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22241. Tycho Double Star Catalogue (TDSC)
ID:
ivo://CDS.VizieR/I/276
Title:
Tycho Double Star Catalogue (TDSC)
Short Name:
I/276
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of 13251 visual double stars, mostly with separations between 0.3 and 1 arcsec, from a dedicated re-reduction of the Tycho data from the star mapper of the ESA Hipparcos satellite. The new doubles are combined with 18160 WDS systems identified in the Tycho-2 Catalogue, and 1220 new Tycho-2 doubles, to form the Tycho Double Star Catalogue, TDSC, a catalogue of absolute astrometry and BT, VT photometry for 66219 components of 32631 double and multiple star systems. We also include results for 32263 single components for systems unresolved in TDSC, and a supplement gives Hipparcos and Tycho-1 data for 4777 additional components. The TDS thus contains a total of 103259 entries. Cross identifications are given to WDS, HD, Hipparcos and Tycho-2
22242. Tycho-Gaia Astrometric Solution (TGAS) Source Table
ID:
ivo://irsa.ipac/Gaia/TGAS
Title:
Tycho-Gaia Astrometric Solution (TGAS) Source Table
Short Name:
Gaia-TGAS
Date:
01 Oct 2018 20:27:21
Publisher:
NASA/IPAC Infrared Science Archive
Description:
This table is a subset of gaia_source comprising those stars in the Hipparcos and Tycho-2 Catalogues for which a full 5-parameter astrometric solution has been possible in Gaia Data Release 1. This is possible because the early Hipparcos epoch positions break some degeneracies due to the limited Gaia time coverage. This table contains a substantial fraction of the around 2.5 million stars in the Hipparcos and Tycho-2 catalogue. Many stars have been excluded due to several reasons, such as saturation, cross-match errors or bad astrometric solution.
22243. Tycho Input Catalogue, Revised version
ID:
ivo://CDS.VizieR/I/197A
Title:
Tycho Input Catalogue, Revised version
Short Name:
I/197A
Date:
21 Oct 2021
Publisher:
CDS
Description:
A Tycho Input Catalogue of three million stars brighter than V=12.1 has been prepared, for the needs of the Tycho mission (Hipparcos satellite). This catalogue results from the cross-matching of a subset of the Hubble Space Telescope Guide Star Catalog with the Hipparcos INCA database. References to these major catalogues, and details about the cross-matching procedures are to be found in the paper published in Astron. Astrophys. 258, 217-222 (May 1992). Among the 3,154,204 stars of the Tycho Input Catalogue, only a bit more than 1 million will appear in the final Tycho catalogue. A preliminary selection was done in the Recognition process, that was based on the first year of the satellite scientific mission (Halbwachs et al., =1994A&A...281L..25H). 1,049,971 stars were thus selected, and are flagged in this version of the Tycho Input Catalogue. The main file contains 3 154 204 records of 80 characters (total size: 256 Mbytes). It is split into four files tic1 to tic4 for easier manipulations. An annex file contains the following additional data for a subset of the stars: (a) the cross-identification with the Hipparcos Input Catalogue (117 778 records, flag 26) (b) the cross-matching with the INCA database (217 625 records, flag 20). The annex file contains 217 625 records (64 char., 14 Mbytes).
22244. Tycho-2 red giant branch and carbon stars
ID:
ivo://CDS.VizieR/J/PAZh/37/769
Title:
Tycho-2 red giant branch and carbon stars
Short Name:
J/PAZh/37/769
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on multicolor photometry from the 2MASS and Tycho-2 catalogues, we have produced a sample of 38368 branch red giants that has less than 1% of admixtures and is complete within 500 pc of the Sun. The sample includes 30671 K giants, 7544 M giants,49 C giants, and 104 suspected supergiants or S stars. The photometric distances have been calculated for K, M, and C stars with an accuracy of 40% together with reddening and extinction estimates. Tycho-2 proper motions and PCRV radial velocities are used to analyze the stellar kinematics. The majority of the selected K and M giants are disk stars with ages of more than 3Gyr. A small number of K and M giants are extremely young or, conversely, thick-disk ones. The spatial distribution and kinematics of the selected C stars force us to consider them as asymptotic branch giants with masses of more than 2 solar masses and ages of less than 2Gyr probably associated with the Gould Belt. The offset of the Sun above the Galactic equator has been found from the distribution of stars to be 13+/-2pc, which coincides with the previously obtained value for the clump red giants.
