- ID:
- ivo://CDS.VizieR/VI/63
- Title:
- Earth Orbit, Precession and Insolation -20Myr to +10Myr
- Short Name:
- VI/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- La93 is a program for computing the precession and obliquity of the Earth for various values of 1) the tidal effect of the Moon (CMAR) 2) the dynamical ellipticity of the Earth (FGAM) The nominal solution La90 corresponds to (CMAR = 0., FGAM = 1). The general solution will be called La93(CMAR,FGAM), thus La90 = La93(0.,1.) and La93(1.,1.) is obtained with the same tidal effect as in Quinn, Tremaine, Duncan (1991), although these solutions are not completely identical (see Laskar, Joutel, Boudin, 1993) The files and software of this package can be used in three different manners: 1) Contruction and Use of the nominal solution La93(0,1) The ASCII files ORBEL*.ASC contain the nominal orbital solution. The ASCII files PREC0*.ASC contain the nominal precession solution. The ASCII files CLIVAR0*.ASC contain the nominal climatic solution. The files PREC*.ASC and CLIVAR*.ASC can also be generated from the enclosed files (see section 2) For the computation of insolation quantities, the user will execute the 'prepinsol' step, and then 'insola'. 2) Construction of a parametrized La93(CMAR, FGAM) new solution The user reconstructs a complete La93(CMAR, FGAM) solution. The compilation of all required programs is obtained by running the command 'make' on a Unix machine. The preparation step 'prepa' needs to be done once, in order to prepare the necessary binary files. Then 'integ' will construct the new solutions for the given parameters (CMAR, FGAM). Alternatively, change in the Makefile the values of CMAR and FGAM before running the 'make clean' command (removes the files computed using the preceding values of CMAR and FGAM), and 'make La93'. 3) Changes in the model of precession, for example to take into account some feedback resulting from redistribution of the ice on the Earth resulting from climate changes. In this case, and in this case only, the user needs to edit the FORTRAN file integ.f More precisely, the subroutines which can be eventually modified are SUBROUTINE INIPRE(IPT) SUBROUTINE PRECES(t,AK,AH,AQ,AP,DK,DH,DQ,DP,AKI,DKI) The users may also want to adapt the driver INTEG to his specific needs
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- ID:
- ivo://CDS.VizieR/J/A+A/509/A3
- Title:
- Earth Orientation Catalog 4 (EOC-4)
- Short Name:
- J/A+A/509/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The astrometric ground-based observations of latitude / universal time variations, covering the interval 1899.7-2003.0, were used in combination with Hipparcos / Tycho positions and some older ground-based catalogs to construct a family of catalogs, tailored for long-term Earth rotation studies. These catalogs, called Earth Orientation Catalogs (EOC-1 through EOC-3) yielded more accurate proper motions than the original Hipparcos Catalogue, and its latest version, EOC-3, even periodic motions for a large portion of the stars. About 4.5 million observations made at 33 observatories are combined with the catalogs ARIHIP, TYCHO-2 etc... in order to obtain EOC-4. Spectral analysis of ground-based data and comparison with the USNO Sixth Catalog of Orbits of Visual Binary Stars are used to discover which of the observed objects display periodic motions, and improved combination procedures are used. The catalog contains 4418 different objects (i.e., stars, components of double stars, photocenters), out of which 599 have significant orbital motions.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/5
- Title:
- EA-type eclipsing binaries observed by LAMOST
- Short Name:
- J/ApJS/235/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About 3196 EA-type binaries (EAs) were observed by LAMOST by 2017 June 16 and their spectral types were derived. Meanwhile, the stellar atmospheric parameters of 2020 EAs were determined. In this paper, those EAs are cataloged and their physical properties and evolutionary states are investigated. The period distribution of EAs suggests that the period limit of tidal locking for the close binaries is about 6 days. It is found that the metallicity of EAs is higher than that of EW-type binaries (EWs), indicating that EAs are generally younger than EWs and they are the progenitors of EWs. The metallicities of long-period EWs (0.4<P<1 days) are the same as those of EAs with the same periods, while their values of Log (g) are usually smaller than those of EAs. These support the evolutionary process that EAs evolve into long-period EWs through the combination of angular momentum loss (AML) via magnetic braking and case A mass transfer. For short-period EWs, their metallicities are lower than those of EAs, while their gravitational accelerations are higher. These reveal that they may be formed from cool short-period EAs through AML via magnetic braking with little mass transfer. For some EWs with high metallicities, they may be contaminated by material from the evolution of unseen neutron stars and black holes or they have third bodies that may help them to form rapidly through a short timescale of pre-contact evolution. The present investigation suggests that the modern EW populations may have formed through a combination of these mechanisms.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A41
- Title:
- EBHIS spectra and HI column density maps
- Short Name:
- J/A+A/585/A41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Effelsberg-Bonn HI Survey (EBHIS) is a new 21-cm survey performed with the 100-m telescope at Effelsberg. It covers the whole northern sky out to a redshift of z~0.07 and comprises HI line emission from the Milky Way and the Local Volume. We aim to substitute the northern-hemisphere part of the Leiden/Argentine/Bonn Milky Way HI survey (LAB) with this first EBHIS data release, which presents the HI gas in the Milky Way regime. The use of a seven-beam L-band array made it feasible to perform this all-sky survey with a 100-m class telescope in a reasonable amount of observing time. State-of-the-art fast-Fourier-transform spectrometers provide the necessary data read-out speed, dynamic range, and spectral resolution to apply software radio-frequency interference mitigation. EBHIS is corrected for stray radiation and employs frequency-dependent flux-density calibration and sophisticated baseline-removal techniques to ensure the highest possible data quality. Detailed analyses of the resulting data products show that EBHIS is not only outperforming LAB in terms of sensitivity and angular resolution, but also matches the intensity-scale of LAB extremely well, allowing EBHIS to be used as a drop-in replacement for LAB. Data products are made available to the public in a variety of forms. Most important, we provide a properly gridded Milky Way HI column density map in HEALPix representation. To maximize the usefulness of EBHIS data, we estimate uncertainties in the HI column density and brightness temperature distributions, accounting for systematic effects.
