Questions tagged [the-sun]
Questions regarding the closest star to Earth, at the centre of the Solar System.
898
questions
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 ...
- 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
...
- 61
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 ...
- 191
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 ...
- 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, ...
- 967
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 ...
- 967
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 ...
- 135
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 ...
- 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 ...
- 61
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 ...
- 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 ...
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 ...
- 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 ...
- 23
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 ...
- 305
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 ...
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 ...
- 155
-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 ...
- 175
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 ...
- 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.
- 171
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 \...
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, ...
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 ...
- 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.
- 959
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 ...
- 4,799
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 ...
- 133
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!
- 3
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 ...
- 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 ...
- 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 ...
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 ...
- 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 (...
- 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'...
- 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-...
- 315
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 ...
- 315
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, ...
- 315
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 ...
- 315
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.
...
- 315
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,...
- 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 ?
user50623
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 ...
- 141
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 ...
- 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 ...
- 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 ...
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 ...
- 288
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 ...
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, ...
- 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 ...
user47732
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)?
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 ...
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 ...
- 11