- ID:
- ivo://CDS.VizieR/J/A+A/633/A133
- Title:
- HD 80653 RV time series
- Short Name:
- J/A+A/633/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ultra-short period (USP) planets are a class of exoplanets with periods shorter than one day. The origin of this sub-population of planets is st ill unclear, with different formation scenarios highly dependent on the composition of the USP planets. A better understanding of this class of exoplanets will, therefore, require an increase in the sample of such planets that have accurate and precise masses and radii, which also includes estimates of the level of irradiation and information about possible companions. Here we report a detailed characterization of a USP planet around the solar-type star HD 80653 = EP 251279430 using the K2 light curve and 108 precise radial velocities obtained with the HARPS-N spectrograph, installed on the Telescopio Nazionale Galileo. From the K2 C16 data, we found one super-Earth planet (Rb=1.613+/-0.071R_{Earth}_) transiting the star on a short-period orbit (Pb=0.719573+/-0.000021d). From our radial velocity measurements, we constrained the mass of HD 80653 b to Mb=5.60+/-0.43M_{Earth}_. We also detected a clear longterm trend in the radial velocity data. We derived the fundamental stellar parameters and determined a radius of R*=1.22+/-0.01R_{sun}_ and mass of M*=1.18+/-0.04M_{sun}_, suggesting that HD 80653 has an age of 2.7+/-1.2Gyr. The bulk density (rho_b_=7.4+/-1.1g/cm^3^) of the planet is consistent with an Earth-like composition of rock and iron and no thick atmosphere. Our analysis of the K2 photometry also suggests hints of a shallow secondary eclipse with a depth of 8.1+/- 3.7ppm. Flux variations along the orbital phase are consistent with zero. The most important contribution might come from the day-side thermal emission from the surface of the planet at T=3480K.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/636/L6
- Title:
- HD 158259 SOPHIE radial velocities
- Short Name:
- J/A+A/636/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the northern hemisphere. As part of this observational program, 290 radial velocity measurements of the 6.4 V magnitude star HD 158259 were obtained. Additionally, TESS photometric measurements of this target are available. We present an analysis of the SOPHIE data and compare our results with the output of the TESS pipeline. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and l_1_ periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact on the planet detection was measured with a new technique. The SOPHIE data support the detection of five planets, each with msini~=6M_{Earth}_, orbiting HD 158259 in 3.4, 5.2, 7.9, 12, and 17.4 days. Though a planetary origin is strongly favored, the 17.4 d signal is classified as a planet candidate due to a slightly lower statistical significance and to its proximity to the expected stellar rotation period. The data also present low frequency variations, most likely originating from a magnetic cycle and instrument systematics. Furthermore, the TESS pipeline reports a significant signal at 2.17 days corresponding to a planet of radius ~=1.2R_{Earth}_. A compatible signal is seen in the radial velocities, which confirms the detection of an additional planet and yields a ~=2M_{Earth}_ mass estimate. We find a system of five planets and a strong candidate near a 3:2 mean motion resonance chain orbiting HD 158259. The planets are found to be outside of the two and three body resonances.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A96
- Title:
- HD189733 spectral variability
- Short Name:
- J/A+A/619/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hot Jupiters are surrounded by extended atmospheres of neutral hydrogen. Observations have provided evidence for in-transit hydrogen H{alpha} absorption as well as variable pre-transit absorption signals. These have been interpreted in terms of a bow shock or an accretion stream that transits the host star before the planet. We test the hypothesis of planetary related H{alpha} absorption by studying the time variability of the H{alpha} and stellar activity-sensitive calcium lines in high-resolution spectra of the planet host HD189733. In the framework of an observing campaign spanning several months, the host star was observed several times per week randomly sampling the orbital phases of the planet. We determine the equivalent width in the H{alpha}, Ca H&K and Ca IRT lines, and subtract stellar rotationally induced activity from the H{alpha} time series via its correlation with the IRT evolution. The residuals are explored for significant differences between the pre-, in-, and out-of-transit phases. We find strong stellar rotational variation with a lifetime of about 20-30 days in all activity indicators, but the corrected H{alpha} time series exhibits no significant periodic variation. We exclude the presence of more than 6.2m{AA}A pre-transit absorption and 5.6m{AA} in-transit absorption in the corrected H{alpha} data at a 99% confidence level. Previously observed H{alpha} absorption signals exceed our upper limits, but they could be related to excited atmospheric states. The H{alpha} variability in the HD189733 system is dominated by stellar activity, and observed signals around the planetary transit may well be caused by short term stellar variability.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A106
- Title:
- HD 284149 SPHERE/IFS spectrum
- Short Name:
- J/A+A/608/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the results of the SPHERE observation of the HD 284149 system, aimed at a more detailed characterisation of both the primary and its brown dwarf companion. We observed HD 284149 in the near-infrared with SPHERE, using the imaging mode (IRDIS+IFS) and the long-slit spectroscopy mode (IRDIS-LSS). The data were reduced using the dedicated SPHERE pipeline, and algorithms such as PCA and TLOCI were applied to reduce the speckle pattern. The IFS images revealed a previously unknown low-mass (~0.16M_{sun}_) stellar companion (HD 294149 B) at ~0.1", compatible with previously observed radial velocity differences, as well as proper motion differences between Gaia and Tycho-2 measurements. The known brown dwarf companion (HD 284149 b) is clearly visible in the IRDIS images. This allowed us to refine both its photometry and astrometry. The analysis of the medium resolution IRDIS long slit spectra also allowed a refinement of temperature and spectral type estimates. A full reassessment of the age and distance of the system was also performed, leading to more precise values of both mass and semi-major axis. As a result of this study, HD 284149 ABb therefore becomes the latest addition to the (short) list of brown dwarfs on wide circumbinary orbits, providing new evidence to support recent claims that object in such configuration occur with a similar frequency to wide companions to single stars.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A140
