CHARM2: Measured stellar radii for Celestia - by ajtribick

CHARM2: Measured stellar radii for Celestia

A view of the CHARM2 add-on script in action.

Note that this add-on is not compatible with the updated star database which will be included in Celestia 1.6.0.
This add-on will be incorporated into the Celestia 1.6.0 release.

Typically Celestia calculates stellar radii using the assumption that a star is a uniform blackbody. This approximation performs poorly in several situations, such as for cool stars whose spectra contain numerous absorption lines from molecules in the atmosphere, or stars for which limb darkening is significant.

Instead of using calculated radii, Celestia can use radii measured from interferometry. The Catalog of High Angular Resolution Measurements (CHARM2) is a compilation of measurements of stellar angular diameters. From this catalog I have extracted radii for 1944 stars. Measurements taking limb darkening into account are used in preference to uniform disk estimates. Where more than one measurement was present for a star, the error-weighted average of the measurements was used.

Also included is a script which marks the stars affected by this add-on. Stars whose radii are estimated taking limb darkening into account are marked in blue, stars with uniform disk diameters are marked in green.

Download the CHARM2 add-on (80KB zip)

Journal reference: Richichi A., Percheron I., Khristoforva M. (2005) - “CHARM2: an updated Catalog of High Angular Resolution Measurements”. Astronomy and Astrophysics 431, 773

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