- 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/613/A47
- Title:
- Radial velocities of 12 evolved stars
- Short Name:
- J/A+A/613/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radial velocities and line bisectors for 12 giants with high Li abundance. We report the discovery of two new planetary systems around HD238914 and TYC3318-01333-1, reveal a binary Li-rich giant HD181368. Although our current phase coverage is not complete, we suggest the presence of planetary mass companions around TYC3663-01966-1 and TYC3105-00152-1. We confirm the previous result for BD+48 740 (Adamow et al, 2012ApJ...754L..15A).
- ID:
- ivo://CDS.VizieR/J/A+A/427/313
- Title:
- Radial velocities of evolved stars. III.
- Short Name:
- J/A+A/427/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotational velocity measurements are presented for a sample of 78 double-lined binary systems with an evolved component. This work is the third part of the large survey carried out with the CORAVEL spectrometer to establish the behavior the rotation for stars evolving off the main sequence (De Medeiros & Mayor, 1999, Cat. <J/A+AS/139/433>; De Medeiros et al. 2002, Cat. <J/A+A/395/97>). Some of the stars show an orbital motion which require some further analysis; the corresponding results will be included in a forthcoming paper. The stars concerned are HD 5303, 82543, 169268, 172088 and 250810.
- ID:
- ivo://CDS.VizieR/J/MNRAS/472/4193
- Title:
- Radial velocities of 1453 FGK
- Short Name:
- J/MNRAS/472/4193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second paper of a series of publications aiming at obtaining a better understanding regarding the nature of type Ia supernovae (SN Ia) progenitors by studying a large sample of detached F, G and K main-sequence stars in close orbits with white dwarf companions (i.e. WD+FGK binaries). We employ the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) data release 4 spectroscopic data base together with Galaxy Evolution Explorer (GALEX) ultraviolet fluxes to identify 1549 WD+FGK binary candidates (1057 of which are new), thus doubling the number of known sources. We measure the radial velocities of 1453 of these binaries from the available LAMOST spectra and/or from spectra obtained by us at a wide variety of different telescopes around the globe. The analysis of the radial velocity data allows us to identify 24 systems displaying more than 3{sigma} radial velocity variation that we classify as close binaries. We also discuss the fraction of close binaries among WD+FGK systems, which we find to be ~10 per cent, and demonstrate that high-resolution spectroscopy is required to efficiently identify double-degenerate SN Ia progenitor candidates.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/117
- Title:
- Radial velocities of four exoplanet candidates
- Short Name:
- J/ApJ/727/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new precise HIRES radial velocity (RV) data sets of five nearby stars obtained at Keck Observatory. HD 31253, HD 218566, HD 177830, HD 99492, and HD 74156 are host stars of spectral classes F through K and show RV variations consistent with new or additional planetary companions in Keplerian motion. The orbital parameters of the candidate planets in the five planetary systems span minimum masses of Msini=27.43M_{sun}_ to 8.28M_J_, periods of 17.05-4696.95 days and eccentricities ranging from circular to extremely eccentric (e~0.63). The fifth star, HD 74156, was known to have both a 52 day and a 2500 day planet, and was claimed to also harbor a third planet at 336 days, in apparent support of the "Packed Planetary System" hypothesis. Our greatly expanded data set for HD 74156 provides strong confirmation of both the 52 day and 2500 day planets, but strongly contradicts the existence of a 336 day planet, and offers no significant evidence for any other planets in the system.
