Red Dwarf Questions

[Kitsune]

I have a few questions about Red Dwarf Stars.

First, because they are extremely faint, how many red dwarf stars can we actually see?
Second, how far out can we actually see Red Dwarf Stars?
Third, do we have any methods of actually dating the dwarf stars that do exist?

[Wyrm]

First, because they are extremely faint, how many red dwarf stars can we actually see?

Very few, in comparison to the number that are actually out there. I'd ballpark somewhere in the hundreds of thousands. Unfortunately, I don't have a near star catalog handy.

Second, how far out can we actually see Red Dwarf Stars?

Red dwarfs are basically 15th magnitude and down, and we can see objects as faint as the 27th magnitude from the ground. This gives us a maximum distance modulus of 12, or a distance of 6340 parsecs for the brightest, 289 parsecs for the dimmest (20th magnitude).

Third, do we have any methods of actually dating the dwarf stars that do exist?

Metallicity. The less metals (lithium and heavier elements) in the star's atmosphere, the older it is. The metals can be measured by looking at the star's spectrum.

[Kitsune]

Very few, in comparison to the number that are actually out there. I'd ballpark somewhere in the hundreds of thousands. Unfortunately, I don't have a near star catalog handy.

Red dwarfs are basically 15th magnitude and down, and we can see objects as faint as the 27th magnitude from the ground. This gives us a maximum distance modulus of 12, or a distance of 6340 parsecs for the brightest, 289 parsecs for the dimmest (20th magnitude).

I looked at a few articles, I did not know we could actually see that many of them and that we could see them so far out. Does a Red Dwarf being a flare star help it to be detected?

Curious, is Parsecs a more correct distance measurement than light years. I had to translate the distances to light years to make it easier for myself.

Metallicity. The less metals (lithium and heavier elements) in the star's atmosphere, the older it is. The metals can be measured by looking at the star's spectrum.

I was curious if there is a way that some of the red dwarf star we can detect may have been in effect been polluted by metal giving a false reading? Has them been considered? I am thinking about the red dwarf being in a stellar nursery with a super massive star producing vast amounts of metal which is then dragging into the red dwarf.

Curious on another matter. We are considering galaxies colliding to form larger galaxies. Is there the possibility of two red dwarfs colliding and a yellow or orange dwarf be created as a result? Again thinking the most likely place for this would be a stellar nursery.

[Wyrm]

I looked at a few articles, I did not know we could actually see that many of them and that we could see them so far out.

You need an 8-meter telescope to see down to 27th magnitude, and long exposure times. To my knowledge nobody has done an actual headcount.

Does a Red Dwarf being a flare star help it to be detected?

Immensely.

Curious, is Parsecs a more correct distance measurement than light years. I had to translate the distances to light years to make it easier for myself.

Google is your friend: "parsec in light years" — 1 Parsec = 3.26163626 light years

Parsecs make it easy to calculate the paralax of the star, and vice versa. It also gives the handy rule of thumb for stellar density, 1 star per cubic parsec.

I was curious if there is a way that some of the red dwarf star we can detect may have been in effect been polluted by metal giving a false reading? Has them been considered? I am thinking about the red dwarf being in a stellar nursery with a super massive star producing vast amounts of metal which is then dragging into the red dwarf.

The metals of a supermassive star stay in the core until it blows up. Even if one did go supernova nearby, the resulting debris field would quickly thin out and dump only the smallest amount of matter into the red dwarf, and only a tiny fraction of that will be metals (even today, the metallicity of stars forming now is very, very small).

Curious on another matter. We are considering galaxies colliding to form larger galaxies. Is there the possibility of two red dwarfs colliding and a yellow or orange dwarf be created as a result? Again thinking the most likely place for this would be a stellar nursery.

Star-star collisions during a galalxy-galaxy collision is very rare, due to the mind-boggling large amount of space between stars. If two unlucky red dwarfs do collide head-on, the likely result is a splat, destroying both stars.