Questions tagged [night-sky]

Questions regarding the visible night sky during nighttime from Earth.

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What exactly is the "paradox" in Olber's Paradox?

To the extent of my understanding, Olber’s paradox states that if the universe was static and homogeneous, we should see a star at every point in the night sky and therefore the night sky should be ...
Sam's user avatar
  • 353
19 votes
2 answers
6k views

Are the stars distributed in uniform distribution, on the celestial dome, with respect to brightness?

Has there ever been a statistical analysis of the distribution of stars in the sky (on the surface of the celestial dome), by brightness? I want to know if they are uniformly distributed. For example, ...
DrZ214's user avatar
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17 votes
1 answer
1k views

How much clearer are stars in earths orbit?

As a child I remember my parents taking camping in California, and upon stepping out of the car I was awestruck at how thick the Milky Way galaxy was and at the number of stars everywhere. I've always ...
Paul's user avatar
  • 377
14 votes
2 answers
7k views

What could be an explanation for a satellite-like moving light in the night sky that dims over time

Last night I saw a bright light moving across the sky. It was probably as bright (or even brighter) than some of the brightest visible stars like Vega and moving quite slowly (so no shooting star) at ...
299792458's user avatar
  • 343
14 votes
2 answers
724 views

How bright would the night sky be in the galactic center?

Given that the star density within a parsec of the center of the Milky Way is about 10 million stars per cubic parsec, how bright would the night sky be if you were on a rocky planet within that ...
Filip Milovanović's user avatar
12 votes
2 answers
7k views

Why don't we see "the milky way" in both directions?

We're (basically) in the middle of an arm of our galaxy. That is to say, we're sitting in the middle of a dense disc of stars. It would seem to me that. You should see: the thick line of the milky way ...
Fattie's user avatar
  • 1,126
12 votes
2 answers
2k views

Will Starlink deface the night sky?

There is some discussion (and there are some questions on this site) about the impact of Starlink on observational astronomy. I am not an astronomer, but I am amazed by the beauty an immensity of the ...
henning's user avatar
  • 231
11 votes
3 answers
3k views

How much do the constellations change if the viewpoint moves within a solar system?

My question is pretty simple. How would the night sky change if you were in a different planet within the same solar system? Specifically the fixed stars. Would the constellations be essentially the ...
skout's user avatar
  • 289
11 votes
2 answers
4k views

How does the Moon move in the "night" sky as seen from the poles?

A photo in the NYTimes article Ice Surveys and Neckties at Dinner: Here’s Life at an Arctic Outpost has got me thinking. During the winter months at either the north or south pole, when it is ...
uhoh's user avatar
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11 votes
3 answers
735 views

Perceiving movement of stars

Are there any stars visible to the naked eye whose position, over a normal human lifetime, can be seen to have changed (relative to other stars in the vicinity)?
Paul Ho's user avatar
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10 votes
1 answer
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What is this, red, blue, white twinkling, star? [duplicate]

I am from Germany and at 11 PM I was outside and I saw a star, rapidly twinkling in blue, red and white. At first, I thought it was a plane, but it didn't move. I took a picture of it, but you can ...
bratbruh's user avatar
  • 101
10 votes
2 answers
4k views

Why does the Milky Way appear to form an arch shape across the sky?

The Milky Way galaxy is disc-shaped and Earth is in its plane: (source) In the following image, the Milky Way appears form an arch shape across the sky: (source) This looks like an out of plane view ...
Sparkler's user avatar
  • 223
10 votes
1 answer
716 views

What would our night sky look like if the solar system was 100 light years from the centre of the Milky Way

When we look at photo's of the centre of the Milky Way, it looks extremely bright due to the concentraion of star systems... If our solar system was only 100 light years from the centre of the Galaxy,...
Our Man in Bananas's user avatar
9 votes
4 answers
161k views

What is this rapidly twinkling red, blue, and white star I saw?

Last night, I was on my balcony at 1AM (PST) and I looked up and saw two stars near the horizon (I'd guess ~30 degrees above the horizon), and they were "twinkling" about twice as fast as other stars ...
Gogeta70's user avatar
  • 193
9 votes
1 answer
862 views

What's the white glow around this star?

A few days ago, I took a photo of the night sky in the mountains of Georgia with my DSLR. There, I noticed that one single star (in the center of the part of the photo that I added below) looks very ...
Daniel's user avatar
  • 193
9 votes
2 answers
463 views

In what parts of the world is it impossible to view the night sky due to light pollution?

Growing up far from any city, I have always been able to view the full night sky. It was just the way how things were. Of course, I knew that light pollution is a thing, and that the sky is a lot less ...
SE - stop firing the good guys's user avatar
8 votes
1 answer
998 views

How am I supposed to locate the planets Uranus and Neptune with a 70 mm f/5.7 refractor?

