- ID:
- ivo://CDS.VizieR/J/AJ/155/114
- Title:
- HAT-TR-318-007: a double-lined M dwarf binary
- Short Name:
- J/AJ/155/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery by the HATNet survey of HAT-TR-318-007, a P=3.34395390+/-0.00000020 day period detached double-lined M dwarf binary with total secondary eclipses. We combine radial velocity (RV) measurements from TRES/FLWO 1.5 m and time-series photometry from HATNet, FLWO 1.2 m, BOS 0.8 m, and NASA K2 Campaign 5, to determine the masses and radii of the component stars: M_A_=0.448+/-0.011 M_{sun}_^N^, M_B_=0.2721_-0.0042_^+0.0041^ M_{sun}_^N^, R_A_=0.4548_-0.0036_^+0.0035^ R_{sun}_^N^, and R_B_=0.2913_-0.0024_^+0.0023^ R_{sun}_^N^. We obtained a FIRE/Magellan near-infrared spectrum of the primary star during a total secondary eclipse, and we use this to obtain disentangled spectra of both components. We determine spectral types of ST_A_=M3.71+/-0.69 and ST_B_=M5.01+/-0.73 and effective temperatures of T_eff,A_=3190+/-110 K and T_eff,B_=3100+/-110 K for the primary and secondary star, respectively. We also measure a metallicity of [Fe/H]=+0.298+/-0.080 for the system. We find that the system has a small, but significant, nonzero eccentricity of 0.0136+/-0.0026. The K2 light curve shows a coherent variation at a period of 3.41315_-0.00032_^+0.00030^ days, which is slightly longer than the orbital period, and which we demonstrate comes from the primary star. We interpret this as the rotation period of the primary. We perform a quantitative comparison between the Dartmouth stellar evolution models and the seven systems, including HAT-TR-318-007, that contain M dwarfs with 0.2 M_{sun}_^N^<M<0.5 M_{sun}_^N^, have metallicity measurements, and have masses and radii determined to better than 5% precision. Discrepancies between the predicted and observed masses and radii are found for three of the systems.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/513/L3
- Title:
- H-band thermal emission of exoplanet WASP-19b
- Short Name:
- J/A+A/513/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital period of only 19 h, and thus, being highly irradiated, is expected to be hot. We measure an H-band occultation depth of (0.259^+0.046^_-0.044_)%, which corresponds to an H-band brightness temperature of T_H_=2580+/-125K. A cloud-free model of the planet's atmosphere, with no redistribution of energy from day-side to night-side, under predicts the planet/star flux density ratio by a factor of two. As the stellar parameters, and thus the level of planetary irradiation, are well-constrained by measurement, it is likely that our model of the planet's atmosphere is too simple.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A5
- Title:
- HD 285507 and AD Leo light and velocity curves
- Short Name:
- J/A+A/638/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The existence of hot Jupiters is still not well understood. Two main channels are thought to be responsible for their current location: a smooth planet migration through the proto-planetary disk or the circularization of an initial high eccentric orbit by tidal dissipation leading to a strong decrease of the semimajor axis. Different formation scenarios result in different observable effects, such as orbital parameters (obliquity/eccentricity), or frequency of planets at different stellar ages. In the context of the GAPS Young-Objects project, we are carrying out a radial velocity survey with the aim to search and characterize young hot-Jupiter planets. Our purpose is to put constraints on evolutionary models and establish statistical properties, such as the frequency of these planets from a homogeneous sample. Since young stars are in general magnetically very active, we performed multi-band (visible and near-infrared) spectroscopy with simultaneous GIANO-B + HARPS-N (GIARPS) observing mode at TNG. This helps to deal with stellar activity and distinguish the nature of radial velocity variations: stellar activity will introduce a wavelength-dependent radial velocity amplitude, whereas a Keplerian signal is achromatic. As a pilot study, we present here the cases of two already claimed hot Jupiters orbiting young stars: HD 285507 b and AD Leo b. Our analysis of simultaneous high-precision GIARPS spectroscopic data confirms the Keplerian nature of HD285507's radial velocities variation and refines the orbital parameters of the hot Jupiter, obtaining an eccentricity consistent with a circular orbit. On the other hand, our analysis does not confirm the signal previously attributed to a planet orbiting AD~Leo. This demonstrates the power of the multi-band spectroscopic technique when observing active stars.
