Abstract
We report the confirmation of three exoplanets transiting TOI-4010 (TIC-352682207), a metal-rich K dwarf observed by the Transiting Exoplanet Survey Satellite in Sectors 24, 25, 52, and 58. ...We confirm these planets with the High Accuracy Radial velocity Planet Searcher for the Northern Hemisphere radial velocity observations and measure their masses with 8−12% precision. TOI-4010 b is a sub-Neptune (
P
= 1.3 days,
R
p
=
3.02
−
0.08
+
0.08
R
⊕
,
M
p
=
11.00
−
1.27
+
1.29
M
⊕
) in the hot-Neptune desert, and is one of the few such planets with known companions. Meanwhile, TOI-4010 c (
P
= 5.4 days,
R
p
=
5.93
−
0.12
+
0.11
R
⊕
,
M
p
=
20.31
−
2.11
+
2.13
M
⊕
) and TOI-4010 d (
P
= 14.7 days,
R
p
=
6.18
−
0.14
+
0.15
R
⊕
,
M
p
=
38.15
−
3.22
+
3.27
M
⊕
) are similarly sized sub-Saturns on short-period orbits. Radial velocity observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a long-period, eccentric orbit (
P
∼ 762 days and
e
∼ 0.26 based on available observations). TOI-4010 is one of the few systems with multiple short-period sub-Saturns to be discovered so far.
Context. The space telescope CoRoT searches for transiting extrasolar planets by continuously monitoring the optical flux of thousands of stars in several fields of view. Aims: We report the ...discovery of CoRoT-10b, a giant planet on a highly eccentric orbit (e = 0.53 ± 0.04) revolving in 13.24 days around a faint (V = 15.22) metal-rich K1V star. Methods: We used CoRoT photometry, radial velocity observations taken with the HARPS spectrograph, and UVES spectra of the parent star to derive the orbital, stellar, and planetary parameters. Results: We derive a radius of the planet of 0.97 ± 0.07 RSUBJup/SUB and a mass of 2.75 ± 0.16 MSUBJup/SUB. The bulk density, ρSUBp/SUB = 3.70 ± 0.83 g cmSUP-3/SUP, is ~2.8 that of Jupiter. The core of CoRoT-10b could contain up to 240 M_⊕ of heavy elements. Moving along its eccentric orbit, the planet experiences a 10.6-fold variation in insolation. Owing to the long circularisation time, τSUBcirc/SUB > 7 Gyr, a resonant perturber is not required to excite and maintain the high eccentricity of CoRoT-10b. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain.
We performed an intensive radial velocity monitoring of XO-2S, the wide companion of the transiting planet-host XO-2N, using HARPS-N at TNG in the framework of the GAPS programme. The radial velocity ...measurements indicate the presence of a new planetary system formed by a planet that is slightly more massive than Jupiter at 0.48 au and a Saturn-mass planet at 0.13 au. Both planetary orbits are moderately eccentric and were found to be dynamically stable. There are also indications of a long-term trend in the radial velocities. This is the first confirmed case of a wide binary whose components both host planets, one of which is transiting, which makes the XO-2 system a unique laboratory for understanding the diversity of planetary systems.
The majority of extra-solar planets have been discovered (or confirmed after follow-up) through radial-velocity (RV) surveys. Using ground-based spectrographs such as High Accuracy Radial Velocity ...Planetary Search (HARPS) and HARPS-North, it is now possible to detect planets that are only a few times the mass of the Earth. However, the presence of dark spots on the stellar surface produces RV signals that are very similar in amplitude to those caused by orbiting low-mass planets. Disentangling these signals has thus become the biggest challenge in the detection of Earth-mass planets using RV surveys. To do so, we use the star's lightcurve to model the RV variations produced by spots. Here we present this method and show the results of its application to CoRoT-7.
The GAPS programme with HARPS-N at TNG Desidera, S; Sozzetti, A; Bonomo, A S ...
