The Color Of Stars.... Reality Versus Scifi

[Spacescifi]

The sun of Krypton is a red dwarf, and I have seen it look reddish while the sky is blue.

That seems right, as stars out out the entire spectrum of colors, it's just their primary is emitted as well.

 

I suspect the mornings would have a reddish hue akin to dusk, growing brighter, maybe pinkish until the sky starts to look normal blue aside from the red sun in the sky.

 

Other stars in scifi: All too often I see colorful hues, like yellow, red, or even green stars in space.

 

In reality our yellow sun looks like a bright white ball in space, as I suspect probably all stars look in outer space, since there is no atmoshere to filter out the colors. Does not matter if you are a red dwarf, a blue giant or even a magntar.... am I right?

Not sure why colors show up in space imaging, unless that is just infrared or UV light being translated that we normally would not see.

I know nebulas give off colors though.

 

But I strongly suspect spaceships flying by stars in space won't be able to identify them based on color by just looking at them with the naked eye.

Is it imaging tech that detects whether a star is yellow, blue or red?

 

Or is it at far distances that stars appear a certain color and not white?

[intelliCom]

*Armchair scientist talk; if wrong, disregard*

The reason distant stars appear as colours between red, yellow, white, and then blue in our night sky is because they're distant enough that they don't burn your eyeballs out. It's not necessarily an optical illusion. Yes, they are technically 'white' since they emit all light, but IIRC, they emit more light in a particular part of the visible spectrum than another part of it due to their temperature.

The colours, IIRC, are within the kelvin scale, where colder stars would appear more orange, while hotter stars are more white-blue.
The colours shown below are the colours of every star in the universe. There are no pink stars or green stars.

Also, for Sci-Fi (rant warning)...

Spoiler

This sure as hell ain't what a star looks like to the human eye, even when underexposed.

It is obviously based on this famous picture of our sun, which was done purely in the ultraviolet spectrum.

It's not even "orange" in that spectrum; it was hued that way because it's much more interesting and more appealing to our "ball of fire" analogy than what the sun actually looks like in visible light.

[Spacescifi]

14 minutes ago, intelliCom said:

*Armchair scientist talk; if wrong, disregard*

The reason distant stars appear as colours between red, yellow, white, and then blue in our night sky is because they're distant enough that they don't burn your eyeballs out. It's not necessarily an optical illusion. Yes, they are technically 'white' since they emit all light, but IIRC, they emit more light in a particular part of the visible spectrum than another part of it due to their temperature.

The colours, IIRC, are within the kelvin scale, where colder stars would appear more orange, while hotter stars are more white-blue.
The colours shown below are the colours of every star in the universe. There are no pink stars or green stars.

Also, for Sci-Fi (rant warning)...

  Hide contents

This sure as hell ain't what a star looks like to the human eye, even when underexposed.

It is obviously based on this famous picture of our sun, which was done purely in the ultraviolet spectrum.

It's not even "orange" in that spectrum; it was hued that way because it's much more interesting and more appealing to our "ball of fire" analogy than what the sun actually looks like in visible light.

I think I understand... what you are saying is that viewing stars on Earth they may be different colors because if the atmospheric filtering... or you saying that whether on earth or in space if distant enough a star will appeara a certain color?

 

That's.... cool!.

 

So in some parts of the universe you could look around a see a bunch of red dots instead of white dots?

Or blue if you are surrounded by blue giants?

Edited January 7, 2023 by Spacescifi

[kerbiloid]

We have a documentary.

Spoiler

 

 

[intelliCom]

8 hours ago, Spacescifi said:

I think I understand... what you are saying is that viewing stars on Earth they may be different colors because if the atmospheric filtering...

Atmosphere isn't a factor. They look like this in space too. Red stars are always red, blue stars are always blue. If the atmosphere was affecting it, wouldn't they be changing colours?

8 hours ago, Spacescifi said:

if distant enough a star will appeara a certain color?