- ID:
- ivo://CDS.VizieR/J/A+A/604/L6
- Title:
- EBLM J0555-57 photometry and RV
- Short Name:
- J/A+A/604/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of an eclipsing binary system with mass-ratio q After identifying a periodic photometric signal received by WASP, we obtained CORALIE spectroscopic radial velocities and follow-up light curves with the Euler and TRAPPIST telescopes. From a joint fit of these data we determine that EBLM J0555-57 consists of a sun-like primary star that is eclipsed by a low-mass companion, on a weakly eccentric 7.8-day orbit. Using a mass estimate for the primary star derived from stellar models, we determine a companion mass of 85+/-4M_Jup_ (0.081M_{sun}_) and a radius of 0.84^+0.14^_-0.04_R_Jup_ (0.084R_{sun}_) that is comparable to that of Saturn. EBLM J0555-57Ab has a surface gravity logg2=5.50^+0.03^_-0.13_ and is one of the densest non-stellar-remnant objects currently known. These measurements are consistent with models of low-mass stars.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A119
- Title:
- EBLM J2349-32 photometry, RV and spectra
- Short Name:
- J/A+A/626/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some M-dwarfs around F-/G-type stars have been measured to be hotter and larger than predicted by stellar evolution models. Inconsistencies between observations and models need to be addressed with more mass, radius, and luminosity measurements of low-mass stars to test and refine evolutionary models. Our aim is to measure the masses, radii and ages of the stars in five low-mass eclipsing binary systems discovered by the WASP survey. We used WASP photometry to establish eclipse-time ephemerides and to obtain initial estimates for the transit depth and width. Radial velocity measurements were simultaneously fitted with follow-up photometry to find the best-fitting orbital solution. This solution was combined with measurements of atmospheric parameters to interpolate evolutionary models and estimate the mass of the primary star, and the mass and radius of the M-dwarf companion. We assess how the best fitting orbital solution changes if an alternative limb-darkening law is used and quantify the systematic effects of unresolved companions. We also gauge how the best-fitting evolutionary model changes if different values are used for the mixing length parameter and helium enhancement. We report the mass and radius of five M-dwarfs and find little evidence of inflation with respect to evolutionary models. The primary stars in two systems are near the "blue hook" stage of their post sequence evolution, resulting in two possible solutions for mass and age. We find that choices in helium enhancement and mixing-length parameter can introduce an additional 3-5% uncertainty in measured M-dwarf mass. Unresolved companions can introduce an additional 3-8% uncertainty in the radius of an M-dwarf, while the choice of limb-darkening law can introduce up to an additional 2% uncertainty. The choices in orbital fitting and evolutionary models can introduce significant uncertainties in measurements of physical properties of such systems.
