0
votes
0answers
11 views

Binary Star question

Is it POSSIBLE that we are a binary system? I have been doing research into this topic and it seems we may infact be a binary system. If we are, what effects would a massive body comming into our ...
1
vote
0answers
11 views

Why does the Chandrasekhar limit affect white dwarfs differently?

The Chandrasekhar limit is the maximum mass of a stable white dwarf star. Beyond this, a carbon-oxygen white dwarf will typically explode in a type 1a supernova, due to the nuclear reactions at those ...
-2
votes
2answers
13 views

Is a wormhole makeable?

In sf movies, a wormhole is easy to make. Take a piece of paper representing 2d space, make the two ends of the paper meet, make a hole, go through the hole and you´re somewhere far away in the ...
0
votes
0answers
10 views

Why is a wormhole asymmetric?

Why are the two sides of a wormhole different? As a wormhole is pictured, things go in on one side and get out again on the other side of the mouth. Or works this the other way too, so that symmetry ...
5
votes
2answers
623 views

What would the night sky look like if the Milky Way were the only galaxy in the universe?

I'm curious to know what the sky would look like without any other galaxies out there. How much do other galaxies factor into the stars we see? Does the Milky Way account for most of them? Would the ...
0
votes
1answer
25 views

What does this information about “upper limit column densities” and “upper limit relative abundances” mean?

I was reading the abstract of a paper regarding attempts at detection of a molecular precursor to the amino acid glycine, and I came across concepts (and notation) that I found confusing. If someone ...
0
votes
0answers
29 views

Birthday of the Universe

With every improvement of measurement we are able to determine the age of the Universe more exactly. I just wondered how much and what means it would need to narrow the range of age so that it would ...
0
votes
0answers
20 views

$\Lambda$CDM model or the BB model? [on hold]

The Lambda CDM model is the parameterization of the Big Bang model, it is also called the consensus model of cosmology in many textbooks and websites. Doesn't parameterization makes the LCDM a ...
-4
votes
1answer
35 views

Could gravity be the 4th dimension? [on hold]

According to Michio Kaku, in his book Hyperspace, he said that in this Hyperspace, there exist a total of 10 dimensions that govern the laws of physics. Is it possible that we too live in a ...
0
votes
1answer
39 views

Does earth have retrograde motion?

I am a beginner. Please let me know whether earth has retrograde motion If it does not, let me know the reason
0
votes
1answer
27 views

Magnification of a telescope

I took an image of Jupiter through my 8" Dobsonian Telescope, attaching a DSLR and a 1.25" Barlow Lens where the eyepiece goes, as shown in this video: https://www.youtube.com/watch?v=reFxoF3XoaU ...
0
votes
0answers
33 views

$\Lambda$CDM Model and the early stages of the Universe

We know that the radiation dominant era lasted for 50,000 years, how? What equations give us the result of 50,000 years and how are we certain that we are talking about radiation dominant era, same ...
3
votes
1answer
72 views

Are larger stars rounder?

The Earth is a very smooth sphere, and the Sun even more so, with only minor fluctuations. I am wondering: are larger stars even rounder? Intuitively, that seems self evident, but I am not so sure. ...
0
votes
1answer
29 views

Why do meteorites explode?

Some meteorites just blaze away, streaking through the sky. This is clearly explained, as they either slow down enough for the flame to cease, or ablate in their entirety, turning to vapor. But some, ...
5
votes
1answer
49 views

How much competition there is for jobs in astronomy compared to other fields of science?

I will soon finish a master's degree in computer science. I have been interested in astronomy for some time, which has included playing around with a Newtonian reflector telescope and reading about ...
0
votes
2answers
41 views

Polar satellites for Global Navigation Systems

Why do we need 7 polar satellites for a navigation system like the Indian Regional Navigation Satellite System (IRNSS)?
1
vote
0answers
15 views

Plot an AltAz grid over a square grid of RADec points

first post here. As I'm new, StackExchange won't let create or use the wcsaxes tag. wcsaxes looks like the most appropriate tool for the job, but astropy is closely related. I think the title says ...
-5
votes
0answers
39 views

The Blackhole “Creator of Stars” [on hold]

I have thought for some time on how Blackholes and Neutron stars behave and interact in the nature of space, Now I know we have made some theory's and are still in the process of observation, we ...
3
votes
1answer
61 views

Stellar mass limits for Neutron Star and Black Holes

Don't hate on me if I am asking a very basic and straightforward thing. I have a few questions about black holes and neutron stars. What is the mass range (in terms of solar masses) for a main ...
1
vote
1answer
74 views

How much time does the ISS take to repeat its orbit?

