Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Pseudoscience-is-malarkey on 15/01/2023 20:52:31

Title: Are red dwarf stars red?
Post by: Pseudoscience-is-malarkey on 15/01/2023 20:52:31

To us, the sun appears yellow, but that is an illusion created by our planet's atmosphere. Is this the same for red dwarves?

EDIT: what I meant to ask is, if we were viewing a red dwarf from somewhere in its interplanetary medium, what color would it appear as?

Title: Re: Are red dwarf stars red?
Post by: Peter11 on 15/01/2023 23:28:40

Surface tempiture red is cold blue is hot.The sun is white and the atmosphere scatters and absorbs the blue light making it look yellow.You can only see red drawfs with a telescope at night so yes they are red.Humans can only see in certain wave lengths we only see them the color our vision allows so due to that limit we see them only in the wavelengths our eyes allow.Most pictures from space have the wavelenght changed to what a human can see or we would not be able to see them like we do.
There is only one star that is red in the night sky and its a Red giant about to nova.

Title: Re: Are red dwarf stars red?
Post by: Kryptid on 16/01/2023 06:15:08

They are typically more of an orange-white than actual red: http://www.vendian.org/mncharity/dir3/starcolor/

Title: Re: Are red dwarf stars red?
Post by: evan_au on 16/01/2023 07:27:31

The retinal "rod" cells that operate at night are not colour-sensitive.
- To see star colours, use a camera.
- In the "old" days with chemical film, leaving the shutter open for a few hours creates streaks of many different colours.

https://en.wikipedia.org/wiki/Star_trail

Title: Re: Are red dwarf stars red?
Post by: evan_au on 17/01/2023 19:53:03

Astronomers have discovered 131 objects within 20 light-years of the Sun. 80 of them are red dwarf stars, and another 22 are even smaller and dimmer.
- Of the 131, only 22 are bright enough to be visible to the naked eye (in a dark-sky location)
- More distant red-dwarf stars (>20 light-years) would be very hard to spot with the naked eye
- It is thought that throughout the galaxy, red-dwarf stars far outnumber stars like the Sun.
- It's hard to know if brown-dwarf stars are even more numerous, because they are so hard to spot (maybe James Webb can help us, here?)

So in general, red dwarf stars would look red, if you could get close enough to see them with your colour vision.

https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs