<p>Obviously, they can exist. There are blue stars:</p>
<p><a href="https://i.sstatic.net/Tmyfg.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Tmyfg.jpg" alt="enter image description here" /></a></p>
<p>There are red stars (red giants):</p>
<p><a href="https://i.sstatic.net/38bgO.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/38bgO.png" alt="enter image description here" /></a></p>
<p>If these happen to circle one another you will perceive the entire system as violet (from Earth).</p>
<p>One of two stars can develop into a red giant while the other stays a hot blue one. It's the question if they can coexist in a double system but I can see no reason why not.</p>

CC BY-SA 4.0
2021-07-01T00:51:51.983Z
This sounds more like a guess based on how the human eye perceives the addition of primary colours. Can you be a bit more specific on the actual star types and wavelengths involved, and how narrow the light spectrum would be for each? Actual stellar examples, rather than unattributed and unlabelled photos, would be useful.
Chappo Hasn't Forgotten
CC BY-SA 4.0
2021-06-30T13:25:46.547Z
2021-06-30T13:25:46.547Z
Deschele Schilder
<p>According to black-body radiation, violet stars are not possible.
Even if there are 1 million Kelvin, they are blue, not violet. But <strong>are violet galaxies, nebulae, clusters etc. possible?</strong></p>
<p>Google found a violet galaxy or nebula or black hole, but it looked like it was just painted at will. Can violet astronomical objects actually exist?</p>
<p>Some nebulae containing oxygen are green. I'm looking for non black-body violet.</p>

CC BY-SA 4.0
2021-06-29T11:11:48.230Z
Does this answer your question? [Why are there no green stars?](https://astronomy.stackexchange.com/questions/10510/why-are-there-no-green-stars)
David Hammen
CC BY-SA 4.0
2021-06-29T11:13:41.217Z
The black body curve in the answer to the linked question shows not only why there are no green stars, but also shows why there are no violet or purple stars. The color of a black body with an effective temperature of infinity is a nice blue.
David Hammen
CC BY-SA 4.0
2021-06-29T11:15:14.673Z
No, I know about Black-body radiation. Green and violet star is impossible. But some of the other astronomical objects may not be black body.
change
CC BY-SA 4.0
2021-06-29T11:15:24.570Z
Also related, [Why don't we see purple stars](https://astronomy.stackexchange.com/questions/28473)? I did not choose that question as a duplicate because the selected answer s just wrong.
David Hammen
CC BY-SA 4.0
2021-06-29T11:26:49.677Z
Some contain oxygen nebula are green. https://en.wikipedia.org/wiki/Green_star_%28astronomy%29
change
CC BY-SA 4.0
2021-06-29T12:02:09.390Z
The linked question says nothing but a green nebula. Do violet nebulae exist?
change
CC BY-SA 4.0
2021-06-29T14:29:26.920Z
Other questions with some "green" in them: [Why is the “green” comet C/2014 Q2 (Lovejoy) red in this picture?](https://astronomy.stackexchange.com/q/17811/7982) and also [Was the “green star” event in NGC 3314 ever figured out or named?](https://astronomy.stackexchange.com/q/35549/7982)
uhoh
CC BY-SA 4.0
2021-06-29T14:53:48.667Z
@DavidHammen even the original question acknowledged from the first sentence that a blackbody spectrum can't be violet, as well as acknowledging other mechanisms by which things can make light. Now that they've gone even further an added additional clarification to the question, I think this one can stay open and be answered. *[Voting to leave open!](https://i.sstatic.net/pPPQu.png)*
uhoh
CC BY-SA 4.0
2021-06-29T15:06:31.893Z
A bright O-type paired in a close double with a bright deep-orange star can *look* violet; that's the best you're going to do.
antlersoft
CC BY-SA 4.0
2021-06-29T15:19:05.830Z
@antlersoft if so then I think that can be an answer; violet is certainly *a color, perceived by humans* so if it can appear violet, it can be called violet.
uhoh
CC BY-SA 4.0
2021-06-30T02:21:04.797Z
o-class and m-class? light blue and orange? It doesn't look violet because of the additive mix. There are too many green ingredients. But I think it might work. Do you have an example?
change
CC BY-SA 4.0
2021-06-30T12:55:35.130Z
I just retracted my close-vote, thanks to @uhoh for the reasoning.
B--rian
CC BY-SA 4.0
2021-07-01T01:10:08.980Z
Thanks @uhoh for the guidance. Yes: a binary system can certainly be considered an "astronomical object", so the question is, in effect, whether there are two classes of stars whose light, *when added*, looks "violet" (and whether it's realistic that **such a binary could exist**, given the probable age differences). The dupe doesn't address this, so I'm voting to keep it open. PS an answer addressing these issues comprehensively and concluding "no, such an object probably doesn't exist" would still be a valuable addition to our Astronony.SE library. :-)
Chappo Hasn't Forgotten
<galaxy><nebula>
Can violet astronomical objects exist?
change
# Can violet astronomical objects exist?

