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

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2
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1answer
37 views

Look up current positions and velocities of solar system objects

I am working on an orbital dynamics code and, for fun, I would like to model the Sun-Earth-Moon system with my code. I can look up the masses of each object just fine, as well as average distances ...
1
vote
2answers
53 views

What is the orbit of Earth around the Sun?

According to wikipedia and other sources, a planet and a star always move in a circular orbit around the common center of mass of the both bodies, in case of Earth and sun, this center of mass lies ...
6
votes
4answers
214 views

How do you define the diameter of the Sun

That is, it's twice the radius where the radius is from the centre of the sun to some edge. But what is that edge?
12
votes
3answers
678 views

Where does the solar system end?

This is a question I've heard many times in the past, and a quick search of the site says it hasn't been asked here, so I figured I might as well ask (and answer) it. I know that it is rare for ...
1
vote
1answer
55 views

Solar System' formation, considering its and universe's age

It's been said that the sun has 4.6 billion years, and the complete solar system to have similar age. The star-class of the sun seems to be quite common. Stars of its class can have 8 or 9 billion ...
9
votes
2answers
249 views

How often do stars pass close (~1ly) to the Sun?

Interstellar exchange of massive objects is difficult across several light years. But as the stars orbit the galaxy the distances between them change. I don't find data for neighbor star distances ...
3
votes
2answers
55 views

Typical wavelength of solar flare

I read that solar flares are customarily viewed in H-alpha light, as a temporary brightening of a small portion of chromosphere. What all can be interpreted from this? Is it because, energy of the ...
2
votes
1answer
44 views

Effect of the absence of atmospheric refraction to sun rise and sunset times

What is the effect of absence of atmospheric refraction on sin rise and sunset time? Is it will be delayed or earlier for sunrise and sunset, and why? Thank you:)
2
votes
1answer
60 views

How does this strategy for chasing the sunset work?

In Randall Munroe's What If? blog he tackles this question: What is the longest possible sunset you can experience while driving, assuming we are obeying the speed limit and driving on paved ...
0
votes
1answer
35 views

Declination and Ascension - the Sun and Andromeda

If Andromeda is overhead at midnight, what is the right ascension of the sun? (andromeda is ar RA =1hr, Dec = +40). I thought I understood what Dec and RA were, but I can't think of how to start this ...
4
votes
2answers
321 views

Will Earth lose the Moon before the Sun goes into supernova?

Ive read on some sites and saw on youtube videos that the moon is getting away from earth by 1-3 cm a year. Is this enough to make the Earth lose the Moon before the Sun goes into Supernova? Im ...
3
votes
1answer
43 views

What is the degree of ionization is the solar photosphere?

I am wondering how many free electrons per baryon and how many free electrons per atom there are in the solar photosphere. This number depends on the abundances of the various atoms found in the ...
2
votes
0answers
32 views

Given a date obtain latitude and longitude where is the sun zenith

Searching is easy to find terminator line (frontier between day and night) or the position of the sun in the sky given a position on the earth and a time; but I can't find how to obtain where is the ...
6
votes
3answers
168 views

Which stars did the Sun form with?

The Sun formed 4.5 billion years ago, in a molecular cloud. I assume that there were other stars in the vicinity (as is common in molecular clouds). Which stars are they? Where are they now? Are they ...
1
vote
1answer
54 views

What are the color progression of a typical sunrise?

"Dawn simulators" are used to simulate a natural sunrise, or at least the physiological effects of one. What temporal sequence of color values (e.g., hue, saturation, brightness, and timing) ...
2
votes
1answer
442 views

In 2016, the summer solstice will coincide with a full moon. How often does this happen?

I found that the solstices work on a 400 year cycle based on this. I can't find anything similar for the lunar cycle. Is there a formula I can use to calculate the date of the full moon?
1
vote
1answer
32 views

How are stellar elemental abundances quoted?

Close to the bottom of page 4 of this article (marked as page 164 in the upper left corner) states Values are given in the logarithmic scale usually adopted by astronomers, A$_{e\ell}$ = log ...
0
votes
3answers
84 views

Mass of sun's core

It is estimated that the sun's core is about 1/5 of the radius of the sun (from Wikipedia). I know that the density of the plasma increases substantially the near the center, and that the volume of ...
0
votes
4answers
127 views

Question about the Sun's Motion

My name is Chris, I am a junior and I'm taking an Astronomy class in my high school. For a homework assignment, I have to explain how the Sun would move across the sky from September 1st through ...
1
vote
1answer
51 views

Star class according to initial mass

Studying the stars classes for my homework (school) i learned that stars are classified by the spectral types (Harvard) and luminosity class (MKK) .. So the sun is a star class ...
1
vote
0answers
61 views

Compute the colour in the AB photometric system

I have a question for homework and don't get it at all: Consider two filters as shown in the figure below. Compute the colour S1 - S2 in the AB system for a star with flux: where is a constant ...
1
vote
1answer
123 views

Does the sky get darker faster during the winter?

When one lives away from the equator, say at around 37° latitude, does the sky get darker faster after the sun sets in the winter as compared to the summer? Why is this the case? I believe that if ...
5
votes
3answers
318 views

What scientific evidence is there to support or refute the Iron Sun Hypothesis?

Professor Oliver Manuel, a professor of nuclear chemistry at the University of Missouri-Rolla, claims in the article Sun Is Made Of Iron, Not Hydrogen, Professor Says that iron, not hydrogen, is ...
0
votes
1answer
44 views

Apocalypse on earth

What would it feel like on Earth if the Earth accelerated due to sudden changes in the solar system like ejection of another planet? Would there be giant tidal waves and other cataclysmic events?
1
vote
0answers
25 views

Observed sun/moon rise/set times to nearest second?

