The SVO-JPLUS archive of ultracool dwarfs

HomeData retrievalNewsDocumentationCoverage MapCreditsHelp-Desk


The archive system implements a very simple search interface that permits queries by coordinates/radius and/or range(*) of magnitudes, colors and effective temperatures. The default search radius is set to 5 arcsec. The user can also select the maximum number of sources to return (with values ranging from 10 to unlimited).

The result of the query is a HTML table with all the sources found in the archive fulfilling the search criteria. Detailed information on the output fields can be obtained placing the mouse over the question mark ("?") located close to the name of the column.

The archive implements the SAMP (Simple Application Messaging Protocol). SAMP allows applications to communicate with each other in a seamless and transparent way for the user. This way, the results of a query can be easily transferred to other VO applications, such as, for instance, Topcat.

Virtual Observatory access

The Virtual Observatory (VO) is an international initiative whose primary goal is to provide an efficient access and analysis of the information hosted in astronomical archives and services. Having a VO-compliant archive is an important added value for an astronomical project to guarantee the optimum scientific exploitation of their datasets.

Our archive system has been designed following the IVOA standards and requirements. In particular, it implements the Cone Search protocol, a standard defined for retrieving records from a catalogue of astronomical sources. The query made through the Cone Search service describes a sky position and an angular distance, defining a cone on the sky. The response returns a list of astronomical sources from the catalogue whose positions lie within the cone, formatted as a VOTable.

Catalogue columns

Field Description Unit UCD Verbosity
RA (ICRS) Right Ascension (ICRS) (degrees) deg POS_EQ_RA_MAIN Minimum
DEC (ICRS) Declination (ICRS) (degrees) deg POS_EQ_DEC_MAIN Minimum
i_JPLUS JPLUS i magnitude mag phot.mag Minimum
z_JPLUS JPLUS z mag phot.mag Minimum
Teff Effective temperature estimated using VOSA K phys.temperature.effective Minimum
Av Extinction estimated using VOSA. mag phys.absorption Minimum
Radius Stellar radius estimated from L = 4 pi r^2 sigma Teff^4, where Teff and L have been calculated using VOSA and Gaia DR2 parallaxes. Rsun phys.size.radius Minimum
eRadius Stellar radius uncertainty Rsun stat.error;phys.size.radius Minimum
SDSS12 SDSS DR12 identifier Maximum
RA_SDSS SDSS DR12 RA deg Maximum
DEC_SDSS SDSS DR12 DEC deg Maximum
umag SDSS DR12 umag magnitude mag phot.mag Maximum
e_umag SDSS DR12 umag magnitude uncertainty mag stat.error;phot.mag Maximum
gmag SDSS DR12 gmag magnitude mag phot.mag Maximum
e_gmag SDSS DR12 gmag magnitude uncertainty mag stat.error;phot.mag Maximum
rmag SDSS DR12 rmag magnitude mag phot.mag Maximum
e_rmag SDSS DR12 rmag magnitude uncertainty mag stat.error;phot.mag Maximum
imag SDSS DR12 imag magnitude mag phot.mag Maximum
e_imag SDSS DR12 imag magnitude uncertainty mag stat.error;phot.mag Maximum
zmag SDSS DR12 zmag magnitude mag phot.mag Maximum
e_zmag SDSS DR12 zmag magnitude uncertainty mag stat.error;phot.mag Maximum
DR2Name Gaia DR2 identifier Default
RA_GaiaDR2 Gaia DR2 RA deg Default
DE_GaiaDR2 Gaia DR2 DEC deg Default
Gmag Gaia DR2 G magnitude mag phot.mag Default
e_Gmag Gaia DR2 G magnitude uncertainty mag stat.error;phot.mag Default
Plx Gaia DR2 parallax Default
e_Plx Gaia DR2 parallax uncertainty Default
pmRA Gaia DR2 pmRA Default
e_pmRA Gaia DR2 pmRA uncertainty Default
pmDE Gaia DR2 pmDE Default
e_pmDE Gaia DR2 pmDE uncertainty Default
Vtan Tangential velocity (v: 4.74 mu d) where mu, d were estimated using Gaia DR2 data. phys.veloc.transverse Default
BPmag Gaia DR2 BP magnitude mag phot.mag Default
e_BPmag Gaia DR2 BP magnitude uncertainty mag stat.error;phot.mag Default
RPmag Gaia DR2 RP magnitude mag phot.mag Default
e_RPmag Gaia DR2 RP magnitude uncertainty mag stat.error;phot.mag Default
2MASS 2MASS identifier Maximum
RA_2MASS 2MASS RA deg Maximum
DE_2MASS 2MASS DEC deg Maximum
Jmag 2MASS Jmag mag phot.mag Maximum
e_Jmag 2MASS Jmag uncertainty mag stat.error;phot.mag Maximum
Hmag 2MASS Hmag mag phot.mag Maximum
e_Hmag 2MASS Hmag uncertainty mag stat.error;phot.mag Maximum
Ksmag 2MASS Kmag mag phot.mag Maximum
e_Ksmag 2MASS Jmag uncertainty mag stat.error;phot.mag Maximum
Qfl_2MASS 2MASS Quality flags Maximum


(*) When a range is specified in a search the user must give both a minimum and maximum value for the corresponding quantity. If only a minimum value is given, all results with values larger than that will be obtained. If only a maximum value is given, all results with values smaller than that will be obtained.
This service uses SVOCat by the SVO