- ID:
- ivo://CDS.VizieR/J/A+A/469/L43
- Title:
- Radial velocities of Gl 581
- Short Name:
- J/A+A/469/L43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This Letter reports on the detection of two super-Earth planets in the Gl 581 system, which is already known to harbour a hot Neptune. One of the planets has a mass of 5M_{earth}_ and resides at the "warm" edge of the habitable zone of the star. It is thus the known exoplanet that most resembles our own Earth. The other planet has a 7.7M_{earth}_ mass and orbits at 0.25AU from the star, close to the "cold" edge of the habitable zone. These two new light planets around an M3 dwarf further confirm the formerly tentative statistical trend toward (i) many more very low-mass planets being found around M dwarfs than around solar-type stars and (ii) low-mass planets outnumbering Jovian planets around M dwarfs.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/PASP/111/1233
- Title:
- Radial Velocities of Globular Cluster Giants
- Short Name:
- J/PASP/111/1233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Velocities are given for 303 giant stars in the globular clusters M3, M13, M15, and M92 from spectra obtained with the 3.5-m WIYN Telescope at the Kitt Peak National Observatory using the Hydra multi-fiber positioner and bench spectrograph. The tables provide the individual identifications, HJD, and velocity for each star observed. The uncertainties in the velocity measurements are typically 1 km.s^-1^ or less.
- ID:
- ivo://CDS.VizieR/J/A+A/526/A112
- Title:
- Radial velocities of HARPS metal-poor sample
- Short Name:
- J/A+A/526/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Searching for extrasolar planets around stars of different metallicity may provide strong constraints to the models of planet formation and evolution. In this paper we present the overall results of a HARPS (a high-precision spectrograph mostly dedicated to deriving precise radial velocities) program to search for planets orbiting a sample of 104 metal-poor stars (selected [Fe/H] below -0.5). Radial velocity time series of each star are presented and searched for signals using several statistical diagnostics. tars with detected signals are presented, including 3 attributed to the presence of previously announced giant planets orbiting the stars HD171028, HD181720, and HD190984. Several binary stars and at least one case of a coherent signal caused by activity-related phenomena are presented. One very promising new, possible giant planet orbiting the star HD107094 is discussed, and the results are analyzed in light of the metallicity-giant planet correlation. We conclude that the frequency of giant planets orbiting metal-poor stars may be higher than previously thought, probably reflecting the higher precision of the HARPS survey. In the metallicity domain of our sample, we also find evidence that the frequency of planets is a steeply rising function of the stellar metal content, as found for higher metallicity stars.
- 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.
- ID:
- ivo://CDS.VizieR/J/PAZh/39/41
- Title:
- Radial velocities of HBHA 4705-03
- Short Name:
- J/PAZh/39/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of photometric and spectroscopic studies for the new eclipsing cataclysmic variable star HBHA 4705-03 with an orbital period of 0.1718 days are presented.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1001
- Title:
- Radial velocities of HD 166181
- Short Name:
- J/AJ/129/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained extensive spectroscopic and velocity spectrometer observations of HD166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the system has additional velocity variations with a period of 2092days, or 5.73yr. This long-period orbit has an eccentricity of 0.76. An analysis of the Hipparcos observations produces a well-determined astrometric orbit for the long-period system that has an inclination of 78{deg}. Mass estimates of the components in this zero-age main-sequence multiple system indicate that the unseen secondary in the 5.73yr orbit may also be a binary. Thus, HD 166181 is at least a triple system and possibly quadruple.
- ID:
- ivo://CDS.VizieR/J/A+A/470/1009
- Title:
- Radial velocities of HD 209625
- Short Name:
- J/A+A/470/1009
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The goal is to test the structure of hot metallic stars, and in particular the structure of a near-surface convection zone using asteroseismic measurements. Indeed, stellar models including a detailed treatment of the radiative diffusion predict the existence of a near-surface convection zone in order to correctly reproduce the anomalies in surface abundances that are observed in Am stars. The Am star HD 209625 was observed with the Harps spectrograph mounted on the 3.6-m telescope at the ESO La Silla Observatory (Chile) during 9 nights in August 2005. This observing run allowed to collect 1243 radial velocity measurements, with a standard deviation of 1.35m/s. The power spectrum associated with these RV measurements does not present any excess. Therefore, either the structure of the external layers of this star does not enable to excite solar-like oscillations, or the amplitudes of the oscillations remains below 20-30cm/s (depending of their frequency range).
- ID:
- ivo://CDS.VizieR/J/A+A/491/883
- Title:
- Radial velocities of HD 60532
- Short Name:
- J/A+A/491/883
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the framework of the search for extrasolar planets and brown dwarfs around early-type stars, we present the results obtained for the F-type main-sequence star HD 60532 (F6V) with HARPS. Using 147 spectra obtained with HARPS at La Silla on a time baseline of two years, we studied the radial velocities of this star. HD 60532 radial velocities are periodically variable, and the variations have a Keplerian origin. This star is surrounded by a planetary system of two planets with minimum masses of 1 and 2.5M_{Jup}_ and orbital separations of 0.76 and 1.58AU, respectively. We also detect high-frequency, small- amplitude (10m/s peak-to-peak) pulsations. Dynamical studies of the system point toward a possible 3:1 mean-motion resonance that should be confirmed within the next decade.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A35
- Title:
- Radial velocities of HD 41248
- Short Name:
- J/A+A/566/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The search for planets orbiting metal-poor stars is of uttermost importance for our understanding of the planet formation models. However, no dedicated searches have been conducted so far for very low mass planets orbiting such objects. Only a few cases of low mass planets orbiting metal-poor stars are thus known. Amongst these, HD 41248 is a metal-poor, solar-type star on which a resonant pair of super-Earth like planets has been announced. This detection was based on 62 radial velocity measurements obtained with the HARPS spectrograph (public data). In the present paper we present a new planet search program that is using the HARPS spectrograph to search for Neptunes and Super-Earths orbiting a sample of metal-poor FGK dwarfs. We then present a detailed analysis of an additional 162 radial velocity measurements of HD 41248, obtained within this program, with the goal of confirming the existence of the proposed planetary system. We analyzed the precise radial velocities, obtained with the HARPS spectrograph, together with several stellar activity diagnostics and line profile indicators. A careful analysis shows no evidence for the planetary system previously announced. One of the signals, with a period of ~25 days, is shown to be related to the rotational period of the star, and is clearly seen in some of the activity proxies. The remaining signal (P~18 days) could not be convincingly retrieved in the new data set. We discuss possible causes for the complex (evolving) signals observed in the data of HD 41248, proposing that they may be explained by the appearance and disappearance of active regions on the surface of a star with strong differential rotation, or by a combination of the sparse data sampling and active region evolution.