(Asked by: username_0 on 2021-06-29)

According to black-body radiation, violet stars are not possible.
Even if there are 1 million Kelvin, they are blue, not violet. But **are violet galaxies, nebulae, clusters etc. possible?**

Google found a violet galaxy or nebula or black hole, but it looked like it was just painted at will. Can violet astronomical objects actually exist?

Some nebulae containing oxygen are green. I'm looking for non black-body violet.

**Tags:** galaxy, nebula
> **Comments:**
> **username_1**: Does this answer your question? [Why are there no green stars?](https://astronomy.stackexchange.com/questions/10510/why-are-there-no-green-stars)  
> **username_1**: The black body curve in the answer to the linked question shows not only why there are no green stars, but also shows why there are no violet or purple stars. The color of a black body with an effective temperature of infinity is a nice blue.  
> **username_0**: No, I know about Black-body radiation. Green and violet star is impossible. But some of the other astronomical objects may not be black body.  
> **username_1**: Also related, [Why don't we see purple stars](https://astronomy.stackexchange.com/questions/28473)? I did not choose that question as a duplicate because the selected answer s just wrong.  
> **username_0**: Some contain oxygen nebula are green. https://en.wikipedia.org/wiki/Green_star_%28astronomy%29  
> **username_0**: The linked question says nothing but a green nebula. Do violet nebulae exist?  
> **username_2**: Other questions with some "green" in them: [Why is the “green” comet C/2014 Q2 (Lovejoy) red in this picture?](https://astronomy.stackexchange.com/q/17811/7982) and also [Was the “green star” event in NGC 3314 ever figured out or named?](https://astronomy.stackexchange.com/q/35549/7982)  
> **username_2**: @DavidHammen even the original question acknowledged from the first sentence that a blackbody spectrum can't be violet, as well as acknowledging other mechanisms by which things can make light. Now that they've gone even further an added additional clarification to the question, I think this one can stay open and be answered. *[Voting to leave open!](https://i.sstatic.net/pPPQu.png)*  
> **username_3**: A bright O-type paired in a close double with a bright deep-orange star can *look* violet; that's the best you're going to do.  
> **username_2**: @antlersoft if so then I think that can be an answer; violet is certainly *a color, perceived by humans* so if it can appear violet, it can be called violet.  
> **username_0**: o-class and m-class? light blue and orange? It doesn't look violet because of the additive mix. There are too many green ingredients. But I think it might work. Do you have an example?  
> **username_4**: I just retracted my close-vote, thanks to @uhoh for the reasoning.  
> **username_5**: Thanks @uhoh for the guidance. Yes: a binary system can certainly be considered an "astronomical object", so the question is, in effect, whether there are two classes of stars whose light, *when added*, looks "violet" (and whether it's realistic that **such a binary could exist**, given the probable age differences). The dupe doesn't address this, so I'm voting to keep it open. PS an answer addressing these issues comprehensively and concluding "no, such an object probably doesn't exist" would still be a valuable addition to our Astronony.SE library. :-)  

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## 1 answers

### Answer by username_6 on 2021-06-30. Score: -3

Obviously, they can exist. There are blue stars:

[![enter image description here](https://i.sstatic.net/Tmyfg.jpg)](https://i.sstatic.net/Tmyfg.jpg)

There are red stars (red giants):

[![enter image description here](https://i.sstatic.net/38bgO.png)](https://i.sstatic.net/38bgO.png)

If these happen to circle one another you will perceive the entire system as violet (from Earth).

One of two stars can develop into a red giant while the other stays a hot blue one. It's the question if they can coexist in a double system but I can see no reason why not.

> **Comments:**
> **username_5**: This sounds more like a guess based on how the human eye perceives the addition of primary colours. Can you be a bit more specific on the actual star types and wavelengths involved, and how narrow the light spectrum would be for each? Actual stellar examples, rather than unattributed and unlabelled photos, would be useful.  

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