# All Questions

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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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### Can things move faster than light inside the event horizon of a black hole?

Black Holes are regions of space where things get weird [Citation Needed]. Past the event horizon of a black hole, any moving particle instantaneously experiences a gravitational acceleration towards ...
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### When a neutron star accretes matter, will its mass increase?

When a nova gets matter, the outcome is that it may lose more matter because of eruption. How about a neutron star? It is necessary that its mass will increase? When will it collapse?
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### What are iron stars?

I have a question about iron stars. I was fascinated about the theory about the inability of protons to decay, and it led me to a point where I read something about some special kind of star called an ...
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### Were parts of the Universe deflating during Inflation?

I was reading about the history of the early universe in Carroll & Ostlie and specifically looking at Inflation, which, as I understand, occurred because our [observable] part of the universe ...
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### Spicules vs Prominences/filaments

What is the difference between spicules and prominences/filaments. I know that they are both in the chromosphere, and I know the difference between provinces and filaments (depends on the view), but ...
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### Can the Sun become a big ball of gold atoms?

The atoms inside the core of sun are continuously fusing and forming other atoms. Can this continuous fusing make gold atoms?
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### Astrophotography - Unable to achieve focus with current setup

I am new to astrophotography and am looking for guidance. I have the following equipment: Orion StarBlast 9814 4.5" Altazimuth Reflector Tabletop telescope 1.25in Telescope Adapter Extension Tube T ...
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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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### 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 observed position of some distant celestial body (e.g. Betelgeuse)? To be ...
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### What uncertainty does an error bar signify in astronomy?

When an astronomer talks about her/his topic and shows an X/Y-plot with error bars. What should one assume that those error bars represent? 1 standard deviation? Or 2? Or some specific significance ...
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### Roll, Pitch and Yaw of Orbital Planes

I have been reading about celestial mechanics and particularly about planetary orbits. I understand that a planet's orbit can be tilted (pitched) with respect to the Earth's ecliptic and that it might ...
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### Eternally collapsing objects?

As has been pointed out by some scientists, that black holes aren't stable bodies but are eternally collapsing objects. How does one come to such a conclusion? Is hawking radiation related to this in ...
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### Finding the suns position in the sky anywhere at any time

What am I looking for? from any point Latitude, Longitude and date D I want to know where the sun is in the sky at any given time anywhere on our planet. I even don't know what the outcome will be ...
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### Is expanding universe adding potential energy?

A system with two massive bodies has potential energy proportional to their separation. Since the universe is expanding, is the potential (and total?) energy of such a system slowly increasing? What ...
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### Image sets for testing stacking algorithms?

I am looking for sets of astronomical images for testing different kinds of stacking algorithms. The idea is simple: if one has $N$ images of the same object, the signal-to-noise ratio of the ...
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### What's to be gained from the New Horizons mission once it's beyond the Kuiper Belt?

Now that we have seen what Pluto has to offer and New Horizons is headed to the Kuiper Belt, is there anything we can gain from the mission in interstellar space after it travels beyond the Kuiper ...
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### Why does Mercury have some cold temperatures? [on hold]

We all know Mercury is very close to the Sun, so why does Mercury have some cold temperatures? In contrast, the chilly night side can get as cold as minus 279 F (minus 173 C). From here.
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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's the distribution curve for meteor sightings?

I know that meteor showers have a "peak" observation time. What does the distribution in time look like? Is one side of the peak steeper/shallower or longer/shorter than the other side, and if so, ...
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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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### 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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### Is it possible to witness a star's death?

Given that the stars' distances to Earth are measured in light-years (for example, Sirius is 8.6 light-years away from Earth), what we are seeing as Sirius now is actually its state 8.6 years ago, ...
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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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### 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 [on hold]

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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### The dark side of the moon [duplicate]

I encountered this statement that the dark side of the moon is hidden from our sights. Could someone please explain?
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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? [closed]

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 [on hold]

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 ...