# All Questions

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### stellar metallicity

I saw a talk recently mentioning that another factor that may determine a star's metallicity (besides age) may be how far from the center of its "birth cluster" it is when the short lived hot central ...
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### How/where to check where the Sun is (constellation)?

I would like to check in which constellation the Sun was in at some time in the past, any recommendations how to do that?
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### Real-time position of a distant celestial body

How might it be possible to determine (via some specific online empemeris or via some well-understood algorithm) the current position of some distant celestial body (e.g. Betelgeuse)?
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### Is the Astronomy community still concerned about the lumpyness of matter distribution in the universe?

A decade or so ago, when I was still a science undergrad, one of the open questions in astrophysics was to explain the uneven distribution of galaxies in the observable universe. That is, why did the ...
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### What if the earth stopped rotating and revolving at the same time?

What will happen to us are we going to move in a tangential direction with earth axis of rotation ?
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### Is the speed of a black holes gravity faster than light?

If light cannot escape a black hole because of it immense gravitational pull, wouldn't that mean that everything that the black hole consumes be sucked in faster than light?
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### Road map for a faster spaceship

New Horizons, speediest yet, is currently running at about 15 km/sec relative to the sun. What is the roadmap for future ? How is it possible to reach much faster speeds ?
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### Sun's apparent motion above the arctic circle during summer solstice

I'm having difficulty with an apparent contradiction about the sun's motion during the summer solstice above the arctic circle. The YouTube video The North Pole Entire Summer of never ending sun ...
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### What is a Seyfert galaxy?

I know Seyfert galaxies are types of active galaxies, but I do not understand what separates them from other types of active galaxies. Are they brighter/not as bright as other types of active ...
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### The dark side of the moon

I encountered this statement that the dark side of the moon is hidden from our sights. Could someone please explain?
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### What is the actual fate of our sun?

I know that, once our nearest neighborhood fusion reactor starts fusing helium in its core, it will become a red giant, then eventually a white dwarf, slowly losing heat until it no longer shines, to ...
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### Can Sun become a big ball of gold atoms?

The atoms inside the core of sun are continuously fusing and forming atoms .Can this continuous fusing make gold atoms ?
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### What causes the aurora of other planets to have different colors?

All I could come up with is it depends on the atmospheric composition of the planet as they will interact with the charged solar particles which might be true but is there is there a definite reason ...
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### Why does radio astronomy offer higher resolution images than optical?

According to this lecture,"Radio astronomy has several advantages over optical astronomy...We can make the highest resolution images, and see things happening on the smallest scales." Why is this? If ...
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### Could the warp drive be possible? [on hold]

Many people say that we'll never reach the speed of light, but if someday we constructed a warp drive, would it be possible to reach that speed? If not, what is maximum velocity we could reach with ...
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### If the Sun became a black hole, would it swallow our entire Solar system?

If the Sun became a black hole, would it destroy all the planets?
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### Relationship between temperature and HRD

If the temperature of a star is increased, and the size of the star is not modified, the point which represent the star in the HRD moves: Upwards to the right Upwards to the left Downwards to the ...
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### IAU Dwarf planet definition Point 2.b - is not a satellite

I am a bit confused with point 2.d of the IAU's resolution on dwarf planets. (2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun (b) has sufficient mass for its ...
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### How long will it take to reach the closest earth like planet

Using the engines today how long will take humanity to reach earth like planets?
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### Any tip on maintaining a log of celestial objects?

I am an amateur observer and Olympus 10x50 binocular is my tool. As I keep locating celestial objects (Planets, Stars etc), I would like to maintain a log of the observed objects. The purpose of the ...
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### Why are there no more images revealed by New Horizon?

Since a few days after the flyby there are no more images published on the NASA page. Why is NASA waiting to publish any more images for some reason? Or is there something happened to New Horizon?
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### What is the largest possible size for a brown dwarf?

What is the largest possible size for a brown dwarf before it has enough mass, capable of sustained fusion, thus becoming a star?
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### What was the orbit of the meteor that impacted the Moon on 2013 September 11?

On 2013 September 11th, a meteor impacted the Moon leaving a 34-meter crater. So far the only info I've found was from youtube (https://www.youtube.com/watch?v=zCFDkj2JtyA) and this site: ...
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### how to assess a periodical signal?

After folding a light curve, we may get some kind of shape. How to tell whether there is a real periodical signal quantifiably? The fluctuation may be small, and the folded shape may not be perfect. ...
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### Can I measure the moon's gravity?

Since I learned about Newton's gravity law, I wonder if I can measure the moon's gravity using (almost) no special equipment. The best I could come up with is a pendulum, which is in a resting ...
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### Star like light moving in the sky, what could it be?

I was camping this weekend away from the city, so my friends and I decided to spend one of the nights watching the sky, since it's impossible to see anything around where we live. After a little ...
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### How is a non-rotating black hole created

How are non-rotating black holes formed? I guess that non-rotating black holes are formed from non-rotating stars but I couldn't find any proof that such a star exists on the internet. If this is ...