- ID:
- ivo://CDS.VizieR/J/ApJ/830/46
- Title:
- Radial velocities of 3 Neptune-mass planet hosts
- Short Name:
- J/ApJ/830/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of three modestly irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD42618b has a minimum mass of 15.4+/-2.4 M_{Earth}_, a semimajor axis of 0.55au, an equilibrium temperature of 337K, and is the first planet discovered to orbit the solar analogue host star, HD42618. We also discover new planets orbiting the known exoplanet host stars HD164922 and HD143761 ({rho} CrB). The new planet orbiting HD164922 has a minimum mass of 12.9+/-1.6 M_{Earth}_ and orbits interior to the previously known Jovian mass planet orbiting at 2.1au. HD164922c has a semimajor axis of 0.34au and an equilibrium temperature of 418K. HD143761c orbits with a semimajor axis of 0.44au, has a minimum mass of 25+/-2 M_{Earth}_, and is the warmest of the three new planets with an equilibrium temperature of 445K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photometry from the Automated Photometric Telescopes (APTs) at Fairborn Observatory failed to detect any transits, but the precise, high-cadence APT photometry helped to disentangle planetary-reflex motion from stellar activity. These planets were discovered as part of an ongoing radial velocity survey of bright, nearby, chromospherically inactive stars using the Automated Planet Finder (APF) telescope at Lick Observatory. The high-cadence APF data combined with nearly two decades of radial velocity data from Keck Observatory and gives unprecedented sensitivity to both short-period low-mass, and long-period intermediate-mass planets.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/527/A63
- Title:
- Radial velocities of 7 new HARPS planetary systems
- Short Name:
- J/A+A/527/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We are conducting a planet search survey with HARPS since seven years. The volume-limited stellar sample includes all F2 to M0 main-sequence stars within 57.5pc, where extrasolar planetary signatures are systematically searched for with the radial-velocity technics. In this paper, we report the discovery of new substellar companions of seven main-sequence stars and one giant star, detected through multiple Doppler measurements with the instrument HARPS installed on the ESO 3.6m telescope, La Silla, Chile.
- ID:
- ivo://CDS.VizieR/J/A+A/563/A22
- Title:
- Radial velocities of 3 new hot Jupiters
- Short Name:
- J/A+A/563/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision radial-velocity measurements of three solar-type stars: HD 13908, HD 159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A139
- Title:
- Radial Velocities of stars observed in M67
- Short Name:
- J/A+A/545/A139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precise stellar radial velocities are used to search for massive (Jupiter masses or higher) exoplanets around the stars of the open cluster M67. We observed a total of 88 main-sequence stars, subgiants, and giants all highly probable members of M67, using four telescopes and instrument combinations: the HARPS spectrograph at the ESO 3.6m, the SOPHIE spectrograph at OHP, the CORALIE spectrograph at the Euler Swiss telescope and the HRS spectrograph at Hobby Eberly Telescope. We investigate whether exoplanets are present by obtaining radial velocities with precisions as good as 10m/s.
- ID:
- ivo://CDS.VizieR/J/A+A/512/A47
- Title:
- Radial velocities of 3 stars with giant planets
- Short Name:
- J/A+A/512/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of three new giant planets around three metal-deficient stars: HD5388b (1.96M_Jup_), HD181720b (0.37M_Jup_), and HD190984b (3.1M_Jup_). All the planets have moderately eccentric orbits (ranging from 0.26 to 0.57), and long orbital periods (from 777 to 4885 days). Two of the stars (HD181720 and HD190984) were part of a program searching for giant planets around a sample of ~100 moderately metal-poor stars, while HD5388 was part of the volume-limited sample of the HARPS GTO program. Our discoveries suggest that giant planets in long period orbits are not uncommon around moderately metal-poor stars. We present the results of a study of streaming motion of galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A145
- Title:
- Radial velocities of 8 stars with giant planets
- Short Name:
- J/A+A/588/A145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new radial velocity measurements of eight stars that were secured with the spectrograph SOPHIE at the 193cm telescope of the Haute-Provence Observatory. The measurements allow detecting and characterizing new giant extrasolar planets. The host stars are dwarfs of spectral types between F5 and K0 and magnitudes of between 6.7 and 9.6; the planets have minimum masses M_p_sini of between 0.4 to 3.8M_Jup_ and orbitalperiods of several days to several months. The data allow only single planets to be discovered around the first six stars (HD 143105, HIP 109600, HD 35759, HIP 109384, HD 220842, and HD 12484), but one of them shows the signature of an additional substellar companion in the system. The seventh star, HIP 65407, allows the discovery of two giant planets that orbit just outside the 12:5 resonance in weak mutual interaction. The last star, HD 141399, was already known to host a four-planet system; our additional data and analyses allow new constraints to be set on it. We present Keplerian orbits of all systems, together with dynamical analyses of the two multi-planet systems. HD 143105 is one of the brightest stars known to host a hot Jupiter, which could allow numerous follow-up studies to be conducted even though this is not a transiting system. The giant planets HIP 109600b, HIP 109384b, and HD 141399c are located in the habitable zone of their host star.
