- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/480/L33
- Title:
- Radial velocities of HD 4113 and HD 156846
- Short Name:
- J/A+A/480/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of two very eccentric planets orbiting HD 4113 and HD 156846 with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope at La Silla. The first planet, HD 4113 b, has minimum mass of msini=1.6+/-0.2M_{Jup}_, a period of P=526.59+/-0.21-days and an eccentricity of e=0.903+/-0.02. It orbits a metal rich G5V star at a=1.28AU, which displays an additional radial velocity drift of 28m/s/ observed during 8 years. The second planet, HD 156846 b, has minimum mass of msini=10.45+/-0.05M_{Jup}_, a period of P=359.51+/-0.09days, an eccentricity of e=0.847+/-0.002 and is located at a=1.0AU from its parent star. HD 156846 is a metal rich G0 dwarf and is also the primary of a wide binary system (a>250AU, P>4000-years). Its stellar companion, IDS 17147-1914 B, is a M4 dwarf.
- ID:
- ivo://CDS.VizieR/J/AJ/154/120
- Title:
- Radial velocities of HD 96511, HR 7578, and KZ And
- Short Name:
- J/AJ/154/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From an extensive number of newly acquired radial velocities we determine the orbital elements for three late-type dwarf systems, HD 96511, HR 7578, and KZ And. The orbital periods are 18.89737+/-0.00002, 46.81610+/-0.00006, and 3.0329113+/-0.0000005 days, respectively, and all three systems are eccentric, although KZ And is just barely so. We have detected lines of the secondary of HD 96511 for the first time. The orbital dimensions (a_1_ sin i and a_2_ sin i) and minimum masses (m_1_ sin^3^i and m_2_ sin^3^i) of the binary components all have accuracies of 0.2% or better. Extensive photometry of the chromospherically active binary HR 7578 confirms a rather long rotation period of 16.446+/-0.002 days and that the K3 V components do not eclipse. We have estimated the basic properties of the stars in the three systems and compared those results with evolutionary tracks. The results for KZ And that we computed with the revised Hipparcos parallax of van Leeuwen (Cat. I/311) produce inconsistencies. That parallax appears to be too large, and so, instead, we used the original Hipparcos parallax of the common proper motion primary, which improves the results, although some problems remain.
- 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/AJ/124/1118
- Title:
- Radial velocities of high-velocity white dwarfs
- Short Name:
- J/AJ/124/1118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocities and complete space motions were measured for 116 white dwarf stars with M dwarf companions (WD+M), including thirteen pairs having "halo-like" velocities. These 116 WD+dM binaries were observed on the 3.5 m telescope at the Apache Point Observatory (APO) on nearly 30 half-nights between 2000 September 4 and 2001 October 20. The APO Double Imaging Spectrograph was used with a 15" slit, yielding a resolution of approximately 2arcsrc/pixel. From the near-solar abundance levels of the M dwarf companions, only one potential stellar halo white dwarf (LP 164-52) was found in the sample, 12 of the 13 high-velocity white dwarfs being actually part of the high-velocity tail of the thick disk rather than the dark matter halo of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/L33
- Title:
- Radial velocities of 2 hot Jupiters in Praesepe
- Short Name:
- J/ApJ/756/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two giant planets orbiting stars in Praesepe (also known as the Beehive Cluster). These are the first known hot Jupiters in an open cluster and the only planets known to orbit Sun-like, main-sequence stars in a cluster. The planets are detected from Doppler-shifted radial velocities; line bisector spans and activity indices show no correlation with orbital phase, confirming the variations are caused by planetary companions. Pr0201b orbits a V=10.52 late F dwarf with a period of 4.4264+/-0.0070 days and has a minimum mass of 0.540+/-0.039M_Jup_, and Pr0211b orbits a V=12.06 late G dwarf with a period of 2.1451+/-0.0012 days and has a minimum mass of 1.844+/-0.064M_Jup_. The detection of two planets among 53 single members surveyed establishes a lower limit of 3.8^+5.0^_-2.4_% on the hot Jupiter frequency in this metal-rich open cluster. Given the precisely known age of the cluster, this discovery also demonstrates that, in at least two cases, giant planet migration occurred within 600Myr after formation. As we endeavor to learn more about the frequency and formation history of planets, environments with well-determined properties--such as open clusters like Praesepe--may provide essential clues to this end.
