Database that resolves how to access records in problematic datasets. There are several distinct types of table: 1) Planetary observations stored in NASA's PDS and ESA's PSA; 2) Small FOV, pointed solar instruments; 3) Observations in the Global H-alpha Network.
This all-sky catalog, described in Monet et al. (2003), consists of positions, proper motions, magnitudes, and other measured quantities for 1,045,175,762 objects. The data were derived from digitizing scans of almost 7,500 photographic plates taken from various sky surveys during the interval from 1949 to 2002. The originating plate material includes five complete coverages of the northern sky and four of the southern sky.
To be included in the catalog, an object must have been detected on two different surveys because isolated, single-survey detections are unreliable. For the earlier USNO-A catalog (which was essentially a two-color, one-epoch catalog), this meant that the object must have had detectable fluxes on both the red and blue plates, and this led to the exclusion of many faint objects with non-neutral colors. Also, the larger epoch difference in the southern survey coverage meant that objects with larger proper motions tended to be excluded. USNO-B1.0 attempts to fix both of these problems. An object detected in the same band at two epochs will be included in USNO-B1.0, as will objects that have significant proper motions, although it is still the case that objects with large motions and extreme colors may be omitted. The selection algorithm requires that spatially coincident detections must be made on any two of the surveys for an object to be classified as real and be included in the catalog.
The catalog is expected to be complete down to V=21. Estimated positional accuracies are 0.2 arcsec, photographic magnitude accuracies are 0.3 mag, and the accuracy for distinguishing stars from non-stellar objects is 85%.
United States Naval Observatory, Flagstaff Station
Short Name:
USNOFS
Date:
11 Apr 2007 08:52:38
Publisher:
US Naval Observatory
Description:
The USNO Flagstaff Station Image and Catalogue archive
provides access to digitized images of the major Schmidt photographic surveys of the sky (POSS-I, POSS-II, SERC-J, SERC-R, SERC-EJ, SERC-ER, AAO-R etc.) and to astrometric catalogues derived from these data, including USNO-A2, USNO-B1 and NOMAD. The site provides catalogue data, finding charts, image data and a merge of the three.
United States Naval Observatory, Flagstaff Station Naming Authority
Short Name:
USNOFS auth
Date:
11 Apr 2007 08:52:38
Publisher:
US Naval Observatory
Description:
The USNO Flagstaff Station Image and Catalogue archive
provides access to digitized images of the major Schmidt photographic surveys of the sky (POSS-I, POSS-II, SERC-J, SERC-R, SERC-EJ, SERC-ER, AAO-R etc.) and to astrometric catalogues derived from these data, including USNO-A2, USNO-B1 and NOMAD. The site provides catalogue data, finding charts, image data and a merge of the three.
This document describes a recommended syntax for writing the string
representation of unit labels ("VOUnits"). In addition, it describes a
set of recognised and deprecated units, which is as far as possible
consistent with other relevant standards (BIPM, ISO/IEC and the IAU). The
intention is that units written to conform to this specification will
likely also be parsable by other well-known parsers. To this end, we
include machine-readable grammars for other units syntaxes.
A low dispersion objective-prism survey for low-redshift emission-line galaxies (ELGs) is being carried out by the University Complutense de Madrid with the Schmidt telescope at the German-Spanish Observatory of Calar Alto (Almeria, Spain). A 4{deg} full aperture prism, which provides a dispersion of 1950{AA}/mm, and IIIa-F emulsion combination has been used to search for ELGs selected by the presence of H{alpha} emission in their spectra. A compilation of descriptions and positions, along with finding charts, is presented for 103 emission-line objects. This is the second list, which contains objects located in a region of the sky covering 201.4{deg}^2^ in seven fields near {alpha}=15h and {delta}=25{deg}.
A new low-dispersion objective-prism search for low-redshift (z<0.045) emission-line galaxies (ELGs) has been carried out by the Universidad Complutense de Madrid using the Schmidt Telescope at the Calar-Alto Observatory. This is a continuation of the UCM Survey, which was performed by visual selection of candidates in photographic plates via the presence of the H{alpha}+[N II]{lambda}6584 blend in emission. In making this new list we have applied an automatic procedure, fully developed by us, for selecting and analyzing ELG candidates on the digitized images obtained with the "Machine Automatique a Mesurer pour l'Astronomie" (MAMA). The analyzed region of the sky covers 189deg^2^ in nine fields near RA=14h and 17h, DE=25{deg}. The final sample contains 113 candidates. Special effort has been made to obtain a large amount of information directly from our uncalibrated plates by using several external calibrations. The parameters obtained for the ELG candidates allow us to study the statistical properties of the sample.
A low dispersion objective-prism survey for low-redshift emission-line galaxies (ELGs) is being carried out by the University Complutense de Madrid with the Schmidt telescope at the German-Spanish Observatory of Calar Alto (Almeria, Spain). A 4deg full aperture prism, which provides a dispersion of 1950A/mm, and IIIa-F emulsion combination has been used to search for ELGs selected by the presence of H{alpha} emission in their spectra. Our survey has proved to be able to recover objects already found by similar surveys with different techniques and, what is more important, to discover new objects not previously catalogued. A compilation of descriptions and positions, along with finding charts when necessary, is presented for 160 extragalactic emission-line objects. This is the first list, which contains objects located in a region of the sky covering 270deg^2^ in 10 fields near {alpha}=0h and {delta}=20deg.