2
votes
1answer
48 views

Could supermassive black holes form in dwarf galaxies?

Supermassive black holes often exist in large galaxies (e.g. the Milky Way, Andromeda). They make up a fair portion of the galaxy's mass. Is it possible for a supermassive black hole to form in a ...
4
votes
1answer
74 views

How is the diameter of a gas giant calculated?

As we know atmospheres of celestial bodies don't just stop at a given distance. They gradually become less dense as you move away from the center. I understand that the diameter of stars is ...
5
votes
2answers
68 views

Maximum and minimum gas giant & ice giant densities

I'm working on a star system generator for a game; I'd like its results to be plausible but they needn't be super-realistic. I've got the orbital distances and masses of each body in the system, and ...
2
votes
2answers
129 views

Is the white hole a myth or not?

I've been doing some research on white holes, and there has not been enough information to provide the answer. Some websites are saying that they might exist, but it is not yet proven. So, is it true ...
2
votes
2answers
116 views

Are there any known objects in a “dual” tidally locked orbit?

Is there any known pair of objects tidally locked with each other? I know the moon is tidally locked with the earth (e.g. one side always facing earth), but I don't know of any pair of objects that ...
3
votes
1answer
53 views

landing on a comet is more important than landing on an asteroid?

Philae landed on comet 67P this year. And it means a big breakthrough for the science and technology of human being. However Hayabusa mission of Japan not only landed on an asteroid but also returned ...
0
votes
2answers
49 views

The multiverse spacetime paradox?

If there are indeed multiple universes, where do they exist? We "know" that outside our universe, consisted of spacetime, there is nothing - i.e. 0 dimensions, no space and no time. So "where" are ...
4
votes
5answers
376 views

What would we find if we could travel 786 trillion light years in any direction

I've sometimes heard of galaxies that are millions or billions of light years away but if we could instantly travel 786 trillion light years in any direction, what are we likely to find? And what if ...
3
votes
1answer
46 views

Position of Neutron stars in H R diagram

Why is that Neutron Stars are never depicted in an H R diagram? They can be placed in the bottom right corner but you will never find any diagram in literature showing neutron stars.
4
votes
1answer
73 views

How should exoplanet discoveries affect SETI?

Given that SETI was created before the discovery of exoplanets, has this changed how they search? Would it make more sense to focus efforts on discovered earth like exoplanets?
3
votes
1answer
46 views

Which wavelength is the most quiet, for a ground-based radio telescope?

This might seem like a backwards question, but I'm interested in what wavelength to select in a (hypothetical) ground-based radio telescope observation to expect detecting as little as possible! :) ...
1
vote
0answers
38 views

How to read 5 degree data of green line intensity

When I open the 5 degree data of Green Coronal Emission line from this, I get a weird table which is not simple like the one for Coronal Index. I am only providing the table for 1939. ...
4
votes
1answer
83 views

What is the temperature of an accretion disc surrounding a supermassive black hole?

What is the temperature of an accretion disc surrounding a supermassive black hole? Is there plasma in the disc?
1
vote
2answers
64 views

Why do comets come from our local Oort cloud instead of from interstellar sources?

Comets form where stars form. And they are then ejected by the orbital changes of giant planets. But why are they ejected to form specifically a local Oort cloud instead of going interstellar and ...
1
vote
0answers
27 views

How do I get from Star Atlas to real life?

This question is about finding the elevation and bearing of a given star at a particular time at Latitude 52N. I look up the RA and Declination of my star. How do I calculate its RA and elevation at ...
5
votes
1answer
74 views

How to see Saturn's rings through a pair of binoculars?

I have a pair of 15x70 binoculars. I would not say what manufacturer to avoid being the subject of 'hold'. The current angular diameter is 15.5 arcseconds. I am wondering if that condition is enough ...
0
votes
4answers
178 views

Is it possible for a star to orbit a planet?

