10
votes
3answers
510 views

Does the Sun belong to a constellation?

Each new star we find is generally considered to be part of the constellation it is nearest to. Our Sun is obviously a star, just much closer. Is our Sun part of any constellation? If so, which ...
4
votes
2answers
50 views

What are shooting stars? [duplicate]

What are shooting stars? How are they formed and how often do they occur during the night? Also, why are there more shooting stars on some nights than on others?
2
votes
3answers
82 views

What gases are needed to make a star?

What gases do you need to start the creation of a star, and why do you need these gases? What are their functions?
9
votes
1answer
38 views

How can we detect water on Mars-like exoplanets?

According to data from Curiosity, Mars' dust holds about 2% water by weight This wasn't previously detected, so the impression we have had of Mars being incredibly dry may need to be altered. Okay it ...
7
votes
1answer
105 views

Why can't we observe the Oort cloud with a telescope?

The Oort cloud is a hypothetical structure based on our observation of long-period comets. There are currently proposals to design probes to confirm the existence of the Oort cloud. Now, sending a ...
10
votes
2answers
112 views

How was the core temperature of the Sun estimated?

It was estimated that the heat inside the core of the Sun inside around 15 000 000 °C - this value is extremely enormous. How did scientists estimate this value?
6
votes
1answer
53 views

How do I build a stargazing aficionado's Sun funnel to observe our nearest star safely?

How do I observe the Sun safely, with tools I could build myself and without breaking the bank? If I wanted to build a Sun funnel on my own and use it on my enthusiast grade telescope, how would I do ...
5
votes
1answer
35 views

What is the significance of the discovery of a pulsar flipping between radio and x-ray emissions?

This morning on the radio I heard about the discovery of a pulsar that, due to its proximity to a companion star, was flipping between a state where it emitted radio waves and one where it emitted ...
8
votes
2answers
76 views

How do stellar temperatures vary?

The temperature of the surface of the Sun (photosphere) is between 4500° - 6000° Kelvin. Inside the core, it's around 15.7 million degrees Kelvin. In other types of stars (neutron stars, white ...
12
votes
1answer
77 views

Why is the Sun's atmosphere (the corona) so hot?

The visible surface of the Sun is 6000 degrees Celsius but the gas in the solar corona is at least 1 million degrees. What heats the solar corona?
6
votes
1answer
46 views

Do any known exoplanetary/solar bodies have “annular” eclipses similar to Earth's?

This was somewhat inspired by this question but is a bit different: I am interested in if there are any known systems in which the angular size of the eclipsing object is almost the same as the ...
6
votes
1answer
67 views

What is the current routine of modern astronomy? [closed]

With about all visible stars catalogued, measured and photographed it seems that chapter is closed. I realize currently while amateur astronomy is big on cataloguing all asteroids in the Solar System, ...
7
votes
1answer
203 views

How does moonrise/moonset azimuth vary with time?

In my tenacious attempts to observe moonrise (surprisingly difficult in a poor weather heavily urbanized hilly area with frequent bad smog, with busy work schedule and a bicycle) I was frequently ...
8
votes
2answers
47 views

What azimuth description systems are in use?

For a time, I thought Azimuth is always direction in degrees, 0 for local, geographic north, 90 for east etc. Then, trying to observe moonrise I downloaded an app that gave azimuth in values between ...
9
votes
2answers
286 views

What is the formula to predict lunar and solar eclipses accurately?

A number of ancient civilizations had devised methods to predict exact dates and times of such eclipses, marking them as important events. Hence I assume the predictions were based on calculations, ...
9
votes
1answer
78 views

Why does the Moon seem larger when it is close to the horizon? [duplicate]

I've noticed that when I look into the sky at night, sometimes the moon appears very large near the horizon. Sometimes it also looks like it has a yellow tint. Is this the light rays bouncing off ...
4
votes
3answers
100 views

I'd like to become an astronomer. What experience do I need? [closed]

I think I'd like to become an astronomer. What degrees and training/experience do I need to become one? I've heard I should take science and mathematics, but I don't know which specific courses I ...
9
votes
1answer
204 views

Why do stars appear to twinkle?

Sometimes at night you will look up to the stars and they will appear to twinkle, getting brighter and darker in bursts. Why does this happen? Is this because of our atmosphere? Would they twinkle ...
8
votes
2answers
145 views

Do other planets in our solar system experience eclipses or is this unique to Earth?

Here on Earth we get to experience lunar and solar eclipses. Is this pure coincidence that everything happens to line up? Do other planets in the solar system experience this phenomenon or is this ...
7
votes
1answer
49 views

What is the relevance of the Tropics and the Polar Circles? Do they Exist on other planets?

The middle line is the equator, the second and fourth line are the tropics, the first and fifth are the polar circles. What is the relevance of these bands on Earth? Do these exist on other ...
9
votes
2answers
103 views

Relativistic effects in stellar dynamical systems

I am curious, if anybody knows of any stellar dynamical systems/environments, where relativistic effects could play a dynamical role on the motion of these stellar systems? As a subquestion - are ...
7
votes
2answers
52 views

What is the difference between asteroids, comets and meteors?

Some celestial objects seem to be referred to as asteroids, some as comets, and some as meteors or meteorites. What is the distinction between all of these different objects? Are any of them the ...
11
votes
2answers
143 views

What physical features determine if a planet is a major, minor or dwarf planet?

Like many, when I was growing up, we always were taught, hence always learned that there were 9 planets. However, recently, decisions were made and all of a sudden there were 8 major planets and a ...
9
votes
1answer
63 views

How is it known that Callisto has no core?