I used to go to my roof to see the ISS, but it is not always visible. Then it appears again but does it appear with the exact same orbit as I saw before? Thanks!
1
vote
1answer
35 views

Is there Kuiper belt/Oort cloud like structure in gas giants?

I know gas giants have moons, just like star have planets, how about kuiper belts or Oort Cloud? Is there any corresponding structure in gas giants? If not, why don't they have?
4
votes
1answer
127 views

What does the Sun's orbit within the Solar System look like?

Everything in the Solar System revolves around the "barycenter": the overall center of mass. This barycenter is not in the center of the Sun. Some articles and essays I've read go so far as to suggest ...
0
votes
1answer
26 views

Pinhole Projector: Can I use a specific solar optical eye piece to focus the Transit of Mercury?

The title pretty much explains this one. Can I use a specific solar optical eye piece, or other optical device, in conjunction with the pinhole projector method to focus the Transit of Mercury? ...
0
votes
1answer
50 views

Can I use an array of inexpensive cameras as an alternative to a telescope?

The link below describes how an array of inexpensive cameras can create very detailed images. Would this work for astronomy? https://graphics.stanford.edu/papers/CameraArray/
1
vote
1answer
56 views

What is the equation of state for a relativistic fluid/gas?

Say we have a relativistic fluid/gas, as we have in some astrophyical systems. Now let us write: $e$ - energy density in the fluid's rest frame. $P$ - pressure in the fluid's rest frame. $n$ - ...
1
vote
2answers
28 views

Does this video catch an Eta Aquarid - Earth skimming meteor?

I did a time-lapse animation looking towards the sunrise from Sydney, Australia on 25th of April. You can see it here around 1m 25s in (that link should jump to just before it appears very near where ...
3
votes
1answer
51 views

How big will Apophis appear?

How big will Apophis appear in the sky at its closest point of approach in 2029? Will it compare to the moon? How long will it linger as it passes?
3
votes
1answer
106 views

Why does Titan have lower surface gravity than the Moon when Titan is more massive?

Reading on Wikipedia I saw that Titan is 80% more massive than the earth's moon but has only 85% the surface gravity. Why is this?
0
votes
3answers
77 views

Is a planetary system star's referred to as their sun?

It's my understanding that the Sun (uppercase) is used to refer to our sun/star, because it is The Sun. Latin name is Sol, hence the Solar System. Even the tag (lowercase sun) on this post has the ...
3
votes
1answer
71 views

Pinhole projector for the Transit of Mercury

Very quick and simple one today. What would be the best/optimal pinhole size for a pinhole projector to observe the transit of Mercury on May 9th? I want to get the optimum between resolution and ...
-2
votes
0answers
45 views

What is the possibility for everyone on earth get sucked into laboratory created black hole? [duplicate]

Assuming that we have created a small scale black hole in earth laboratory, now how big is the chance that we all get sucked into it?
0
votes
1answer
30 views

V838 Monocerotis Supernova images morphed into nice video, but why so few original images?

This NYTimes video shows what I think is a series of real Hubble images which have been "morphed" artistically to appear to be continuously expanding. (also see The V838 Monocerotis Star Still Has ...
0
votes
1answer
13 views

Calculate right ascension in Zenith at this moment in my location

I've been searching on Internet about how to calculate which RA is in zenith at a given location in a given time but I haven't find anything (or maybe I don't know how to search). Using my star ...
1
vote
1answer
47 views

Why does shell fusion produce more energy than core fusion?

Stars go from the main sequence phase to the red giant branch due to the depletion of hydrogen in the core. As a result, the star contracts and shell hydrogen fusion begins, which apparently produces ...
5
votes
1answer
69 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
59 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
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 ...
2
votes
1answer
40 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.
5
votes
1answer
92 views

Watching the Mercury transit with improvised devices

I have learned that it is not possible to watch the upcoming Mercury transit with the plain eye (using special filter glasses). Is it possible to watch the transit with improvised devices (like a ...
1
vote
1answer
57 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?
6
votes
1answer
145 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 ...
0
votes
1answer
56 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 ...
0
votes
2answers
32 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 ...
0
votes
3answers
94 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
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 ...
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.
1
vote
3answers
75 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
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
65 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 ...
5
votes
3answers
147 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 ...

15 30 50 per page