- Title:
- HD169142 SPHERE images
- Short Name:
- J/A+A/623/A140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Young planets are expected to cause cavities, spirals, and kinematic perturbations in protostellar disks that may be used to infer their presence. However, a clear detection of still-forming planets embedded within gas-rich disks is still rare. HD169142 is a very young Herbig Ae-Be star surrounded by a pre-transitional disk, composed of at least three rings. While claims of sub-stellar objects around this star have been made previously, follow-up studies remain inconclusive. The complex structure of this disk is not yet well understood. We used the high contrast imager SPHERE at ESO Very large Telescope to obtain a sequence of high-resolution, high-contrast images of the immediate surroundings of this star over about three years in the wavelength range 0.95-2.25um. This enables a photometric and astrometric analysis of the structures in the disk. While we were unable to definitively confirm the previous claims of a massive sub-stellar object at 0.1-0.15arcsec from the star, we found both spirals and blobs within the disk. The spiral pattern may be explained as due to the presence of a primary, a secondary, and a tertiary arm excited by a planet of a few Jupiter masses lying along the primary arm, likely in the cavities between the rings. The blobs orbit the star consistently with Keplerian motion, allowing a dynamical determination of the mass of the star. While most of these blobs are located within the rings, we found that one of them lies in the cavity between the rings, along the primary arm of the spiral design. This blob might be due to a planet that might also be responsible for the spiral pattern observed within the rings and for the cavity between the two rings. The planet itself is not detected at short wavelengths, where we only see a dust cloud illuminated by stellar light, but the planetary photosphere might be responsible for the emission observed in the K1 and K2 bands. The mass of this putative planet may be constrained using photometric and dynamical arguments. While uncertainties are large, the mass should be between 1 and 4 Jupiter masses. The brightest blobs are found at the 1:2 resonance with this putative planet.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A68
- Title:
- HD 137496 system discovery
- Short Name:
- J/A+A/657/A68
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Most of the currently known planets are small worlds with radii between that of the Earth and Neptune. The characterization of planets in this regime shows a large diversity in compositions and system architectures, with distributions hinting at a multitude of formation and evolution scenarios. However, many planetary populations, such as high-density planets, are significantly under-sampled limiting our understanding on planet formation and evolution. NCORES is a large observing program conducted on the HARPS high-resolution spectrograph which aims to confirm the planetary status and to measure the masses of small transiting planetary candidates detected by transit photometry surveys in order to constrain their internal composition.Methods.Using photometry from the K2 satellite and radial velocities measured with the HARPS and CORALIE spectrographs, we search for planets around the bright (Vmag=10) and slightly evolved Sun-like star HD 137496. We precisely estimate the stellar parameters, M*=1.035+/-0.022M_{sun}_, R*= 1.587+/-0.028R_{sun}_, Teff=5799+/-61K,together with the chemical composition (e.g. [Fe/H]=-0.027+/-0.040dex) of the slightly evolved star. We detect two planets orbiting HD 137496. The inner planet, HD 137496 b, is a super-Mercury (an Earth-sized planet with the density of Mercury) with a mass of Mb=4.04+/-0.55M_{sun}_), a radius of Rb=1.31^+0.06^_-0.05_R_{sun}_ and a density of {rho}b=10.49^+2.08^_-1.82_g/cm^3^. From interior modeling analysis we find that the planet is composed mainly of iron, with the core representing over 70% of the planet's mass (Mcore/Mtotal=0.73^+0.11^_-0.12_). The outer planet, HD 137496 c, is an eccentric (e=0.477+/-0.004), long period (P=479.9^+1.0^_-1.1_days) giant planet (Mc*sinic=7.66+/-0.11M_{Jup}_) for which we do not detect a transit. HD 137496 b is one of the few super-Mercuries detected to date. The accurate characterization reported here enhances its role as a key target to better understand the formation and evolution of planetary systems. The detection of an eccentric long period giant companion also reinforces the link between the presence of small transiting inner planets and long period gas giants.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A16
- Title:
- HD 2685 TESS photometry
- Short Name:
- J/A+A/625/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the confirmation of a transiting giant planet around the relatively hot (Teff=6801+/-56K) star HD 2685, whose transit signal was detected in Sector 1 data of NASA's TESS mission. We confirmed the planetary nature of the transit signal using Doppler velocimetric measurements with CHIRON, CORALIE, and FEROS, as well as using photometric data obtained with the Chilean-Hungarian Automated Telescope and the Las Cumbres Observatory. From the joint analysis of photometry and radial velocities, we derived the following parameters for HD 2685b: P=4.12688^+0.00005^_-0.00004_-days, e=0.091^+0.039^_-0.047_, M_P_=1.17+/-0.12M_J_, and R_P_=1.44+/-0.05R_J_. This system is a typical example of an inflated transiting hot Jupiter in a low-eccentricity orbit. Based on the apparent visual magnitude (V=9.6mag) of the host star, this is one of the brightest known stars hosting a transiting hot Jupiter, and it is a good example of the upcoming systems that will be detected by TESS during the two-year primary mission. This is also an excellent target for future ground- and space-based atmospheric characterization as well as a good candidate for measuring the projected spin-orbit misalignment angle through the Rossiter-McLaughlin effect.
