- ID:
- ivo://astronet.ru/cas/tycho2-suppl_1
- Title:
- The Tycho-2 Catalogue of the 2.5 Million Brightest Stars
- Short Name:
- tycho2-suppl_1
- Date:
- 17 Jun 2006 18:44:05
- Publisher:
- Sternberg Astronomical Institute Virtual Observatory Project
- Description:
- The Tycho-2 Catalogue is an astrometric reference catalogue containing positions and proper motions as well as two-colour photometric data for the 2.5 million brightest stars in the sky. The Tycho-2 positions and magnitudes are based on precisely the same observations as the original Tycho Catalogue (hereafter Tycho-1) collected by the star mapper of the ESA Hipparcos satellite, but Tycho-2 is much bigger and slightly more precise, owing to a more advanced reduction technique. Components of double stars with separations down to 0.8 arcsec are included. Proper motions precise to about 2.5 mas/yr are given as derived from a comparison with the Astrographic Catalogue and 143 other ground-based astrometric catalogues, all reduced to the Hipparcos celestial coordinate system. Tycho-2 supersedes in most applications Tycho-1, as well as the ACT and TRC catalogues based on Tycho-1. Supplement-1 lists stars from the Hipparcos and Tycho-1 Catalogues which are not in Tycho-2. Supplement-2 lists 1146 Tycho-1 stars which are probably either false or heavily disturbed. For more information, please consult the Tycho-2 home page: http://www.astro.ku.dk/~erik/Tycho-2 Catalogue Characteristics: The principal characteristics of the Tycho-2 Catalogue are summarized below. By means of proper motions the positions are transferred to the year 2000.0, the epoch of the catalogue. The median values of internal standard errors are given. Mean satellite observation epoch ~J1991.5 Epoch of the Tycho-2 Catalogue J2000.0 Reference system ICRS coincidence with ICRS (1) +/-0.6 mas deviation from inertial (1) +/-0.25 mas/yr Number of entries 2,539,913 Astrometric standard errors (2) V_T_ < 9 mag 7 mas all stars, positions 60 mas all stars, proper motions 2.5 mas/yr Photometric std. errors (3) on V_T_ V_T_ < 9 mag 0.013 mag all stars 0.10 mag Star density b= 0 deg 150 stars/sq.deg. b= +/-30 deg 50 stars/sq.deg. b= +/-90 deg 25 stars/sq.deg. Completeness to 90 per cent V ~ 11.5 mag Completeness to 99 per cent V ~ 11.0 mag Number of Tycho observations ~300 10^6^ Note (1): about all 3 axes Note (2): ratio of external to internal standard errors is ~1.0 for positions and for proper motions. Systematic errors are less than 1 mas and 0.5 mas/yr Note (3): ratio of photometric external to internal standard errors at V_T_ > 9 mag is below 1.5
Number of results to display per page
Search Results
- ID:
- ivo://astronet.ru/cas/tycho2-suppl_2
- Title:
- The Tycho-2 Catalogue of the 2.5 Million Brightest Stars
- Short Name:
- tycho2-suppl_2
- Date:
- 17 Jun 2006 18:44:05
- Publisher:
- Sternberg Astronomical Institute Virtual Observatory Project
- Description:
- The Tycho-2 Catalogue is an astrometric reference catalogue containing positions and proper motions as well as two-colour photometric data for the 2.5 million brightest stars in the sky. The Tycho-2 positions and magnitudes are based on precisely the same observations as the original Tycho Catalogue (hereafter Tycho-1) collected by the star mapper of the ESA Hipparcos satellite, but Tycho-2 is much bigger and slightly more precise, owing to a more advanced reduction technique. Components of double stars with separations down to 0.8 arcsec are included. Proper motions precise to about 2.5 mas/yr are given as derived from a comparison with the Astrographic Catalogue and 143 other ground-based astrometric catalogues, all reduced to the Hipparcos celestial coordinate system. Tycho-2 supersedes in most applications Tycho-1, as well as the ACT and TRC catalogues based on Tycho-1. Supplement-1 lists stars from the Hipparcos and Tycho-1 Catalogues which are not in Tycho-2. Supplement-2 lists 1146 Tycho-1 stars which are probably either false or heavily disturbed. For more information, please consult the Tycho-2 home page: http://www.astro.ku.dk/~erik/Tycho-2 Catalogue Characteristics: The principal characteristics of the Tycho-2 Catalogue are summarized below. By means of proper motions the positions are