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45 votes
Accepted

Why wasn't the planet Uranus recognized by ancient cultures?

The source of light that is Uranus was observed as far back as 128 BC. However it was misidentified as star as late as the 1760's. Then it was observed by Herschel in 1781, who also misidentified it,...
StephenG - Help Ukraine's user avatar
44 votes

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

Naked eye stars are not distributed uniformly in the sky. That is because the median naked eye star is at a distance of 440 light years, and this is far enough away that some of the details of ...
ProfRob's user avatar
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30 votes
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What exactly is the "paradox" in Olber's Paradox?

Olber's Paradox was created at a time before the idea of a finite universe was accepted. (It was thought of in the 1600's). In order to resolve Olber's Paradox, you have to introduce the idea that ...
Phiteros's user avatar
  • 3,166
30 votes
Accepted

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

Yes, the night sky formed by everything outside the solar system will look the same from every planet in our solar system. Similarly an observer in any other system will not see a difference between ...
planetmaker's user avatar
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29 votes
Accepted

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

I'll turn my comment into a full answer. To put it simply, we actually do see the Milky Way all around us, even in the diametrically opposite direction from the galactic core. You can see this in the ...
zephyr's user avatar
  • 15k
28 votes
Accepted

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

From your description, this was most likely a Satellite Flare. This is the Sun reflecting off a highly reflective part of the satellite. The most famous type was the flares from the Iridium ...
Greg Miller's user avatar
  • 5,932
27 votes

Why wasn't the planet Uranus recognized by ancient cultures?

I like ScienceSnake's comment - a combination of faintness and its comparatively small apparent motion. It was observed in 1690 by John Flamsteed on several occasions, but because it moved so little ...
Bumptious Q Bangwhistle's user avatar
22 votes
Accepted

How much clearer are stars in earths orbit?

It varies. The best astronomical sites have a visual band extinction of 0.1 mag, which means that only $\sim 10$ per cent of light is absorbed/scattered in the atmosphere. In dusty, smoggy or ...
ProfRob's user avatar
  • 155k
21 votes

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

The Earth is a sphere (or is nearly a sphere). So to make a map of the whole Earth you would need to project it onto a flat surface. When you do this you create distortions. For example, on many maps, ...
James K's user avatar
  • 125k
21 votes

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

No, it will change! The amount it will change will depend on how far the star you are looking at is from Earth. Here is an image comparison of the same field taken from the New Horizons probe (...
Mike's user avatar
  • 368
20 votes

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

It is not possible to know. The speed of light is the speed of information. The information "the star has exploded" cannot travel faster than the speed of light, so there is no way to know ...
James K's user avatar
  • 125k
20 votes

What is this, red, blue, white twinkling, star?

The star is most likely Vega. It doesn't actually twinkle, the technical term for this is "scintillation", and is purely an atmospheric effect. The general idea is that stars are so far away,...
Greg Miller's user avatar
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18 votes
Accepted

What's the white glow around this star?

Astrometry.net has identified your star field as being part of the Andromeda constellation. The diffuse object in the centre of your image is the Andromeda Galaxy (Messier 31). The bright star to the ...
Mick's user avatar
  • 1,546
17 votes

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

Right now you won't. Both are on the "wrong" side of the sun and so not easily observable from Earth. At the moment (early 2020s) they are in the constellation of Aries and Pices which are ...
James K's user avatar
  • 125k
16 votes
Accepted

Will Starlink deface the night sky?

Satellites just add moving lights to the sky, they do not obscure stars. However, some may find that disrupting their view of what a sky should look like. The visual magnitude of starlink satellites ...
Anders Sandberg's user avatar
15 votes

Why wasn't the planet Uranus recognized by ancient cultures?

It would require a lucky coincidence As noted by others, Uranus is faint and easy to misidentify as a fixed star. However, Bourtembourg 2013 claims that Uranus was observed already in 128 BC by ...
Martin Modrák's user avatar
14 votes

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

If the photo is from today (24 November 2023), then the "star" is Jupiter, a planet. It's hard to see any ring around the moon in the photo, but rings are typically due to high clouds, and ...
Dr Chuck's user avatar
  • 4,349
13 votes
Accepted

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

I think your requirements can be met by Stellarium. It is a freely available open-source planetarium software available for PC, and can be used offline. There is also a web version, which you can try ...
lordparthurnaax's user avatar
13 votes

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

It very likely IS a satellite which is moving from the sunlit part into the shadow of the earth, dimming more and more as it crosses from the day side through twilight (partial earth shadow) to night.
planetmaker's user avatar
  • 19.9k
12 votes
Accepted

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

There is an accepted answer already, but there is a couple known cases of a star we know has gone supernova, and yet we can still see it. This source describes one such unique circumstance. The star ...
Cody's user avatar
  • 1,180
12 votes

Will Starlink deface the night sky?

A nightmare for star hopping I can only speak as an amateur astronomer with a 10-inch Dobsonian. My telescope has no GOTO or tracking, so if I want to find something interesting in the sky, I have to ...
Eric Duminil's user avatar
  • 1,395
11 votes

How can we see Venus at night?

Before we begin: how far a planet is seen from the Sun is called elongation, and it's measured in degrees. 0° elongation means it's right on top of the Sun (or behind); 180° elongation means it's ...
Florin Andrei's user avatar
11 votes
Accepted

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

It's most probably Sirius. At this time of year (at 1 am local time) it's low in the sky in the East, so there is a lot of atmosphere in the way, and as Sirius is a bright bluish star, it will show ...
Dr Chuck's user avatar
  • 4,349
11 votes
Accepted

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

The moon is quite interesting as you get near the poles. It still moves round due to the Earth's rotation once a day, but it also orbits with a period of a month so what you get is two weeks of moon ...
Rory Alsop's user avatar
  • 5,102
11 votes

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

Alright I finally finished this program so I could take a look at each tier individually and see for myself. First of all, the projection type does indeed matter, so I will explain it here. It needs ...
DrZ214's user avatar
  • 1,970
10 votes
Accepted

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

Interesting question. Assuming the figure of 10 million stars per cubic parsec is correct, there's still one missing piece of information to try getting a estimate: The size of this region with a very ...
ksousa's user avatar
  • 1,201
10 votes

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

tl;dr astrophotographers shouldn't carry their cameras in their pockets :-) I took photos of the Moon and Jupiter with my cell phone last night as well. I keep my phone in my pocket and the lens ...
uhoh's user avatar
  • 30.6k
9 votes

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

The question has been addressed, but for completeness I should like to remark that the most thorough and readily understandable discussion of Olber's Paradox is that of E. Harrison in his book ...
JonesTheAstronomer's user avatar
9 votes

Is there a star everywhere you look?

Only about 1 in $10^{12}$ sightlines end on the surface of a star (or 1 in 50,000 if you include the Sun). The rest end where/when the cosmic microwave background formed. Details There are thought to ...
ProfRob's user avatar
  • 155k
8 votes

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

The main effect would be that the Milky Way would become much more prominent and asymmetric. At the moment, our view into the Galactic plane is limited to around 1000-3000 parsecs by dust. If you ...
ProfRob's user avatar
  • 155k

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