-cool dwarf star. I went looking for more information on that kind of star, and found very little. The Wikipedia article on it lengthened from a minimal stub to ...
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How hard is it to find the Sun's "sisters?"
As @ProfRob stated in his excellent answer regarding the ejection of the Solar System's fifth gas giant,
It is for similar reasons that, even though the Sun was probably born in a cluster of $\sim 10^...
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Why are orbits elliptical instead of circular?
Why do planets rotate around a star in a specific elliptical orbit with the star at one of it's foci? Why isn't the orbit a circle?
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How Would a Neutron Star Actually Appear?
Having seen many pictures produced by artists of neutron stars and planets that orbit some of them, I was wondering how a pulsar would appear to a human being, in visible light (assuming the intense ...
user10106
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What would the effects be on Earth if Jupiter was turned into a star?
In Clarke's book 2010, the monolith and its brethren turned Jupiter into the small star nicknamed Lucifer. Ignoring the reality that we won't have any magical ...
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Is S2 still the fastest known star in the galaxy?
Wikipedia's entry for the star S2 says that it has
the fastest known ballistic orbit, reaching speeds exceeding 5,000
km/s (11,000,000 mph, or 1⁄60 the speed of light) and acceleration of
about 1.5 ...
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Why will HD 84406 be chosen as the first target for testing JWST?
HD 84406, is a star approximately 241 light-years away in the constellation of Ursa Major. HD 84406 will be the first star to be imaged by the James Webb Space Telescope in order to test the focus of ...
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Will new stars stop forming at some point of time?
New stars keep forming in the universe thanks to all the nebulae. Now, we need Hydrogen to form stars and there would a time when all the hydrogen will get exhausted, and no more star formation will ...
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Did atoms in human body indeed come from stars?
I think I am not alone who saw videos about that we (humans) are made of same atoms which someday were in stars. In other words, some atoms in our bodies are from stars which exploded billions of ...
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Can lightning occur in stars like the Sun?
In the Wikipedia article about lightining, the following explanation is given about the electrification process in clouds:
The details of the charging process are still being studied by
scientists, ...
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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 ...
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What's the percentage of strange matter inside a star at any time?
Is there any amount of strange matter (or "top matter"?) inside stars?
By strange matter I mean matter made out of flavours of quark other than up/down.
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Exoplanet dip in transit light curve when the planet passes behind the star
In the animation below, I don't understand why the brightness slightly decreases when the planet is behind the star.
Where does this effect come from?
user16492
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Does any iron fuse in stars before they go supernova?
I understand that iron and all heavier elements consume more energy to produce than they make, and that is what eventually leads to a supernova. I also understand that a lot of the heavier elements ...
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How many stars can stay close to each other without collapsing?
Is it possible for two stars to exist close to each other?
"Close" is relative; let's assume that two stars are close to each other if they are at the center of the same solar system.
It's ...
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What does it mean for a star to go nova or supernova? Can I safely observe these?
What does it mean for a star when people say it goes 'nova' or super nova, what are the differences?
More importantly, can I safely observe these with an amateur telescope? I imagine they would be ...
user96
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How are constellations intact if the stars are rotating around galactic nuclei?
From what I understood, the Milky Way (or stars in the Milky Way) doesn't rotate like a collection of points in a disc due to the presence of some invisible matter. In theory, the angular velocities ...
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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?
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What is the upper and lower limit of temperatures found on stars?
What are the most extreme temperatures (both hot and cold) stars have been detected at? Is there an upper and lower limit for the detected temperature of stars?
user8
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Why do stars appear to twinkle?
Sometimes at night you will look up to the stars and they will appear to twinkle, getting brighter and darker in bursts.
Why does this happen? Is this because of our atmosphere? Would they twinkle ...
user96
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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 ...
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Hydrogen burning vs Hydrogen fusing
Does the term "Hydrogen burning" mean the same as "Hydrogen fusing" in astronomy? If not, then what is the product of "Hydrogen burning"? Assume the product of "...
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Could stars form outside of galaxies?
Is it possible for there to be a dense enough nebula to form stars outside of any galaxy? Does a galaxy have a minimum size to produce stars? Or could you have a few dozen stars clustered together by ...