- ID:
- ivo://CDS.VizieR/J/A+A/537/A59
- Title:
- Radial velocities of gamma Cas
- Short Name:
- J/A+A/537/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A detailed analysis of more than 800 electronic high-resolution spectra of gamma Cas, which were obtained during a time interval of over 6000 days (16.84yr) at several observatories, documents the smooth variations in the density and/or extend of its circumstellar envelope. We found a clear anticorrelation between the peak intensity and FWHM of the H{alpha} emission, which seems to agree with recent models of such emission lines.
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- ID:
- ivo://CDS.VizieR/J/ApJ/783/3
- Title:
- Radial velocities of 1 Gem
- Short Name:
- J/ApJ/783/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used precise differential astrometry from the Palomar High-precision Astrometric Search for Exoplanet Systems project and radial-velocity measurements covering a time span of 40yr to determine the orbital parameters of the 1 Geminorum triple system. We present the first detection of the spectral lines of the third component of the system, together with precise mass (0.5%) and distance (0.15%) determinations for this system. In addition, our astrometry allows us to make the first determination of the mutual inclination of the orbits.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1001
- Title:
- Radial velocities of HD 166181
- Short Name:
- J/AJ/129/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained extensive spectroscopic and velocity spectrometer observations of HD166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the system has additional velocity variations with a period of 2092days, or 5.73yr. This long-period orbit has an eccentricity of 0.76. An analysis of the Hipparcos observations produces a well-determined astrometric orbit for the long-period system that has an inclination of 78{deg}. Mass estimates of the components in this zero-age main-sequence multiple system indicate that the unseen secondary in the 5.73yr orbit may also be a binary. Thus, HD 166181 is at least a triple system and possibly quadruple.
- ID:
- ivo://CDS.VizieR/J/A+A/470/1009
- Title:
- Radial velocities of HD 209625
- Short Name:
- J/A+A/470/1009
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The goal is to test the structure of hot metallic stars, and in particular the structure of a near-surface convection zone using asteroseismic measurements. Indeed, stellar models including a detailed treatment of the radiative diffusion predict the existence of a near-surface convection zone in order to correctly reproduce the anomalies in surface abundances that are observed in Am stars. The Am star HD 209625 was observed with the Harps spectrograph mounted on the 3.6-m telescope at the ESO La Silla Observatory (Chile) during 9 nights in August 2005. This observing run allowed to collect 1243 radial velocity measurements, with a standard deviation of 1.35m/s. The power spectrum associated with these RV measurements does not present any excess. Therefore, either the structure of the external layers of this star does not enable to excite solar-like oscillations, or the amplitudes of the oscillations remains below 20-30cm/s (depending of their frequency range).
- ID:
- ivo://CDS.VizieR/J/ApJ/662/602
- Title:
- Radial velocities of HD 110555
- Short Name:
- J/ApJ/662/602
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We develop a technique to measure radial velocities of stars from spectra that present four sets of lines. The algorithm is an extension of the two-dimensional cross-correlation method TODCOR to four dimensions. It computes the correlation of the observed spectrum against a combination of four templates with all possible shifts, and it also allows for the derivation of the light ratios of the components. After testing the algorithm and demonstrating its ability to measure Doppler shifts accurately even under conditions of heavy line blending, we apply it to the case of the quadruple-lined system HD 110555. The primary and secondary components of this previously known visual binary ({rho}~0.4") are each shown to be double-lined spectroscopic binaries with periods of 57 days and 76 days, respectively, making the system a hierarchical quadruple. The secondary in the 76 days subsystem contributes only 2.5% to the total light, illustrating the ability of the method to measure velocities of very faint components.
- ID:
- ivo://CDS.VizieR/J/A+A/395/885
- Title:
- Radial velocities of HD 553
- Short Name:
- J/A+A/395/885
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 553 was discovered as an eclipsing binary by Hipparcos. Here, we present the first radial velocity curve for this system. It is found, that HD 553 is a double-lined spectroscopic binary. Despite the large luminosity difference, the two components of this system are of very similar mass. The primary, a K0-giant, fills a large fraction of its Roche-lobe. The secondary is, despite its very similar mass, still a late-type dwarf. The radial velocity curve allows to constrain several stellar and system parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/426/695
- Title:
- Radial velocities of HD 41004A/B
- Short Name:
- J/A+A/426/695
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In previous works we reported the detection of a brown-dwarf companion orbiting the faint stellar component of the visual binary HD41004. This had been achieved by applying the multi-order TwO-Dimensional CORrelation (TODCOR) algorithm to CORALIE spectra. A long-term trend of the primary component had also been detected. In this paper we report on follow-up observations that seem to unravel the nature of this long-term trend. The new measurements are consistent with the presence of a 2.5M_J_ planet in an eccentric orbit around HD41004A. Thus, HD41004 is a unique hierarchical system where we have a brown-dwarf that accompanies the faint M-component, and a planet that orbits the brighter K-component.