transferred to the year 2000.0, the epoch of the catalogue. The median values of internal standard errors are given. Mean satellite observation epoch ~J1991.5 Epoch of the Tycho-2 Catalogue J2000.0 Reference system ICRS coincidence with ICRS (1) +/-0.6 mas deviation from inertial (1) +/-0.25 mas/yr Number of entries 2,539,913 Astrometric standard errors (2) V_T_ < 9 mag 7 mas all stars, positions 60 mas all stars, proper motions 2.5 mas/yr Photometric std. errors (3) on V_T_ V_T_ < 9 mag 0.013 mag all stars 0.10 mag Star density b= 0 deg 150 stars/sq.deg. b= +/-30 deg 50 stars/sq.deg. b= +/-90 deg 25 stars/sq.deg. Completeness to 90 per cent V ~ 11.5 mag Completeness to 99 per cent V ~ 11.0 mag Number of Tycho observations ~300 10^6^ Note (1): about all 3 axes Note (2): ratio of external to internal standard errors is ~1.0 for positions and for proper motions. Systematic errors are less than 1 mas and 0.5 mas/yr Note (3): ratio of photometric external to internal standard errors at V_T_ > 9 mag is below 1.5
- ID:
- ivo://CDS.VizieR/I/250
- Title:
- The Tycho Reference Catalogue
- Short Name:
- I/250
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Tycho Reference Catalogue (TRC) contains high-quality positions and proper motions for 990182 stars of the Tycho Catalogue. The proper motions were derived from Tycho positions and Astrographic Catalogue positions reduced to the Hipparcos system. The median accuracy of the TRC position components is 40 mas at J1991.25. The median accuracy of the proper motion is about 2.5 mas/yr. Systematic errors are less than about 1.0 mas(/yr). The quality of the proper motions in TRC is assessed by comparison with the Hipparcos and Tycho Catalogues. Comparison with the recent ACT Catalogue which is based on an independent reduction of the same observations as used for constructing the TRC is reported.
- ID:
- ivo://CDS.VizieR/III/231
- Title:
- The Tycho-2 Spectral Type Catalog
- Short Name:
- III/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained spectral types for 351,863 stars in the Tycho-2 catalog <I/259> by cross-referencing the Tycho-2 catalog against the Michigan Catalogs <III/31>, <III/51>, <III/80>, <III/133>, and <III/214>; the Catalog of Stellar Spectra Classified in the Morgan-Keenan System <III/18>; the MK Classification Extension <III/78>; the FK5 catalog parts I and II <I/149> and <I/175>; and the PPM North and South catalogs <I/146> and <I/193>.
- ID:
- ivo://CDS.VizieR/I/294A
- Title:
- The UCAC2 Bright Star Supplement
- Short Name:
- I/294A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UCAC2 Bright Star Supplement (UCAC2 BSS) is meant to be used with the Second U.S. Naval Observatory CCD Astrograph Catalog (UCAC2, CDS Catalogue number <I/289>) to fill in the missing bright stars and yet-to-be observed northern regions of the UCAC2. In total 430,000 stars, mostly from the region north of +40 degrees declination, make up this supplementary data set. All astrometric data were extracted from either the Hipparcos Catalogue or the Tycho-2 Catalogue; photometric data were extracted from the Hipparcos, Tycho-2, and 2MASS catalogues. Cross references between the data sources are given.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/71.270
- Title:
- The UGC isolated galaxy pair catalog
- Short Name:
- J/other/AstBu/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present paper is devoted to the construction of a catalog of isolated galaxy pairs from the Uppsala Galaxy Catalog (UGC), using accurate radial velocities. The UGC lists 12 921 galaxies to {delta}>-2:30 and is complete to an apparent diameter of 1{arcmin}. The criteria used to define the isolated galaxy pairs are based on velocity, interdistance, reciprocity and isolation information. A peculiar investigation has allowed to gather very accurate radial velocities for pair members, from high quality HI and optical measurements (median uncertainty on velocity differences 10km/s). Our final catalog contains 1005 galaxy pairs with {rho}>2.5, of which 509 have {rho}>5 (50% of the pairs, i.e. 8% of the UGC galaxies) and 273 are highly isolated with {rho}>10 (27% of the pairs, i.e. 4% of the UGC galaxies). Some global properties of the pair catalog are given.