22245. Tycho-2 stars in Galactic Bulge Survey
ID:
ivo://CDS.VizieR/J/ApJ/761/162
Title:
Tycho-2 stars in Galactic Bulge Survey
Short Name:
J/ApJ/761/162
Date:
21 Oct 2021
Publisher:
CDS
Description:
We identify 69 X-ray sources discovered by the Galactic Bulge Survey (GBS) that are coincident with or very close to bright stars in the Tycho-2 catalog. Additionally, two other GBS sources are resolved binary companions to Tycho-2 stars where both components are separately detected in X-rays. Most of these are likely to be real matches, but we identify nine objects with large and significant X-ray-to-optical offsets as either detections of resolved binary companions or chance alignments. We collate known spectral types for these objects, and also examine Two Micron All Sky Survey colors, variability information from the All-Sky Automated Survey, and X-ray hardness ratios for the brightest objects. Nearly a third of the stars are found to be optically variable, divided roughly evenly between irregular variations and periodic modulations. All fall among the softest objects identified by the GBS. The sample forms a very mixed selection, ranging in spectral class from O9 to M3. In some cases, the X-ray emission appears consistent with normal coronal emission from late-type stars, or wind emission from early-types, but the sample also includes one known Algol, one W UMa system, two Be stars, and several X-ray bright objects likely to be coronally active stars or binaries. Surprisingly, a substantial fraction of the spectroscopically classified, non-coincidental sample (12 out of 38 objects) have late B or A type counterparts. Many of these exhibit redder near-IR colors than expected for their spectral type and/or variability, and it is likely that the X-rays originate from a late-type companion star in most or all of these objects.
22246. Tycho-2 stars with IR excess
ID:
ivo://CDS.VizieR/J/MNRAS/363/1111
Title:
Tycho-2 stars with IR excess
Short Name:
J/MNRAS/363/1111
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stars of all evolutionary phases have been found to have excess infrared emission due to the presence of circumstellar material. To identify such stars, we have positionally correlated the infrared Mid-Course Space Experiment (MSX) Point Source Catalogue (<V/114>) and the Tycho-2 optical catalogue (<I/259>). Near-mid-infrared colour criteria have been developed to select infrared excess stars. The search yielded 1938 excess stars; over half (979) have never previously been detected by IRAS. The excess stars were found to be young objects such as Herbig Ae/Be and Be stars, and evolved objects such as OH/IR (infrared) and carbon stars. A number of B-type excess stars were also discovered whose infrared colours could not be readily explained by known catalogued objects.
22247. Tycho variables stars
ID:
ivo://CDS.VizieR/II/233
Title:
Tycho variables stars
Short Name:
II/233
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of the classification procedure described in Piquard's PhD thesis applied to the 1091 stars presented in Piquard et al. (2001. Cat. <J/A+A/373/576>). In those six tables we give indication of variability type for all the stars detected as variables in Piquard et al. (2001, Cat. <J/A+A/373/576>). First of all, we looked for periodic signals in the light curves using adapted Renson's (Renson, 1978A&A....63..125R) and Stellingwerf's (Stellingwerf, 1978ApJ...224..953S) methods applied to the tree different photometric bands from Tycho (Cat. <I/239>): T, B_T_, V_T_ (the T band is defined from the added count-rates in the B_T_ and V_T_ channels, Grossmann et al.. 1995A&A...304..110G). Then we developed a semi-automatic method using 5 parameters (Period, color index, reduced proper motion from Tycho-2 catalogue (Cat. <I/259>), 2 indicators of the shape of the light curve) and a maximum likelihood method, combined with a careful look on the light curves. Finaly, the identification of the variability type is kept only if the resulting light curve is convincing (periodic the star has the P status, if not periodic the star has the U status); else we need more information about the star and is has the A status. All this identifications are indications since the quality of the light curves are often poor, particularly when the star is fainter than T=10.
