72
6 Catalogues and Constellations
variable (which the suspected catalogue omits). Stars within the GCVS are prefixed
with GCVS, or in some cases, for example those in the SIMBAD database, they are
prefixed by V
∗ . The American Association of Variable Star Observers (AAVSO) also
keeps a variable star catalogue, the International Variable Star Index, which currently
holds over 20 million variable stars, many observed by amateurs.
6.4 Databases
Most of the catalogues listed above were originally supplied in printed form, which
makes searching and cross-referencing somewhat tiresome. Later versions, such as
the GSC and the SDSS, are supplied on CD-ROM (or DVD) that are machine readable
and allow for fast searches. However, the trend is now to have online access with
catalogues accessible by a web-based SQL search tool. In some cases, multiple
catalogues are held at a single site and may be cross-matched with relative ease.
The most important online astronomical catalogue is SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data), an online catalogue formed from the concatenation of a large number of astronomical catalogues.
At the time of writing, SIMBAD contained over five million objects, all located
outside of the solar system. SIMBAD is searchable by both name and location and
interacts with the Aladin application used for creating, amongst other things, finder
charts. It supports multiple coordinate systems, including J2000, B1950, and Galactic, and it provides bibliographical references to celestial objects. SIMBAD can be
accessed at http://simbad.u-strasbg.fr/simbad/ (Fig. 6.2).
Minor Planet Centre
For solar system objects (other than planets), the principal catalogue is the one held by
the International Astronomical Union’s Minor Planet Center (MPC). Like SIMBAD,
the MPC is a searchable database containing over 600,000 asteroids, comets, moons,
and other bodies, whose positions are regularly updated in order to provide accurate
ephemeris information (the data that allows the calculation of an object’s position in
the sky). The MPC website has a useful New Object Ephemeris Generator, which
you can use to help plan observations as well as for uploading solar system object
data into planetarium software such as Stellarium. It also has a list of objects making
their closest approach to Earth on the home page. The MPC’s website can be found
at https://minorplanetcenter.net/.
Exoplanets
Two invaluable websites for exoplanet observers is Exoplanets.Eu, which holds an
online, open-source database of all confirmed exoplanets (http://exoplanet.eu), and
the Exoplanet Transit Database (http://var2.astro.cz/ETD/), which has a vast database
on transits, with viewable data as well as a prediction of upcoming transits and
previous observational data on transits. You can also push your own data to the
website.
6 Catalogues and Constellations
variable (which the suspected catalogue omits). Stars within the GCVS are prefixed
with GCVS, or in some cases, for example those in the SIMBAD database, they are
prefixed by V
∗ . The American Association of Variable Star Observers (AAVSO) also
keeps a variable star catalogue, the International Variable Star Index, which currently
holds over 20 million variable stars, many observed by amateurs.
6.4 Databases
Most of the catalogues listed above were originally supplied in printed form, which
makes searching and cross-referencing somewhat tiresome. Later versions, such as
the GSC and the SDSS, are supplied on CD-ROM (or DVD) that are machine readable
and allow for fast searches. However, the trend is now to have online access with
catalogues accessible by a web-based SQL search tool. In some cases, multiple
catalogues are held at a single site and may be cross-matched with relative ease.
The most important online astronomical catalogue is SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data), an online catalogue formed from the concatenation of a large number of astronomical catalogues.
At the time of writing, SIMBAD contained over five million objects, all located
outside of the solar system. SIMBAD is searchable by both name and location and
interacts with the Aladin application used for creating, amongst other things, finder
charts. It supports multiple coordinate systems, including J2000, B1950, and Galactic, and it provides bibliographical references to celestial objects. SIMBAD can be
accessed at http://simbad.u-strasbg.fr/simbad/ (Fig. 6.2).
Minor Planet Centre
For solar system objects (other than planets), the principal catalogue is the one held by
the International Astronomical Union’s Minor Planet Center (MPC). Like SIMBAD,
the MPC is a searchable database containing over 600,000 asteroids, comets, moons,
and other bodies, whose positions are regularly updated in order to provide accurate
ephemeris information (the data that allows the calculation of an object’s position in
the sky). The MPC website has a useful New Object Ephemeris Generator, which
you can use to help plan observations as well as for uploading solar system object
data into planetarium software such as Stellarium. It also has a list of objects making
their closest approach to Earth on the home page. The MPC’s website can be found
at https://minorplanetcenter.net/.
Exoplanets
Two invaluable websites for exoplanet observers is Exoplanets.Eu, which holds an
online, open-source database of all confirmed exoplanets (http://exoplanet.eu), and
the Exoplanet Transit Database (http://var2.astro.cz/ETD/), which has a vast database
on transits, with viewable data as well as a prediction of upcoming transits and
previous observational data on transits. You can also push your own data to the
website.