- ID:
- ivo://CDS.VizieR/J/MNRAS/506/306
- Title:
- EBLM project. VIII.43 M-dwarf light curve
- Short Name:
- J/MNRAS/506/306
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accuracy of theoretical mass, radius and effective temperature values for M-dwarf stars is an active topic of debate. Differences between observed and theoretical values have raised the possibility that current theoretical stellar structure and evolution models are inaccurate towards the low-mass end of the main sequence. To explore this issue we use the CHEOPS satellite to obtain high-precision light curves of eclipsing binaries with low mass stellar companions. We use these light curves combined with the spectroscopic orbit for the solar-type companion to measure the mass, radius and effective temperature of the M-dwarf star. Here we present the analysis of three eclipsing binaries. We use the pycheops data analysis software to fit the observed transit and eclipse events of each system. Two of our systems were also observed by the TESS satellite - we similarly analyse these light curves for comparison. We find consistent results between CHEOPS and TESS, presenting three stellar radii and two stellar effective temperature values of low-mass stellar objects. These initial results from our on-going observing programme with CHEOPS show that we can expect to have ~24 new mass, radius and effective temperature measurements for very low mass stars within the next few years.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A45
- Title:
- E-BOSS. II. Catalogue second release
- Short Name:
- J/A+A/578/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar bow shocks have been studied not only observationally, but also theoretically since the late 1980s. Only a few catalogues of them exist. The bow shocks show emission along all the electromagnetic spectrum, but they are detected more easily in infrared wavelengths. The release of new and high-quality infrared data eases the discovery and subsequent study of new objects. We search stellar bow-shock candidates associated with nearby runaway stars, and gather them together with those found elsewhere, to enlarge the list of the E-BOSS first release. We aim to characterize the bow-shock candidates and provide a database suitable for statistical studies. We investigate the low-frequency radio emission at the position of the bow-shock features, that can contribute to further studies of high-energy emission from these objects. We considered samples from different literature sources and searched for bow-shaped structures associated with stars in the Wide-field Infrared Survey Explorer (WISE) images. We looked for each bow-shock candidate on centimeter radio surveys. We reunited 45 bow-shock candidates and generated composed WISE images to show the emission in different infrared bands. Among them there are new sources, previously studied objects, and bow shocks found serendipitously. Five bow shocks show evidence of radio emission. Stellar bow shocks constitute an active field with open questions and enormous amounts of data to be analyzed. Future research at all wavelengths databases, and use of instruments like Gaia, will provide a more complete picture of these objects. For instance, infrared spectral energy distributions can give information about physical parameters of the bow shock matter. In addition, dedicated high-sensitivity radio observations can help to understand the radio-{gamma} connection.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/109
- Title:
- EBs in Ruprecht 147. II. EPIC 219568666 LC & RVs
- Short Name:
- J/ApJ/887/109
- Date:
- 30 Nov 2021
- Publisher:
- CDS
- Description:
- We report our spectroscopic monitoring of the detached, grazing, and slightly eccentric 12 day double-lined eclipsing binary EPIC 219568666 in the old nearby open cluster Ruprecht 147. This is the second eclipsing system to be analyzed in this cluster, following our earlier study of EPIC 219394517. Our analysis of the radial velocities combined with the light curve from the K2 mission yields absolute masses and radii for EPIC 219568666 of M_1_=1.121+/-0.013M_{sun}_ and R_1_=1.1779+/-0.0070R_{sun}_ for the F8 primary and M_2_=0.7334+/-0.0050M_{sun}_ and R_2_=0.640+/-0.017R_{sun}_ for the faint secondary. Comparison with current stellar evolution models calculated for the known metallicity of the cluster points to a primary star that is oversized, as is often seen in active M dwarfs, but this seems rather unlikely for a star of its mass and with a low level of activity. Instead, we suspect a subtle bias in the radius ratio inferred from the photometry, despite our best efforts to avoid it, which may be related to the presence of spots on one or both stars. The radius sum for the binary, which bypasses this possible problem, indicates an age of 2.76+/-0.61Gyr, which is in good agreement with a similar estimate from the binary in our earlier study.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/162
- Title:
- EBs in Ruprecht 147. III. EPIC 219552514
- Short Name:
- J/ApJ/896/162
- Date:
- 30 Nov 2021 07:09:45
- Publisher:
- CDS
- Description:
- Spectroscopic observations are reported for the 2.75 day, double-lined, detached eclipsing binary EPIC 219552514 located at the turnoff of the old nearby open cluster Ruprecht 147. A joint analysis of our radial-velocity measurements and the K2 light curve leads to masses of M1=1.509_-0.056_^+0.063^M_{sun}_ and M2=0.649_-0.014_^+0.015^M_{sun}_ for the primary and secondary, along with radii of R1=2.505_-0.031_^+0.026^R_{sun}_ and R2=0.652_-0.012_^+0.013^R_{sun}_, respectively. The effective temperatures are 6180+/-100K for the F7 primary and 4010+/-170K for the late K secondary. The orbit is circular, and the stars' rotation appears to be synchronized with the orbital motion. This is the third eclipsing system analyzed in the same cluster, following our earlier studies of EPIC 219394517 and EPIC 219568666. By comparison with stellar evolution models from the PARSEC series, we infer an age of 2.67_-0.55_^+0.39^Gyr that is consistent with the estimates for the other two systems. EPIC 219552514 is a hierarchical triple system, with the period of the slightly eccentric outer orbit being 463 days. The unseen tertiary is either a low-mass M dwarf or a white dwarf.