- ID:
- ivo://CDS.VizieR/J/A+A/577/A26
- Title:
- Radial velocities of hot subluminous stars
- Short Name:
- J/A+A/577/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims to find sdBs with compact companions such as massive white dwarfs, neutron stars, or black holes. Here we provide classifications, atmospheric parameters, and a complete radial velocity (RV) catalogue containing 1914 single measurements for a sample of 177 hot subluminous stars discovered based on SDSS DR7; 110 stars show significant RV variability, while 67 qualify as candidates. We constrain the fraction of close massive compact companions of hydrogen-rich hot subdwarfs in our sample to be smaller than 1.3%, which is already close to the theoretical predictions. However, the sample might still contain such binaries with longer periods exceeding 8d. We detect a mismatch between the {Delta}RV_max_-distribution of the sdB and the more evolved sdOB and sdO stars, which challenges our understanding of their evolutionary connection. Furthermore, irregular RV variations of unknown origin with amplitudes of up to 180km/s on timescales of years, days, and even hours have been detected in some He-sdO stars. They might be connected to irregular photometric variations in some cases.
- ID:
- ivo://CDS.VizieR/J/A+A/336/263
- Title:
- Radial velocities of HR 4049
- Short Name:
- J/A+A/336/263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The C I, Na I D, and H{alpha} lines of the post-AGB binary HR 4049 have been studied. Na I D variability results from a photospheric absorption component ([Na/H]=-1.6+/-0.2) which follows the velocity of the primary and a stationary, non-photospheric component. An emission component is attributed to the circumbinary disc, and an absorption component to mass-loss from the system with a velocity of 5.3+/-0.5km/s. The H{alpha} profile varies with the orbital period. The two strong shell type emission peaks are identified as from one single broad emission feature with an absorption centered around -7.5km/s. The intensity variations are largely attributed to a differential amount of reddening towards the H{alpha} emitting region and the stellar continuum. The radial velocities suggest that the H{alpha} emission moves in phase with the primary, but with a slightly lower velocity amplitude. From this we infer that the H{alpha} emission comes from outside the orbit of the primary, but still gravitationally bound to the primary. H{alpha} also shows a weak emission feature at -21.3+/-3.5km/s, which originates from the circumbinary disc and a weak absorption feature at -7.5+/-1.6km/s due to absorption by the circumbinary disc. We propose two competing models that could account for the observed velocity and intensity variations of the H{alpha} profile. Model I: light from the primary reflects on a localized spot near the inner radius of the circumbinary disc which is closest to the primary. Model II: H{alpha} emission originates in the outer layers of the extended atmosphere of the primary due to activity. These activities are locked to the position of the primary in its orbit. We discuss the similarities of variability and shape of the H{alpha} emission of HR 4049 with those of early type T-Tauri stars (e.g SU Aur).
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/3197
- Title:
- Radial velocities of Hyades members
- Short Name:
- J/MNRAS/477/3197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the membership of the Hyades open cluster, derive kinematically modelled parallaxes of its members, and study the colour-absolute magnitude diagram of the cluster. We use Gaia DR1 Tycho-Gaia Astrometric Solution (TGAS) data complemented by Hipparcos-2 data for bright stars not contained in TGAS. We supplement the astrometric data with radial velocities collected from a dozen literature sources. By assuming that all cluster members move with the mean cluster velocity to within the velocity dispersion, we use the observed and the expected motions of the stars to determine individual cluster membership probabilities. We subsequently derive improved parallaxes through maximum-likelihood kinematic modelling of the cluster. This method has an iterative component to deal with 'outliers', caused for instance by double stars or escaping members. Our method extends an existing method and supports the mixed presence of stars with and without radial velocities. We find 251 candidate members, 200 of which have a literature radial velocity, and 70 of which are new candidate members with TGAS astrometry. The cluster is roughly spherical in its centre but significantly flattened at larger radii. The observed colour-absolute magnitude diagram shows a clear binary sequence. The kinematically modelled parallaxes that we derive are a factor ~1.7/2.9 more precise than the TGAS/ Hipparcos-2 values and allow us to derive an extremely sharp main sequence. This sequence shows evidence for fine-detailed structure that is elegantly explained by the full spectrum turbulence model of convection.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3579
- Title:
- Radial velocities of Hyades stars
- Short Name:
- J/AJ/127/3579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a radial velocity survey of a sample of Hyades stars and discuss the effects of stellar activity on radial velocity measurements. The level of radial velocity scatter due to rotational modulation of stellar surface features for the Hyades is in agreement with the 1997 predictions of Saar and Donahue (1997ApJ...485..319S) - the maximum radial velocity rms of up to ~50m/s, with an average rms of ~16m/s. In this sample of 93 stars we find one new binary, two stars with linear trends indicative of binary companions, and no close-in giant planets. We discuss the limits on extrasolar planet detection in the Hyades and the constraints imposed on radial velocity surveys of young stars.