Is it possible for a red dwarf to orbit a gas giant? OR Has this happened and it is just assumed that the gas giant is orbiting the star?
4
votes
1answer
100 views

Cancelling out earth rotation speed, Altazimuth mount

I have a Dobsonian telescope. It is using Altazimuth mount. Basic idea of using it is to target the object by moving telescope vertical axis perpendicular to the ground, and an elevation axis that ...
-2
votes
1answer
70 views

What are the odds of (Semi) Intelligent Life in the Milky Way? [closed]

I know that it can vary A LOT if you are using the Drake Equation but using realistic figures, how likely is it to discover a civilisation that is at least semi-intelligent (stone age - medieval era, ...
-1
votes
1answer
38 views

One Universe or Multiverse? [closed]

I watched a program where four astrophysicists were debating this topic. I couldn't fully understand what they were saying but wanted to ask others' opinions on whether there is only one Universe or ...
-1
votes
0answers
31 views

Do the Fundamental Laws of Physics support a White Hole? [duplicate]

Many astronomy enthusiasts know about black holes. However, few know about the theoretical white hole and I am recruiting all of the people of the astronomy community to help me figure this out. Do ...
4
votes
1answer
65 views

Likelihood of a stable system with a dwarf planet's orbit inside that of a gas giant

I keep thinking of various planetary system configurations, and would like to know: What are the fundamental references based on Monte Carlo long-term simulation of planetary systems' evolution that ...
10
votes
4answers
139 views

What is the orbital path of the newly discovered star-less planet PSO J318.5-22?

Recent results from Institute for Astronomy at the University of Hawaii at Manoa claim that there is a Jupiter-sized gas giant planet that is independent of a star about 80 light-years from Earth. ...
2
votes
1answer
79 views

Can Jupiter's bands be made out using a 15x70 pair of binoculars? [closed]

I have been getting mixed opinions on this. I have a 15x70 Pair of Binoculars. I have tried staring at Jupiter for several minutes with it, I was able to see the Galilean moons, in fact the last time ...
1
vote
0answers
24 views

What module(s) on the ISS do the Soyuz dock to? [migrated]

I've started to notice more and more as I study the ISS, that I can only ever find pictures of one Soyuz docked. Where is the other one? Lets say their sending up a crew of 6 for an expedition. A ...
3
votes
1answer
32 views

How can I make Stellarium match the magnitude of stars visible in London, UK?

Can someone recommend some Stellarium settings to mimic the amount of light pollution, and magnitude of stars that should be visible on a clear night in London, UK?
4
votes
3answers
125 views

How are rogue planets discovered?

Planets are usually found by observing a star and waiting for the light level to drop when a planet passes in front of it, but what about rogue planets that don't have host stars?
0
votes
1answer
27 views

How do we get radio signals of the big bang?

From TV shows I have known that we still get some radio signals of the big bang and they are every where. My question is is the universe expanding so fast that even electromagnetic wave has failed to ...
2
votes
1answer
47 views

Gravitational tidal force problem

if we have spherical mass held by its self-gravity, there will be a limit to distance - let's say it is $r$ - that the center of this body may approach a much more massive body (lets we call $M$ ...
-4
votes
2answers
109 views

Could we actually freeze a star?

I read an article recently that said NASA has discovered a brown dwarf that has frozen. If we had the technology, resources, and supplies, could we actually freeze a star and stop it from burning its ...
6
votes
0answers
617 views

Are there any planned extra-solar missions by NASA or others? [migrated]

Voyager 1 and 2 have been gone for a LONG time now (decades) and presumably we can produce bigger, faster and better probes these days that could tell us a lot more about the heliosphere. I've not ...
3
votes
1answer
45 views

Universe as 2d sphere surface - a round trip?

If Universe's analogy is 2D surface of the sphere, could we come around in circle? Say on Earth you decided to travel straight in one direction, after completing one full circle you'd find yourself at ...
1
vote
2answers
71 views

Full Moon Position of Sun

I am trying to figure out the position of sun with respect to moon on a full moon day. Here's an image from certain wiki which I do not find convincing. 1 If the sun rays point as shown in the image ...
0
votes
1answer
24 views

Why is a star at its highest point when local sidereal time = RA (right ascension)?

I'm currently taking a course called Introduction to Astronomy at Coursera. It's not very formal so they didn't present a proof of the statement in the title. I understand why logically one could ...
3
votes
1answer
44 views

What to look for in a tripod for binoculars?

