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- ID:
- ivo://CDS.VizieR/III/53
- Title:
- Stars classified from S2/68 UV line features
- Short Name:
- III/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog provides the spectral classifications of 1900 stars from the papers listed in References. The classifications were made from spectra obtained by the S2/68 sky survey telescope experiment aboard the TD1 satellite.
- ID:
- ivo://nasa.heasarc/td1
- Title:
- TD1 Stellar Ultraviolet Fluxes Catalog
- Short Name:
- TD1
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Belgian/UK Ultraviolet Sky Survey Telescope (S2/68) in the ESRO TD1 satellite carried out a controlled scan of the entire sky. It measured the absolute ultraviolet flux distribution between 2740A and 1350A of point sources down to 10th visual magnitude for unreddened early B stars. The S2/68 experiment has been described by Boksenberg et al. (1973MNRAS.163..291B), and the absolute calibration by Humphries et al. (1976A&A....49..389H). The TD1 Catalog of Stellar Ultraviolet Fluxes represents results from the sky-scan experiment on the TD1 satellite of the European Space Research Organization (ESRO), now part of ESA. It lists the absolute fluxes, in four passbands, for 31,215 stars: <pre> Passband Center: 274.0nm 236.5nm 196.5nm 156.5nm Effective Width: 31.0nm 33.0nm 33.0nm 33.0nm </pre> The stars have been selected subject to the constraint that the signal-to-noise ratio should be at least 10.0 in any one of the four passbands. Null values of a flux field and an error field indicate there are no valid data for the star. This usually arises with close pairs of stars whose spectra overlap. Five standard flux error values are greater than 99.99, and were too large for the format of the flux field in the original table. Thus, the flux error values which were greater than 99.99 are given as 99.99. Many of the fainter stars of spectral type later than A5 do not have significant signals in all of the spectrophotometric channels (particularly the 1565A channel). Consequently, after the removal of the background, they can randomly give rise to small negative values of flux. Those negative values were not suppressed, but are given together with their error, as they can be significant when considered as part of a statistical sample. Although the sky coverage is essentially complete, the catalog does not contain the fluxes for all stars that fall within the limit of the sensitivity of the instrument. If any star expected to be present is missing, then its signal is probably blended with that of a nearby star, in which case the data have been discarded. The original contents of the HEASARC's TD1 database table came from a magnetic tape sent to NASA/Goddard Space Flight Center by Dr. G.I. Thompson of the Royal Observatory in Edinburgh, Scotland. The HEASARC recreated this database table in August 2005, based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/59B">CDS Catalog II/59B</a> file catalog.dat.gz, in an effort to modernize its parameter names and documentation, as well as to add Galactic coordinates. The data in the CDS version originally came from "Selected Astronomical Catalogs" Vol. 1 CD-ROM released by the NASA Astronomical Data Center (ADC) in 1991. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/III/39A
- Title:
- UV Bright Star Spectrophotometric Catalog
- Short Name:
- III/39A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains observations carried out by the S2/68 Ultraviolet Sky Survey Telescope (UVSST) aboard the ESRO Satellite TD-1, which measured the absolute ultraviolet flux distribution between 2740A (274nm) and 1350A (135nm). The data presented in this catalogue were obtained during the first observation period, which lasted from 19 March 1972 to 31 October 1972, and contains the brightest objects, for which the signal is good enough to give valuable spectrophotometric information. The Faint Star Catalogue, which contains the photometric data of the stars up to the limit of detectability of the instrument, is known as the "Catalogue of Ultraviolet Fluxes", by Thompson et al. (catalog <II/59>) The S2/68 experiment has been described by Boksenberg et al. (=1973MNRAS.163..291B) and the absolute calibration by Humphries et al. (=1976A&A....49..389H).
- ID:
- ivo://CDS.VizieR/II/86
- Title:
- UV Bright-Star Spectrophotometric Supplement
- Short Name:
- II/86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue is a supplement of the Ultraviolet Bright Star Spectrophotometric Catalogue (=III/39A). It contains observations carried out by the S2/68 Ultraviolet Sky Survey Telescope (UVSST) aboard the ESRO satellite TD-1. The data presented in this supplement were obtained during the second and third observation periods, which lasted from 19 February 1973 to 30 September 1973 and from 16 February to 6 May 1974. The S2/68 experiment has been described by Boksenberg et al. (=1973MNRAS.163..291B) Owing to the optical scanning mode, most of the stars observed during the first observational period, the spectra of which are included in the "Ultraviolet Bright-Star Spectrophotometric Catalogue", were seen again by the telescope. This supplement, however, has been limited to the spectra of stars that were not observed during the first period. The data reduction and selection criteria are identical to those underlying the main Catalogue and hence the data presented in the Supplement are directly comparable with those in the main Catalogue. The Supplement contains data for 435 stars. For a statistical summary of the observed stars, see the tables I and II in the published version of the Supplement. The spectrum scanning itself was achieved by the movement of a star image across the wide entrance slot of the spectrophotometer, which caused the corresponding spectrum image to pass over the three exit slits in the direction of dispersion. The motion of the primary image during each detector integration interval (0.148 s) was equivalent to 19.4 A, depending on the channel. The wavelength range covered was 1350 - 2550 A. The passband of the photometer channel, defined by a glass transmission filter and the photocathode tube response, was centered at 2740 A and had a full width at half height of 310 A.