Astronomy and astrophysics (Berlin),
06/2013, Letnik:
554
Journal Article
Recenzirano
Odprti dostop
In the context of the programme Global Architecture of Planetary Systems (GAPS), we have performed radial velocity monitoring of the metal-poor star HIP 11952 on 35 nights during about 150 days using ...the newly installed high-resolution spectrograph HARPS-N at the TNG and HARPS at the ESO 3.6 m telescope. The radial velocities show a scatter of 7 m s super(-1) compatible with the measurement errors for such a moderately warm metal-poor star (T sub(eff) = 6040 + or - 120 K; Fe/H = -1.9 + or - 0.1). We exclude the presence of the two giant planets with periods of 6.95 + or - 0.01 d and 290.0 + or - 16.2 d and radial velocity semi-amplitudes of 100.3 + or - 19.4 m s super(-1) and 105.2 + or - 14.7 m s super(-1) respectively, which have recently been announced. This result is important because HIP 11952 was thought to be the most metal-poor star hosting a planetary system with giant planets, which challenged some models of planet formation.
Context. An accurate characterization of the known exoplanet population is key to understanding the origin and evolution of planetary systems. Determining true planetary masses through the radial ...velocity (RV) method is expected to experience a great improvement thanks to the availability of ultra-stable echelle spectrographs. Aims. We took advantage of the extreme precision of the new-generation echelle spectrograph ESPRESSO to characterize the transiting planetary system orbiting the G2V star K2-38 located at 194 pc from the Sun with V ~ 11.4. This system is particularly interesting because it could contain the densest planet detected to date. Methods. We carried out a photometric analysis of the available K2 photometric light curve of this star to measure the radius of its two known planets, K2-38b and K2-38c, with Pb = 4.01593 ± 0.00050 d and Pc = 10.56103 ± 0.00090 d, respectively. Using 43 ESPRESSO high-precision RV measurements taken over the course of 8 months along with the 14 previously published HIRES RV measurements, we modeled the orbits of the two planets through a Markov chain Monte Carlo analysis, significantly improving their mass measurements. Results. Using ESPRESSO spectra, we derived the stellar parameters, Teff = 5731 ± 66, log g = 4.38 ± 0.11 dex, and Fe/H = 0.26 ± 0.05 dex, and thus the mass and radius of K2-38, M⋆ = 1.03−0.02+0.04 M⊕ and R⋆ = 1.06−0.06+0.09 R⊕. We determine new values for the planetary properties of both planets. We characterize K2-38b as a super-Earth with RP = 1.54 ± 0.14 R⊕ and Mp = 7.3−1.0+1.1 M⊕, and K2-38c as a sub-Neptune with RP = 2.29 ± 0.26 R⊕ and Mp = 8.3−1.3+1.3 M⊕. Combining the radius and mass measurements, we derived a mean density of ρp = 11.0−2.8+4.1 g cm−3 for K2-38b and ρp = 3.8−1.1+1.8 g cm−3 for K2-38c, confirming K2-38b as one of the densest planets known to date. Conclusions. The best description for the composition of K2-38b comes from an iron-rich Mercury-like model, while K2-38c is better described by a rocky-model with H2 envelope. The maximum collision stripping boundary shows how giant impacts could be the cause for the high density of K2-38b. The irradiation received by each planet places them on opposite sides of the radius valley. We find evidence of a long-period signal in the RV time-series whose origin could be linked to a 0.25–3 MJ planet or stellar activity.
The GAPS programme with HARPS-N at TNG Covino, E.; Esposito, M.; Barbieri, M. ...