- ID:
- ivo://CDS.VizieR/J/A+A/511/A45
- Title:
- HD 147018, 171238 and 204313 radial velocities
- Short Name:
- J/A+A/511/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of a double planetary system around HD140718 as well as the discovery of two long period and massive planets orbiting HD171238 and HD204313. Those discoveries were made with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope located at La Silla Observatory, Chile. The planetary system orbiting the nearby G9 dwarf HD147018 is composed of an eccentric inner planet (e=0.47) with twice the mass of Jupiter (2.1M_Jup_) and with an orbital period of 44.24-days. The outer planet is even more massive (6.6M_Jup_) with a slightly eccentric orbit (e=0.13) and a period of 1008-days. The planet orbiting HD171238 has a minimum mass of 2.6M_Jup_, a period of 1523-days and an eccentricity of 0.40. It orbits a G8 dwarfs at 2.5AU. The last planet, HD204313 b, is a 4.0 M_Jup_-planet with a period of 5.3-years and has a low eccentricity (e=0.13). It orbits a G5 dwarfs at 3.1AU. The three parent stars are metal rich, which further strengthened the case that massive planets tend to form around metal rich stars.
- ID:
- ivo://CDS.VizieR/J/A+A/375/L27
- Title:
- HD 80606b, a planet on an extremely elongated orbit
- Short Name:
- J/A+A/375/L27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we list the measured equivalent widths we used for estimating the stellar atmospheric parameters of the two components of the visual binary HD 80606-HD 80607. We also list our 61 individual radial velocity measurements for HD 80606. The radial-velocity measurements were obtained using the HIRES spectrograph mounted on the KECK1 10-m Telescope at the KECK Observatory (Hawaii, USA) and the ELODIE spectrograph mounted on the 1.93-m Telescope at Observatoire de Haute-Provence (France). The equivalent widths measurements for HD 80606 and HD 80607 were obtained using two additional high signal-to-noise HIRES spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A60
- Title:
- HD 22496 b ESPRESSO RVs
- Short Name:
- J/A+A/654/A60
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The ESPRESSO spectrograph is a new powerful tool developed to detect and characterize extrasolar planets. Its design allows an unprecedented radial velocity precision (down to a few tens of cm/s) and long-term thermomechanical stability. We present the first stand-alone detection of an extrasolar planet by blind radial velocity search using ESPRESSO; our aim is to show the power of the instrument in characterizing planetary signals at different periodicities in long observing time spans. We used 41 ESPRESSO measurements of HD 22496 obtained within a time span of 895 days with a median photon noise of 18cm/s. A radial velocity analysis was performed to test the presence of planets in the system and to account for the stellar activity of this K5-K7 main-sequence star. For benchmarking and comparison, we attempted the detection with 43 archive HARPS measurements and in this work we compare the results yielded by the two datasets. We also used four TESS sectors to search for transits. We find radial velocity variations compatible with a close-in planet with an orbital period of P=5.09071+/-0.00026 days when simultaneously accounting for the effects of stellar activity on longer timescales (Prot=34.99_-0.53_^+0.58^ days). We characterize the physical and orbital properties of the planet and find a minimum mass of 5.57_-0.68_^+0.73^M_{sun}_, right in the dichotomic regime between rocky and gaseous planets. Although not transiting according to TESS data, if aligned with the stellar spin axis, the absolute mass of the planet must be below 16M_{sun}_. We find no significant evidence for additional signals in the data with semi-amplitudes above 56cm/s at 95% confidence. With a modest set of radial velocity measurements, ESPRESSO is capable of detecting and characterizing low-mass planets and constraining the presence of planets in the habitable zone of K dwarfs down to the rocky-mass regime.
- ID:
- ivo://CDS.VizieR/J/A+A/609/L5
- Title:
- HD147379 b velocity curve
- Short Name:
- J/A+A/609/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V=8.9mag, M=0.58+/-0.08M_{sun}_), a bright M0.0 V star at a distance of 10.7pc, is found to undergo periodic RV variations with a semi-amplitude of K=5.1+/-0.4m/s and a period of P=86.54+/-0.06d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass m_P_sini=25+/-2M_{Earth}_, 1.5 times the mass of Neptune, with an orbital semi-major axis a=0.32au and low eccentricity (e<0.13). HD 147379 b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1d (and its first harmonic), which we attribute to the rotation period of the star.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A93
- Title:
- HD 79211 CARMENES radial velocities
- Short Name:
- J/A+A/637/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on radial velocity time series for two M0.0V stars, GJ 338 B and GJ 338 A, using the CARMENES spectrograph, complemented by ground-telescope photometry from Las Cumbres and Sierra Nevada observatories. We obtained 159 and 70 radial velocity measurements of GJ 338 B and A, respectively, with the CARMENES visible channel between 2016 January and 2018 October. We also compiled additional relative radial velocity measurements from the literature and a collection of astrometric data that cover 200yr of observations to solve for the binary orbit. We found dynamical masses of 0.64+/-0.07M_{sun}_ for GJ338B and 0.69+/-0.07M_{sun}_ for GJ338A. The CARMENES radial velocity periodograms show significant peaks at 16.61+/-0.04d (GJ 338 B) and 16.3+/-3.5d (GJ 338 A), which have counterparts at the same frequencies in CARMENES activity indicators and photometric light curves. We attribute these to stellar rotation. GJ 338 B shows two additional, significant signals at 8.27+/-0.01 and 24.45+/-0.02d, with no obvious counterparts in the stellar activity indices. The former is likely the first harmonic of the star's rotation, while we ascribe the latter to the existence of a super-Earth planet with a minimum mass of 10.27+/-1.47M_{Earth}_ orbiting GJ 338 B.
