How to retrieve all spectra of stars
For example, how to retrieve all the spectra of stars with spectral
type between A0 and A2?
It is a very general question. You may wish to select the members of the
Hyades, or AGB stars, or whatever class of objects may be present
in the catalogue of the ELODIE archive and/or download the
corresponding spectra with an apropriate on-the-fly processing.
with specific characteristics ?
There are two different cases. Either you may select your sample by putting
constraints on some physical parameters or you may want to access a
sample made by yourself or taken from the litterature.
1. Making a sample from constraints on physical parameters
Presently the possibilities of setting physical constraints are very
restricted. The only facility proposed is to select objects from
a region of the sky!
There are to types of information on which we plan to allow
selections to be made: (1) observational parameters and
(2) physical parameters.
The observational parameters, generated when the observations were done
and included in the FITS header (meta-data) are stored in a table of the
database and we will provide, after completion of phase 2 of development
(September 2004), an advanced selection menu to put constraints on
signal-to-noise, date of observation, name of observer or other
parameters (suggestions are welcome).
The selection on physical parameters will rely on the availability of
these parameters and actually there is a project of a "server of
fundamental parameters of stars" to be opened next year at Observatoire de
Bordeaux. This server will provide the effective temperature, surface
gravity and metallicity (extension of the Cayrel et al. catalogue)
and will also give estimates of absolute magnitude, plus an indication of
spectral classification, photometry...
The latter parameters are now available from the Simbad database and we
are currently studying improvements of cross-access with Simbad.
Possibly, in the future, Simbad will give direct access to the entries
in the ELODIE archive.
We hope that basic physical parameters will be included in the version
to be released in September 2004, to allow selection of samples from
2. Using a pre-defined sample or loading your own sample
The ELODIE archive has inherited from HyperLeda the concept of
pre-defined samples. Any search in the archive may be limited to such a
given list of objects. The list of pre-defined samples can easily be
extended and any suggestion is welcome. You can also possibly contribute
your own preferred sample (you would have to send us a description of
this sample and a list of objects).
Uploading a sample is a facility scheduled for September 2004.
3. Getting the spectra for a sample
To download a list of spectra we encourage the use of a script rather than
the web interface, though of course this latter option is still a
We recommend to read the document:
"Other ways of accessing the Elodie archive".