0
votes
2answers
184 views

How far into the future can we go by traveling close to a black hole?

If we sent someone on a path that passed as near as possible to a black hole without getting pulled in, how far into the future would they go due to time dilation? Let's assume the black hole is 5 ...
5
votes
1answer
80 views

Why are certain elements so common?

I understand why hydrogen and helium are the most common elements in the universe. I also understand iron, because that's where stellar fusion stops. But why are (specifically) oxygen, carbon and neon ...
1
vote
2answers
64 views

Are there any electrons inside the sun / a star?

Like the question says, are there electrons inside an active star, or has all the matter been so thoroughly ionized / plasmarized that the electrons are long gone? I ask because it would make sense ...
0
votes
1answer
82 views

Cluster of fast moving stars

We live in NW Tasmania in a country town and tonight out walking I pointed out a long cluster of stars to my sister as they made an unusual shape but then we realised they were moving really fast - we ...
0
votes
1answer
50 views

Locations of farthest matter

Regarding matter that has the highest redshifts, do we see such matter in every general direction we look (relative to Earth: up down left right front back)?
0
votes
1answer
25 views

A good place to start? [duplicate]

I am a high school student (going into 11th grade next year), who will be taking an introduction to astronomy and astrophysics as part of my core curriculum. As such, I would like to get a head start ...
0
votes
2answers
33 views

Tunnel vision while viewing through a reflector

I have a Celestron astromaster130 eq. While viewing through its eyepiece, or using a smartphone camera for photography purpose there is always a definitive no light region( it is circular in ...
2
votes
0answers
17 views

Telescope optical tolerance from central axis

I sometimes encounter telescopes/binoculars with a decent objective diameter but are very difficult to use because they only work when the eye is looking down the central axis (i.e. in the centre of ...
15
votes
3answers
5k views

Why does the Earth have a tilt of ~23°?

Is there a reason that the Earth has the tilt that it does (~23°)? How do we know which way is supposed to be 0°? Does this tilt have major consequences on the planet? Has it changed and will it ...
2
votes
1answer
41 views

Evidence of CMB redshift

Are there any known spectral lines shifted by ~1100? If not, then how certain is mainstream that the CMB has a redshift of ~1100? All I see is a blackbody radiation curve void of spectral lines.
2
votes
2answers
120 views

Advancement of perihelion, data

I was looking for accurate and up-to-date data regarding the advancement of the perihelion of the planets in the Solar System, the only ones I've found so far are at least 90 years old bout I really ...
6
votes
1answer
154 views

Can you see city lights on the Moon from Earth?

This is the opposite of another question. That question is about whether you could see cities on Earth if you were standing on the Moon. Let's there are cities on the Moon and you're standing on the ...
1
vote
1answer
64 views

Could there be a brown dwarf in our solar system? [duplicate]

Is it possible that a brown dwarf object could be orbiting our star and undetected so far by wise surveys?
0
votes
1answer
67 views

What is the last nuclear reaction in a binary system before supernova?

I understand that binary star systems may cause type Ia supernovae. I have a question regarding supernova explosion in a binary system. What is the last nuclear reaction before massive explosion? I ...
0
votes
1answer
58 views

Seeing a galaxy (quasar) greater than 46.6 billion light years away

Assuming the Big Bang was 13.8 Billion Years ago: Is it possible to observe a Galaxy's redshift showing distances slightly greater than that, like 48 Billion Light Years away? I understand that in a ...
3
votes
1answer
63 views

Universal point for sky observation

Is there a place on Earth, where polar axis lies on the horizont and heaven equator is in zenit? If it exists, can I, in theory, see all the constelations available worldwide this night?
0
votes
1answer
64 views

State vectors of “interesting” multiple stars

I'd like to show a demonstration of Runge Kutta integration of real systems using examples of interesting multiple stars, where "interesting" means you can see through a small telescope that they are ...
0
votes
1answer
70 views

How much do the mascons on the moon affect surface gravity?