I can locate all of the planets other than Uranus and Neptune. This is mainly because they are very dim and I live where there is just enough light pollution so that I can't spot them. I have a Gysker ...
Oscar's user avatar
  • 99
8 votes
2 answers
521 views

What would the night sky have looked like 12.9 billion years ago when galaxies first started to form?

If I stood on a theoretical earth at the time that galaxies were just starting to form, what would the sky have looked like? Due to the smaller size of the universe would it have been densely packed ...
Duke Dougal's user avatar
8 votes
2 answers
5k views

Why do I see rainbows around the moon?

Regularly, I see rainbows around the moon. Here is approximately what I see: Right at the edge of the moon, I see a bright blue ring of light. Further out, I see an inner rainbow. This is not as ...
Caters's user avatar
  • 269
7 votes
2 answers
720 views

My local night sky is so bright that I can only see the Moon, so would a low-cost telescope be any use?

Light pollution is so bad near our home that we can't see anything other the Moon in the night sky. For instance there is a street light on all night right in our lane and there are many other housing ...
user2617804's user avatar
7 votes
2 answers
696 views

How will planets behave in the night sky as seen by Mars colonists?

Certainly among the first colonists on Mars there will be a few people interested in Astronomy enough to enjoy the night sky. For them, familliar Mars will be missing and there will be a new, ...
uhoh's user avatar
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6 votes
4 answers
3k views

Is there an example of a star that is already dead, but can still be seen on Earth?

While looking up at the stars I wondered, what are the odds that some of them are already dead. I did some research and found a very interesting article here. It states that the odds are rather small, ...
Micha's user avatar
  • 163
6 votes
1 answer
290 views

Is there a star everywhere you look?

What % of the sky is occupied? Intuitively, when you look up at night most of the sky is black "space". Of course, our eyes are not very sensitive, so that's a dubious measurement. Imagine ...
gomennathan's user avatar
6 votes
2 answers
808 views

Mars night sky -- Phobos and Deimos?

I'm having a debate about how bright Martian nights would be, in terms of both the sky itself and ground illumination. This answer seems to indicate that the stars would be only dimly visible, and ...
Skatche's user avatar
  • 163
6 votes
1 answer
684 views

What would the night sky look like if the interstellar medium didn't exist to absorb or block light?

I was curious about how much brighter it would be and how much further we could see.
Pulchritude's user avatar
6 votes
1 answer
217 views

Sky surface brightness vs magnitude limit visibility

I am wondering how we can calculate the magnitude limit of the celestial object, which could be visible at the given sky surface brightness conditions. We already know that Venus and Jupiter are ...
Geographos's user avatar
6 votes
1 answer
118 views

Making an application to draw the night sky of other planets

I'm making an application for drawing a night sky of planets other than Earth. Ultimately my app may be used to draw a night skies of a hypothetical planets in other solar systems. I'm doing it ...
Felix.leg's user avatar
  • 221
6 votes
0 answers
328 views

What would go into the design of a simple sky quality meter, used to measure night sky brightness?

@MCG's answer mentions several methods to classify night sky quality or brightness, and goes on to say: Additionally, you could always purchase a SQM (Sky quality meter) which is a small, portable ...
uhoh's user avatar
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5 votes
2 answers
1k views

Is there a webpage that shows the night sky but can filter out dim stars?

This webpage is very good for viewing the night sky and learning the names of the stars Timeanddate - Astronomy However, it shows too many stars. Because I live in the city, I can only see about 50 ...
bobsmith76's user avatar
5 votes
3 answers
1k views

Did the night sky ever change in recorded history?

I wonder whether there has ever been a major change of the firmament in recorded history, like changes in the positions of stars, changes in constellations, or stars disappearing after going supernova....
John's user avatar
  • 75
5 votes
2 answers
198 views

App that shows what's passing in sky?

I'm not an astronomer but I enjoy looking up at the sky. So tonight I saw something moving in the sky. It looked like a star, and it was definitely not a plane (I checked in flightradar). Is there ...
rbhat's user avatar
  • 401
5 votes
1 answer
413 views

What inaccuracies are in this Stellarium depiction of the sky?

I found this depiction on Stellarium of the sky as seen from near the Apollo 12 landing site on January 11, 2131. The earth is the black circle in the arm of the Milky Way. Here is a similar view ...
Bob516's user avatar
  • 1,467
5 votes
1 answer
352 views

Naked-eye limiting magnitude: mismatch between Wikipedia, online converter and Shaefer's formula

I'm trying to make sense of the difference between the reference Sky Quality Meter (SQM) readings given in the Wikipedia article on Bortle scale, online converters like [1] that are based on Shaefer's ...
Ruslan's user avatar
  • 897
4 votes
4 answers
5k views

What is the ring of light around the moon and which star seen near it?

