- ID:
- ivo://CDS.VizieR/J/AJ/162/66
- Title:
- Radial Velocities in HD50526 system with CORALIE
- Short Name:
- J/AJ/162/66
- Date:
- 14 Mar 2022 08:24:15
- Publisher:
- CDS
- Description:
- We present a photometric and spectroscopic study of HD50526, an ellipsoidal binary member of the group Double Periodic Variable stars. Performing data mining in photometric surveys and conducting new spectroscopic observations with several spectrographs during 2008-2015, we obtained orbital and stellar parameters of the system. The radial velocities were analyzed with the genetic PIKAIA algorithm, whereas Doppler tomography maps for the H{alpha} and H{beta} lines were constructed with the Total Variation Minimization code. An optimized simplex algorithm was used to solve the inverse problem adjusting the light curve with the best stellar parameters for the system. We find an orbital period of 6.701{+/-}0.001d and a long photometric cycle of 191{+/-}2 days. We detected the spectral features of the coldest star and modeled it with a logg=2.79{+/-}0.02dex giant of mass 1.13{+/-}0.02 M{sun} and effective temperature 10500{+/-}125K. In addition, we determine a mass ratio q=0.206{+/-}0.033 and that the hot star is a B-type dwarf of mass 5.48{+/-}0.02M{sun}. The V-band orbital light curve can be modeled including the presence of an accretion disk around the hotter star. This fills the Roche lobe of the hotter star and has a radius 14.74{+/-}0.02R{sun} and the temperature at the outer edge is 9400 K. Two bright spots located in the disk account for the global morphology of the light curve. The Doppler tomography maps of H{alpha} and H{beta} reveal complex structures of mass fluxes in the system.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/580/A14
- Title:
- Radial Velocities of 3 giant stars with planets
- Short Name:
- J/A+A/580/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two giant planets around the intermediate-mass evolved star HIP65891 and HIP107773. The best Keplerian fit to the HIP65891 and HIP107773 radial velocities leads to the following orbital parameters: P=1084.5d; Mpsini=6.0M_Jup_; e=0.13 and P=144.3d; Mpsini=2.0M_Jup_; e=0.09, respectively. In addition, we confirm the planetary nature of the outer object orbiting the giant star HIP67851. The orbital parameters of HIP67851c are: P=2131.8d, Mpsini=6.0M_Jup_, and e=0.17.
- ID:
- ivo://CDS.VizieR/J/A+A/474/293
- Title:
- Radial velocities of GJ 674
- Short Name:
- J/A+A/474/293
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper reports the discovery of a 11M_{earth}_ planet orbiting the nearby M dwarf GJ 674. The paper also shows the star has a spot on its surface. The spot modulates the radial-velocity, the photometric measurements as well as the spectroscopic indices. Here we list the radial-velocity data measured with HARPS (a high-resolution spectrograph providing high precision radial velocities), the spectroscopic indices measured on the same spectra gathered with HARPS and the photometric measurements gathered with the C2 Camera of the EULER Telescope.
- 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/A+A/448/155
- Title:
- Radial velocities of Leo I globular clusters
- Short Name:
- J/A+A/448/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VLT/FLAMES radial velocities for 50 Globular Clusters (GCs), 37 field stars and 21 unclassified objects around the Leo I group galaxies NGC 3379 and NGC 3384 are presented. Object Id and BVR photometry are from Rhode & Zepf (2004AJ....127..302R). Positions (J2000.0) should be accurate to ~0"2 or better w.r.t. the GSC2.1 catalogue. Heliocentric radial velocities and their errors were estimated by fitting the peak (see the width, heigh, and Tonry & Davies (1979AJ.....84.1511T) coefficient) of the cross-correlation function (CCF) with the IRAF/RV package task FXCOR, using simulatenous and ELODIE library stellar templates. Objects have been assigned three quality class, class A being the most secure velocity determination, and class C the least secure; the latter objects require confirmation, and such GCs were not considered for the dynamical analysis presented in the paper.
- ID:
- ivo://CDS.VizieR/J/AJ/160/3
- Title:
- Radial velocities of M-dwarf LTT 3780 with HARPS
- Short Name:
- J/AJ/160/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT3780 (TIC36724087, TOI-732, V=13.07, Ks=8.204, Rs=0.374R{sun}, Ms=0.401 M{sun}, d=22pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of P_b_=0.77, P_c_=12.25days and sizes r_p,b_=1.33{+/-}0.07, r_p,c_=2.30{+/-}0.16R{earth}, the two planets span the radius valley in period-radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of m_p,b_=2.62_-0.46_^+0.48^ and m_p,c_=8.6_-1.3_^+1.6^M{earth}, which indicates that LTT3780b has a bulk composition consistent with being Earth-like, while LTT3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT3780, along with the measured planetary parameters, render LTT3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.
