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1. Abundances of {phi} Her
ID:
ivo://CDS.VizieR/J/ApJ/655/1046
Title:
Abundances of {phi} Her
Short Name:
J/ApJ/655/1046
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations of the mercury-manganese star phi Her with the Navy Prototype Optical Interferometer (NPOI) conclusively reveal the previously unseen companion in this single-lined binary system. The NPOI data were used to predict a spectral type of A8 V for the secondary star phi Her B. This prediction was subsequently confirmed by spectroscopic observations obtained at the Dominion Astrophysical Observatory. phi Her B is rotating at 50+/-3km/s, in contrast to the 8 km/s lines of phi Her A. Recognizing the lines from the secondary permits one to separate them from those of the primary. The abundance analysis of phi Her A shows an abundance pattern similar to those of other HgMn stars, with Al being very under-abundant and Sc, Cr, Mn, Zn, Ga, Sr, Y, Zr, Ba, Ce, and Hg being very overabundant.
2. Accurate astrometry & RVs of 4 multiple systems
ID:
ivo://CDS.VizieR/J/ApJ/838/54
Title:
Accurate astrometry & RVs of 4 multiple systems
Short Name:
J/ApJ/838/54
Date:
21 Oct 2021
Publisher:
CDS
Description:
This work extends the still modest number of multiple stars with known relative orbit orientation. Accurate astrometry and radial velocities are used jointly to compute or update outer and inner orbits in three nearby triple systems, HIP 101955 (orbital periods 38.68 and 2.51yr), HIP 103987 (19.20 and 1.035yr), HIP 111805 (30.13 and 1.50yr), and in one quadruple system, HIP 2643 (periods 70.3, 4.85, and 0.276yr), all composed of solar-type stars. The masses are estimated from the absolute magnitudes and checked using the orbits. The ratios of outer to inner periods (from 14 to 20) and the eccentricities of the outer orbits are moderate. These systems are dynamically stable, but not very far from the stability limit. In three systems, all orbits are approximately coplanar and have small eccentricity, while in HIP101955 the inner orbit with e=0.6 is highly inclined.
3. Accurate masses and radii of normal stars
ID:
ivo://CDS.VizieR/J/other/A+ARV/18.67
Title:
Accurate masses and radii of normal stars
Short Name:
J/other/A+ARV/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
This article presents and discusses a critical compilation of accurate, fundamental determinations of stellar masses and radii. We have identified 95 detached binary systems containing 190 stars (94 eclipsing systems, and alpha Centauri) that satisfy our criterion that the mass and radius of both stars be known within errors of +/-3% accuracy or better. All of them are non-interacting systems, and so the stars should have evolved as if they were single. This sample more than doubles that of the earlier similar review by Andersen (Astron. Astrophys. Rev. 3:91-126, 1991), extends the mass range at both ends and, for the first time, includes an extragalactic binary. In every case, we have examined the original data and recomputed the stellar parameters with a consistent set of assumptions and physical constants.
4. Accurate SB2 radial velocities
ID:
ivo://CDS.VizieR/J/MNRAS/496/1355
Title:
Accurate SB2 radial velocities
Short Name:
J/MNRAS/496/1355
Date:
21 Oct 2021
Publisher:
CDS
Description:
Double-lined spectroscopic binaries (SB2s) are one of the main sources of stellar masses, as additional observations are only needed to give the inclinations of the orbital planes in order to obtain the individual masses of the components. For this reason, we are observing a selection of SB2s using the SOPHIE spectrograph at the Haute-Provence observatory in order to precisely determine their orbital elements. Our objective is to finally obtain masses with an accuracy of the order of one percent by combining our radial velocity (RV) measurements and the astrometric measurements that will come from the Gaia satellite. We present here the RVs and the re-determined orbits of 10 SB2s. In order to verify the masses we will derive from Gaia, we obtained interferometric measurements of the ESO VLTI for one of these SB2s. Adding the interferometric or speckle measurements already published by us or by others for 4 other stars, we finally obtain the masses of the components of 5 binary stars, with masses ranging from 0.51 to 2.2 solar masses, including main-sequence dwarfs and some more evolved stars whose location in the HR diagram has been estimated.
5. Accurate SB2 radial velocities
ID:
ivo://CDS.VizieR/J/MNRAS/474/731
Title:
Accurate SB2 radial velocities
Short Name:
J/MNRAS/474/731
Date:
21 Oct 2021
Publisher:
CDS
Description:
The orbital motion of non-contact double-lined spectroscopic binaries (SB2s), with periods of a few tens of days to several years, holds unique, accurate information on individual stellar masses, which only long-term monitoring can unlock. The combination of radial velocity measurements from high-resolution spectrographs and astrometric measurements from high-precision interferometers allows the derivation of SB2 component masses down to the percent precision. Since 2010, we have observed a large sample of SB2s with the SOPHIE spectrograph at the Observatoire de Haute-Provence, aiming at the derivation of orbital elements with sufficient accuracy to obtain masses of components with relative errors as low as 1 per cent when the astrometric measurements of the Gaia satellite are taken into account. In this paper, we present the results from 6 yr of observations of 14 SB2 systems with periods ranging from 33 to 4185 days. Using the TODMOR algorithm, we computed radial velocities from the spectra and then derived the orbital elements of these binary systems. The minimum masses of the 28 stellar components are then obtained with an average sample accuracy of 1.0+/-0.2 per cent. Combining the radial velocities with existing interferometric measurements, we derived the masses of the primary and secondary components of HIP 61100, HIP 95995 and HIP 101382 with relative errors for components (A,B) of, respectively, (2.0, 1.7) per cent, (3.7, 3.7) per cent and (0.2, 0.1) per cent. Using the CESAM2K stellar evolution code, we constrained the initial He abundance, age and metallicity for HIP 61100 and HIP 95995.