In this amatuer photograph, the following are to be noted: There is a faint ring of light around the moon. What is the distance we see this at. From the ground it looks like a hundred meters. There ...
Nick's user avatar
  • 239
4 votes
2 answers
3k views

How can we know if a star which is visible in our night sky goes supernova?

Let's say there is a star about 3000 light-years away from earth visible in our night sky. If this star were to go supernova tomorrow(not relative to earth's night sky), we would know about it 3000 ...
Schwarz Kugelblitz's user avatar
4 votes
1 answer
216 views

Sky density of milky-way stars vs external galaxies

I am interested to know if any particular slice of sky contains more galaxies or more stars (in the milky way, although would be interested to factor in extra-galactic stars, and even rogue planets) ...
Rabbi Kaii's user avatar
4 votes
1 answer
213 views

How do I know that I’ve found Neptune?

So, recently I went out for a look at Neptune with my telescope and I found the general area of where Neptune was. However, when I took a see for myself, there were a ton of blue stars everywhere and ...
Prince Pugs's user avatar
4 votes
3 answers
456 views

Density of stars on celestial sphere

The pattern of stars on the surface of the celestial sphere seems perceptually to have an universally looking structure. If you pick a region of the sky at random, for instance by using the (excellent)...
meduz's user avatar
  • 345
4 votes
1 answer
1k views

Stars in multiple constellations

Are there examples of single stars that are a part of multiple constellations? What about stars that are part of one Western constellation and one non-Western? Thanks in advance!
dshipper's user avatar
  • 143
4 votes
1 answer
1k views

What did the night sky look like 100,000 years ago?

Question in the title. Would any constellations be identifiable?
GoingFTL's user avatar
  • 586
3 votes
2 answers
7k views

Where can I find a visible star dataset?

I'm trying to do a project for a databases class where I have a user enter their current location and I tell them what constellations/planets/etc are visible in their area. I've seen this data ...
lmotl3's user avatar
  • 33
3 votes
2 answers
3k views

From our world's perspective, does the full moon look larger in one city than it does in another?

When I was a very little girl, my dad talked about the HUGE full moon he saw while in the navy. He made the comment during a full moon we were having in Western NYS. He said, this (harvest) moon is ...
Bea Devorah's user avatar
3 votes
1 answer
161 views

Why does light pollution make the night sky completely black without stars?

I have seens pics of the night sky in areas that naturally have little population like deserts, cold regions and forests and the night sky is slighly bright and colored by shades of blue, red, purple ...
user44346's user avatar
3 votes
3 answers
2k views

Star map - finding stars

Assume you are given a star map that doesn't have the name of the stars on it. You know the latitude, longitude of the observer and the local time (year, month, day, local time). How could I proceed ...
Alex S's user avatar
  • 51
3 votes
2 answers
290 views

Events I cannot explain

In the last few days I experienced two events I cannot explain. I watch the sky since I was a child so I'm aware of most events like satellites, ISS, Iridium flares, etc... First event It was about 22:...
Mark's user avatar
  • 359
3 votes
1 answer
215 views

Is the dot on the photo - Mars?

The below photos were taken yesterday (August 4, 2018) at about 10 p.m. from the plane over the Black Sea. We were seeing the light dot on the left for at least 10-20 minutes. It looked like a bright ...
Oleg's user avatar
  • 133
3 votes
1 answer
730 views

Brightest star visible from Italy and Argentina

A friend of mine tends to ask crazy question about everything. Today he ask me what is the brightest star that is visible on both the hemisphere and in particular from Italy and Argentina. I tried to ...
yngabl's user avatar
  • 131
3 votes
1 answer
272 views

How come the northern and southern lights are the same?

Not an expert, hence the question. To my knowledge the magnetic field of the earth travels south to north. Wouldn't there be a bias on whether the charged particles causing the auroras are negatively ...
user avatar
3 votes
1 answer
140 views

Sky in the very far future / past

Motivated by this question about a stranded submarine in the Jurassic I would like to know: Is there anything remotely left of our current skyline if we go back or forward millions of years so that ...
Thorsten S.'s user avatar
3 votes
2 answers
119 views

Are there any bright non-stellar objects which make up asterisms?

Hopefully the title is very self-explanatory. I was wondering if there were any non-stellar objects, such as bright galaxies, which when looking with the naked eye were mistaken for stars in the time ...
MichaelJRoberts's user avatar