Tycho catalog skymap v2.0 (threshold magnitude 5.0, high-res)
NASA/Goddard Space Flight Center
The skymap shows stars from the Tycho and Hipparcos star catalogs, provided by the ESO/ECF generic catalog server. The map is plotted in plate carrée projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs.
The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the threshold magnitude, usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible.
About 2.4 million stars are plotted, but many may be below the pixel intensity resolution.- http://svs.gsfc.nasa.gov/goto?3572 (TIFF image)
- Both the image and the description are from the page above; more details available there.
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