I'm sure this has been mentioned before, I can't find the thread though:
I notice some stars have spectral types/sizes that don't correspond to their luminosities. For example, HD 176468 is shown as a K2 V, yet it has a luminosity of 23 Sols. Hipparcos doesn't give a size for this star, it just says it's K2, so presumably the size was added in Celestia? (it looks like this should be a K2 III to have that luminosity)
Can I assume the luminosity shown in Celestia for the stars is correct (relative to HIPPARCOS at least) and that the size is wrong here - I presume the luminosity is calculated from the apparent magnitude in the HIPPARCOS data?
Incorrect star types?
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Topic authorEvil Dr Ganymede
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granthutchison
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Celestia uses the distance and app mag in Hipparcos to calculate the absolute luminosity, and from that the size of the star. If there's a mismatch in the Hipparcos data, the star ends up being an inappropriate size and luminosity for its reported spectral class. The error is either in the distance or the spectral class. Or both.
Grant
Grant