- ID:
- ivo://CDS.VizieR/J/A+A/573/L5
- Title:
- Radial velocity data of Kepler-432
- Short Name:
- J/A+A/573/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first disclosure of the planetary nature of Kepler-432 b (aka Kepler object of interest KOI-1299.01). We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By a simultaneous fit of these new data and Kepler photometry, we found that KOI-1299 b is a dense transiting exoplanet, having a mass of Mp=4.87+/-0.48M_Jup_ and radius of Rp=1.120+/-0.036R_Jup_. The planet revolves around a K giant star, ascending the red giant branch, every 52.5d, moving on a highly eccentric orbit with e=0.535+/-0.030. By analysing two NIR high-resolution images, we found that a star occurs at 1:100 from Kepler-432, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, KOI-1299 occupies an almost-desert region of parameter space, which is important to constrain the evolutionary processes of planetary systems.
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- ID:
- ivo://CDS.VizieR/J/A+A/593/A5
- Title:
- Radial velocity fitting challenge dataset
- Short Name:
- J/A+A/593/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar signals are the main limitation for precise radial-velocity (RV) measurements. These signals arise from the photosphere of the stars. The m/s perturbation created by these signals prevents the detection and mass characterization of small-mass planetary candidates such as Earth-twins. Several methods have been proposed to mitigate stellar signals in RV measurements. However, without precisely knowing the stellar and planetary signals in real observations, it is extremely difficult to test the efficiency of these methods. The goal of the RV fitting challenge is to generate simulated RV data including stellar and planetary signals and to perform a blind test within the community to test the efficiency of the different methods proposed to recover planetary signals despite stellar signals. In this first paper, we describe the simulation used to model the measurements of the RV fitting challenge. Each simulated planetary system includes the signals from instrumental noise, stellar oscillations, granulation, supergranulation, stellar activity, and observed and simulated planetary systems. In addition to RV variations, this simulation also models the effects of instrumental noise and stellar signals on activity observables obtained by HARPS-type high-resolution spectrographs, that is, the calcium activity index log(R'HK),and the bisector span and full width at half maximum of the cross-correlation function. We publish the 15 systems used for the RV fitting challenge including the details about the planetary systems that were injected into each of them.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A142
- Title:
- Radial velocity for GJ 1132
- Short Name:
- J/A+A/618/A142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The source GJ1132 is a nearby red dwarf known to host a transiting Earth-size planet. After its initial detection, we pursued an intense follow-up with the HARPS velocimeter. We now confirm the detection of GJ1132b with radial velocities alone. We refined its orbital parameters, and in particular, its mass (m_b_= 1.66+/-0.23M_{sun}_), density ({rho}_b_=6.3+/-1.3g/cm^3^), and eccentricity (e_b_<0.22; 95%). We also detected at least one more planet in the system. GJ1132c is a super-Earth with period P_c_=8.93+/-0.01-days and minimum mass m_c_sini_c_=2.64+/-0.44M_{sun}_. Receiving about 1.9 times more flux than Earth in our solar system, its equilibrium temperature is that of a temperate planet (T_eq_=230-300K for albedos A=0.75-0.00), which places GJ1132c near the inner edge of the so-called habitable zone. Despite an a priori favorable orientation for the system, Spitzer observations reject most transit configurations, leaving a posterior probability <1% that GJ11 32c transits. GJ1132(d) is a third signal with period P_d_=177+/-5-days attributed to either a planet candidate with minimum mass m_d_sini_d_=8.4^+1.7^_-2.5_M_{sun}_ or stellar activity. Its Doppler signal is the most powerful in our HARPS time series but appears on a timescale where either the stellar rotation or a magnetic cycle are viable alternatives to the planet hypothesis. On the one hand, the period is different than that measured for the stellar rotation (~125-days), and a Bayesian statistical analysis we performed with a Markov chain Monte Carlo and Gaussian processes demonstrates that the signal is better described by a Keplerian function than by correlated noise. On the other hand, periodograms of spectral indices sensitive to stellar activity show power excess at similar periods to that of this third signal, and radial velocity shifts induced by stellar activity can also match a Keplerian function. We therefore prefer to leave the status of GJ1132(d) undecided.
