- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/511/A21
- Title:
- Radial velocities of GJ876 planetary system
- Short Name:
- J/A+A/511/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precise radial-velocity measurements for data acquired with the HARPS spectrograph infer that three planets orbit the M4 dwarf star GJ 876. In particular, we confirm the existence of planet d, which orbits every 1.93785-days. We find that its orbit may have significant eccentricity (e=0.14), and deduce a more accurate estimate of its minimum mass of 6.3M_{Earth}_.
- 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.
- 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/AJ/150/169
- Title:
- Radial velocities of HD 6434
- Short Name:
- J/AJ/150/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The current goal of exoplanetary science is not only focused on detecting but characterizing planetary systems in hopes of understanding how they formed, evolved, and relate to the solar system. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) combines both radial velocity (RV) and photometric data in order to achieve unprecedented ground-based precision in the fundamental properties of nearby, bright, exoplanet-hosting systems. Here we discuss HD 6434 and its planet, HD 6434b, which has a M_p_sini=0.44M_J_ mass and orbits every 22.0170 days with an eccentricity of 0.146. We have combined previously published RV data with new measurements to derive a predicted transit duration of ~6 hr, or 0.25 days, and a transit probability of 4%. Additionally, we have photometrically observed the planetary system using both the 0.9 and 1.0m telescopes at the Cerro Tololo Inter-American Observatory, covering 75.4% of the predicted transit window. We reduced the data using the automated TERMS Photometry Pipeline, developed to ensure consistent and accurate results. We determine a dispositive null result for the transit of HD 6434b, excluding the full transit to a depth of 0.9% and grazing transit due to impact parameter limitations to a depth of 1.6%.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/614/A133
- Title:
- Radial velocities of HD215152
- Short Name:
- J/A+A/614/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of four super-earth planets around HD215152, with orbital periods of 5.76, 7.28, 10.86, and 25.2d, and minimum masses of 1.8, 1.7, 2.8, and 2.9M_Earth_ respectively. This discovery is based on 373 high quality radial velocity measurements taken by HARPS over thirteen years. Given the low masses of the planets, the S/N is not sufficient to constrain the planets eccentricities. However, a preliminary dynamical analysis suggests that eccentricities should be typically lower than about 0.03 for the system to remain stable. With two pairs of planets with a period ratio smaller than 1.5, with short orbital periods, small masses, and small eccentricities, HD215152 is similar to the very compact multi-planet systems found by Kepler, and very rare in RV surveys. This discovery proves that those systems are reachable with the RV technique, however they require a huge amount of observations to be characterized.