- ID:
- ivo://CDS.VizieR/VI/104
- Title:
- The Ultraviolet Imaging Telescope (UIT)
- Short Name:
- VI/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UIT was one of three ultraviolet telescopes on the ASTRO-1 mission flown on the space shuttle Columbia during 2-10 December 1990. The same three instruments were later flown on the space shuttle Endeavour during 3-17 March 1995, as part of the ASTRO-2 mission. Exposures were obtained on 70-mm photographic film in the 1200-3300 Angstrom range using broadband filters and later digitized using a Perkin-Elmer microdensitometer. Image resolution was 3 arcseconds over a 40 minute field of view. Overall, UIT-1 obtained 821 exposures of 66 targets, and UIT-2 obtained 758 images of 193 targets.
- ID:
- ivo://CDS.VizieR/J/A+A/434/201
- Title:
- The 35um absorption line towards 1612MHz masers
- Short Name:
- J/A+A/434/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 1612MHz hydroxyl maser in circumstellar envelopes has long been thought to be pumped by 34.6{mu}m photons. Only recently, the Infrared Space Observatory has made possible spectroscopic observations which enable the direct confirmation of this pumping mechanism in a few cases. To look for the presence of this pumping line, we have searched the Infrared Space Observatory Data Archive and found 178 spectra with data around 34.6{mu}m for 87 galactic 1612MHz masers.
- ID:
- ivo://CDS.VizieR/I/344
- Title:
- The URAT Parallax Catalog (UPC). Update 2018
- Short Name:
- I/344
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- United States Naval Observatory (USNO) Robotic Astrometric Telescope (URAT) Parallax Catalog south (UPCs) and north (UPCn). These data are based on the accepted paper for the Astronomical Journal (2018) by C. Finch, N. Zacharias, and W.-C. Jao, "URAT south parallax results: discovery of new nearby stars" (2018AJ....155..176F). The southern data are new, while the northern data contain a subset of the previously published UPC catalog after applying the more stringent selection criteria of the south data and supplementing the data with columns of the southern data. The previously published URAT Parallax Catalog (UPC) paper is: C. Finch and N. Zacharias (2016AJ....151..160F, Cat. J/AJ/151/160) (arXiv:1604.06739).
22120. The Ursa Major cluster. I.
- ID:
- ivo://CDS.VizieR/J/AJ/112/2471
- Title:
- The Ursa Major cluster. I.
- Short Name:
- J/AJ/112/2471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Ursa Major Cluster has received remarkably little attention, although it is as near as the Virgo Cluster and contains a comparable number of H I-rich galaxies. In this paper, criteria for group membership are discussed and data are presented for 79 galaxies identified with the group. Of these, all 79 have been imaged at B,R,I bands with CCDs, 70 have been imaged at K' with a HgCdTe array detector, and 70 have been detected in the H I 21 cm line. A complete sample of 62 galaxies brighter than M_B=-16.5 is identified. Images and gradients in surface brightness and color are presented at a common linear scale. As has been seen previously, the galaxies with the reddest global colors are reddest at the centers and get bluer at large radii. However, curiously, among the galaxies with the bluest global colors there are systems with very blue cores that get redder at large radii.