- ID:
- ivo://CDS.VizieR/J/A+A/613/A25
- Title:
- Radial velocity for Ross 128
- Short Name:
- J/A+A/613/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- After that a new technique combining high-contrast imaging and high-dispersion spectroscopy successfully detected the atmosphere of a giant planet, it soon became contemplated as one of the most promising avenues to study the atmosphere of Earth-size worlds. With the forthcoming ELTs, it shall gain the angular resolution and sensitivity to even detect O2 in the atmosphere of planets orbiting red dwarfs. This is a strong motivation to make the census of planets around cool stars which habitable zones can be resolved by ELTs, i.e. for M dwarfs within ~5-parsecs. In that context, our HARPS survey is already a major contributor to that sample of nearby planets. Here we report on our radial-velocity observations of Ross 128 (Proxima Virginis, GJ447, HIP 57548), a M4 dwarf just 3.4-parsec away from our Sun. We detect it is host of an exo-Earth with a projected mass m*sini=1.35M_{sun}_ and an orbital period of 9.9-days. Ross 128 b receives ~1.38 as much flux as Earth from the Sun and has an equilibrium temperature between 269K (resp. 213K) for an Earth-like (resp. Venus-like) albedo. According to recent studies, it is located at the inner edge of the so called habitable zone. An 80-day long light curve performed by K2 during campaign C01 excludes Ross 128 b is a transiting planet. Together with ASAS photometry and other activity indices, it argues for a long rotational period and a weak activity which, in the context of habitability, gives a high merit to the detection. Today, Ross 128 b is the second closest known exo-Earth after Proxima Centauri b (1.3 parsec) and the closest known temperate planet around a quiet star. At maximum elongation, the planet-star angular separation of 15 milli-arcsec will be resolved by the ELT (>3{lambda}/D) in all optical bands of O_2_.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A73
- Title:
- Radial Velocity for WASP-54b, WASP-56b and WASP-57b
- Short Name:
- J/A+A/551/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet, and orbits a F9 star, evolving off the main sequence, every 3.69 days. WASP-56b and WASP-57b orbit main sequence stars of spectral type G6 every 4.67 and 2.84 days, respectively. WASP-56b and WASP-57b show no radius anomaly and a high density implying a large core of heavy elements; possibly as high as 50M_Earth_ in the case of WASP-57b. We present the Radial Velocity and line bisector span measurements for the transiting planet host stars WASP-54, WASP-56 and WASP-57.
- ID:
- ivo://CDS.VizieR/J/A+A/576/A48
- Title:
- Radial velocity monitoring for 6 stars
- Short Name:
- J/A+A/576/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe radial-velocity time series obtained by HARPS on the 3.60m telescope in La Silla (ESO, Chile) over ten years and report the discovery of five new giant exoplanets in distant orbits; these new planets orbit the stars HD 564, HD 30669, HD 108341, and BD-11 4672. Their periods range from 492 to 1684-days, semi-major axes range from 1.2 to 2.69AU, and eccentricities range from 0 to 0.85. Their minimum mass ranges from 0.33 to 3.5M_Jup_. We also refine the parameters of two planets announced previously around HD 113538, based on a longer series of measurements. The planets have a period of 663+/-8 and 1818+/-25-days, orbital eccentricities of 0.14+/-0.08 and 0.20+/-0.04, and minimum masses of 0.36+/-0.04 and 0.93+/-0.06M_Jup_. Finally, we report the discovery of a new hot-Jupiter planet around an active star, HD 103720; the planet has a period of 4.5557+/-0.0001-days and a minimum mass of 0.62+/-0.025M_Jup_. We discuss the fundamental parameters of these systems and limitations due to stellar activity in quiet stars with typical 2m/s radial velocity precision.
