Re: [nbos] Determining Stellar Values"Mike Oliver" Thu Feb 21st, 2008
I'm only an amateur astronomer and my astrophysics is very sketchy.
However, I use the Norton Star Atlas a great deal for my observational
activities and I know it contains a whole raft of formulae and technical
info. Try borrowing a copy from your library and see if it has what you
[mailto:nbossoftware-bounces-at-nbos.com] On Behalf Of Dalton Calford
Sent: 20 February 2008 17:13
Subject: [nbos] Determining Stellar Values
I am trying to take some real universe data and convert it into csv data
that can be used with AS2.
The data I have is in the following format
1. StarID: The database primary key from a larger "master database" of
2. HIP : The Hipparcos identity number
3. HD: The star's ID in the Henry Draper catalog, if known.
4. HR: The star's ID in the Harvard Revised catalog, which is the same
as its number in the Yale Bright Star Catalog.
5. Gliese: The star's ID in the third edition of the Gliese Catalog of
6. BayerFlamsteed: The Bayer / Flamsteed designation, from the Fifth
Edition of the Yale Bright Star Catalog. This is a combination of the
two designations. The Flamsteed number, if present, is given first; then
a three-letter abbreviation for the Bayer Greek letter; the Bayer
superscript number, if present; and finally, the three-letter
constellation abbreviation. Thus Alpha Andromedae has the field value
"21Alp And", and Kappa1 Sculptoris (no Flamsteed number) has "Kap1Scl".
7. ProperName: A common name for the star, such as "Barnard's Star" or
"Sirius". I have taken these names primarily from the Hipparcos
project's web site, which lists representative names for the 150
brightest stars and many of the 150 closest stars. I have added a few
names to this list. Most of the additions are designations from catalogs
mostly now forgotten (e.g., Lalande, Groombridge, and Gould ["G."])
except for certain nearby stars which are still best known by these
8. RA: The star's right ascension
9. Dec: declination, for epoch 2000.0. Stars present only in the Gliese
Catalog, which uses 1950.0 coordinates, have had these coordinates
precessed to 2000.
10. Distance: The star's distance in parsecs, the most common unit in
astrometry. To convert parsecs to light years, multiply by 3.262. A
value of 10000000 indicates missing or dubious (e.g., negative) parallax
data in Hipparcos.
9. Mag: The star's apparent visual magnitude.
10. AbsMag: The star's absolute visual magnitude (its apparent magnitude
from a distance of 10 parsecs).
11. Spectrum: The star's spectral type, if known.
12. ColorIndex: The star's color index (blue magnitude - visual
magnitude), where known.
13. X,Y,Z: The Cartesian coordinates of the star, in a system based on
the equatorial coordinates as seen from Earth. +X is in the direction of
the vernal equinox (at epoch 2000), +Z towards the north celestial pole,
and +Y in the direction of R.A. 6 hours, declination 0 degrees.
14. VX,VY,VZ: The Cartesian velocity components of the star, in the same
coordinate system described immediately above. They are determined from
the proper motion and the radial velocity (when known). The velocity
unit is parsecs per year; these are small values (around 10-5 to 10-6),
but they enormously simplify calculations using parsecs as base units
for celestial mapping.
>From the AbsMag (the absolute magnitude or how it would look from 10 pc
distance) I can determine the Luminosity as
Luminosity = (10^0.4x(4.7-AbsMag))*(3.8x10^26)
But I need a formula for the Mass and Radius of the Star, given the
Does anyone know how to get this information (expressed as an excel
formula if possible)
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