Where can I find a list of observed (not computed) sun/moon rise/set times to the nearest second, along with the location (latitude, longitude, altitude [or enough information to find these three ...
2
votes
1answer
75 views

Are ascending node of sun, the point of intersection of prime meridian and equator and center of earth all collinear?

I did a bit of googling but couldn't find the exact answer, so are the following 3 points collinear or not ? 1_center of earth 2_ascending(or descending) node of sun 3_point of intersection of ...
-4
votes
3answers
152 views

I know when the human history ends. Or not?

If you think that we born on 1920...2000 and knows that the sun will explode 4 to 5 billion years from now. you will say that the time is a strange thing. I can not say that i will die before i know ...
2
votes
3answers
80 views

the metal distribution in our solar system

The sun dominates in our solar system. I wonder whether in every aspect the sun play the most role in our system. For example, all kinds of metals are mainly located in the sun instead of the rest ...
8
votes
1answer
829 views

Finding the solar noon based on longitude and latitude?

Please could someone advise the best method of finding the solar noon based upon location? http://pveducation.org/pvcdrom/properties-of-sunlight/suns-position The stuff on here has been helpful but ...
3
votes
4answers
316 views

What would the effects be on Earth if Jupiter was turned into a star?

In Clarke's book 2010, the monolith and its brethren turned Jupiter into the small star nicknamed Lucifer. Ignoring the reality that we won't have any magical ...
1
vote
1answer
97 views

Hour angle sunrise calculation problem

I am trying to program a sunrise/sunset calculator using this formula tutorial. If you follow the steps, eventually you get to this formula for "H" (the "hour angle"): $H = \arccos( [\sin(-0.83) - ...
9
votes
3answers
358 views

Is it a coincidence that both the sun and moon look of same size from earth?

The sun is huge when compared to moon. Despite the huge difference in their size and distance from earth, Is it purely coincidental that they both look almost the same from earth?
40
votes
3answers
1k 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 ...
3
votes
2answers
96 views

Apogalacticon and Perigalacticon

What is the length of the apogalacticon and perigalacticon of the Sun and Milky Way? The general terms seem to be apoapsis and periapsis. My greatest efforts at Googling have failed miserably. If ...
3
votes
1answer
26 views

How can the Advanced Composition Explorer (ACE) warn of incoming solar storms?

How can the Advanced Composition Explorer (ACE) warn of incoming solar storms when is is invested with radiation? Discovery.com article Solar Storm Warning Satellite on Last Legs states that: ...
11
votes
3answers
386 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?
2
votes
2answers
110 views

Is it possible to move a planet out of its orbit? At least a lighter planet?

As observed by many researches our sun will be exhausted in a distant future. So anyone thinks driving our planet (or any planet) closer to the sun for more light and heat is a solution for the life ...
4
votes
1answer
192 views

Sun path at poles

At places other than the poles, the sun is seen to "rise" on the Eastern horizon and to "set" on the Western horizon. After a period of night, the sun "reappears" on the Eastern horizon. At the ...
1
vote
1answer
41 views

Why there are three equations governing blackbody emission?

I learnt that the spectrum of a black body can be explained using Planck distribution Rayleigh -Jeans equation and Weins displacement law Can anyone tell me why there are three different equations ...
5
votes
4answers
155 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?
3
votes
3answers
135 views

Does the Sun have hard radiation?

Does the Sun spread hard radiation waves around the Solar System? If so, why are we safe here (or are we even safe)?
12
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3answers
2k 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
1answer
642 views

Calculate latitude and longitude based on date and sun

I can't seem to find this algorithm, if it exists. Can you calculate the longitude and latitude of where you are standing based on the date and the angle of the sun? Also, would the algorithm work for ...
3
votes
2answers
37 views

How does solar activity (e.g. flares, coronal mass ejections) change over the life cycle of a Sun-like star?

As a Sun-like star is born from a collapsed nebula and generates energy by nuclear fusion some of that energy is converted to magnetic fields which fuel solar activity. How does that activity evolve ...
8
votes
3answers
230 views

Is the rotation of the Sun and the rotation/orbit of the Moon around the Earth a coincidence?

While looking at sunspot information in connection with Amateur Radio, I found that the Sun rotates on a period from 27 days to 31 days. Its rotation is differential, at the equator it spins at a ...
-2
votes
2answers
81 views

One year on the sun [closed]

This might be a weird question, but I'll ask it anyway. If one year on earth is the time it takes for the earth to orbit around the sun, then (if it were possible for humans to survive on the sun), ...
-2
votes
1answer
60 views

Does the sun have a protective shield

Does the sun have a protective layer that at least diminishes its radiation. I know the earth's atmosphere protects us from harmful rays. But does the sun have a sort of shield as well that if removed ...
0
votes
1answer
52 views

Can the Sun be used as a point source of light to achive better focus?

There's a limit to how well sunlight can be focused by a parabolic reflector or a lens because the Sun is not a point source. I wonder if the sunlight could be engineered to work as if it was (much ...
3
votes
2answers
113 views

Is the Sun homogeneous?

Does the Sun have the same composition and density everywhee within it? How does it vary in other stars?
4
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3answers
338 views

Did we ever actually see the earth revolving around the sun? Is the geocentric model completely disproved?

Did we ever actually see the Earth revolving around the Sun? Also, is the geocentric model completely disproved or was it sidelined because the heliocentric model made things easier to understand? ...