Astronomy and astrophysics (Berlin),
06/2013, Letnik:
554
Journal Article
Recenzirano
Odprti dostop
Context. Our understanding of the formation and evolution of planetary systems is still fragmentary because most of the current data provide limited information about the orbital structure and ...dynamics of these systems. The knowledge of the orbital properties for a variety of systems and at different ages yields information on planet migration and on star-planet tidal interaction mechanisms. Aims. In this context, a long-term, multi-purpose, observational programme has started with HARPS-N at TNG and aims to characterise the global architectural properties of exoplanetary systems. The goal of this first paper is to fully characterise the orbital properties of the transiting system Qatar-1 as well as the physical properties of the star and the planet. Methods. We exploit HARPS-N high-precision radial velocity measurements obtained during a transit to measure the Rossiter-McLaughlin effect in the Qatar-1 system, and out-of-transit measurements to redetermine the spectroscopic orbit. New photometric-transit light-curves were analysed and a spectroscopic characterisation of the host star atmospheric parameters was performed based on various methods (line equivalent width ratios, spectral synthesis, spectral energy distribution). Results. We achieved a significant improvement in the accuracy of the orbital parameters and derived the spin-orbit alignment of the system; this information, combined with the spectroscopic determination of the host star properties (rotation, Teff, log g, metallicity), allows us to derive the fundamental physical parameters for star and planet (masses and radii). The orbital solution for the Qatar-1 system is consistent with a circular orbit and the system presents a sky-projected obliquity of λ = − 8.4 ± 7.1 deg. The planet, with a mass of 1.33 ± 0.05 MJ, is found to be significantly more massive than previously reported. The host star is confirmed to be metal-rich (Fe/H = 0.20 ± 0.10) and slowly rotating (vsinI = 1.7 ± 0.3 km s-1), though moderately active, as indicated by the strong chromospheric emission in the Ca ii H&K line cores (log R'HK ≈ -4.60). Conclusions. We find that the system is well aligned and fits well within the general λ versus Teff trend. We can definitely rule out any significant orbital eccentricity. The evolutionary status of the system is inferred based on gyrochronology, and the present orbital configuration and timescale for orbital decay are discussed in terms of star-planet tidal interactions.
Simulations of frames from existing and upcoming high-resolution spectrographs, targeted for high accuracy radial velocity measurements, are computationally demanding (both in time and space). We ...present in this paper an innovative approach based on both parallelization and distribution of the workload. By using NVIDIA CUDA custom-made kernels and state-of-the-art cloud-computing architectures in a Platform as a Service (PaaS) approach, we implemented a modular and scalable end-to-end simulator that is able to render synthetic frames with an accuracy of the order of few cm/sec, while keeping the computational time low. We applied our approach to two spectrographs. For VLT-ESPRESSO we give a sound comparison between the actual data and the simulations showing the obtained spectral formats and the recovered instrumental profile. We also simulate data for the upcoming HIRES at the ELT and investigate the overall performance in terms of computational time and scalability against the size of the problem. In addition we demonstrate the interface with data-reduction systems and we preliminary show that the data can be reduced successfully by existing methods.
The PRIAMO study is a cross-sectional longitudinal observational study aimed at describing epidemiology and evolution of non-motor symptoms (NMS) in patients with different forms of parkinsonism ...recruited in 55 Italian centres and evaluated over 24 months. In this paper, we are reporting prevalence and clinical characteristics of NMS in patients with atypical and secondary parkinsonism. Out of 1307 consecutive patients with a diagnosis of parkinsonism, 83 patients had vascular parkinsonism (VP), 34 had multiple system atrophy (MSA), 30 had progressive supranuclear palsy (PSP), 14 had dementia with Lewy bodies (DLB) and 11 had corticobasal degeneration (CBD). MSA and DLB had the highest number of NMS domains and symptoms, respectively. Gastrointestinal symptoms, pain, urinary problems and postural instability due to orthostatic hypotension were most frequent in MSA. Sleep disturbances were also common with a prevalence of approximately 70% in all diagnostic groups but CBD (36%). Psychiatric symptoms and attention and memory impairment were frequently observed in all diagnoses but were most prevalent among DLB patients, whereas the prevalence of skin and respiratory disorders was rather low in all forms, ranging between 10 and 30%. Atypical parkinsonism patients also reported a low QoL, with no significant differences among the different forms, whereas PD and VP patients had a better QoL.
Simulations of frames from existing and upcoming high-resolution spectrographs, targeted for high accuracy radial velocity measurements, are computationally demanding (both in time and space). We ...present in this paper an innovative approach based on both parallelization and distribution of the workload. By using NVIDIA CUDA custom-made kernels and state-of-the-art cloud-computing architectures in a Platform as a Service (PaaS) approach, we implemented a modular and scalable end-to-end simulator that is able to render synthetic frames with an accuracy of the order of few cm/sec, while keeping the computational time low. We applied our approach to two spectrographs. For VLT-ESPRESSO we give a sound comparison between the actual data and the simulations showing the obtained spectral formats and the recovered instrumental profile. We also simulate data for the upcoming HIRES at the ELT and investigate the overall performance in terms of computational time and scalability against the size of the problem. In addition we demonstrate the interface with data-reduction systems and we preliminary show that the data can be reduced successfully by existing methods.
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