0
votes
1answer
56 views

Black holes and time relation

Why Is it said that if someone is being sucked inside a black hole then he/she may see that time is running slowly?
0
votes
2answers
80 views

What is the future of our universe?

Is the universe heading towards a Big Freeze, a Big Rip, a Big Crunch or a Big Bounce? Or is it part of an infinitely recurring cyclic model?
1
vote
2answers
124 views

Are we sure solar cycle is not related to the orbit of Jupiter?

Are we still debating the relationship between Jupiter and solar cycle? If not, what is the common or mainstream opinion about this topic? Or in other words, have we disproved the solar cycle is ...
0
votes
1answer
117 views

What is the shape of the Sun's orbit around the Earth taking into account elliptical orbits?

Consider the non-inertial frame that is at rest with respect to the Earth's revolution around the Sun. (Ignore the Earth's rotation around its own axis.) My question is, what is the shape of the ...
0
votes
3answers
96 views

Why is it that we can"t feel how fast the Earth is moving? [closed]

We are moving like 100,000 mph. And why do we not fall off going that fast
0
votes
2answers
42 views

Do massive OB stars accrete mass the same way as the black holes they turn into do?

It is often said, in spite of sci fi often having illustrated the opposite, that stellar mass black holes do not gravitationally attract material in their environment into themselves anymore than a ...
5
votes
0answers
71 views

What is the frequency distribution for luminosity classes in the Milky Way Galaxy?

I'm working on a game concept that does some mild simulation of realistic stellar classes and luminosities. In particular, I'd like to roughly model the general frequencies of the classes and ...
0
votes
0answers
15 views

Star Formation in the future [duplicate]

From what I understand stars form in dense clouds of hydrogen and helium molecules. Only so much hydrogen and helium were "created" from the Big Bang or rather formed if you may. Is it conceivably ...
0
votes
0answers
37 views

Resources on planetary stability

I am a fifth (and last) year undergraduate student in Physics with good level of Mathematics formation and basic Astrophysics formation. I recently read some theories about Solar System formation and ...
3
votes
1answer
124 views

What if we throw two solid objects parallel in space? Do those two objects have any chance to collide with each other?

What will happen if just throw two solid objects (for example, solid footballs) parallel in outer space and those two objects are floating and going far away in the universe. So is there any ...
1
vote
1answer
51 views

Eclipse — Solar and Lunar

Q. Why is solar and lunar eclipse not seen from all parts of the earth at the same time? I think its because of the revolution of the earth but i am not sure. I want a more reliable answer.
-6
votes
2answers
75 views

How do we know so much about the sun since we can't go near it? [closed]

I am wanting to learn everything there is to learn about the Sun from our solar system to the ends of the universe.
6
votes
2answers
196 views

How unusual is the solar system?

In Isaac Asimov's Foundation series, the main characters are looking for the long-lost Earth. There are two major features of the solar system that seem to make it unusual among the millions of ...
4
votes
4answers
159 views

Is it possible for a virus to come from a meteorite?

So I am not a true scientist and I was just wondering if an extraterrestrial rock from space can have some dangerous unidentified virus or bacteria that can be deadly and wipe out the Earth if it not ...
9
votes
1answer
590 views

Is the Sun really a medium size star?

It is often said that the Sun is a medium size, or even dim star, but is that true? According to this list of stars within 21 light years, only six stars are brighter than the Sun out of the closest ...
1
vote
0answers
50 views

Calculating AZ and ALT from RA and DEC: values are slightly different from Stellarium

I'm developing my own planetarium software and I using Stellarium to check if the values a get from my software are correct or not. All values are roughly equal, being different only in the seconds. ...
4
votes
1answer
120 views

How can we hear the sound of the Sun?

Recently NASA has revealed that they have recorded the sound of Sun. They say that it produces a sound like "Om". I can't understand how they can hear it. To the best of my knowledge, sound can't ...
0
votes
0answers
17 views

Dust mass-loss rate from a massive star given a set of parameters?

