I Are almost all stars in the night sky brighter than the Sun?

[snorkack]

Snorkack, in the "comments" column, the comment for 61 Cygni AB says that it is "the dimmest visible star". What exactly did you mean by that? Wouldn't the dimmest visible star be magnitude 6.0?

It has the largest absolute magnitude of any star with visual magnitude under 6,0. All other visible stars are intrinsically brighter.
A complicating factor is that it is significantly binary. Addition of magnitudes is an inconvenient thing (raise to fractional power, add, then take a logarithm), so doing it by heart I preferred to round to one significant number and mentioned the approximateness in my list.
Check the distances to the binaries in my list. I systematically quoted the combined magnitude for apparent magnitude, because this is what eye sees (the binaries being not resolved by eye) and then the separate magnitudes for components (because this, like the true distance, is the truth out there).

 

[wolf1728]

In my list I added the comment "by absolute magnitude."
(Though I didn't mention this in the comments, 61 Cygni is significant for being the first star to have its distance accurately measured). (Bessel in 1838).
As far as the distances in the list, my only source was using the formula:
distance (parsecs) = 10^((m -M + 5)/5)

 

[Janus]

Here's a graphic I cobbled together that shows all the stars,including individual the members of multiple star systems( with the the exception of the "pup''(Sirius b) as it is too small to show up at the scale I used.) out to 6 parsecs.
Left to right is distance in parsecs. The blue vertical lines are absolute magnitude. The stars are shown to scale in size and the colors are their visible blackbody color. (or at least as close as I could get by converting star temp to RGB values)
I might try to continue it on past 6 parsecs, but I'm already running into information gaps. I had to quesstimate the radii of some of the smaller red dwarfs based on their temp and absolute magnitude as I couldn't find any sources that listed the information. As I try to move further out, I'm sure that this will become the case more often.

 

[snorkack]

(Though I didn't mention this in the comments, 61 Cygni is significant for being the first star to have its distance accurately measured). (Bessel in 1838).
As far as the distances in the list, my only source was using the formula:
distance (parsecs) = 10^((m -M + 5)/5)

Yes, but to the wrong magnitude.
The distance of 61 Cygni is 11,4 ly.
The visual magnitudes of components are +5,20 and +6,05, and the absolute ones +7,49 and +8,31 (I note errors in last numbers - these inconsistencies are common in quoted data). Since the components, with angular separation of 30 arc seconds, are not separated by eye, the combined magnitude is +4,8.

 

[wolf1728]

I changed the distance of 61 Cygni AB.
There are 42 stars in that list ending with a distance of 48.7 light years.
The limiting distance for a 4.85 absolute magnitude star to be visible is 55.3 light years.
Making an unscientific guess, if we were to extend that list to 55.3 light years, the number of stars would probably be less than 60.
Since there are about 6,000 stars that can be seen with the unaided eye, would it be safe to say that if you were to look at any star in the night sky, the probability would be greater than 99% that it is brighter than the Sun?

 

[snorkack]

Also:

1. HD 38858 5,97/5,01
2. Gliese 667 5,9/6,29+7,24

 

[Janus]

I've extended my graphic out to 10 parsecs. The image is a bit large to insert into the post so I'll just give the link to the full-size image:
http://home.earthlink.net/~parvey/sitebuildercontent/sitebuilderpictures/starchart2.jpg

 

[Janus]

Okay, it seems that the list goes out to a distance of 48.7 light years. If we want to make this an inclusive list, we'd have to make sure that all stars up to 55.3 light years have been checked. (If any of you know of a URL where I could search, I'd be glad to research the list out to 55.3 light years).
Snorkack, in the "comments" column, the comment for 61 Cygni AB says that it is "the dimmest visible star". What exactly did you mean by that? Wouldn't the dimmest visible star be magnitude 6.0?

Doing a query on VizieR, I came up with 144 stars within the distance where the Sun would be just visible at a visible magnitude of 6. of those 144, 44-47 have absolute magnitudes larger than the Sun*. This means that of the almost 6000 stars visible in the night sky by the unaided eye, only those 44-47 are less luminous than the Sun.

* The absolute magnitude was calculated from the visual magnitude and the parallax. Since there is an margin of error for the parallax, there is also a margin of error for the absolute magnitude.

 

[wolf1728]

So, if there are only about 44 - 47 stars less luminous than the Sun (with an apparent magnitude brighter than 6), then the probability of seeing a star in the night sky that is intrinsically brighter than the Sun is greater than 99%.
Thanks to Janus for doing that research and the graphic and thanks to snorkack for researching those two lists of stars.
And thanks to everybody that helped!

 

[snorkack]

This means that of the almost 6000 stars visible in the night sky by the unaided eye,

This is a commonly quoted number; but from http://www.astronomycafe.net/qadir/q1257.html I see a different number.
Not a reliable source, though - giving 3 under 0,0.

 

[Withertdm]

Space. The final frontier. These are the voyages of the starship Enterprise. (Star Trek theme plays)