6. Accurate SB2 radial velocities
ID:
ivo://CDS.VizieR/J/MNRAS/458/3272
Title:
Accurate SB2 radial velocities
Short Name:
J/MNRAS/458/3272
Date:
21 Oct 2021
Publisher:
CDS
Description:
In anticipation of the Gaia astrometric mission, a large sample of spectroscopic binaries has been observed since 2010 with the Spectrographe pour l'Observation des PHenomenes des Interieurs Stellaires et des Exoplanetes spectrograph at the Haute-Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient to finally obtain the masses of the components with relative errors as small as 1 per cent when the astrometric measurements of Gaia are taken into account. In this paper, we present the results from five years of observations of 10 SB2 systems with periods ranging from 37 to 881d. Using the todmor algorithm, we computed radial velocities from the spectra, and then derived the orbital elements of these binary systems. The minimum masses of the components are then obtained with an accuracy better than 1.2 per cent for the 10 binaries. Combining the radial velocities with existing interferometric measurements, we derived the masses of the primary and secondary components of HIP 87895 with an accuracy of 0.98 and 1.2 per cent, respectively.
7. 10 active binary radial velocities
ID:
ivo://CDS.VizieR/J/A+AS/137/369
Title:
10 active binary radial velocities
Short Name:
J/A+AS/137/369
Date:
21 Oct 2021
Publisher:
CDS
Description:
Orbital elements have been determined for 10 chromospherically active binaries from a combination of new velocities and velocities in the literature. First orbits for three binaries, HD 33363, HD 152178, and HD 208472, are presented, as well as updated orbits for seven other binaries. Two of the latter systems, LN Peg and HD 106225 were discovered to be triple, and both short- and long-period orbits have been computed for each. Fundamental properties have been determined for the chromospherically active primary in each system.
8. Active red giants asteroseismic & rotation param.
ID:
ivo://CDS.VizieR/J/A+A/639/A63
Title:
Active red giants asteroseismic & rotation param.
Short Name:
J/A+A/639/A63
Date:
08 Feb 2022
Publisher:
CDS
Description:
Oscillating red-giant stars have provided a wealth of asteroseismic information regarding their interiors and evolutionary states, and access to their fundamental properties enable detailed studies of the Milky Way. The objective of this work is to determine what fraction of red-giant stars shows photometric rotational modulation, and understand its origin. One of the underlying questions is the role of close binarity in this population, standing upon the fact that red giants in short-period binary systems (less than 150 days or so) have been observed to display strong rotational modulation. We select a sample of about 4500 relatively bright red giants observed by Kepler, and show that about 370 of them (~8%) display rotational modulation. Almost all have oscillation amplitudes below the median of the sample, while 30 of them are not oscillating at all. Of the 85 of these red giants with rotational modulation chosen for follow-up radial-velocity observation and analysis, 34 show clear evidence of spectroscopic binarity. Surprisingly, 26 of the 30 non-oscillators are in this group of binaries. To the contrary, about 85% of the active red giants with detectable oscillations are not part of close binaries. With the help of stellar masses and evolutionary states computed from the oscillation properties, we shed light on the origin of their activity. It appears that low-mass red-giant branch stars tend to be magnetically inactive, while intermediate-mass ones tend to be highly active. The opposite trends are true for helium-core burning (red clump) stars, whereby the lower-mass clump stars are comparatively more active and the higher-mass ones less so. In other words, we find that low-mass red-giant branch stars gain angular momentum as they evolve to clump stars, while higher-mass ones lose angular momentum. The trend observed with low-mass stars leads to possible scenarios of planet engulfment or other merging events during the shell-burning phase. Regarding intermediate-mass stars, the rotation periods that we measure are long with respect to theoretical expectations reported in the literature, which reinforces the existence of an unidentified sink of angular momentum after the main sequence. This article establishes strong links between rotational modulation, tidal interactions, (surface) magnetic fields, and oscillation suppression. There is a wealth of physics to be studied in these targets not available in the Sun.
9. ADS 9731: a new sextuple system
ID:
ivo://CDS.VizieR/J/PAZh/24/918
Title:
ADS 9731: a new sextuple system
Short Name:
J/PAZh/24/918
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations with the correlation radial velocity meter of ADS 9731 were carried out during 1996-1997. We established that the components A and D of the visual quadruple system ADS 9731 are spectroscopic binaries with periods of 3.87 and 14.3 days, respectively. Their orbits are computed. New photometry has demonstrated the absence of eclipses in the close pair Aab. The spectral types and luminosities of all six components matching the are found.
10. ADS 11061 radial velocities
ID:
ivo://CDS.VizieR/J/A+A/409/245
Title:
ADS 11061 radial velocities
Short Name:
J/A+A/409/245
Date:
21 Oct 2021
Publisher:
CDS
Description:
The evolutionary status and origin of the most eccentric known binary in a quadruple system, 41 Dra (e=0.9754, period 3.413yr), are discussed. New observations include the much improved combined speckle-interferometric orbit, resolved photometry of the components and their spectroscopic analysis. The age of the system is 2.5+/-0.2Gyr; all four components are likely coeval. The high eccentricity of the orbit together with known age and masses provide a constraint on the tidal circularization theory: it seems that the eccentric orbit survived because the convective zones of the F-type dwarfs were very thin. Now as the components of 41 Dra are leaving the Main Sequence, their increased interaction at each periastron passage may result in detectable changes in period and eccentricity.

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