Questions tagged [the-sun]

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

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12 votes
6 answers
2k views

How to describe the Sun's location to an alien from our Galaxy?

Let's say you got to the planet orbiting other star in our Galaxy through the wormhole. You think that the travel was instant but you're not 100% sure and it is not exactly known. The planet is ...
J. A.'s user avatar
  • 123
0 votes
0 answers
58 views

calculating the position of the sun by using degrees and determining date and time

so i found this code and even looked up the documentation on swe_suncross() most i've seen its - 88 degrees but can one determine this using any degrees ...
dimitri33's user avatar
4 votes
2 answers
326 views

Is Venus in our sun's habitable zone?

I know that Venus is closer to the sun than Earth and if an article I read is to be believed, Venus is hotter than Mercury even though the latter is closer to the Sun. The explanation for this odd ...
Agent Smith's user avatar
0 votes
2 answers
69 views

Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?

Stars have to be a certain size to initiate fusion to begin with, correct? Isn't this why brown dwarfs are considered 'failed stars'? But wouldn't the Sun (and other stars with sufficient mass, like ...
Kurt Hikes's user avatar
  • 4,799
1 vote
1 answer
89 views

Does the Sun have different unique orbits around barycenters?

After reading this question and seeing its image I thought about this question I'm going to publish. Does the Sun have different unique orbits around the barycenter for its multiple planets? If yes, ...
Snack Exchange's user avatar
0 votes
2 answers
1k views

How do people of the opposite side see the Moon and the Sun?

I was looking in the StarTracker android application from Tehran, Iran; and this is the screenshot: As you can see the Moon covers a small portion of the Sun. The green line above them is the ...
Snack Exchange's user avatar
2 votes
1 answer
117 views

Calculating Position of Sun in GPS Frame Relative to 0°00'00.0"N 0°00'00.0"E: Determining Vernal Equinox Offset

I am trying to calculate the position of the sun, in GPS coordinates terms, from a given date. As of right now, I know how to accurately calculate the equatorial Right Ascension and Declination, and ...
Michael Bonnet's user avatar
23 votes
3 answers
3k views

Did the Sun's light always peak in the green wavelengths?

So, I know the sun is getting brighter over it's lifespan and I'm wondering how that affects its emission spectrum. The reason I'm asking this is because I find it weird that plants reflect green ...
Elhammo's user avatar
  • 1,077
1 vote
2 answers
112 views

Sun or moon, finding the date and time of crossing a specific longitude

the Sun is currently in Virgo ♍, 13°7'9" or longitude 56.0762 degrees how does one calculate when exactly the Sun will reach this position again. Since the moon is doing a spin in 29.x days lets ...
dimitri33's user avatar
7 votes
2 answers
852 views

Is there a (proposed) name for Coatlicue's progenitor?

Our sun's theorized progenitor star carries the (proposed) name Coatlicue. Since our sun is thought to be a third generation* star there should be two generations preceding it - and therefore one ...
nada's user avatar
  • 201
2 votes
0 answers
52 views

Ghost images coronado telescope

I have just purchased a Coronado Solarmax III 70mm. To make it clear I am not an astronomer or an astrographer. I just need the telescope for an art installation purpose. I am having trouble with ...
Clint Calleja's user avatar
1 vote
2 answers
141 views

Why isn't a month 28 days?

1 days is a rotation of earth. 1 years is an orbit of the sun. I've always beleived that one month is 1 period of the moon orbiting earth but the inconsistent distribution of days throughout the ...
Ethan's user avatar
  • 119
2 votes
1 answer
57 views

lunar north node in heliocentric terms?

I am wondering how to get the heliocentric longitude and latitude for the Lunar North Node, for example. I have been able to extract from the Swiss Ephemeris api the geocentric and heliocentric ...
kh_model's user avatar
0 votes
1 answer
221 views

How old are the total solar eclipses as we see them today? [closed]

I've seen it referenced often that "total solar eclipses" (of the kind we see today where the corona of the Sun is visible as opposed to all of it being blocked) have become possible only ...
Rohit Pandey's user avatar
1 vote
1 answer
100 views

Celestial Navigation - How to calculate Longitude?

I'm trying to learn celestial navigation using the Sun to determine longitude. I'm starting to understand some of these concepts, but I can't figure out how to calculate longitude accurately. Hoping ...
Joseph Samela's user avatar
1 vote
1 answer
62 views

Will the Earth tidally lock to the Moon (ignoring Sun's expansion)

At some point, won't the tidal forces from the Moon be less than the ones from the Sun? Would that mean that the Moon stops moving away, or would the process still continue. Would the Earth start ...
user138890's user avatar
-3 votes
1 answer
149 views

Planets revolving counter clockwise around the Sun

Planets revolving around the Sun Hypothetical case: What could have been or no impact if the planets viz Earth, Jupiter, Saturn, Mercury, Venus, Mars, Pluto, Uranus, Neptune in different orbits ...
Prashant Akerkar's user avatar
3 votes
0 answers
70 views

To what extent does the increased average airmass the Sun's light passes through contribute to the seasons?

