- ID:
- ivo://CDS.VizieR/J/A+A/625/A59
- Title:
- tau Boo Radial velocities & astrometric data
- Short Name:
- J/A+A/625/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation of planets in compact or highly eccentric binaries and the migration of hot Jupiters are two outstanding problems in planet formation. Detailed characterisation of known systems is important for informing and testing models. The hot Jupiter {tau} Boo Ab orbits the primary star in the long-period (P>~1000yr), highly eccentric (e~0.9) double star system {tau} Bootis. Due to the long orbital period, the orbit of the stellar binary is poorly constrained. Here we aim to constrain the orbit of the stellar binary {tau} Boo AB in order to investigate the formation and migration history of the system. The mutual orbital inclination of the stellar companion and the hot Jupiter has important implications for planet migration. The binary eccentricity and periastron distance are important for understanding the conditions under which {tau} Boo formed. We combine more than 150 years of astrometric data with twenty-five years of high-precision radial velocities. The combination of sky-projected and line-of-sight measurements places tight constraints on the orbital inclination, eccentricity, and periastron distance of {tau} Boo AB. We determine the orbit of {tau} Boo B and find an orbital inclination of 47.2^+2.7^_-3.7_{deg}, a periastron distance of 28.3^+2.3^_-3.0_au, and an eccentricity of 0.87^+0.04^_-0.03_. We find that the orbital inclinations of {tau} Boo Ab and {tau} Boo B, as well as the stellar spin-axis of {tau} Boo A coincide at ~45 degrees, a result consistent with the assumption of a well-aligned, coplanar system. The likely aligned, coplanar configuration suggests planetary migration within a well-aligned protoplanetary disc. Due to the high eccentricity and small periastron distance of {tau} Boo B, the protoplanetary disc was tidally truncated at ~6au. We suggest that {tau} Boo Ab formed near the edge of the truncated disc and migrated inwards with high eccentricity due to spiral waves generated by the stellar companion.
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- ID:
- ivo://CDS.VizieR/J/ApJ/803/90
- Title:
- {tau} Cet chemical composition
- Short Name:
- J/ApJ/803/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- {tau} Ceti (HD10700), a G8 dwarf with mass 0.78M_{sun}_, is a close (3.65pc) Sun-like star where five possibly terrestrial planet candidates (minimum masses of 2, 3.1, 3.5, 4.3, and 6.7M_{Earth}_) have recently been discovered. We report abundances of 23 elements using spectra from the MIKE spectrograph on Magellan. We find [Fe/H]=-0.49 and T_eff_=5387K. Using stellar models with the abundances determined here, we calculate the position of the classical habitable zone (HZ) with time. At the current best fit age, 7.63_-1.5_^+0.87^Gyr, up to two planets (e and f) may be in the HZ, depending on atmospheric properties. The Mg/Si ratio of the star is found to be 1.78, which is much greater than for Earth (~1.2). With a system that has such an excess of Mg/Si ratio it is possible that the mineralogical make-up of planets around {tau} Ceti could be significantly different from that of Earth, with possible oversaturation of MgO, resulting in an increase in the content of olivine and ferropericlase compared with Earth. The increase in MgO would have a drastic impact on the rheology of the mantles of the planets around {tau} Ceti.
- ID:
- ivo://CDS.VizieR/J/ApJ/581/1194
- Title:
- Taurus-Auriga PMS stars ages and Teff
- Short Name:
- J/ApJ/581/1194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To understand the formation of stellar groups, one must first document carefully the birth pattern within real clusters and associations. In this study of Taurus-Auriga, we combine pre-main-sequence ages from our own evolutionary tracks with stellar positions from observational surveys. Aided by the extensive millimeter data on the molecular clouds, we develop a picture of the region's history.