I've been looking for examples at how mass-loss rates are determined. I'm studying a circumstellar dust shell ejected from a Wolf-Rayet star. I have some parameters like, expansion velocity of the ...
0
votes
2answers
120 views

Where does Jupiter's gravitational force come from? Why don't Jupiters gasses fly away?

Gravitational force is the attractive force between any two masses. What about gaseous planets, where do they get their attractive force from? While the big rocky planets don't have enough ...
0
votes
1answer
40 views

Absolute/apparent magnitude and distance for HIP31978 inconsistent?

EDIT: I am still following up, but here's the latest response from Wolfram: Paclet servers are updated and optimized for each version of Mathematica, so I suspect you may be working on an older ...
0
votes
2answers
44 views

Do great spot like features favour appear in south hemisphere?

As we know, both Jupiter and Neptune have great spot like features in South hemisphere, and Saturn has dragon storm in south hemisphere, is it true that great spot like features appear in South ...
2
votes
4answers
118 views

From which exoplanets is our sun the brightest star on the night sky?

The brightest star on the night sky is Sirius, here in the Earth. But are there any exoplanets, where the brightest star on the night sky is our sun?
1
vote
2answers
108 views

Is solar wind a source of water?

Solar wind may contain some hydrogen and oxygen atoms which is the composition of water, some of them may move to the poles of earth, my question is, is solar wind also a source of water in earth?
1
vote
1answer
48 views

What happens when an Ultra Massive Black Hole cannibalize another?

Say hypothetically an UMBH with 50 billion solar masses (supposedly upper limit) is beginning to merge with another (Super)MBH similar to Sagittarius A* that sits at the center of the Milky Way ...
12
votes
1answer
236 views

Have we ever observed a body, such as a large asteroid, “hitting” the Sun?

Some other SE questions about launching ICBM's into the sun got me wondering whether we have ever observed an object on a path that intersected with the Sun? How close did it get?
2
votes
1answer
52 views

When I read that a system is located x light years away, why is there no direction?

Well, I just read an article about a galaxy with two black holes, and it stated that the galaxy is 1 billion light-years away. Why is there no direction given? If the Big Bang happened, and things are ...
0
votes
2answers
137 views

Question about space-time

In the Big Bang model of the Universe, every observable thing is thought to have expanded very abruptly from a point of infinite density and zero volume. However, the problem with this assertion is ...
1
vote
1answer
330 views

How to calculate the temperature of a star

I need a way to calculate the effective temperature (surface temperature) of a star for a stellar model. I need something in the form Te=.... I have: Radius in m mass in kg the composition of ...
5
votes
3answers
283 views

Should this photo of the sun's surface actually be white?

If I'm told correctly (eg. What Color is the Sun?) that the sun is actually white, should the photo on that page actually be white too? Is it just doctored to meet peoples expectations?: Likewise ...
2
votes
1answer
93 views

What part of the milky way do we see from earth?

When looking up at the night sky, we can sometimes observe a bright band of stars stretching across it. I know this is our galaxy but exactly what are we looking at? Could we look at the centre of ...
2
votes
2answers
125 views

Why isn't everything yellow(ish)?

I understand that - although appearing yellow - the sun is white. And that this is because the other light colours are scattered by the atmosphere. For example: Google image search for "The Sun from ...
1
vote
1answer
20 views

Could a “burping” supermassive black hole be responsible for a spiral galaxy's look?

I read an article which suggests black holes could influence the production of stars in the galaxy as the black hole can burst out powerful X-rays to "snowplow" the surrounding dust and gas. Although ...
1
vote
1answer
31 views

What constellations touch the 9-degree wide Zodiac?

Say Barry, could you abuse the answer-your-own-question feature of this site, and answer the following question: As noted in How many constellations in the Zodiac? the ecliptic itself touches 13 ...
1
vote
1answer
62 views

uses of coordinate systems

Wikipedia describes the five following celestial coordinate systems each with rectangular/spherical variants: horizontal equatorial ecliptic galactic supergalactic What are the practical preferred ...
6
votes
1answer
301 views

Is there any real chance of getting hit with a meteorite if we build a base on the moon?