The traditional explanation for the cause of seasons I have heard is that because of the angle of the axis of the Earth with respect to the ecliptic, the angle at which light rays hit the Earth's ...
Peter's user avatar
  • 31
6 votes
1 answer
99 views

How did we figure out that Stars become red giants and when did we find out that they will?

I always hear that the Sun will be one but never when we found that out or how.
R-Obsessive's user avatar
0 votes
0 answers
53 views

Demonstration- formula for angle between horizon and ecliptic

The most precise and quite intuitive formula I could find online is here: https://www.celestialprogramming.com/snippets/angleBetweenEclipticAndHorizon.html $$\cos I = \cos ϵ \sin ϕ − \sin ϵ \cos ϕ \...
astrid lovespie's user avatar
2 votes
0 answers
109 views

If the distance from Earth to the Sun was filled with air, how loud would the sun be?

Based on this question: If there was air between the Sun and Earth, how warm would we get? Many sources state that if sound wasn't limited by matter, we would hear the Sun at around 100dB constantly, ...
dependsonmany's user avatar
1 vote
1 answer
84 views

Where do these materials on the Sun come from, if not nothingness?

In this video, I see that for hours, it seems that the flow keeps going from the 11h direction to the Sun's surface - while there looks like nothing is coming to the top of the loop to provide a ...
longtry's user avatar
  • 403
6 votes
1 answer
144 views

Which star has the highest known metallicity?

Which star has the highest known metallicity? The highest I know of is Sirius Which a Metallicity of +0.5, which corresponds to have a Ratio of Fe to H 3 times that of the sun.
blademan9999's user avatar
10 votes
1 answer
3k views

Is the Sun hotter today, in terms of absolute temperature (i.e., NOT total luminosity), than it was in the distant past?

I am constantly reading that the Sun is at least 20% 'hotter', in terms of total radiation/luminosity, than it was a few million years after its formation (i.e., after the Hayashi stage...) But what ...
Kurt Hikes's user avatar
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3 votes
1 answer
156 views

Where can I download the historic sunrise and sunset times for a location?

As the question indicates, I would like to know the sunrise and sunset times of a location. This is to evaluate the impact of day and night variations of a time series. Is there a way to download this ...
No-Time-To-Day's user avatar
0 votes
2 answers
123 views

How to calculate the apparent magnitude of sun?

I know the apparent magnitude of sun is -26.74, but I wonder how to get this value if we don't know the absolute magnitude? Thanks!
Lance798's user avatar
1 vote
2 answers
173 views

How do the phases of Venus prove heliocentrism?

I have been doing research about the Copernican Revolution, and one of the main arguments that caused many astronomers to change their minds was Galileo's observation of all phases of Venus. The proof ...
fartgeek's user avatar
  • 113
1 vote
1 answer
192 views

Will the Sun fall into a black hole? If so, when and which one?

According to the Wikipedia page "Timeline of the far future", stellar remnants not ejected from their galaxies will fall into the central supermassive black holes over a time scale of around ...
qdinar's user avatar
  • 145
2 votes
0 answers
36 views

Radius and surface temp of red giant Sun [duplicate]

There is wildly conflicting information going around about the predicted parameters of the Sun as a red giant. The estimates for the radius vary from 100 to even 256 solar radii (with the larger ...
Adam Kamil Gola's user avatar
6 votes
3 answers
180 views

How close is a typical New Moon to the Sun in the sky?

In a Solar Eclipse, the Sun, Earth and Moon are exactly colinear (well some area of the Earth where the eclipse is visible), and these are relatively rare. But in addition, Sun, Earth and Moon are ...
Bennet's user avatar
  • 213
0 votes
0 answers
61 views

Visibility of solar flaring region from Jupiter

I numerically calculated the following numbers. The geocentric longitude of the Sun on 25 November 1999 at 00:00 UT was 243.52 degrees (numerically calculated with an error of 1 degree). On this date (...
Smarty's user avatar
  • 61
6 votes
1 answer
815 views

How will the expansion of the Sun influence Earth as a celestial body after 5 billion years?

