Measurements in SIMBAD contain various original observing data collected from the literature, as well as some historical compilations (e.g. GCVS, GCRV, or PLX catalogues).
Stellar diameters, see 2001A&A...367..521P for an
explanation of the coding of the
methods of measurements.
Applies to any astronomical object, galactic or
Please check the unit, which can be pc (galactic stars),
kpc, or Mpc (galaxies),
especially to make selections on criteria.
Historically devoted to stars, this measurement contains
Teff, logg, and Fe/H.
However we also collect the metallicity of other
astronomical objects in this
section. Note that FeI/H, FeII/H, and M/H are not
Spectral types from UV, optical, or infrared
spectroscopy. Spectral types estimated
from photometric observations only are not collected.
(Formerly named MK, standing for Morgan & Keenan
Stellar rotational velocities (vsini)
Devoted to variable stars. Contains the
classification as given by the authors, maximum and
minimum magnitudes, photometric
band of the measurements, and period. (Formerly named V*)
Applies to any astronomical object, galactic or extra-
Lists heliocentric velocities, or LSR velocities, or cz,
or redshifts. Please
check the flag type which can be v, lsr, z, or cz,
especially to make selections
Some catalogues were ingested in SIMBAD in a measurement section before the birth of the VizieR
database. Since then they have been included in VizieR. Therefore they have been removed from SIMBAD
to avoid an unuseful duplication of data. The following historical catalogues can be accessed directly
in VizieR from a SIMBAD page by clicking on the VizieR icon next to the name : CEL, cl.g (name ACO),
Einstein (name 2E), GJ, HGAM, IRAS, IRC, JP11, SAO, TD1, as well UBV and hbet (name GEN#), and uvby(1) (name uvby98).
Velocities and redshifts :
There were 5 different measurements in SIMBAD to collect
heliocentric velocities, cz, and redshifts : orv, rvel, GCRV, z, and ze. All these data have
been transfered into the new and unique Velocities measurement. Note however that, unfortunately,
there was no field to record the measurement uncertainty in some old measurements.
In general, to get as many photometric data as possible on a given object from its SIMBAD
page, we recommand to use the photometry viewer. Do not forget however that this is just a Xmatch
within a search radius; it does not guarantee that all the data actually apply to the same source.