How far away - and how big - is Betelgeuse?????????

I've run into an incredible range of distances from us given for this
star...and a good summary of many of them at
http://wnt.cc.utexas.edu/~ecannon/

What is the best source for how far Betelgeuse is from us...and how
big it really is?

Rick.

In article , Rick
wrote:
What is the best source for how far Betelgeuse is from us...and how
big it really is?

SIMBAD is the typical starting point for this sort of query:
http://simbad.u-strasbg.fr/sim-fid.pl

Enter "Betelgeuse" into the `identifier' box and let it grind.
You'll get data including this:

Radial velocity (v:Km/s) or Redshift (z)
v +21.0 [ .9] A 1953GCRV..C......0W
Parallaxes (mas)
7.63 [1.64] A 1997A&A...323L..49P

The reference is to the Hipparcos catalogue.
A parallax of 0.0076 arc seconds implies a distance of 3.26
(ly/parsec)/0.0076 ly =~ 429 ly

If you've got an angular diameter from interferometry, then you
can calculate the absolute diameter from the range (above) and the
angular diameter.

--
Aidan Karley,
Aberdeen, Scotland,
Location: 57°10'11" N, 02°08'43" W (sub-tropical Aberdeen), 0.021233

(rick) wrote in message . com...
I've run into an incredible range of distances from us given for this
star...and a good summary of many of them at
http://wnt.cc.utexas.edu/~ecannon/

What is the best source for how far Betelgeuse is from us...and how
big it really is?

Rick.

------------

a) Far, far away.
b) Bigger than a breadbox

Remember, you read it here first.