Science news have flooded our news feed again about how our Sun could swallow Earth. This time due to a real documentation of a similar event in an other system. theguardian washingtonpost From what I'...
Demis's user avatar
  • 883
1 vote
1 answer
89 views

Bremsstrahlung's role in the sun

Due to nuclear fusion that produces gamma rays which goes through compton scattering, in the end, on the surface, visible, infrared light ends up as before then, gamma rays lost energy and became x-...
Giorgi Lagidze's user avatar
0 votes
2 answers
96 views

the sun - relationship between gravity and temperature

In the sun's core, we know it's very hot. I was curious to research why it was exactly and I think 99% of answers are not fully correct. They say that it's because of nuclear fusions. I'd not agree as ...
Giorgi Lagidze's user avatar
0 votes
0 answers
27 views

sun - do gamma rays reach radiative zone

So in the sun's core, gamma rays are produced and right away, in the few milimetters, compton scattering happens. As I understand the compton effect, gamma ray will first collide with free electron, ...
Giorgi Lagidze's user avatar
1 vote
2 answers
131 views

sun's core - how much x-rays get emitted

We know from the sun, we receive x-rays, gamma-rays but at a very small number of photons. Question 1: why not much ? is it because most of the x-rays are absorbed in a process of ionization of the ...
Giorgi Lagidze's user avatar
0 votes
1 answer
90 views

Emitting light from the Sun [closed]

I might be asking too many questions here, but they all seem related to each other and knowing them simultaneously is the only way to understand this subject as I have tried my best googling already. ...
Giorgi Lagidze's user avatar
1 vote
3 answers
683 views

why does earth have speed?

I understand that Earth has a quite big speed such as it ends up around the orbit. The sun can't really attract it till the end due to Earth's speed and earth really can't escape due to gravity, hence,...
Matt's user avatar
  • 203
1 vote
0 answers
33 views

Could a sheet of plasma ejected from the sun's surface magnetically reconnect with itself and eject bits of itself which then also reconnect?

Could the Corona of the sun be getting heated by large sheets of plasma ejecting smaller sheets and these in turn ejecting smaller sheets ?
user avatar
3 votes
1 answer
67 views

Would impacting plasma clouds destroy electronics on Earth or make them only temporarily inactive?

We read that solar flares have increased again recently. At the same time, it is always reported that the plasma clouds hitting the Earth would, under certain conditions, disable all electronics on ...
Maik Lowrey's user avatar
16 votes
12 answers
6k views

Why are there not a whole number of solar days in a solar year?

I've been trying to find an answer to this question for some time now, and I seem to be missing something. I understand that the rotation and revolution of the Earth are not synchronized. I understand ...
Jimmy Jam's user avatar
  • 169
7 votes
1 answer
801 views

How do I calculate the moment of the solstice?

I'm trying to calculate the moment of the upcoming summer solstice using astropy, and I can't seem to get an answer that matches the accepted values that I see online. I thought that the moment of the ...
Roy Smart's user avatar
  • 1,054
0 votes
1 answer
143 views

How certain is the Sun's classification?

Curious Question here. How do we know the Sun is a G-Type Star? Our sun (Classed as G2V) apparently lies around the 5,780 Kelvin. Yet NASA generalizes it as 6,000 K- and is apparently white even ...
Andyhasaquestion's user avatar
2 votes
0 answers
38 views

Display the lines of solar altitude on the map

Following this question: Calculate lines of equal solar altitude I would like to have the possibility of displaying the lines of equal solar altitude on the map as per the image below: including also ...
Geographos's user avatar
0 votes
0 answers
57 views

Does the slowing of the spin of the Earth's core result in more coronal mass ejections?

Some recent studies indicate that the slowing of the spin of the Earth's core happens on a periodic basis, such as when it slowed 50 years ago in the 1970s and 80s. Would this slowing of the inner ...
Phaedra Greenwood's user avatar
2 votes
1 answer
311 views

Is the solar system barycenter affecting the Earth weather?

I do not have the numbers but I guess the solar system barycenter should move much more than the Earth radius, and if that is correct then it should not be affecting the Earth's temperature. I mean, ...
Enrique's user avatar
  • 267
-2 votes
1 answer
193 views

What caused a huge piece of the Sun to break off?

There seems to be a huge piece of the sun that broke off at approximately 53 degrees. There's at least one article that describes it in these terms. This, to me, seems to be a CME (Coronal Mass ...
user avatar
4 votes
1 answer
113 views

See Venus in daylight

At what distance (in angular degrees) from the Sun, could we see Venus, in mid daylight, with a pair of binoculars (7x50)?
Jacquelin Hardy's user avatar
3 votes
3 answers
273 views

Why is the angle at which the sun sets the same as your latitude? [closed]

I learned in class that the sun sets at an angle when it is not an equinox. I also learned that the angle at which it sets is a good approximation of your latitude on earth. I am having trouble ...
Susanoo D Ace's user avatar
1 vote
0 answers
55 views

How does the entropy diffusivity changes with radius in the Sun?

Could you please explain - How does the entropy diffusivity changes with radius in the Sun? As far I know, In the convection zone, the entropy diffusivity increases as the temperature and density ...
stayhappy's user avatar

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