Because, again, you're not close enough to it for it to burn out your eyes. Far enough away, and it appears 'less bright' than it would, revealing whatever colour it outputs more.

If you were in the same solar system as the star, the star would probably appear just as bright and white as ours.

8 hours ago, Spacescifi said:

So in some parts of the universe you could look around a see a bunch of red dots instead of white dots?

That's not what I said. Colours do not change by location, atmosphere. Red stars are always red, blue stars are always blue. They do look brighter when you are closer to them. Bright enough, and they might as well be pure white because it's that bright for the human eye.

A "red dwarf" would appear red in our sky. A "white supergiant" would appear white in our sky. If we looked at the solar system from far away, our sun would appear yellow, but only from far away. Please refer to the graph below.

Note "temperature", the hotter it is, the bluer it is, the colder it is, the redder it is.

Spoiler

 

[farmerben]

On 1/7/2023 at 9:13 AM, intelliCom said:

*Armchair scientist talk; if wrong, disregard*

The reason distant stars appear as colours between red, yellow, white, and then blue in our night sky is because they're distant enough that they don't burn your eyeballs out. It's not necessarily an optical illusion. Yes, they are technically 'white' since they emit all light, but IIRC, they emit more light in a particular part of the visible spectrum than another part of it due to their temperature.

The colours, IIRC, are within the kelvin scale, where colder stars would appear more orange, while hotter stars are more white-blue.
The colours shown below are the colours of every star in the universe. There are no pink stars or green stars.

Also, for Sci-Fi (rant warning)...

  Hide contents

This sure as hell ain't what a star looks like to the human eye, even when underexposed.

It is obviously based on this famous picture of our sun, which was done purely in the ultraviolet spectrum.

It's not even "orange" in that spectrum; it was hued that way because it's much more interesting and more appealing to our "ball of fire" analogy than what the sun actually looks like in visible light.

So any pink or green stars could be a signal of intelligent life visible to distant galaxies.

Edited January 8, 2023 by farmerben

[intelliCom]

5 hours ago, farmerben said:

So any pink or green stars could be a signal of intelligent life visible to distant galaxies.

No, because stars cannot be pink or green. It would simply be a pink or green light, not necessarily associated with fusion energy.

But as for a bright pink or green light being a sign of intelligent life? Maybe. Then again, copper burns as green, so don't take any flash of pink or green as automatically being aliens.

Edited January 9, 2023 by intelliCom

[kerbiloid]

10 hours ago, farmerben said:

So any pink or green stars could be a signal of intelligent life visible to distant galaxies.

Yes, because only intelligent life can make absinthe and see the green stars.

[K^2]

On 1/7/2023 at 4:29 PM, intelliCom said:

Atmosphere isn't a factor.

I wouldn't go so far as to say that it's not a factor. But stars do, indeed, have color even when viewed from beyond the atmosphere, and yes, that color is determined by the temperature of the star's photosphere. Earth's atmosphere can alter the color a little bit, however, and the shimmers of color you sometimes see in the brighter stars are entirely an atmospheric effect. (If you're seeing the actual color of the star change in real time, it went nova.)

 

 

[intelliCom]

51 minutes ago, K^2 said:

I wouldn't go so far as to say that it's not a factor. But stars do, indeed, have color even when viewed from beyond the atmosphere, and yes, that color is determined by the temperature of the star's photosphere. Earth's atmosphere can alter the color a little bit, however, and the shimmers of color you sometimes see in the brighter stars are entirely an atmospheric effect. (If you're seeing the actual color of the star change in real time, it went nova.)

True. After all, the planets in the sky have different colour within the earth's atmosphere compared to outside of it.
However, it's so negligible that red, yellow, white, and blue stars are practically going to be the same in both situations. I guess I should really say "Atmosphere isn't a significant factor".

Spacescifi implied that the atmosphere was the reason why stars are different colours.

On 1/8/2023 at 1:28 AM, Spacescifi said:

what you are saying is that viewing stars on Earth they may be different colors because if the atmospheric filtering

Edited January 9, 2023 by intelliCom