21344. Taurus Catalog
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/Taurus
- Title:
- Taurus Catalog
- Short Name:
- Taurus Catalog
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Space Telescope Survey of the Taurus is a Legacy III project titled, Taurus 2: Finishing the Spitzer Map of the Taurus Molecular Clouds (Taurus). The Taurus Spitzer Legacy project has mapped ≈44 square degrees of the Taurus star-formation region using the IRAC and MIPS cameras aboard the Spitzer Space Telescope. In this release, the team provides a bandmerged catalog of 269,358 point sources for the initial 70% of the survey area ("Taurus 1"). Flux densities are reported for the 3.6, 4.5, 5.8, 8.0, and 24 micron bands of IRAC and MIPS. MIPS 70 micron flux densities are also given for a small number of sources. Aperture photometry at three radii is provided for IRAC sources. PSF-fitting photometry is reported for MIPS flux densities.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/457
- Title:
- Taurus dark cloud background star catalog
- Short Name:
- J/ApJS/176/457
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Normal field stars located behind dense clouds are a valuable resource in interstellar astrophysics, as they provide continua in which to study phenomena such as gas-phase and solid-state absorption features, interstellar extinction, and polarization. This paper reports the results of a search for highly reddened stars behind the Taurus Dark Cloud complex. We use the Two Micron All Sky Survey (2MASS) Point Source Catalog to survey a ~50deg^2^ area of the cloud to a limiting magnitude of Ks=10.0. Photometry in the 1.2-2.2um passbands from 2MASS is combined with photometry at longer infrared wavelengths (3.6-12um) from the Spitzer Space Telescope and the Infrared Astronomical Satellite to provide effective discrimination between reddened field stars and young stellar objects (YSOs) embedded in the cloud. Our final catalog contains 248 confirmed or probable background field stars, together with estimates of their total visual extinctions, which span the range 2<A_V_<29mag. We also identify the 2MASS source J04292083+2742074 (IRAS 04262+2735) as a previously unrecognized candidate YSO, based on the presence of infrared emission greatly in excess of that predicted for a normal reddened photosphere at wavelengths >5um.
- ID:
- ivo://irsa.ipac/Spitzer/Images/Taurus
- Title:
- Taurus 2: Finishing the Spitzer Map of the Taurus Molecular Clouds
- Short Name:
- Taurus
- Date:
- 27 Oct 2022 19:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Taurus Spitzer Legacy project has mapped ≈44 square degrees of the Taurus star-formation region using the IRAC and MIPS cameras aboard the Spitzer Space Telescope.
- ID:
- ivo://CDS.VizieR/J/AJ/159/273
- Title:
- Taurus members & nonmembers with K2 data
- Short Name:
- J/AJ/159/273
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of K2 light curves (LCs) from Campaigns 4 and 13 for members of the young (~3Myr) Taurus association, in addition to an older (~30Myr) population of stars that is largely in the foreground of the Taurus molecular clouds. Out of 156 of the highest-confidence Taurus members, we find that 81% are periodic. Our sample of young foreground stars is biased and incomplete, but nearly all stars (37/38) are periodic. The overall distribution of rotation rates as a function of color (a proxy for mass) is similar to that found in other clusters: the slowest rotators are among the early M spectral types, with faster rotation toward both earlier FGK and later M types. The relationship between period and color/mass exhibited by older clusters such as the Pleiades is already in place by Taurus age. The foreground population has very few stars but is consistent with the USco and Pleiades period distributions. As found in other young clusters, stars with disks rotate on average slower, and few with disks are found rotating faster than ~2days. The overall amplitude of the LCs decreases with age, and higher-mass stars have generally lower amplitudes than lower-mass stars. Stars with disks have on average larger amplitudes than stars without disks, though the physical mechanisms driving the variability and the resulting LC morphologies are also different between these two classes.