- ID:
- ivo://CDS.VizieR/J/AJ/153/142
- Title:
- Radial velocities of systems hosting sub-Saturns
- Short Name:
- J/AJ/153/142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a Keck/HIRES radial velocity campaign to study four sub-Saturn-sized planets, K2-27b, K2-32b, K2-39b, and K2-108b, with the goal of understanding their masses, orbits, and heavy-element enrichment. The planets have similar sizes (R_P_=4.5-5.5R_{Earth}_), but have dissimilar masses (M_P_=16-60M_{Earth}_), implying a diversity in their core and envelope masses. K2-32b is the least massive (M_P_=16.5+/-2.7M_{Earth}_) and orbits in close proximity to two sub-Neptunes near a 3:2:1 period commensurability. K2-27b and K2-39b are significantly more massive at M_P_=30.9+/-4.6M_{Earth}_ and M_P_=39.8+/-4.4M_{Earth}_, respectively, and show no signs of additional planets. K2-108b is the most massive at M_P_=59.4+/-4.4M_{Earth}_, implying a large reservoir of heavy elements of about {simeq}50M__. Sub-Saturns as a population have a large diversity in planet mass at a given size. They exhibit remarkably little correlation between mass and size; sub-Saturns range from {simeq}6-60M_{Earth}_, regardless of size. We find a strong correlation between planet mass and host star metallicity, suggesting that metal-rich disks form more massive planet cores. The most massive sub-Saturns tend to lack detected companions and have moderately eccentric orbits, perhaps as a result of a previous epoch of dynamical instability. Finally, we observe only a weak correlation between the planet envelope fraction and present-day equilibrium temperature, suggesting that photo-evaporation does not play a dominant role in determining the amount of gas sub-Saturns accrete from their protoplanetary disks.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A144
- Title:
- Radial velocities of 15 targets
- Short Name:
- J/A+A/588/A144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocity planet search surveys of nearby solar-type stars have shown a strong scarcity of brown dwarf companions within ~5AU. There is presently no comprehensive explanation for this lack of brown dwarf companions; therefore, increasing the sample of such objects is crucial to understand their formation and evolution. Based on precise radial velocities obtained using the SOPHIE spectrograph at Observatoire de Haute-Provence we characterise the orbital parameters of 15 companions to solar-type stars and constrain their true mass using astrometric data from the Hipparcos space mission. The nine companions not shown to be stellar in nature have minimum masses ranging from ~13 to 70M_Jup , and are well distributed across the planet/brown dwarf mass regime, making them an important contribution to the known population of massive companions around solar-type stars. We characterise six companions as stellar in nature with masses ranging from a minimum mass of 76+/-4M_Jup_ to a mass of 0.35+/-0.03M_{sun}_. The orbital parameters of two previously known substellar candidates are improved.
- ID:
- ivo://CDS.VizieR/J/A+A/517/L1
- Title:
- Radial velocities of WASP-8b planet
- Short Name:
- J/A+A/517/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of WASP-8, a transiting planet of 2.25+/-0.08M_{jup}_ on a strongly inclined eccentric 8.15-day orbit, moving in a retrograde direction to the rotation of its late-G host star. Evidence is found that the star is in a multiple stellar system with two other companions. The dynamical complexity of the system indicates that it may have experienced secular interactions such as the Kozai mechanism or a formation that differs from the "classical" disc-migration theory.
- ID:
- ivo://CDS.VizieR/J/A+A/524/A25
- Title:
- Radial Velocities on 6 exoplanet host stars
- Short Name:
- J/A+A/524/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle beta between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We found that three of our targets have a projected spin-orbit angle above 90 degrees: WASP-2b: beta=153^+11^_-15_{deg}, WASP-15b: beta=139.6^+5.2^_-4.3_{deg} and WASP-17b: beta=148.5^+5.1^_-4.2_{deg} ; the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0 degrees. There is no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All orbits are close to circular, with only one firm detection of eccentricity on WASP-18b with e=0.00848^+0.00085^_-0.00095_. No long term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of beta and our six, we attempt to statistically determine the distribution of the real spin-orbit angle psi and find that between about 45 and 85% of hot Jupiters have psi>30{deg}. Observations and predictions using the Kozai mechanism match well. If these observational facts are confirmed in the future, we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration. At present, standard disc migration cannot explain the observations without invoking at least another additional process.