Why does the Millennium Star Atlas show distances in light-years, when the rest of the Hipparcos Catalogue works in milliarcsec and its related reciprocal, the parsec?
A. Most of the Hipparcos and Tycho Catalogue material is primarily of use to professional astronomers, who tend to prefer use of the parsec as the unit of distance measurement. The Millennium Star Atlas should serve the professionals, but we hope it will have great value for the amateur astronomer. Sky & Telescope know that from their correspondence, the light-year is more welcomed. We felt the use of the light-year was therefore preferable in this context. If an accurate distance (and error) estimate is needed, the user will have to extract these data from the main catalogue in any case.
Related Questions
- How do I get more details of objects shown in the Millennium Star Atlas? For example, how do I get the period and other details of the variable objects shown in the Atlas?
- How often do I need to download Comet Orbital Elements into STAR Atlas:PRO ?
- How do I download Comet Orbital Elements to STAR Atlas: PRO ?
