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- ID:
- ivo://CDS.VizieR/J/MNRAS/362/1167
- Title:
- Radial velocities of 14 southern Cepheids
- Short Name:
- J/MNRAS/362/1167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution spectroscopic observations and species-by-species radial velocities of a number of southern Cepheids. The stars (BP Cir, V350 Sgr, AX Cir, V636 Sco, W Sgr, S Mus, {beta} Dor, TT Aql, Y Oph, YZ Car, SW Vel, X Pup, T Mon and l Car) were observed as part of a long-term programme at Mt John University Observatory. Radial velocities were determined with the line bisector technique, and have a precision of ~300m/s. Velocity differences as large as 30km/s were found for H and Ca II when referenced to the metallic line velocity curves, but more subtle variations (of 12km/s) were also detected in many other species. Pulsational phase anticorrelations are found between lines of Si II and Ba II, confirming the propagation time delay between line-forming layers producing these two species. We find that the amplitude and phase differences between the various species increase with period.
- ID:
- ivo://CDS.VizieR/J/AJ/132/1539
- Title:
- Radial velocities of southern close binaries
- Short Name:
- J/AJ/132/1539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocity measurements and sine-curve fits to the orbital velocity variations are presented for nine contact binaries: V1464 Aql, V759 Cen, DE Oct, MW Pav, BQ Phe, EL Aqr, SX Crv, VZ Lib, and GR Vir. For the first five of these, our observations are the first available radial velocity data. For the three remaining radial velocity variables, CE Hyi is a known visual binary, while CL Cet and V1084 Sco are suspected to be multiple systems in which the contact binary is spectrally dominated by its companion (which itself is a binary in V1084 Sco). Five additional variable stars, V872 Ara, BD Cap, HIP 69300, BX Ind, and V388 Pav, are of unknown type, but most are pulsating stars; we give their mean radial velocities and vsini.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/2055
- Title:
- Radial velocities of southern SIM grid stars
- Short Name:
- J/MNRAS/446/2055
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present analysis of precision radial velocities (RV) of 1134 mostly red giant stars in the southern sky, selected as candidate astrometric grid objects for the Space Interferometry Mission (SIM). Only a few (typically, two or three) spectroscopic observations per star have been collected, with the main goal of screening binary systems. The estimated rate of spectroscopic binarity in this sample of red giants is 32 per cent at the 0.95 confidence level, and 46 per cent at the 0.75 confidence. The true binarity rate is likely to be higher, because our method is not quite sensitive to very wide binaries and low-mass companions. The estimated lower and upper bounds of stellar RV jitter for the entire sample are 24 and 51m/s, respectively; the adopted mean value is 37m/s. A few objects of interest are identified with large variations of RV, implying abnormally high mass ratios.
- ID:
- ivo://CDS.VizieR/III/105
- Title:
- Radial Velocities of Southern Stars with CORAVEL
- Short Name:
- III/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains 1595 photoelectric radial-velocity observations for 790 bright southern stars of spectral type F5 and later. One of the purposes of this project is to make a complete southern sky radial velocity coverage using the second CORAVEL photoelectric radial velocity scanner. The first CORAVEL operating at Observatoire de Haute-Provence was used to observe the stars in the Northern Hemisphere. Two CORAVEL observations per star were made with CORAVEL photoelectric radial velocity scanner on the Danish 1.54-m telescope at ESO, La Silla, Chile. The mean velocities are accurate to about 0.15 km/s r.m.s. for sharp-lined constant stars, errors increasing somewhat for stars with significant rotation. The present data complete and supersede the preliminary data for 500 stars supplied in advance of publications for inclusions in the fourth edition of The Bright Star Catalogue. At the time this project was planned, there were still some 1500 stars in The Bright Star Catalogue for which no radial-velocity information was available -- virtually all of them in the Southern Hemisphere. For the stars of type F5 and later, photoelectric scanning techniques can be used with much increased efficiency and accuracy. The catalog includes HD numbers with component designation for visual binary components from Jeffers et al. (1963), HR numbers, FK4 or FK4 Supplement numbers, visual magnitudes, MK spectral classes, mean velocities, velocity variability parameters, rotation classes as assigned from the measured linewidths, and remarks and information for individual measurements in a separate file.