My Astronomy book claims that scientists have discovered that Callisto, a moon of Jupiter, has no hot inner core. In fact, it says, Callisto has a core much like the nucleus of a comet. Is this still ...
10
votes
2answers
53 views

Near-Earth supernova

There are 51 stars within 17 light years of the Earth (source). If one of these stars was to become a supernova, how would they effect the Earth?
5
votes
1answer
68 views

What is the current accepted hypothesis of what caused Triton's retrograde orbit around Neptune?

According to the NASA overview about Triton, this, the largest satellite of Neptune is unique in that it has a retrograde orbit around Neptune. The page also suggests that Triton is a captured Kuiper ...
6
votes
1answer
93 views

Why does the moon sometimes appear giant and a orange red color near the horizon?

I've read various ideas about why the moon looks larger on the horizon. The most reasonable one in my opinion is that it is due to how our brain calculates (perceives) distance, with objects high ...
6
votes
1answer
22 views

Is the Apophis asteroid a concern?

I was watching the TED lecture How to defend Earth from asteroids , and the speaker Phil Plait spoke of the possibility of this asteroid hitting Earth. Is this really a concern?
6
votes
1answer
53 views

What percent of planets are in the position that they could be viewed edge-on from Earth? (and thus able to undergo transits)

Star number 12644769 from the Kepler Input Catalog was identified as an eclipsing binary with a 41-day period, from the detection of its mutual eclipses (9). Eclipses occur because the orbital ...
7
votes
1answer
35 views

What are Trojan Asteroids and where are they located?

Asides from the main Asteroid Belt, there are Trojan Asteroids - what are these and where are they located?
3
votes
2answers
52 views

What is a wormhole?

I have learned that there are white holes and black holes in the universe, but I am confused as to what a wormhole is. Is it a tunnel that connects black and white holes?
3
votes
2answers
83 views

How long does it take to produce a star? Why does it take that long?

I wonder, why stars take a really long time to become stars? Is it because it needs to gain mass? Or heat up? Something like that? And could it be sped up at all?
10
votes
1answer
529 views

How can I collimate a dobsonian telescope with a laser collimator?

I've had a dobsonian telescope for a while now, but I've never been able to collimate it. I thought I had it collimated once, but when I looked through it the star didn't look right, it looked kind ...
3
votes
4answers
106 views

Do all objects get larger in an “expanding universe”?

I'm envisioning an analogy of the universe as a plane with marbles in that plane to represent different planets. Now, if this plane expands how does this work? I assume that it is not like 'nothing' ...
14
votes
1answer
213 views

Milky Way Galaxy from Earth

I've seen a lot of beautiful pictures of the Milky Way from Earth such as this: ...but I can't understand what the cloudy ribbon at the bottom the horizon is. Is it a super-large nebula? Or is it ...
28
votes
2answers
505 views

Does the Sun rotate?

The planets rotate as an after effect of their creation, the dust clouds that compressed span as they did so and the inertia has kept it rotating ever since. It's fairly easy to prove that planetary ...
8
votes
1answer
51 views

What is a White Hole?

White holes are purely hypothetical at this point and are considered only because it is assumed something like it could exist as the balance to black-holes. Reading this article seems mostly writers ...
6
votes
3answers
45 views

Are there ways other than the collapse of a star which have been observed to form black holes?

Every time I hear about a black hole, it's always in conjunction with the collapse of a star. Have any other processes been observed to create a black hole?
9
votes
1answer
223 views

Is the moon moving further away from Earth and closer to the Sun? Why?

According to The NASA Moon Facts page: The moon is actually moving away from earth at a rate of 1.5 inches per year. Why is the moon moving further away from the Earth? Is this a result of the ...
8
votes
1answer
109 views

Why do the planets in our solar system orbit in the same plane?

(Yes I'm excluding Pluto from this the same way it was excluded for not being a planet) Observing the planets orbit of the Sun they all seem relatively planar and roughly all orbit along the same ...
6
votes
2answers
50 views

What are the Earth-like features of Titan?

This NASA site says that hidden beneath the smog of Titan are Cirrus like clouds and This space article describes how Titan's atmosphere is similar to Earth's too. What other features does Titan ...
5
votes
2answers
128 views

Do parallel universes exist?

Do other universes like ours exist? If they exist, how do we know that they exist when we have even not seen the ends of our own universe?
9
votes
2answers
93 views

How hot must a star get before it is considered to be a star?

How hot must a star get before it actually becomes a star? Why does it need to get so hot? Please find an official site to quote from, if you can.
5
votes
3answers
54 views

What qualifies as a good place for stargazing, i.e. with least light pollution?

I know that minimal light pollution is a must for stargazing, and a place which is away from civilization is better. Does altitude of a place matter for light pollution? Does it affect the quality ...
4
votes
1answer
44 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 ...
9
votes
1answer
88 views

On what scale does the universe expand?

According to the theory (or my understanding of it), the universe is not only expanding, but speeding up. If the galaxies are moving apart, are the solar systems within them also moving apart from ...
6
votes
1answer
40 views

What are the metrics of observation conditions?

How do professional astronomers measure and describe (ambient) observation conditions? I know smog, light contamination from the city lights, fog, clouds, rain/snow, humidity etc all contribute ...
6
votes
2answers
89 views

What causes a neutron star to become a pulsar?

Leading on from this pulsar question, what criteria/processes make neutron stars become pulsars, do all neutron stars become pulsars?
8
votes
2answers
100 views

How many galaxies have been discovered?

I know Andromeda is our nearest galaxy. But how many known galaxies have been discovered and what are they?
17
votes
2answers
217 views

What is a parsec and how is it measured?

Astronomical units of measurement are mostly pretty straight-forward: Astronomical Units refer to the mean Earth-Sun distance (~150 million km or 93 million miles) Light years are the distance light ...

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