The gravity anomalies on the moon (generally accepted to be caused by mascons) are powerful enough to affect the orbit of satellites. I'm trying to determine how much effect they would have on a ...
1
vote
3answers
77 views

Are we center of universe? [duplicate]

So I just learned that CMB redshift is 1100 regardless where we look (up down left right). According to Hubble's Law that makes it around 46 billion light years away, making it the farthest matter ...
0
votes
3answers
96 views

What is the volume of the universe?

Of course it is not exactly known how big the universe is, but I thougt that the universe is about 100 billion lightyears in diameter. But if that is true can you also make an estimation of the volume ...
0
votes
2answers
116 views

Accidental or deliberate? [duplicate]

We know that the visual size of the Sun and Moon from the Earth in our lifetime (!) is nearly equivalent. Now my question: Is this event is random? Or have a scientific reason? For example, maybe ...
9
votes
5answers
2k views

Does the gravity of the planets affect the orbit of other planets in our solar system?

When one planet passes near another during its trip around the sun, does their gravitational pull is strong enough to disrupt noticeably each other's orbit ?
2
votes
2answers
85 views

A beginner project in plotting celestial bodies in 3D coordinate space

As a data visualization task, I'd like to plot some celestial bodies in 3D coordinate space. I assumed there would be a lot of databases where celestial bodies are recorded along with an XYZ ...
0
votes
1answer
75 views

What was that Asteroid/Comet in the 90s?

I am now in my mid 20s and I remember when I was 6-10 years old, there was a comet or asteroid that flew really close to earth. I remember being able to see the object very clearly as if it were the ...
8
votes
3answers
154 views

What will be Supernova SN 2014J's peak brightness?

What is the expected maximum apparent magnitude of supernova SN 2014J? When will it attain peak brightness?
0
votes
0answers
14 views

How does unmanned probe avoid the (gravity pull of) stars, planets, comets and other gravity source? [migrated]

Refer to the ambitious probe sent by Yuri Milner, Stephen Hawking and Mark Zuckerberg to Alpha Centauri: Yuri Milner is spending $100 million on a probe that could travel to Alpha Centauri ...
5
votes
1answer
236 views

What’s the object between the earth and the sun currently showing in Google maps?

If I select satellite imagery in Google maps and zoom out, the earth is shown in space. It shows light/dark regions correctly updated, but there’s an object between the earth and the sun. It looks too ...
2
votes
1answer
90 views

What does “EW(Hα)” mean?

I came across a website saying that classical T Tauris have an "EW(Hα) > 5 angstroms". Does anybody know what "EW" means? Thanks.
5
votes
3answers
160 views

Why do the gas giants in the Solar System have comparatively large orbits compared to the inner planets?

Ever since I observed the depictions of the Solar System, I was obsessed with the question of why the gas giants (outer planets) have very large orbits, compared to the planets that are closer to the ...
1
vote
1answer
66 views

Is it possible that Titan is a kuiper object captured by Saturn?

I think Titan may be just captured by Saturn, not formed with Saturn together, because: It has so much nitrogen and methane, which is similar to Pluto and Triton Except Titan, other moons of Saturn ...
1
vote
1answer
83 views

Were there any images of a transitary event of Jupiter or Saturn as imaged by a deep probe mission

I'm quite certain that there isn't any actual images of a transitory event of Jupiter or Saturn across the solar disk from say e.g.,s the Voyager probe, Pioneer 10/11 or even recent New Horizons ...
5
votes
3answers
216 views

What proportion of planetary systems have been found with 'Hot Jupiters'

According to the NASA website "The strange attraction of Hot Jupiters", one of the main types of exoplanets that have been detected are Hot Jupiters, which are These are behemoth worlds that ...
2
votes
2answers
42 views

Triple stars with retrograde orbits

Where can I find the observed frequency of triple star systems where the outer star is in a retrograde orbit?
1
vote
2answers
145 views

What is the fifth moon-like object I saw around jupiter through my telescope?