I've been reading an article today on how the European Space Agency (ESA) has an interest in building a space village on the moon which will be 3D printed and assembled by robots. Eventually people ...
3
votes
1answer
212 views

What is the temperature inside a Black Hole?

Is it insanely hot? Cause of so much gravity? Is it close to absolute zero? Cause the matter is so closely packed, there is hardly any space for particles to move? Is it room temperature? Cause ...
2
votes
5answers
146 views

Fusion of elements inside heavy stars

I am confused with nucleosynthesis inside supernovae. I have read that the heavier elements are made through fusion of lighter element's namely hydrogen and helium. Does the star "store" all the ...
0
votes
1answer
27 views

Number of galaxies per redshift

Does exist something like a distribution of number of galaxies per redshift interval? I'm studying galaxy formation and evolution, and I'm curious to know how many todays' galaxies (with redshift ...
0
votes
0answers
22 views

Accuracy of Laplace Method for determining orbital elements

Recently I had to implement Laplace method and apply it to 3 observations of Mars (10 days in between two observations). The results were pretty good, with discrepancies with real data well below 5% ...
0
votes
1answer
55 views

Conversion from Equatorial Coordinate to Horizon Coordinates

I'm developing my own Planetarium software using C++ following the book Practical Astronomy with your Calculator or Spreadsheet 4th Edition. I don't know if I my formulas are correct or not, but when ...
2
votes
1answer
35 views

Can angular information be known more precisely than the diffraction limit?

The diffraction limit deals with the ability to determine if two things are separate. I am interested in the ability to find the the centroid of a single object. Imagine a star with no near ...
1
vote
1answer
76 views

What was James Bradley's calculation to calculate the speed of light?

Looking into the history of how the speed of light came to be determined, to what we know it to be today, James Bradley is often mentioned. He was credited with the discovery of the aberration of ...
1
vote
2answers
80 views

Center of the universe

Big bang is not an explosion, but an expansion of space and time. Universe had almost infinite density... wait a moment. If it had ALMOST infinite density, it had a certain volume, and thus, space ...
1
vote
1answer
83 views

How do we know that the Universe is still expanding now?

Yes, I know that most galaxies have a red shift and that means they are moving away from us. The problem is that the farthest galaxies are 13.8 billion light years away. That means that the info is ...
0
votes
1answer
82 views

Alignments of planets [duplicate]

I am going to ask an odd question, It is: In most of the images of our solar system we see that the planets are arranged in a straight line. As the paths of the planets are elliptical, could it be ...
4
votes
1answer
167 views

Why aren't new stars in Earth's relative proximity constantly discovered?

Okay, bear with me. In layman's terms: The estimates vary, but on a clear night, away from big cities, one can see up to 5000 stars in the sky. All those are in the Milky Way, but they're hardly ...
1
vote
0answers
52 views

Which is the most accurate stars catalogue for J2000 epoch?

I'm developing a planetarium software. I have no idea about how to obtain stars right ascension and declination. Searching on Internet I have found that Wikipedia has AR and DEC for a lot of stars. ...
1
vote
3answers
43 views

Is the duration of a sidereal year stable?

According to this essay by Phil Plait, the duration of Earth's sidereal year is 31,558,149 seconds. Is this figure stable? If I were to meaure Earth's orbit several million (or billions) of years in ...
4
votes
2answers
326 views

Camera reaching the event horizon

This question came to my mind after reading this. I think it is safe to assume that the supposedly thrown camera would not reach the event horizon in one piece. So my question is : If I dropped a ...
6
votes
2answers
181 views

Trying to understand the way Saturn's ring look in this famous Cassini image

You all probably know the famous The day the Earth Smiled image. For the life of me I can't understand what's going on with the rings there. Seems like the "bottom" half of the rings is the half that ...

15 30 50 per page