- ID:
- ivo://nasa.heasarc/taurusxmm
- Title:
- Taurus Molecular Cloud XMM-Newton X-Ray Source Catalog
- Short Name:
- TAURUSXMM
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) surveys the most populated ~5 square degrees of the Taurus Molecular Cloud, using the XMM-Newton X-ray observatory to study the thermal structure, variability, and long-term evolution of hot plasma, to investigate the magnetic dynamo, and to search for new potential members of the association. The authors present overall correlations with fundamental stellar parameters that were derived from the previous literature. The present overview paper introduces the project and provides the basic results from the X-ray analysis of all sources detected in the XEST survey. Comprehensive tables in the published paper summarize the stellar properties of all the targets surveyed. The survey goes deeper than previous X-ray surveys of Taurus by about an order of magnitude and for the first time systematically accesses very faint and strongly absorbed TMC objects. The authors find a detection rate of 85% and 98% for classical and weak-line T Tauri stars (CTTS and WTTS), respectively, and identify about half of the surveyed protostars and brown dwarfs. Overall, 136 out of 169 surveyed stellar systems were detected. The authors describe an X-ray luminosity vs. mass correlation, discuss the distribution of X-ray-to-bolometric luminosity ratios, and show evidence for lower X-ray luminosities in CTTS compared to WTTS. The complete catalog of all X-ray sources (stellar and non-stellar) detected in the 28 XEST fields is presented in this table. The catalog provides X-ray coordinates, their uncertainties, X-ray count rates and their uncertainties, and X-ray hardness ratios for 2347 detected X-ray sources. If two XEST fields overlap, the same sources may have been identified twice, with different XEST IDs assigned, notice. This table was created by the HEASARC in July 2007 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/468/353">CDS Catalog J/A+A/468/353</a> file table14.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/186/259
- Title:
- Taurus Spitzer survey: new candidate members
- Short Name:
- J/ApJS/186/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the properties of pre-main-sequence objects in the Taurus molecular clouds as observed in seven mid- and far-infrared bands with the Spitzer Space Telescope. There are 215 previously identified members of the Taurus star-forming region in our ~44deg^2^ map; these members exhibit a range of Spitzer colors that we take to define young stars still surrounded by circumstellar dust (noting that ~20% of the bona fide Taurus members exhibit no detectable dust excesses). We looked for new objects in the survey field with similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet imaging, and found 148 new candidate members of Taurus. We have obtained follow-up spectroscopy for about half the candidate sample, thus far confirming 34 new members, three probable new members, and 10 possible new members, an increase of 15%-20% in Taurus members. Of the objects for which we have spectroscopy, seven are now confirmed extragalactic objects, and one is a background Be star. The remaining 93 candidate objects await additional analysis and/or data to be confirmed or rejected as Taurus members. Most of the new members are Class II M stars and are located along the same cloud filaments as the previously identified Taurus members. Among non-members with Spitzer colors similar to young, dusty stars are evolved Be stars, planetary nebulae, carbon stars, galaxies, and active galactic nuclei.
21350. Taurus ultra-wide pairs
- ID:
- ivo://CDS.VizieR/J/A+A/599/A14
- Title:
- Taurus ultra-wide pairs
- Short Name:
- J/A+A/599/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work analyses the spatial distribution of stars in Taurus with a specific focus on multiple stars and wide pairs in order to derive new constraints on star formation and early dynamical evolution scenarios. We collected the multiplicity data of stars in Taurus to build an up-to-date stellar/multiplicity catalog. We first present a general study of nearest-neighbor statistics on spatial random distribution, comparing its analytical distribution and moments to those obtained from Monte Carlo samplings. We introduce the one-point correlation {Psi} function to complement the pair correlation function and define the spatial regimes departing from randomness in Taurus. We then perform a set of statistical studies to characterize the binary regime that prevails in Taurus. The {Psi} function in Taurus has a scale-free trend with a similar exponent as the correlation function at small scale. It extends almost 3 decades up to ~60kAU showing a potential extended wide binary regime. This was hidden in the correlation function due to the clustering pattern blending. Distinguishing two stellar populations, single stars versus multiple systems (separation <=1kAU), within Class II/III stars observed at high angular resolution, we highlight a major spatial neighborhood difference between the two populations using nearest-neighbor statistics. The multiple systems are three times more likely to have a distant companion within 10kAU when compared to single stars. We show that this is due to the presence of most probable physical ultra-wide pairs (UWPs, defined as such from their mutual nearest neighbor property), that are themselves generally composed of multiple systems containing up to five stars altogether. More generally, our work highlights; 1) a new large population of candidate UWPs in Taurus within the range 1-60kAU in Taurus and 2) the major local structural role they play up to 60kAU. There are three different types of UWPs; either composed of two tight and comparatively massive stars (MM), by one single and one multiple (SM), or by two distant low-mass singles (SS) stars. These UWPs are biased towards high multiplicity and higher-stellar-mass components at shorter separations. The multiplicity fraction per ultra-wide pair with separation less than 10kAU may be as high as 83.5+/-19.6%. We suggest that these young pre-main sequence UWPs may be pristine imprints of their spatial configuration at birth resulting from a cascade fragmentation scenario of the natal molecular core. They could be the older counterparts, at least for those separated by less than 10kAU, to the <=0.5Myr prestellar cores/Class 0 multiple objects observed at radio/millimeter wavelengths.