Tonight while observing Jupiter I was able to see a five (what looked like) moons. I have observed Jupiter often before and only been able to make out the four galilean moons. It's my understanding ...
2
votes
1answer
149 views

How can a naked singularity be possible?

How can we have a singularity, without a black hole around it? How would one form? What does it do?
0
votes
1answer
48 views

Astronomy Olympiad Gravitation Qn

Question: Approximately once in 5 years people on Earth can observe bright comets whose nuclei have radius about 1km. The orbits of such comets are close to parabolic. Assuming that these nuclei are ...
0
votes
1answer
71 views

How to calculate a planet's apparent size when the planet is viewed from a moon in orbit around it?

Specifically in this case, how large would Jupiter be seen in the Io's sky in comparison to the moon in the Earth's sky? How to calculate this? Also, if somebody knows any online software which lets ...
0
votes
1answer
65 views

Jupiter appearing odd through a 6" reflector

Recently I have been trying to get a good look at Jupiter through my 6" Orion reflector, but the image seems to always come out as an oblong white streak. I've tried changing the lenses I'm using, but ...
8
votes
2answers
164 views

How long would it take for a rogue planet to evaporate in the late stages of the Universe?

I've read once a popular science book, in which the author calculated how long would it take for the most massive black holes to evaporate because of Hawking radiation. He claimed that after that time ...
7
votes
2answers
84 views

Does the radius of the Universe correspond to its total entropy?

I heard a claim that due to holographic principle, the surface area of the cosmic horizon corresponds to the universe's total entropy. As such the initial state had zero surface area and later ...
6
votes
2answers
95 views

Does the shape of a supernova remnant depend on the progenitor star's magnetic field?

The magnetic field activity in a star can be very chaotic and my question is are they somehow related?
3
votes
3answers
128 views

What Makes Stars Hot?

Simple question, but can't seem to find the answer anywhere. It can't be nuclear fusion because nuclear fusion occurs as a result of the heat. And it can't be because of gravity because it's believed ...
1
vote
1answer
42 views

Do other stars have Oort clouds? [duplicate]

Stars have in the past passed within 1 light year from the Sun, and will do so in the future too. If they have Oort clouds, would there not be interactions between their Oort cloud objects and the ...
8
votes
1answer
68 views

What are the best candidates for solar lensing of exoplanets, and what would the results be?

If we were able to send a probe to 550AU from the Sun, which exoplanets could be examined, to what resolution, and what form would the examination take? It is radio telescopy only, or would it be ...
0
votes
1answer
35 views

How do I see DSO's in my telescope? [duplicate]

I just bought a new telescope. I tried it out, and I even woke up at 3am when the moon set so there was light pollution. I have an 8 inch dobsonian telescope with a focal length of 1200 mm. For some ...
3
votes
2answers
75 views

How to read Babylonians' tablet that were used to track Jupiter's movements?

There is a science news article on how Babylonians used geometry to track Jupiter’s movements. Here is an image of cuneiform tablet which shows Jupiter's movements. From a layman's point of view, ...
0
votes
1answer
65 views

Three-torus model of the universe

I want to ask a question about the Three-torus model of the universe, as described in wikipedia: https://en.wikipedia.org/wiki/Three-torus_model_of_the_universe "is a proposed model describing the ...
0
votes
1answer
82 views

Cosmological redshift and comparing past galaxy sizes

If you were to divide the present-day universe into cubes with sides 10 million light-years long, each cube would contain, on average, about one galaxy similar in size to the Milky Way. Now suppose ...
4
votes
1answer
116 views

Redshift for gravitational waves?

According to general relativity, would gravitational waves experience the same sort of redshift that electromagnetic waves experience due to the expansion of the universe? And are there astrophysical ...
0
votes
1answer
38 views

How to form Copper from Calcium in a supernova explosion?

What are the reasonable chain of reactions to form copper (63, 29) from ca(40, 20) during supernova explosion? And how it will happen? I do not understand the theory behind it. I thought that the ...

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