22248. TYC 3700-1384-1, V1511 Her, V1179 Her minima
ID:
ivo://CDS.VizieR/J/MNRAS/501/4935
Title:
TYC 3700-1384-1, V1511 Her, V1179 Her minima
Short Name:
J/MNRAS/501/4935
Date:
21 Oct 2021
Publisher:
CDS
Description:
The first multi-colour light curve models and period studies for the totally eclipsing W UMa stars TYC 3700-1384-1, V1511 Her and V1179 Her are presented. All three stars are A-subtype W UMa stars of spectral type F. The light curve solutions show that TYC 3700-1384-1 has a moderately low mass ratio of q=0.182+/-0.001 and a degree of overcontact of f=49%. For V1179 Her a mass ratio q=0.153+/-0.001 and a degree of overcontact of f=48% is derived. The solution for V1511 Her is inconclusive, however the mass ratio is expected to be between 0.13<q<0.15. The evolutionary status is compared with zero-age main sequence stars taking into account energy transfer from the primary to the secondary component. The primary component of TYC 3700-1384-1 fits well in the main-sequence, while V1179 Her is more evolved. The period study reveals for all three stars a continuously increasing period at a rate of dP/dt=6.1x10^-7^d/yr, dP/dt=5.0x10^-7^d/yr and dP/dt=9.6x10^-7^d/yr for TYC 3700-1384-1, V1511 Her and V1179 Her respectively. The estimated mass transfer rates derived from these period changes are 1.6x10^-7^M_{sun}_/yr for TYC 3700-1384-1 and 1.9x10^-7^M_{sun}_/yr for V1179 Her.
22249. Type 1 AGN at low z. II.
ID:
ivo://CDS.VizieR/J/MNRAS/426/2703
Title:
Type 1 AGN at low z. II.
Short Name:
J/MNRAS/426/2703
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the relative strength of the narrow emission lines in a Sloan Digital Sky Survey based sample of broad H{alpha} selected active galactic nuclei (AGN), defined in Paper I (Stern & Laor, 2010, Cat. J/MNRAS/423/600).
22250. Type 1 AGN at low z. III.
ID:
ivo://CDS.VizieR/J/MNRAS/431/836
Title:
Type 1 AGN at low z. III.
Short Name:
J/MNRAS/431/836
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the optical narrow-line ratios in a Sloan Digital Sky Survey (SDSS) based sample of 3175 broad H{alpha} selected type 1 active galactic nuclei (AGN), and explore their positions in the BPT diagrams as a function of the AGN and the host properties. We find the following: (1) the luminosities of all measured narrow lines (H{alpha}, H{beta}, [OIII], [NII], [SII], [OI]) show a Baldwin relation relative to the broad H{alpha} luminosity LbH{alpha}, with slopes in the range of 0.53-0.72. (2) About 20 percent of the type 1 AGN reside within the "Composite" and "star-forming" (SF) regions of the Baldwin, Phillips & Terlevich (BPT) diagrams. These objects also show excess narrow H{alpha} and ultraviolet (UV) luminosities, for their LbH{alpha}, consistent with contribution from star formation which dominates the narrow-lines emission, as expected from their positions in the BPT diagrams. (3) The type 1 which reside within the AGN region in the BPT diagrams, are offset to lower [SII]/H{alpha} and [NII]/H{alpha} luminosity ratios, compared to type 2 AGN. This offset is a selection effect, related to the lower AGN/host luminosity selection of the type 2 AGN selected from the SDSS galaxy sample. (4) The [NII]/H{alpha} and [NII]/[SII] ratios in type 1 AGN increase with the host mass, as expected if the mass-metallicity relation of quiescent galaxies holds for the AGN narrow-line region (NLR). (5) The broad lines optical Fe ii is higher for a higher [NII]/H{alpha}, at a fixed Lbol and Eddington ratio L/LEdd. This suggests that the broad line region metallicity is also related to the host mass. (6) The fraction of AGN which are low-ionization nuclear emission-line regions (LINERs) increases sharply with decreasing L/LEdd. This fraction is the same for type 1 and type 2 AGN. (7) The BPT position is unaffected by the amount of dust extinction of the optical-UV continuum, which suggests that the extincting dust resides on scales larger than the narrow-line region (NLR).

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