- ID:
- ivo://CDS.VizieR/J/A+A/603/L5
- Title:
- HD106315c I light curve
- Short Name:
- J/A+A/603/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Space-based transit surveys such as K2 and the Transiting Exoplanets Survey Satellite (TESS) allow the detection of small transiting planets with orbital periods greater than 10 days. Few of these warm Neptunes are currently known around stars bright enough to allow for detailed follow-up observations dedicated to their atmospheric characterization. The 21-day period and 3.95R_Earth_ planet HD106315c has been discovered by K2 based on the observation of two of its transits. We observed HD 106315 using the 1.2m Euler telescope equipped with the EulerCam camera on two occasions to confirm the transit using broadband photometry and refine the planetary period. Based on two observed transits of HD106315c, we detect its ~1mmag transit and obtain a precise measurement of the planetary ephemerides, which are critical for planning further follow-up observations. We used the attained precision together with the predicted yield from the TESS mission to evaluate the potential for ground-based confirmation of Neptune-sized planets found by TESS. We find that one-meter class telescopes on the ground equipped with precise photometers could substantially contribute to the follow-up of 162 TESS candidates orbiting stars with magnitudes of V<14. Of these candidates, 74 planets orbit stars with V<12 and 12 planets orbit V<10, which makes them high-priority objects for atmospheric characterization with high-end instrumentation.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A50
- Title:
- HD 164922 d HARPS-N time series
- Short Name:
- J/A+A/639/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of exoplanetary systems show that a wide variety of architectures are possible. Determining the rate of occurrence of Solar System analogs - with inner terrestrial planets and outer gas giants - is still an open question. In the framework of the Global Architecture of Planetary Systems (GAPS) project we collected more than 300 spectra with HARPS-N at the Telescopio Nazionale Galileo for the bright G9V star HD164922. This target is known to host one gas giant planet in a wide orbit (Pb~1200-days, semi-major axis ~2au) and a Neptune-mass planet with a period Pc~76-days. Our aim was to investigate the presence of additional low-mass companions in the inner region of the system. We compared the radial velocities (RV) and the activity indices derived from the HARPS-N time series to measure the rotation period of the star and used a Gaussian process regression to describe the behaviour of the stellar activity.We exploited this information in a combined model of planetary and stellar activity signals in an RV time-series composed of almost 700 high-precision RVs, both from HARPS-N and literature data. We performed a dynamical analysis to evaluate the stability of the system and the allowed regions for additional potential companions. We performed experiments of injection and recovery of additional planetary signals to gauge the sensitivity thresholds in minimum mass and orbital separation imposed by our data. Thanks to the high sensitivity of the HARPS-N dataset, we detect an additional inner super-Earth with an RV semi-amplitude of 1.3+/-0.2m/s and a minimum mass of m_d_sini=4+/-/1M_{Earth}_. It orbits HD164922 with a period of 12.4580.003 days. We disentangle the planetary signal from activity and measure a stellar rotation period of ~42 days. The dynamical analysis shows the long term stability of the orbits of the three-planet system and allows us to identify the permitted regions for additional planets in the semi-major axis ranges 0.18-0.21au and 0.6-1.4au. The latter partially includes the habitable zone of the system. We did not detect any planet in these regions, down to minimum detectable masses of 5 and 18M_{Earth}_, respectively. A larger region of allowed planets is expected beyond the orbit of planet b, where our sampling rules-out bodies with minimum mass >50MM_{Earth}. The planetary orbital parameters and the location of the snow line suggest that this system has been shaped by a gas disk migration process that halted after its dissipation.