I have been looking at large astronomy binoculars in the 25x100 and 20x80 range. Clearly, these monsters cannot be held steady by hand, or even be held at all for any reasonable length of time using ...
1
vote
0answers
24 views

Is Nomad data heliocentric or geocentric?

I'm wondering if the data in star catalogues are heliocentric equatorial coordinates or geocentric equatorial coordinates. Also given the distance between stars compared to the distance between the ...
1
vote
2answers
62 views

Which is the most early type star with a planet discovered by radial velocity method?

We have discovered planets in Beta_Pictoris(A6V)here and Fomalhaut alpha(A3v)here. However they were discovered by direct images. There should be an stellar type limit by RV? What is the most ...
10
votes
3answers
313 views

Will Saturn's rings become a moon?

Planets form from disks of matter orbiting around a star; some moons form from disks of matter orbiting planets. If this were going to happen around Saturn, approximately how much time would it take?
1
vote
1answer
121 views

Why can't the surfaces of stars be observed?

If I'm correctly informed, only three stars: Sol, Betelgeuse and Altair have surfaces which have been resolved by telescopes. All other stars are only point sources of light, even in the greatest of ...
0
votes
1answer
22 views

Orbital elements: Difference between longitude of perihelion and argument of perifocus

I am learning orbital elements and one thing isn't clear to me. When I look at the Horizon's ephemeris data for Mars, this gives me argument of perifocus equal to roughly 286.53 degrees on epoch ...
0
votes
1answer
170 views

Can A Black Hole Exist?

In 1939, Robert Oppenheimer and other concluded that a certain neutron stars could collapse to black holes and no known law of physics would intervene. As far as I can tell, there is no observational ...
8
votes
1answer
114 views

How long do planetary rings last?

I'm surprised that this question hasn't been asked before (here or on Physics), to the best of my knowledge. It's one that I might have asked when I was a bit younger, and one that I think other ...
2
votes
1answer
76 views

In regards to the holographic principle, what exactly is information? [closed]

I'm having trouble understanding what exactly "information" is in the context of the holographic principle suggested by string theory. Can it be equated to a matrix of ones and zeros? Does this ...
0
votes
2answers
50 views

What are the arguments against the Feng and Gallo thin disk explanation of galactic rotation curves?

The well-known galaxy rotation problem is described here. Basically (as one moves outward from the galactic centre, $R$ increasing) the observed pattern of variation in orbital speed $V$ is very ...
1
vote
3answers
80 views

Would Pluto keep an orbit without its moon?

I haven't studied space that much, but I know that Pluto has very little gravity, but just enough to keep a human on its surface. Would Pluto keep a regular orbit around the sun without some extra ...
1
vote
2answers
117 views

How did Bradley arrive at the +/- correct speed of light when he calculated it?

After Bradley discovered stellar aberration and the corresponding constant of aberration he was able to calculate the speed of light, since he knew the speed of the Earth around the Sun. As far as I ...
1
vote
1answer
31 views

What is the boundary in the atmosphere seen in this video?

This video, which shows time-lapse views of Earth from the ISS, consistently shows some sort of hard boundary in the atmosphere, below which there seems to be significant reflection from sunlight ...
8
votes
2answers
769 views

How far is the Earth/Sun above/below the galactic plane, and is it heading toward/away from it?

How far is the Earth/Sun above/below the galactic plane, and is it heading toward/away from it? We know the Sun is orbiting the galactic center every 225 million years. But how far are we from the ...
3
votes
2answers
88 views

What should I look for in an astronomy tripod?

I have a Celstron SkyMaster 20x80 binoculars, and a tripod — Vanguard 263AT with a SBH-100 head. The binoculars weighs 2.2kg, while the head is rated to a loading capacity of 10kg, and the legs to a ...
3
votes
1answer
42 views

The role of gravity during planetesimal accretion

As far as I understand, during the formation of a planetary disc, grains of dust stick together due to collisions and chemical bonding. Considering the size of the grain - say, 1 mm - and the speed - ...

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