8
votes
Accepted
Velocity dispersion of stars in galaxies
When looking at say an elliptical galaxy, the line of sight velocity dispersion is usually measured from the spectra of very many unresolved stars. The line of sight velocity dispersion is calculated ...
- 158k
2
votes
How to estimate artificial satellite brightness as seen from another satellite?
There will hopefully be better answers based on equations for apparent magnitude which use albedo and phase angle (albedo is problematic for spacecraft because they can have big flat shiny surfaces ...
- 30.2k
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