Questions regarding the closest star to Earth, at the centre of the Solar System.

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3answers
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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
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1answer
118 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 ...
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2answers
239 views

Does the orbital variation in planetary gravity affect the Sun's corona

Dimitris (see below) argues that the syzygies of the Earth and Venus and those of Mercury, Earth and Jupiter distort the Sun's corona, which in some way affects climate on the scale of hundreds of ...
6
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1answer
259 views

How can one explain the apparent motion of the Sun from a heliocentric point of view?

From a horizontal frame of reference, the path of the Sun looks like a part of a circle in a tilted plane, as shown in this picture: ...
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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 ...
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1answer
101 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 ...
3
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1answer
116 views

Why is the Sun's brightness and radius increasing, but not its temperature?

On the Sun's article on Wikipedia, there is an image showing how the Sun's brightness, radius and temperature have changed over time: For the past (and next) few billion years, I see the luminosity ...
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1answer
100 views

Why would astronomers want to eclipse the Sun?

I've heard that some astronomers are building an artifical solar-eclipse ship, that should help us to dim the diffraction of the Sun. Why don't we just wait till night? What is the function of the ...
3
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1answer
35 views

Solar / lunar positions in ECEF using SOFA C libraries

I'd like to calculate the positions of the sun and moon in the ECEF coordinate system using the SOFA (http://www.iausofa.org/current_C.html) libraries given a Julian day input. So far, I've got this ...
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1answer
35 views

The relation between the light of full moon and the distance between the sun and the earth

If we want the full moon to be 2 times more bright,how we should change the distance between the sun and the earth? Thanks for your help.
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1answer
56 views

Term for altitude of the sun?

The sun travels in an arc across the sky. Where I live, during the summer the arc rises higher, but in the winter the arc is lower. Once might speak of highest altitude or elevation the sun reaches ...
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0answers
30 views

How common are Stars that have no orbiting planets? [duplicate]

How common are Stars that have no orbiting planets compared to Stars that do?
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2answers
203 views

Is it true that the sun goes down to the west?

I know the sun doesn't go down but we are moving and is it true that the sun goes down to the west? I've read on many webpages that this is not entirely true.
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4answers
276 views

the metal distribution in our solar system

The sun dominates in our solar system. I wonder whether in every aspect the sun plays the most important role in our system. For example, all kinds of metals are mainly located in the sun instead of ...
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2answers
46 views

Are Wikipedia's sun ecliptic-coordinate formulae accurate?

I'm creating a C++ program that calculates the ecliptic coordinates based on the formulae from Wikipedia But, my calculations appear off. The mean anomaly for today, for example, should be ...
10
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7answers
3k views

Why doesn't Earth's axis change during the year?

My understanding is that the Earth's axis points in the same direction in space during its entire orbit around the sun. And this is what causes our seasons. My question is why doesn't the axis follow ...
9
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3answers
475 views

How old is our Sun in Galactic years?

A year is measured as the amount of time it takes Earth to orbit the Sun once, a Galactic year is the time it takes our sun to make one full orbit of the center of the Galaxy. In Galactic years, how ...
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1answer
80 views

Could the sun burn a human floating next to it? [closed]

If a human was naked a few hundred feet from the sun, floating, with no atmosphere, not affected by the vacuum of space or UV radiation. Would the sun burn him/her? Or not have any effect?
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1answer
46 views

Can we apply Kepler's law of planetary motion to the moons motion around the earth?

I have been trying to understand Kepler's law of planetary motion for a while. So I was thinking, if it would even apply to the moon orbiting around the earth. Does the moon too orbit in an ellipse ...
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5answers
2k 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 ...
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0answers
37 views

Latitude and Longitude from Right Ascension and declination angles [duplicate]

Given Declination and Right ascension(RA) of Sun ,How can I calculate the position of sun in terms of Earth's Latitude and Longitude(Or the vector from Centre of Earth to Centre of Sun will pass ...
10
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1answer
1k views

Why do comets appear to have a continuous supply of dust?

Comets orbiting the sun have a tail that points away from the Sun, due to the solar wind. (Strictly speaking, a comet can have both a type I tail - ion tail, and a type II tail - a dust tail. This ...
8
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1answer
140 views

What would the Sun be like if nuclear reactions could not proceed via quantum tunneling?

Without quantum tunneling our Sun wouldn't be hot or massive enough to produce the energy it does at the moment. So what would have been the temperature or mass of our Sun without quantum tunneling of ...
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0answers
20 views

Convergence of galaxies [duplicate]

What would happen to Earth and other planets after about millions of years at the time of convergence of milky way galaxy with andromeda galaxy? (Supposing the planets and the sun are still there and ...
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2answers
95 views

Rate of Mass Loss from the Solar Wind

This is problem 1-4 from Principles of Stellar Evolution and Nucleosynthesis by Clayton: Assuming at the Earth a characteristic velocity of 400km/s and density of 10amu/cm$^{3}$ for the solar wind, ...
4
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1answer
40 views

How are the element abundances calculated for a meteorite in the Hydrogen log10 scale?

