High Energy Astrophysics Science Archive Research Center. The home page for all the X-ray archives.
The Internet's Virtual Telescope.
Jet Propulsion Laboratory - Links to Galileo, Pathfinder and other Mars missions and more...
Italian X-ray teslescope.
Hanbook of Spacs Astronomy
Zobeck's digital version of "Handbook of Space Astronomy and Astrophysics"
Numerical Recipes
Numerical Recipes In fortran - Digital Version.
Table of the Nuclides
Table of the Nuclides - Chemical and Atomic lookup table.
A chemical calculator - Information on any known chemical molecule.
Cepheid Database
The Galactic Cepheid Database - from the David Dunlap Observatory
1421 catalogues of which search by key_word, missions or spectral band. From Center de Donees astronomiques de Strasbourg
Nasa's Extragalactic Database
Standard Stars
Optical UV Standard Stars list
Large Scale Survey Project
The working group on wide field imaging is compiling a list of URL's related to ongoing survey projects.
List of object extractet from the Palomar Sky Survey. Very useful for identification of objects in the field.
Magnitude/Flux/Jansky Converter
A nice convinient converter for practical uses - from the NICMOS coordinating system.
On line Digitized Sky Survey
Spectral line catalog
The spectral line catalog of all elements + spectral energy distribution for them. The interface is a bit old but very usefull.
Hipparcos search facility
Hipparcos mission search facility, combines the HIC and TICHo catalogs.
Hipparcos Sky PLot
A nice Java based applet for the sky from the Hipparcos and Tycho catalogs