- ID:
- ivo://CDS.VizieR/J/A+A/402/1033
- Title:
- BV photometry of UX Ari in 1987-2002
- Short Name:
- J/A+A/402/1033
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 14.3 years of previously unpublished photometric observations of UX Ari. The observations were obtained between 1987.9 and 2002.2 using the T3 0.4-metre Automatic Photoelectric Telescope at Fairborn Observatory and consist of 1228 B band and 1213 V band measurements. The comparison star was 62 Ari and the check star was 59 Ari. We have analyzed the new data together with previously published photometric observations. The V magnitude shows variations with dominant periods of about 12 and 25 years, where the longest period seems to correspond to an activity cycle. The previously reported anticorrelation between the B V colour and V magnitude variations is confirmed.
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- ID:
- ivo://CDS.VizieR/J/A+A/601/A133
- Title:
- BVRI light curves of 3 massive binaries
- Short Name:
- J/A+A/601/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The role of mass and momentum exchanges in close massive binaries is very important in the subsequent evolution of the components. Such exchanges produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars detach again. We investigated these effects for the close O-star binary LSS 3074 (O4f+O6-7:(f):), which is a good candidate for a past Roche lobe overflow (RLOF) episode because of its very short orbital period, P=2.185-days, and the luminosity classes of both components. We determined a new orbital solution for the system. We studied the photometric light curves to determine the inclination of the orbit and Roche lobe filling factors of both stars. Using phase-resolved spectroscopy, we performed the disentangling of the optical spectra of the two stars. We then analysed the reconstructed primary and secondary spectra with the CMFGEN model atmosphere code to determine stellar parameters, such as the effective temperatures and surface gravities, and to constrain the chemical composition of the components. We confirm the apparent low stellar masses and radii reported in previous studies. We also find a strong overabundance in nitrogen and a strong carbon and oxygen depletion in both primary and secondary atmospheres, together with a strong enrichment in helium of the primary star. We propose several possible evolutionary pathways through a RLOF process to explain the current parameters of the system. We confirm that the system is apparently in overcontact configuration and has lost a significant portion of its mass to its surroundings. We suggest that some of the discrepancies between the spectroscopic and photometric properties of LSS 3074 could stem from the impact of a strong radiation pressure of the primary.
- ID:
- ivo://CDS.VizieR/J/other/Obs/116.382
- Title:
- BVRI Photometry of Spectroscopic Binaries
- Short Name:
- J/other/Obs/116.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BVRI photometry has been obtained for 82 of the spectroscopic binaries with orbits published in The Observatory by Griffin and his collaborators. The observations were obtained on nineteen nights during 1994-95. Given here are the star name, Griffin's paper number for the spectroscopic orbit, the abbreviated calendar date and heliocentric Julian Date (HJD) of the observation, the derived V, (B-V), (V-R)c, and (R-I)c values, and the phase in the spectroscopic orbit. The mean photometric values are listed in the final entry for each star. One night of poor quality, 950128, was given half weight in forming the means. The rms error of a single observation is about 0.025 mag. for all indices.
- ID:
- ivo://CDS.VizieR/J/A+AS/146/103
- Title:
- CaII H&K to CaII IRT echelle spectra
- Short Name:
- J/A+AS/146/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. High resolution echelle spectra including all the optical chromospheric activity indicators from the CaII H&K to CaII IRT lines are analysed here for 16 systems. The chromospheric contribution in these lines has been determined using the spectral subtraction technique. Very broad wings have been found in the subtracted H{alpha} profile of the very active star HU Vir. These profiles are well matched using a two-component Gaussian fit (narrow and broad) and the broad component can be interpreted as arising from microflaring. Red-shifted absorption features in the H{alpha} line have been detected in several systems and excess emission in the blue wing of FG UMa was also detected. These features indicate that several dynamical processes, or a combination of them, may be involved. Using the E_H{alpha}_/E_H{beta}_ ratio as a diagnostic we have detected prominence-like extended material viewed off the limb in many stars of the sample, and prominences viewed against the disk at some orbital phases in the dwarfs OU Gem and BF Lyn. The He I D_3_ line has been detected as an absorption feature in mainly all the giants of the sample. Total filling-in of the He I D_3_, probably due to microflaring activity, is observed in HU Vir. Self-absorption with red asymmetry is detected in the CaII H&K lines of the giants 12 Cam, FG UMa and BM CVn. All the stars analysed show clear filled-in CaII IRT lines or even notable emission reversal. The small values of the E_8542_/E_8498_ ratio we have found indicate CaII IRT emission arises from plage-like regions. Orbital phase modulation of the chromospheric emission has been detected in some systems, in the case of HU Vir evidence of an active longitude area has been found.
- ID:
- ivo://CDS.VizieR/J/A+A/444/643
- Title:
- Candidate spectroscopic binaries in SDSS
- Short Name:
- J/A+A/444/643
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have examined the radial velocity data for stars spectroscopically observed by the Sloan Digital Sky Survey (SDSS) more than once to investigate the incidence of spectroscopic binaries, and to evaluate the accuracy of the SDSS stellar radial velocities.
