- ID:
- ivo://CDS.VizieR/J/A+A/408/305
- Title:
- Spectroscopic observations of delta Sco
- Short Name:
- J/A+A/408/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectroscopic monitoring program of the binary system Scorpii, whose primary became a Be star after the last periastron encounter in the Summer of 2000. The observations cover a period of 2 years (March 2001-June 2003) and are a continuation of our previous campaign reported in Miroshnichenko et al. (2001A&A...377..485M). We found that the emission-line spectrum was gradually strengthening over the whole monitoring period. Several short-term increases of the line emission, possibly due to outbursts of matter ejected from the stellar surface, were detected. The outbursts seem to be responsible for the brightness fadings, seen afterwards. We attempt to explain the overall observed line and continuum behaviour in terms of a circumstellar disk, growing in density and size. The disk is most likely Keplerian with an outer radius of and a mean expansion speed of ~0.4km/s.
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- ID:
- ivo://CDS.VizieR/J/A+A/501/291
- Title:
- Spectroscopic observations of HD 152219
- Short Name:
- J/A+A/501/291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 152219 is a massive binary system with O9.5 III + B1-2 V/III components and a short orbital period of 4.2d. Its primary component further displays clear line profile variability (LPV). The primary component being located within the pulsational instability domain predicted for high-luminosity stars, we previously suggested that the observed LPV could be associated with non-radial pulsations. The aim of the present work is to determine the nature of the observed LPV in the spectrum of the primary component of HD 152219. During a 4-night FEROS monitoring campaign, we collected a new set of 134 high signal-to-noise spectra. These new observations were then used to re-investigate the variability of different line profiles in the spectrum of HD~152219. Based on the present analysis, we discard the non-radial pulsations and point out the Rossiter-McLaughlin effect as the cause of the LPV in HD 152219. The upper limit on the amplitude of possible weak pulsations is set at a few parts per thousand of the continuum level.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A89
- Title:
- Spectroscopic orbit of Capella
- Short Name:
- J/A+A/531/A89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Capella is among the few binary stars with two evolved giant components. The hotter component is a chromospherically active star within the Hertzsprung gap, while the cooler star is possibly helium-core burning. The known inclination of the orbital plane from astrometry in combination with precise radial velocities will allow very accurate masses to be determined for the individual Capella stars. This will constrain their evolutionary stage and possibly the role of the active star's magnetic field on the dynamical evolution of the binary system. We obtained a total of 438 high-resolution echelle spectra during the years 2007-2010 and used the measured velocities to recompute the orbital elements. Our double-lined orbital solution yields average residuals of 64m/s for the cool component and 297m/s for the more rapidly rotating hotter component.
- ID:
- ivo://CDS.VizieR/J/AJ/152/46
- Title:
- Spectroscopic orbits for 15 late-type stars
- Short Name:
- J/AJ/152/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic orbital elements are determined for 15 stars with periods from 8 to 6528days with six orbits computed for the first time. Improved astrometric orbits are computed for two stars and one new orbit is derived. Visual orbits were previously determined for four stars, four stars are members of multiple systems, and five stars have Hipparcos "G" designations or have been resolved by speckle interferometry. For the nine binaries with previous spectroscopic orbits, we determine improved or comparable elements. For HD28271 and HD200790, our spectroscopic results support the conclusions of previous authors that the large values of their mass functions and lack of detectable secondary spectrum argue for the secondary in each case being a pair of low-mass dwarfs. The orbits given here may be useful in combination with future interferometric and Gaia satellite observations.
- ID:
- ivo://CDS.VizieR/J/AJ/156/117
- Title:
- Spectroscopic orbits for late-type stars. II.
- Short Name:
- J/AJ/156/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined spectroscopic orbital elements for 13 systems - 10 single-lined binaries and three double-lined binaries. For the three binaries with previously published spectroscopic orbits, we have computed improved or comparable elements. While two systems have relatively short periods between 10 and 19 days, the remaining systems have much longer periods ranging from 604 to 9669 days. One of the single-lined systems, HD 142640, shows both short-period and long-period velocity variations and so is triple. For three systems - HD 59380, HD 160933, and HD 161163 - we have combined our spectroscopic results with Hipparcos astrometric observations to obtain astrometric orbits. For HD 14802 we have determined a joint orbital solution from spectroscopic velocities and interferometric observations. The orbits given here will be useful in combination with future interferometric and Gaia satellite observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/466/415
- Title:
- Spectroscopic orbits for three binaries
- Short Name:
- J/ApJ/466/415
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present orbital solutions for three low-amplitude spectroscopic binaries discovered in a sample of 20 solar-type IAU radial velocity standard stars observed with the Digital Speedometers at the Harvard- Smithsonian Center for Astrophysics. We update the orbital solutions for HD 114762 and HD 140913, and present a preliminary new solution for HD 29587. For all three orbits, the minimum mass for the secondary is less than 0.08M_{sun}_, the borderline between stellar and substellar masses. We consider the probability that all three binaries have small enough inclination angles so that their companions are above the substellar limit. To do so, we treat the 20 IAU standards as a sample drawn from a population of binaries with a mass-ratio distribution that does not allow any substellar companions. We calculate the probability that such a sample could still have three binaries, with the low-amplitude orbits actually found within the IAU sample. We show that this probability is small, depending on the specific mass-ratio distribution. For example, a flat mass-ratio distribution that assumes there are no substellar companions can be excluded at a high confidence level, 99.7%. We further show that our three detections may imply that the secondary-mass distribution rises near the substellar limit. However, the observations do not yet allow us to distinguish whether the unseen companions of HD 114762, HD 140913, and HD 29587 have stellar or substellar masses. In particular, recent attempts to estimate the mass of the companion of HD 114762 based on assumptions about the intrinsic rotation of the primary are inconclusive, and the companion could easily have a mass as low as 0.02M_{sun}_. We compare our three detections with the null results of four very precise radial velocity searches for substellar companions. The difference is indeed puzzling but can be accounted for if just a small fraction of the solar-type stars, of the order of a few percent, have companions with masses near the substellar limit.