- ID:
- ivo://CDS.VizieR/J/ApJS/182/97
- Title:
- Radial velocities of multi-planet systems
- Short Name:
- J/ApJS/182/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extrasolar multiple-planet systems provide valuable opportunities for testing theories of planet formation and evolution. The architectures of the known multiple-planet systems demonstrate a fascinating level of diversity, which motivates the search for additional examples of such systems in order to better constrain their formation and dynamical histories. Here we describe a comprehensive investigation of 22 planetary systems in an effort to answer three questions: (1) are there additional planets? (2) where could additional planets reside in stable orbits? and (3) what limits can these observations place on such objects? We find no evidence for additional bodies in any of these systems; indeed, these new data do not support three previously announced planets (HD 20367 b: Udry et al., 2003ASPCC..294...17U; HD 74156 d: Bean et al., 2008ApJ...672.1202B; and 47 UMa c: Fischer et al., 2002ApJ...564.1028F). The dynamical simulations show that nearly all of the 22 systems have large regions in which additional planets could exist in stable orbits. The detection-limit computations indicate that this study is sensitive to close-in Neptune-mass planets for most of the systems targeted. We conclude with a discussion on the implications of these nondetections.
- ID:
- ivo://CDS.VizieR/J/AJ/161/106
- Title:
- Radial velocities of 12 Psc and HD 159062
- Short Name:
- J/AJ/161/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of a white dwarf companion to the G1 V star 12Psc found as part of a Keck adaptive optics imaging survey of long-term accelerating stars from the McDonald Observatory Planet Search Program. Twenty years of precise radial-velocity monitoring of 12Psc with the Tull Spectrograph at the Harlan J. Smith telescope reveals a moderate radial acceleration (~10m/s/yr), which together with relative astrometry from Keck/NIRC2 and the astrometric acceleration between Hipparcos and Gaia DR2 yields a dynamical mass of M_B_=0.605_-0.022_^+0.021^M{sun} for 12PscB, a semimajor axis of 40_-4_^+2^au, and an eccentricity of 0.84{+/-}0.08. We also report an updated orbital fit of the white dwarf companion to the metal-poor (but barium-rich) G9 V dwarf HD159062 based on new radial velocity observations from the High-Resolution Spectrograph at the Hobby-Eberly Telescope and astrometry from Keck/NIRC2. A joint fit of the available relative astrometry, radial velocities, and tangential astrometric acceleration yields a dynamical mass of M_B_=0.609_-0.011_^+0.010^M{sun} for HD159062B, a semimajor axis of 60_-7_^+5^au, and preference for circular orbits (e<0.42 at 95% confidence). 12PscB and HD159062B join a small list of resolved Sirius-like benchmark white dwarfs with precise dynamical mass measurements which serve as valuable tests of white dwarf mass-radius cooling models and probes of AGB wind accretion onto their main-sequence companions.
- 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/ApJ/681/1254
- Title:
- Radial velocities of stars in the Galactic Center
- Short Name:
- J/ApJ/681/1254
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from K-band slit scan observations of a ~20"x20" region of the Galactic center (GC) in two separate epochs more than 5 years apart. The high-resolution (R={lamda}/{Delta}{lambda}>=14000) observations allow the most accurate radial velocity and acceleration measurements of the stars in the central parsec of the Galaxy. Detected stars can be divided into three groups based on the CO absorption band heads at ~2.2935um and the HeII lines at ~2.0581 and ~2.112, 2.113um: cool, narrow-line hot, and broad-line hot. The radial velocities of the cool, late-type stars have approximately a symmetrical distribution with its center at ~-7.8+/-10.3km/s and a standard deviation ~113.7+/-10.3km/s. Although our statistics are dominated by the brightest stars, we estimate a central black hole mass of (3.9+/-1.1)x10^6^M_{sun}_, consistent with current estimates from complete orbits of individual stars. Our surface density profile and the velocity dispersion of the late-type stars support the existence of a low-density region at the Galactic center suggested by earlier observations.