- ID:
- ivo://CDS.VizieR/J/AJ/155/190
- Title:
- Carina Nebula hot stars: stellar parameters and RVs
- Short Name:
- J/AJ/155/190
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Carina Nebula is an active star-forming region in the southern sky that is of particular interest due to the presence of a large number of massive stars in a wide array of evolutionary stages. Here, we present the results of the spectroscopic analysis of 82 B-type stars and 33 O-type stars that were observed in 2013 and 2014. For 82 B-type stars without line blending, we fit model spectra from the Tlusty BSTAR2006 grid to the observed profiles of H{gamma} and He {lambda}{lambda}4026, 4388, and 4471 to measure the effective temperatures, surface gravities, and projected rotational velocities. We also measure the masses, ages, radii, bolometric luminosities, and distances of these stars. From the radial velocities measured in our sample, we find 31 single lined spectroscopic binary candidates. We find a high dispersion of radial velocities among our sample stars, and we argue that the Carina Nebula stellar population has not yet relaxed and become virialized.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/42
- Title:
- CARMENES obs. of the binary system LB-1
- Short Name:
- J/ApJ/900/42
- Date:
- 21 Mar 2022 09:26:37
- Publisher:
- CDS
- Description:
- The mass, origin, and evolutionary stage of the binary system LB-1 have been intensely debated, following the claim that it hosts an ~70M_{sun}_ black hole, in stark contrast with the expectations for Galactic remnants. We conducted a high-resolution, phase-resolved spectroscopic study of its Paschen lines, using the Calar Alto 3.5m telescope. We find that Pa{beta} and Pa{gamma} (after subtraction of the stellar absorption component) are well fitted with a standard double-peaked disk profile. We measured the velocity shifts of the red and blue peaks at 28 orbital phases: the line center has an orbital motion in perfect antiphase with the secondary, and the radial velocity amplitude ranges from 8 to 13km/s, for different methods of profile modeling. We interpret this curve as proof that the disk traces the orbital motion of the primary, ruling out the circumbinary disk and the hierarchical triple scenarios. The phase-averaged peak-to-peak half-separation (a proxy for the projected rotational velocity of the outer part of the disk) is ~70km/s, larger than the orbital velocity of the secondary and inconsistent with a circumbinary disk. From those results, we infer a primary mass 4-8 times higher than the secondary mass. Moreover, we show that the intensity ratio of the blue and red peaks has a sinusoidal behavior in phase with the secondary, which we attribute to external irradiation of the outer part of the disk. Finally, we discuss our findings in the context of competing scenarios proposed for LB-1. Further astrometric Gaia data will test between alternative solutions.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A32
- Title:
- CARMENES SB2 orbital parameters
- Short Name:
- J/A+A/619/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CARMENES spectrograph is surveying ~300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Using spectroscopic observations we determine the orbital and physical properties of nine new double-line spectroscopic binary systems by analysing their radial velocity curves. We use two-dimensional cross-correlation techniques to derive the radial velocities of the targets, which are then employed to determine the orbital properties. Photometric data from the literature are also analysed to search for possible eclipses and to measure stellar variability, which can yield rotation periods. Out of the 342 stars in the CARMENES sample, only 9 have been found to be SB2s. We provide empirical orbital properties and minimum masses for the sample of spectroscopic binaries, with periods ranging from 1.13 to 8000 days and eccentricities up to ~0.54. Absolute masses are also estimated from mass-luminosity calibrations, ranging between ~0.1M_{sun}_ and ~0.6M_{sun}_. These new binary systems increase the number of double-line M dwarf binary systems with known orbital parameters by 14%, and suggest that low-mass binaries seem to have lower mass ratios than more massive systems.
- ID:
- ivo://CDS.VizieR/J/AN/340/386
- Title:
- Catalogue of spectroscopic binary candidate stars
- Short Name:
- J/AN/340/386
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the recently published Gaia second data release that includes measurements of the mean radial velocity of about 7.2 million stars, we performed a systematic comparison with other existing radial velocity catalogs to search for variations in the radial velocity measurements, with the goal that detected differences may indicate that these stars are possibly spectroscopic binary stars with only one visible component (SB1). We present a catalog of spectroscopic binary candidate stars containing 35246 stars, compiled to encourage follow-up observations obtaining spectra at different epochs of orbits of these stars to verify their binarity and to study these systems using radial velocity curves. Comparing the Gaia DR2 database with the K-M dwarf catalog, we found 16 stars that show radial velocity variations. In a comparison with the Pulkovo radial velocity catalog of Hipparcos stars, we identified a total of 539 SB1 candidate stars. In the largest radial velocity catalog available, the radial velocity experiment (RAVE) catalog, we found a total of 34691 stars that show radial velocity variations when compared to the Gaia DR2 data.
- ID:
- ivo://CDS.VizieR/J/AJ/148/48
- Title:
- CHARA obs. of omega And, HD 178911, xi Cep
- Short Name:
- J/AJ/148/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- When observed with optical long-baseline interferometers, components of a binary star that are sufficiently separated produce their own interferometric fringe packets; these are referred to as separated fringe packet (SFP) binaries. These SFP binaries can overlap in angular separation with the regime of systems resolvable by speckle interferometry at single, large-aperture telescopes and can provide additional measurements for preliminary orbits lacking good phase coverage, help constrain elements of already established orbits, and locate new binaries in the undersampled regime between the bounds of spectroscopic surveys and speckle interferometry. In this process, a visibility calibration star is not needed, and the SFPs can provide an accurate vector separation. In this paper, we apply the SFP approach to {omega} Andromeda, HD 178911, and {xi} Cephei with the CLIMB three-beam combiner at the CHARA Array. For these systems we determine component masses and parallax of 0.963+/-0.049M_{sun}_ and 0.860+/-0.051M_{sun}_ and 39.54+/-1.85mas for {omega} Andromeda, for HD 178911 of 0.802+/-0.055M_{sun}_and 0.622+/-0.053M_{sun}_with 28.26+/-1.70mas, and masses of 1.045+/-0.031M_{sun}_and 0.408+/-0.066M_{sun}_and 38.10+/-2.81mas for {xi} Cephei.