- ID:
- ivo://CDS.VizieR/J/A+A/319/481
- Title:
- Radial velocities of 10 spectroscopic binaries
- Short Name:
- J/A+A/319/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new orbits for ten (single-lined) spectroscopic binaries in seven open clusters: NGC 2489, 2567, 3033, 5822, 6134, 6664 and IC 2488 based on 243 individual radial velocities obtained with the southern CORAVEL scanner. The orbital periods range from 98.5 to 3566 days. The shortest-period orbit is circular, as expected. Seven of the binaries are confirmed cluster members, one is a possible member, and two are clearly non-members. Maximum masses from photometric separation and minimum masses from the spectroscopic orbits define the mass of the secondaries within an interval of M_max_-M_min_=0.5M_{sun}_. NGC 6664 #54 seems to have a rather massive secondary (M>3M_{sun}_), but the UBV colours appear normal for a luminous red giant, while significantly bluer (B-V) and (U-B) colours would be expected. It could be a triple system, the secondary being itself a short period binary. This paper brings the number of orbits published in this programme to 53, 45 of which are confirmed red-giant cluster members and 8 are non-members
- ID:
- ivo://CDS.VizieR/J/AJ/145/41
- Title:
- Radial velocities of 33 spectroscopic binaries
- Short Name:
- J/AJ/145/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Orbital elements of 37 single-lined spectroscopic binary systems (SB1s) and 5 double-lined spectroscopic binary systems (SB2s) were determined using high-dispersion spectroscopy. To determine the orbital elements accurately, we carried out precise Doppler shift measurements using the HIgh Dispersion Echelle Spectrograph mounted on the Okayama Astrophysical Observatory 1.88 m telescope. We achieved a radial-velocity precision of ~10 m.s^-1^ over seven years of observations. The targeted binaries have spectral types between F5 and K3, and are brighter than the 7th magnitude in the V band. The orbital elements of 28 SB1s and 5 SB2s were determined at least 10 times more precisely than previous measurements. Among the remaining nine SB1s, five objects were found to be single stars, and the orbital elements of four objects were not determined because our observations did not cover the entire orbital period. We checked the absorption lines from the secondary star for 28 SB1s and found that three objects were in fact SB2s.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/146
- Title:
- Radial velocities of stars in Bootes I
- Short Name:
- J/ApJ/736/146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We develop, implement, and characterize an enhanced data reduction approach which delivers precise, accurate, radial velocities from moderate resolution spectroscopy with the fiber-fed VLT/FLAMES+GIRAFFE facility. This facility, with appropriate care, delivers radial velocities adequate to resolve the intrinsic velocity dispersions of the very faint dwarf spheroidal (dSph) galaxies. Importantly, repeated measurements let us reliably calibrate our individual velocity errors (0.2km/s<={delta}_V_<=5km/s) and directly detect stars with variable radial velocities. We show, by application to the Bootes I dSph, that the intrinsic velocity dispersion of this system is significantly below 6.5km/s reported by previous studies. Our data favor a two-population model of Bootes I, consisting of a majority "cold" stellar component, with velocity dispersion 2.4^+0.9^_-0.5_km/s, and a minority "hot" stellar component, with velocity dispersion ~9km/s, although we cannot completely rule out a single component distribution with velocity dispersion 4.6^0.8^_-0.6_km/s. We speculate that this complex velocity distribution actually reflects the distribution of velocity anisotropy in Bootes I, which is a measure of its formation processes.
- ID:
- ivo://CDS.VizieR/J/ApJ/443/124
- Title:
- Radial Velocities of Stars in M4
- Short Name:
- J/ApJ/443/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The internal stellar velocity distribution of the globular cluster M4 is evaluated from nearly 200 new radial velocity measurements good to 1 km/s and a rederivation of existing proper motions. The mean radial velocity of the cluster is 70.9 +/- 0.6 km/s. The velocity dispersion is 3.5 +/- 0.3 km/s at the core, dropping marginally towards the outskirts. Such a low internal dispersion is somewhat at odds with the cluster's orbit, for which the perigalacticon is sufficiently close to the galactic center that the probability of cluster disruption is high; a tidal radius two-thirds the currently accepted value would eliminate the discrepancy. The cluster mass-to-light ratio is also small, M/L_V = 1.0 +/- 0.4 in solar units. M4 thus joins M22 as a cluster of moderate mass and concentration with a mass-to-light ratio among the lowest known. The astrometric distance to the cluster is also smaller than expected, 1.72 +/- 0.14 kpc. This is only consistent with conventional estimates of the luminosity of horizontal branch stars provided an extinction law R = A_V/E(B-V) ~ 4 is adopted, as has been suggested recently by several authors.
- ID:
- ivo://CDS.VizieR/J/A+A/415/145
- Title:
- Radial velocities of 16 stars in NGC 6913
- Short Name:
- J/A+A/415/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Between 1996 and 2003 we obtained 226 high resolution spectra of 16 stars in the field of the young open cluster NGC 6913, to constrain its main properties and study its internal kinematics. Twelve of the program stars turned out to be members, one of them probably unbound. Nine are binaries (one eclipsing and another double lined) and for seven of them the observations allowed us to derive the orbital elements. All but two of the nine discovered binaries are cluster members. In spite of the young age (a few Myr), the cluster already shows signs that could be interpreted as evidence of dynamical relaxation and mass segregation. However, they may be also the result of an unconventional formation scenario. The dynamical (virial) mass as estimated from the radial velocity dispersion is larger than the cluster luminous mass, which may be explained by a combination of the optically thick interstellar cloud that occults part of the cluster, the unbound state or undetected very wide binary orbit of some of the members that inflate the velocity dispersion and a high inclination for the axis of possible cluster angular momentum. All the discovered binaries are hard enough to survive average close encounters within the cluster and do not yet show signs of relaxation of the orbital elements to values typical of field binaries.
