WWW Access to the HST Data Archive

Kirk Borne and Tim Kimball
borne@stsci.edu, kimball@stsci.edu
Space Telescope Science Institute
The Space Telescope Science Institute (STScI) in Baltimore, Maryland provides the primary data archive facility for Hubble Space Telescope (HST) data. Users of the HST Data Archive can browse the catalog of observations using our StarView user interface, which is accessible on the Internet by logging into one of our two host computers through a guest account. In order to retrieve public data from the Archive, users must register with us; a registration form is available on the Web. For users who would like to run the StarView windowing software locally and only use the network to access the HST database, we provide distributed versions of the StarView software for SunOS and for VMS (Solaris and Alpha ports are also planned). Binaries for Distributed StarView can be downloaded via the Web at the push of a button.

Through our Web interface, we are able to provide several on-line documents and conference papers to assist researchers who are planning to use the HST data. In addition, we provide instructions for new users who are just getting started with the Archive.

Several ASCII listings of the Archive holdings are available via the Web. However, the StarView user interface provides the most general access to the HST catalog through a variety of search screens. StarView also provides a mechanism for previewing spectra and images prior to retrieving the archived HST data. A prototype Web interface to the HST catalog is under development, which will allow for simple catalog searches and for data previewing directly via the WWW.

New developments within the Archive group at STScI include:

The HST Archive currently contains 368,300 distinct datasets, corresponding to 82,300 science observations. Of these, 36,700 are images and 30,900 are spectra. In addition, there are 5,100 photometric observations and 9,600 astrometric observations available. The observed targets have covered all categories of astronomical objects, of which 40% have been extragalactic, 50% galactic, and 10% within the solar system. The entire volume of the HST Data Archive system is currently 1.64 terabytes, and it is increasing at the rate of roughly 2 gigabytes per day. Users are retrieving data from the archive at nearly the same rate (2 Gbytes/day) through our StarView user interface. In addition, there are currently about 3300 accesses to the HST Data Archive Web pages each week.

The HST Data Archive is becoming an increasingly active astronomical research facility and the Web is providing greater and easier access to the data holdings of the archive for researchers, educators, students, and the astronomically interested general public.

Kirk Borne and Tim Kimball
Mar 28, 1995