Sorgente           alfa       delta      distance

  Galactic Center     266.        -29.
  LMC                  82.        -69.
  SMC                  14.        -72.
  Andromeda            10.         42.
  M33                  22.5        30.
  M101                210.         55.
  M81                 150.         70.
  Virgo Cluster       190.         11.


               Astrophysical Constants

   1 sideral year       = 3.1558149984D7 s
   1 light year         = 9.4605E15 m
   1 astronomical unit  = 1.495985E11 m
   1 parsec             = 3.0856E16 m
   1 solar mass         = 1.989E30 kg
   Earth mass           = 5.977E24 kg
   Equatorial radius    = 6.37817E6 m

Other sites for data

• AstroWeb: Astronomy/Astrophysics on the Internet

• AstroWeb: by country, by subject

• WebStars

• The Star*s Family of Astronomy Resources

• Astronomer's Bazaar

• NASA Astronomical Data Center

• The NASA Astrophysics Data System Home Page

• Geophysical Data from the Solid Earth

• The Web Nebulae (photo archive)

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Astronomical catalogs

• CDS: The Catalogue of Catalogues

• CDS: Nearby Galaxies

Relativistic Astrophysics

• Supernovae Research Home Page

• Obs. de Paris: Departement d'Astrophysique Relativiste et de Cosmologie

• Radio Pulsar Resources

• The Princeton Pulsar Group

• Astronomy and Astrophysics (!!)

• 3D Head-On Collision of Two Neutron Stars

• Axisymmetric Collision of Two Neutron Stars

• Colliding Black Holes

Other interesting astonomical sites

• IAU WWW home page

• The WWW Virtual Library: Astronomy and Astrophysics

• University of California Search for Extraterrestrial Civilizations

• Royal Greenwich Observatory

• Osservatorio Astronomico di Roma

• Paris-Meudon-Nançay Observatory

Mantained by S. Frasca e P. Astone