- ID:
- ivo://CDS.VizieR/J/ApJ/818/34
- Title:
- Radial velocity monitoring of 5 FGK stars
- Short Name:
- J/ApJ/818/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 ({psi}^1^ Dra B) by the McDonald Observatory planet search. The planet HD 95872b has a minimum mass of 4.6M_Jup_ and an orbital semimajor axis of 5.2AU. The giant planet {psi}^1^ Dra Bb has a minimum mass of 1.5M_Jup_ and an orbital semimajor axis of 4.4AU. Both of these planets qualify as Jupiter analogs. These results are based on over one and a half decades of precise radial velocity (RV) measurements collected by our program using the McDonald Observatory Tull Coude spectrograph at the 2.7m Harlan J. Smith Telescope. In the case of {psi}^1^ Dra B we also detect a long-term nonlinear trend in our data that indicates the presence of an additional giant planet, similar to the Jupiter-Saturn pair. The primary of the binary star system, {psi}^1^ Dra A, exhibits a very large amplitude RV variation due to another stellar companion. We detect this additional member using speckle imaging. We also report two cases --HD 10086 and HD 102870 ({beta} Virginis)-- of significant RV variation consistent with the presence of a planet, but that are probably caused by stellar activity, rather than reflexive Keplerian motion. These two cases stress the importance of monitoring the magnetic activity level of a target star, as long-term activity cycles can mimic the presence of a Jupiter-analog planet.
- ID:
- ivo://CDS.VizieR/J/AJ/150/12
- Title:
- Radial velocity of HD 33643
- Short Name:
- J/AJ/150/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of 1.28+/-0.18M_J_, radius of 1.533^+0.046^_-0.047_R_J_, and an orbital period of 2.7347749+/-0.0000039days. The bright host star (HD33643; KELT-7) is an F-star with V=8.54, T_eff_=6789^+50^_-49_K, [Fe/H]=0.139^+0.075^_-0.081_, and logg=4.149+/-0.019. It has a mass of 1.535^+0.066^_-0.054_M_{Sun}_, a radius of 1.732^+0.043^_-0.045_R_{Sun}_, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which Kilodegree Extremely Little Telescope (KELT) has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star (73+/-0.5km/s) results in a Rossiter-McLaughlin effect with an unusually large amplitude of several hundred m/s. We find that the orbit normal of the planet is likely to be well-aligned with the stellar spin axis, with a projected spin-orbit alignment of {lambda}=9.7{deg}+/-5.2{deg}. This is currently the second most rapidly rotating star to have a reflex signal (and thus mass determination) due to a planetary companion measured.
- ID:
- ivo://CDS.VizieR/J/A+A/526/A111
- Title:
- Radial velocity of HD 85390, 90156 and 103197
- Short Name:
- J/A+A/526/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of three new extrasolar planets orbiting the solar type stars HD 85390, HD 90156 and HD 103197 with the HARPS spectrograph mounted on the ESO 3.6-m telescope at La Silla observatory. HD 85390 has a planetary companion with a projected intermediate mass (42.0M_earth_) on a 788-day orbit (a=1.52AU) with an eccentricity of 0.41, for which there is no analogue in the solar system. A drift in the data indicates the presence of another companion on a long period orbit, which is however not covered by our measurements. HD 90156 is orbited by a warm Neptune analogue with a minimum mass of 17.98M_earth_ (1.05M_neptune_), a period of 49.8 days (a=0.25AU) and an eccentricity of 0.31. HD 103197 has an intermediate mass planet on a circular orbit (P=47.8d, Msini=31.2M_earth_). We discuss the formation of planets of intermediate mass (30-100M_earth_) which should be rare inside a few AU according to core accretion formation models.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1085
- Title:
- Radii of exoplanet host stars
- Short Name:
- J/ApJ/694/1085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present interferometric angular sizes for 12 stars with known planetary companions, for comparison with 28 additional main-sequence stars not known to host planets. For all objects we estimate bolometric fluxes and reddenings through spectral-energy distribution (SED) fits, and in conjunction with the angular sizes, measurements of effective temperature. The angular sizes of these stars are sufficiently small that the fundamental resolution limits of our primary instrument, the Palomar Testbed Interferometer, are investigated at the sub-milliarcsecond level and empirically established based upon known performance limits. We demonstrate that the effective temperature scale as a function of dereddened (V-K)0 color is statistically identical for stars with and without planets. Additionally, in an Appendix we provide SED fits for the 166 stars with known planets which have sufficient photometry available in the literature for such fits; this derived "XO-Rad" database includes homogeneous estimates of bolometric flux, reddening, and angular size.