- 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/628/A39
- Title:
- Radial velocities of GJ 357
- Short Name:
- J/A+A/628/A39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of a transiting Earth-size planet around GJ 357, a nearby M2.5 V star, using data from the Transiting Exoplanet Survey Satellite (TESS). GJ 357 b (TOI-562.01) is a transiting, hot, Earth-sized planet (Teq=525+/-11K) with a radius of R_b_=1.217+/-0.084R_{Earth}_ and an orbital period of P_b_=3.93d. Precise stellar radial velocities from CARMENES and PFS, as well as archival data from HIRES, UVES, and HARPS also display a 3.93-day periodicity, confirming the existence of the planet and leading to a planetary mass of M_b_=1.84+/-0.31M_{Earth}_. In addition to the radial velocity signal for GJ 357 b, more periodicities are present in the data indicating the presence of two more planets in the system: GJ 357 c, with a minimum mass of M_c_=3.40+/-0.46M_{Earth}_ in a 9.12d orbit, and GJ 357 d, with a minimum mass of M_d_=6.1+/-1.0M_{Earth}_ in a 55.7d orbit inside the habitable zone. The host is relatively inactive and exhibits a photometric rotation period of Prot=78+/-2d. GJ 357 b is to date the second closest transiting planet to the Sun, making it a prime target for further investigations such as transmission spectroscopy. Therefore, GJ 357 b represents one of the best terrestrial planets suitable for atmospheric characterization with the upcoming JWST and ground-based ELTs.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A171
- Title:
- Radial velocities of GJ 3779 and GJ 1265
- Short Name:
- J/A+A/620/A171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We announce the discovery of two planetary companions orbiting around the low-mass stars Ross 1020 (GJ 3779, M4.0V) and LP 819-052 (GJ 1265, M4.5V). The discovery is based on the analysis of CARMENES radial velocity (RV) observations in the visual channel as part of its survey for exoplanets around M dwarfs. In the case of GJ 1265, CARMENES observations were complemented with publicly available Doppler measurements from HARPS. The datasets reveal two planetary companions, one for each star, that share very similar properties: minimum masses of 8.0+/-0.5M_{Earth}_ and 7.4+/-0.5M_{Earth}_ in low-eccentricity orbits with periods of 3.023+/-0.001d and 3.651+/-0.001d for GJ 3779 b and GJ 1265 b, respectively. The periodic signals around three days found in the RV data have no counterpart in any spectral activity indicator. Furthermore, we collected available photometric data for the two host stars, which confirm that the additional Doppler variations found at periods of approximately 95d can be attributed to the rotation of the stars. The addition of these planets to a mass-period diagram of known planets around M dwarfs suggests a bimodal distribution with a lack of short-period low-mass planets in the range of 2-5M_{Earth}_. It also indicates that super-Earths (>5M_{Earth}_) currently detected by RV and transit techniques around M stars are usually found in systems dominated by a single planet.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/L223
- Title:
- Radial velocities of HAT-P-11
- Short Name:
- J/ApJ/723/L223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We find the orbit of the Neptune-sized exoplanet HAT-P-11b to be highly inclined relative to the equatorial plane of its host star. This conclusion is based on spectroscopic observations of two transits, which allowed the Rossiter-McLaughlin effect to be detected with an amplitude of 1.5m/s. The sky-projected obliquity is 103^+26^_-10_deg. This is the smallest exoplanet for which spin-orbit alignment has been measured. The result favors a migration scenario involving few-body interactions followed by tidal dissipation. This finding also conforms with the pattern that the systems with the weakest tidal interactions have the widest spread in obliquities. We predict that the high obliquity of HAT-P-11 will be manifest in transit light curves from the Kepler spacecraft: starspot-crossing anomalies will recur at most once per stellar rotation period, rather than once per orbital period as they would for a well-aligned system.
- ID:
- ivo://CDS.VizieR/J/ApJ/772/80
- Title:
- Radial velocities of HAT-P-17
- Short Name:
- J/ApJ/772/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the measured projected obliquity -the sky-projected angle between the stellar spin axis and orbital angular momentum- of the inner planet of the HAT-P-17 multi-planet system. We measure the sky-projected obliquity of the star to be {lambda}=19_-16_^+14^deg by modeling the Rossiter-McLaughlin effect in Keck/HIRES radial velocities (RVs). The anomalous RV time series shows an asymmetry relative to the midtransit time, ordinarily suggesting a nonzero obliquity -but in this case at least part of the asymmetry may be due to the convective blueshift, increasing the uncertainty in the determination of {lambda}. We employ the semi-analytical approach of Hirano et al. (2011ApJ...742...69H) that includes the effects of macroturbulence, instrumental broadening, and convective blueshift to accurately model the anomaly in the net RV caused by the planet eclipsing part of the rotating star. Obliquity measurements are an important tool for testing theories of planet formation and migration. To date, the measured obliquities of ~50 Jovian planets span the full range, from prograde to retrograde, with planets orbiting cool stars preferentially showing alignment of stellar spins and planetary orbits. Our results are consistent with this pattern emerging from tidal interactions in the convective envelopes of cool stars and close-in planets. In addition, our 1.8yr of new RVs for this system show that the orbit of the outer planet is more poorly constrained than previously thought, with an orbital period now in the range of 10-36yr.