In astronomy, solar abundances are often calculated or tabulated per $10^{12}$ H atoms. I understand that in case of the Sun this can be done because H atoms are in majority or are present for a scale ...
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1answer
49 views

Procession of the Equinox

I just learned about procession of the equinox, i.e. the Earth's axis tilts one degree every 72 years. And it takes 72 years/degree x 360 degrees = 25,920 There are many theories to this, i.e. ...
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1answer
187 views

If the Sun got larger, but maintained its luminosity, would the Earth get hotter or colder?

A recent question If the Sun were bigger but colder, Earth would be hotter or colder? asked - if the Sun got bigger and cooler, would the Earth heat up or cool down. I think the answer to that is ...
11
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1answer
8k views

How many sun-like stars are there in the universe?

After yesterday's announcement of the Kepler telescope finding a huge amount of newly observed exoplanets, i saw a headline claiming that as much as 22% of sun like stars in the universe have planets ...
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1answer
179 views

Is the Earth Really Spinning? (honest question)

Most people consider it common knowledge that the Sun's "movement" in the sky is only perceived due to the Earth's "spin and movement". Based on this, you'd think that the stars in the night sky ...
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2answers
90 views

Can black holes collide with the Sun? In that case what will happen? [duplicate]

Can a black hole collide with the Sun? What will happen in that case? Will the Sun survive?
6
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1answer
427 views

How do star densities work?

If we take a look at stars more massive than the Sun, their densities vary a lot. UY Scuti is an extremely low-density star that's only 8.5x more massive than the Sun, but is 1000-2000x its size. ...
9
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5answers
1k views

Why do stars become red giants?

Disclaimer: I’m not a career astronomer. I don’t own a telescope. I have no professional credentials. But I do find this stuff fascinating, and I consume all the astronomy documentaries I can. ...
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4answers
10k 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 ...
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1answer
101 views

Is this Universe scenario correct? [closed]

I will try to give you my reasoning behind my scenario. Ok I've researched and found That 95 percent of the galaxy has been formed already, And the other 5 percent is still to ...
3
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4answers
150 views

Compared with similar stars, does the sun itself have properties that make life on Earth possible?

We often hear our solar system has properties for life. For example, it is far away from the center of Galaxy. It has Jupiter far away to protect us from asteroids. It has optimum size of territorial ...
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4answers
343 views

Using the Sun as a Gravitational Lens

Can the Sun be used as a gravitational lens to achieve better telescopic viewing? Can this effect be practically used to view celestial objects?
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3answers
192 views

Does the Sun impose back it's tidal forces onto the Earth (such as the Earth's to the Moon)?

It is known that each year the Moon is moving away from the Earth due to tidal forces. What about the Earth relative to the Sun?
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1answer
84 views

Is there sufficient evidence to confirm additional Planet in solar system

I have watched this scishow episode where Hank says that astronomers believe there is another planet in our solar system. Link He says that it's because how asteroids and comments are being pushed ...
2
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1answer
74 views

Where is the materials of comet after it crashed into the sun?

If a comet crashes into the sun, where will the substance (eg: water,silicon) be? Will they be inside the sun? Or they will be ejected from sun again?
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2answers
163 views

Will a Ball placed close to Sun fall into it?

Like a ball falls on the earth due to gravity, if suppose we are able to place a ball close enough to the sun. Will the ball fall into the sun due to its gravity or will it be pushed away due to its ...
3
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1answer
199 views

Are there good animations of the movement of proximate stars over long time periods?

After reading about Barnard's Star and how it's approaching us 140 km/sec, I'm curious if there are any visualizations of how the nearest stars to Sol will be moving over the next 100k years or so. ...
18
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3answers
305 views

Is it odd that our Sun has so many planets?

The internet is abuzz with the new evidence of the possible ninth planet in our Solar System. With those nine objects, the asteroid belt, the Kuiper belt, and everything else in our Solar System - the ...
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2answers
83 views

Does the sun itself present the problem of global warming is it the main cause? [closed]

the sun itself is not responsible for global warming, it must be that the temperature is changing due to climate changes. Anyone?
15
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2answers
2k views

How bright would the sun appear from the hypothetical Planet Nine proposed by Caltech?

Theoretical Planet Nine, proposed by Caltech's Mike Brown and Konstantin Batygin, is said to have a 15-20 thousand year orbit. Approximately how bright would the sun appear from Planet Nine aphelion ...
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4answers
105 views

What do we mean by Sunrise and Sunset?

If the Earth rotates on its own axis, then what do we mean by sunrise and sunset?
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2answers
121 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 ...
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2answers
79 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?
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2answers
67 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.
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1answer
560 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 ...