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1500 questions
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What is it exactly about these flares of infrared light from Sgr A* that "confirms" it is a supermassive black hole?
CNET.com's SCI-TECH
Scientists confirm a 'supermassive black hole' at the heart of our galaxy
It's "mind-boggling", they say.
This links to Astronomy.com's Scientists finally confirm the Milky Way has a supermassive black hole
This links to ESO's…
uhoh
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How much greater is the star density in our galactic bar?
How much denser is it in the galactic bar than the "normal" density at the same radius?
Is it just a few percent? or is it, say, "three times" as dense?
Or are other factors at play: star brightness, gasses?
Or do we really not know?
Fattie
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Which part of the milky way does the image show?
As a general question and more in specific regarding the image above: Which part of the milky way, planets, stars, clusters are included in the image?
How can I know which entities are included in different pictures?
nick
15
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3 answers
Would an analogue of the definition for planets also work for moons?
This is a follow up question to What exactly is a "moon"? The conclusions I draw from James K's answer is that the IAU should define what a moon is. They haven't done so yet, but they should.
The obvious way to go about defining "moon" would be to…
Allure
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Can any information leave a black hole?
Referring to this question, is there any information that can leave black holes? Are they causing a permanent information loss in our Universe?
Aschratt
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What will happen to the shape of a galaxy when a super massive black hole lying in its center dies(evaporates out)?
What's at the Center of the Milky Way?
In this article it is said that a supermassive black hole lies in the center of milky way galaxy.
At its center, surrounded by 200-400 billion stars and undetectable to the human eye and by direct…
Paran
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Blowing up an asteroid/comet really potentially worse?
Often on television shows and in articles I see it mentioned that it'd always be bad to blow up an asteroid or comet because then the energy would just be spread out and cause even more damage.
According to some estimates I've seen around 100 tons…
simontemplar
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Would time go by infinitely fast when crossing the event horizon of a black hole?
If you were to fall into a black hole, my understanding is that from your reference point, time would speed up (looking out to the rest of the universe), approaching infinity when approaching the event horizon. If this is correct, would you see the…
Jonathan
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What is the limiting abundances of elements at the end of the stelliferous era?
Is there any reputable published source on expected elemental abundances at the end of the era of stellar fusion? I am here interested in the contents of galaxies; much of intergalactic gas will be lost and remain primordial.
Adams & Laughlin…
Anders Sandberg
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How does moonrise/moonset azimuth vary with time?
In my tenacious attempts to observe moonrise (surprisingly difficult in a poor weather heavily urbanized hilly area with frequent bad smog, with busy work schedule and a bicycle) I was frequently trying to find good observation spots that would…
SF.
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Why isn't interstellar medium pulled in towards nearest massive object?
How does the ISM resist gravity? That's the only force acting on it, and all other particles seem to collect together to form stars. What makes the ISM so special among other particles?
Max
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Why does the Moon seem larger when it is close to the horizon?
I've noticed that when I look into the sky at night, sometimes the moon appears very large near the horizon. Sometimes it also looks like it has a yellow tint.
Is this the light rays bouncing off the moon differently, or the atmosphere of the…
Timtech
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Why does Neptune only have one major moon?
Neptune is profoundly anomalous when it comes to moons among the gas giants. Jupiter has its four massive moons, Saturn has a several large spherical bodies and Uranus, a world similar in size to Neptune has five or so major moons.
Yet Neptune, the…
Mr Kusnetsov
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5 answers
What will a lunar eclipse look like from moon?
What will a lunar eclipse look like from moon? Will earth become a completely dark circle?
Santhosh
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Can I make a black hole with one or two atoms?
So I was watching something that said
if we compressed Earth into the size of a peanut: we would get a black hole;
if we compressed Mount Everest into a few nano-meters; we would get a black hole.
Can I make a black hole with one or two atoms? If…
Bradley
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