458. HD 80606 transits
- ID:
- ivo://CDS.VizieR/J/MNRAS/419/2233
- Title:
- HD 80606 transits
- Short Name:
- J/MNRAS/419/2233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observations of HD 80606 using the 10.4-m Gran Telescopio Canarias and the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) tunable filter imager. We acquired very high precision, narrow-band photometry in four bandpasses around the KI absorption feature during the 2010 January transit of HD 80606b and during out-of-transit observations conducted in 2010 January and April. We obtained differential photometric precisions of ~2.08x10^-4^ for the in-transit flux ratio measured at 769.91nm, which probes the KI line core.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A152
- Title:
- HD101584 VLTI/PIONIER images
- Short Name:
- J/A+A/642/A152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observed orbital characteristics of post-asymptotic giant branch (post-AGB) and post-red giant branch (post-RGB) binaries are not understood. We suspect that the missing ingredients to explain them probably lie in the continuous interaction of the central binary with its circumstellar environment. We aim at studying the circumbinary material in these complex systems by investigating the connection between the innermost and large-scale structures. We perform high-angular resolution observations in the near-infrared continuum of HD101584, which has a complex structure as seen at millimeter wavelengths with a disk-like morphology and a bipolar outflow due to an episode of strong binary interaction. To account for the complexity of the target we first perform an image reconstruction and use this result to fit a geometrical model to extract the morphological and thermal features of the environment. The image reveals an unexpected double-ring structure. We interpret the inner ring to be produced by emission from dust located in the plane of the disk and the outer ring to be produced by emission from dust that is located 1.6[D/1kpc] au above the disk plane. The inner ring diameter (3.94[D/1kpc] au), and temperature (T=1540+/-10K) are compatible with the dust sublimation front of the disk. The origin of the out-of-plane ring (with a diameter of 7.39[D/1kpc] au and a temperature of 1014+/-10K) could be due to episodic ejection or a dust condensation front in the outflow. The observed outer ring is possibly linked with the blue-shifted side of the large scale outflow seen by ALMA and is tracing its launching location to the central star. Such observations give morphological constraints on the ejection mechanism. Additional observations are needed to constrain the origin of the out-of-plane structure.
- ID:
- ivo://CDS.VizieR/J/ApJ/832/131
- Title:
- HD 88133 11-yrs radial velocity measurements
- Short Name:
- J/ApJ/832/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We target the thermal emission spectrum of the non-transiting gas giant HD 88133 b with high-resolution near-infrared spectroscopy, by treating the planet and its host star as a spectroscopic binary. For sufficiently deep summed flux observations of the star and planet across multiple epochs, it is possible to resolve the signal of the hot gas giant's atmosphere compared to the brighter stellar spectrum, at a level consistent with the aggregate shot noise of the full data set. To do this, we first perform a principal component analysis to remove the contribution of the Earth's atmosphere to the observed spectra. Then, we use a cross-correlation analysis to tease out the spectra of the host star and HD 88133 b to determine its orbit and identify key sources of atmospheric opacity. In total, six epochs of Keck NIRSPEC L-band observations and three epochs of Keck NIRSPEC K-band observations of the HD 88133 system were obtained. Based on an analysis of the maximum likelihood curves calculated from the multi-epoch cross-correlation of the full data set with two atmospheric models, we report the direct detection of the emission spectrum of the non-transiting exoplanet HD 88133 b and measure a radial projection of the Keplerian orbital velocity of 40+/-15km/s, a true mass of 1.02_-0.28_^+0.61^M_J_, a nearly face-on orbital inclination of 15_-5_^+6^{deg}, and an atmosphere opacity structure at high dispersion dominated by water vapor. This, combined with 11 years of radial velocity measurements of the system, provides the most up-to-date ephemeris for HD 88133.