- ID:
- ivo://CDS.VizieR/J/A+A/404/775
- Title:
- Radial velocities of HD 41004A/B
- Short Name:
- J/A+A/404/775
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents an application of the TwO-Dimensional CORrelation (TODCOR) algorithm to multi-order spectra. The combination of many orders enables the detection and measurement of the radial velocities of very faint companions. The technique is first applied here to the case of HD 41004, where the secondary is 3.68 magnitudes fainter than the primary in the V band. When applied to CORALIE spectra of this system, the technique measures the secondary velocities with a precision of 0.6km/s and facilitates an orbital solution of the HD 41004B subsystem. The orbit of HD 41004B is nearly circular, with a companion of a 19M_J_ minimum mass. The precision achieved for the primary is 10m/s, allowing the measurement of a long-term trend in the velocities of HD 41004A.
- ID:
- ivo://CDS.VizieR/J/AJ/149/63
- Title:
- Radial velocities of HD 54371, HR 2692, and 16 UMa
- Short Name:
- J/AJ/149/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With extensive sets of new radial velocities we have determined orbital elements for three previously known spectroscopic binaries, HD 54371, HR 2692, and 16 UMa. All three systems have had the lines of their secondaries detected for the first time. The orbital periods range from 16.24 to 113.23days, and the three binaries have modestly or moderately eccentric orbits. The secondary to primary mass ratios range from 0.50 to 0.64. The orbital dimensions (a_1_sini and a_2_sini) and minimum masses (m_1_sin^3^i and m_2_sin^3^i) of the binary components all have accuracies of {<=}1%. With our spectroscopic results and the Hipparcos data, we also have determined astrometric orbits for two of the three systems, HR 2692 and 16 UMa. The primaries of HD 54371 and 16 UMa are solar-type stars, and their secondaries are likely K or M dwarfs. The primary of HR 2692 is a late-type subgiant and its secondary is a G or K dwarf. The primaries of both HR 2692 and 16 UMa may be pseudosynchronously rotating, while that of HD 54371 is rotating faster than its pseudosynchronous velocity.
- ID:
- ivo://CDS.VizieR/J/ApJ/751/4
- Title:
- Radial velocities of massive stars in Cyg OB2
- Short Name:
- J/ApJ/751/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work provides a statistical analysis of the massive star binary characteristics in the Cygnus OB2 association using radial velocity information of 114 B3-O5 primary stars and orbital properties for the 24 known binaries. We compare these data to a series of Monte Carlo simulations to infer the intrinsic binary fraction and distributions of mass ratios, periods, and eccentricities. We model the distribution of mass ratio, log-period, and eccentricity as power laws and find best-fitting indices of {alpha}=0.1+/-0.5, {beta}=0.2+/-0.4, and {gamma}=-0.6+/-0.3, respectively. These distributions indicate a preference for massive companions, short periods, and low eccentricities. Our analysis indicates that the binary fraction of the cluster is 44%+/-8% if all binary systems are (artificially) assumed to have P<1000 days; if the power-law period distribution is extrapolated to 10^4^ years, then a plausible upper limit for bound systems, the binary fraction is ~90%+/-10%. Of these binary (or higher order) systems, ~45% will have companions close enough to interact during pre- or post-main-sequence evolution (semi-major axis <~4.7AU). The period distribution for P<26 days is not well reproduced by any single power law owing to an excess of systems with periods around 3-5 days (0.08-0.31AU) and a relative shortage of systems with periods around 7-14 days (0.14-0.62AU). We explore the idea that these longer-period systems evolved to produce the observed excess of short-period systems. The best-fitting binary parameters imply that secondaries generate, on average, ~16% of the V-band light in young massive populations. This means that photometrically based distance measurements for young massive clusters and associations will be systematically low by ~8% (0.16 mag in the distance modulus) if the luminous contributions of unresolved secondaries are not taken into account.