- ID:
- ivo://CDS.VizieR/J/A+A/282/831
- Title:
- Spectroscopic orbits of three K dwarf stars
- Short Name:
- J/A+A/282/831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectroscopic orbits of single-lined binary dwarfs HD 23439B, HD 237287 and HD 217580 are derived from the radial velocities measured with two correlation radial-velocity spectrometers: correlation radial velocity (CORAVEL) at the 1m Swiss telescope of Observatoire de Haute-Provence, and radial velocity meters (RVM) used on several telescopes. The mutual agreement of these two data sets is analyzed and found to be quite good. The estimated minimum mass of secondary component corresponds to that of M-type dwarf for the first 2 systems and is equal to 0.06 solar mass for HD 217580.
- ID:
- ivo://CDS.VizieR/J/A+A/391/641
- Title:
- Spectroscopic study of sigma Geminorum from IUE
- Short Name:
- J/A+A/391/641
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IUE spectra of {sigma} Gem have been taken from the NASA IUE archive using IDL (Interactive Data Language). The spectra have been observed in 1979-1986 period. All the spectra analysed in the present study have NEWSIPS reductions and consist of 25 LWP, 8 LWR and 5 SWP images in high resolution, and 2 LWP and 14 SWP images in low dispersion. The emission lines, identified as activity indicators and originating in the chromosphere and transition region, are seen in the spectra. The emission line fluxes and equivalent widths are computed based on Gaussian profile fitting procedures to examine the existence of any line flux variation that depends on time or orbital phase. It was found that there is a flux variation with time and orbital phase that is in good agreement with the photometric light curve variation. By comparing the flux variation with simultaneous light curve variation, it can be shown that there is a relation between the ultraviolet flux variation and the spot activity of the system, as shown by Ayres et al. (1984ApJ...279..197A) and Engvold et al. (1988A&A...192..234E) based on their IUE (with IUESIPS reduction) spectral analysis. Moreover, it was inferred that there is no ultraviolet excess in {sigma} Gem by comparing the spectra of {beta} Gem taken as a comparison star. The Mg II h and k radial velocity curves of {sigma} Gem were in a good agreement with data obtained by Eker (1986MNRAS.221..947E) and Duemmler et al. (1997A&AS..123..209D).
- ID:
- ivo://CDS.VizieR/J/ApJ/652/681
- Title:
- Spectroscopic subcomponents in multiple systems
- Short Name:
- J/ApJ/652/681
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We propose a methodology for analyzing triple stellar systems that include a visual double star wherein one of the components is a single- or double-lined spectroscopic binary. By using this methodology, we can calculate the most probable values of the spectroscopic binary's inclination, the angular separation between its components, and its stellar masses, and we can even estimate the spectral types. For a few W UMa-type eclipsing binaries, stellar radii are also determined. Moreover, we present new formulae for calculating stellar masses depending on spectral type. In this way we have studied 61 triple systems, five of them W UMatype eclipsing binaries with low-mass subcomponents. In addition, we study nine quadruple systems, applying the same methodology and considering them twice as a triple system.
- ID:
- ivo://CDS.VizieR/J/A+A/382/118
- Title:
- Spectroscopic sub-systems in multiple stars
- Short Name:
- J/A+A/382/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large sample of visual multiples of spectral types F5-M has been surveyed for the presence of spectroscopic sub-systems. In table 1 we provide basic identifiers for the components or their combinations, average radial velocities, parameters of correlation dips and analysis of the velocity variability and physical relation. Notes contain comments and additional identifiers. Individual radial velocities yet unpublished are listed in table 2. Table 6 is extracted from the Multiple Star Catalog (Cat. <J/A+AS/124/75>) for the analysis of the statistics of spectroscopic+visual multiple stellar systems.
