Context. M-dwarf stars are promising targets for identifying and characterizing potentially habitable planets. K2-3 is a nearby (45 pc), early-type M dwarf hosting three small transiting planets, the ...outermost of which orbits close to the inner edge of the stellar (optimistic) habitable zone. The K2-3 system is well suited for follow-up characterization studies aimed at determining accurate masses and bulk densities of the three planets. Aims. Using a total of 329 radial velocity measurements collected over 2.5 years with the HARPS-N and HARPS spectrographs and a proper treatment of the stellar activity signal, we aim to improve measurements of the masses and bulk densities of the K2-3 planets. We use our results to investigate the physical structure of the planets. Methods. We analysed radial velocity time series extracted with two independent pipelines using Gaussian process regression. We adopted a quasi-periodic kernel to model the stellar magnetic activity jointly with the planetary signals. We used Monte Carlo simulations to investigate the robustness of our mass measurements of K2-3 c and K2-3 d, and to explore how additional high-cadence radial velocity observations might improve these values. Results. Even though the stellar activity component is the strongest signal present in the radial velocity time series, we are able to derive masses for both planet b (Mb = 6.6 ± 1.1 M⊕) and planet c (Mc = 3.1−1.2+1.3 M⊕) $M_{\textrm{c}}=3.1^{+1.3}_{-1.2}$Mc=3.1−1.2+1.3. The Doppler signal from K2-3 d remains undetected, likely because of its low amplitude compared to the radial velocity signal induced by the stellar activity. The closeness of the orbital period of K2-3 d to the stellar rotation period could also make the detection of the planetary signal complicated. Based on our ability to recover injected signals in simulated data, we tentatively estimate the mass of K2-3 d to be Md = 2.7 −0.8+1.2 M⊕ $_{\textrm{-0.8}}^{\textrm{+1.2}}$-0.8+1.2 M⊕. These mass measurements imply that the bulk densities and therefore the interior structures of the three planets may be similar. In particular, the planets may either have small H/He envelopes (<1%) or massive water layers, with a water content ≥50% of their total mass, on top of rocky cores. Placing further constraints on the bulk densities of K2-3 c and d is difficult; in particular, we would not have been able to detect the Doppler signal of K2-3 d even by adopting a semester of intense, high-cadence radial velocity observations with HARPS-N and HARPS.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
55.
The GAPS programme with HARPS-N at TNG Borsa, F.; Scandariato, G.; Rainer, M. ...
Astronomy and astrophysics (Berlin),
6/2015, Volume:
578
Journal Article
Peer reviewed
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FMFMET, NUK, UL, UM, UPUK
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
57.
The GAPS Programme at TNG Mancini, L.; Esposito, M.; Covino, E. ...
Astronomy and astrophysics (Berlin),
08/2022, Volume:
664
Journal Article
Peer reviewed
Open access
Context.
The measurement of the spin-orbit alignment of hot Jupiters, including a range of orbital and physical properties, can provide information about the evolution of the orbits of this special ...class of giant planets.
Aims.
We aim to refine the orbital and physical parameters and determine the sky-projected planet orbital obliquity λ of five eccentric (
e
≅ 0.1–0.3) transiting planetary systems: HAT-P-15, HAT-P-17, HAT-P-21, HAT-P-26, and HAT-P-29, whose parent stars have an effective temperature between 5100 K <
T
eff
< 6200 K. Each of the systems hosts a hot Jupiter, except for HAT-P-26, which hosts a Neptune-mass planet.
Methods.
We observed transit events of these planets with the HARPS-N spectrograph, obtaining high-precision radial velocity measurements that allow us to measure the Rossiter–McLaughlin effect for each of the target systems. We used these new HARPS-N spectra and archival data, including those from
Gaia
, to better characterise the stellar atmospheric parameters. The photometric parameters for four of the hot Jupiters were recalculated using 17 new transit light curves, obtained with an array of medium-class telescopes, and data from the TESS space telescope. HATNet time-series photometric data were checked for the signatures of rotation periods of the target stars and their spin axis inclination.
Results.
From the analysis of the Rossiter-McLaughlin effect, we derived a sky-projected obliquity of
λ
= 13° ± 6°,
λ
= −26.3° ± 6.7°,
λ
= −0.7° ± 12.5°,
λ
= −26° ± 16°, for HAT-P-15 b, HAT-P-17 b, HAT-P-21 b, and HAT-P-29 b, respectively. Based on theoretical considerations, these small values of λ should be of primordial origin, with the possible exception of HAT-P-21. Due to the quality of the data, we were not able to fully constrain λ for HAT-P-26 b, although a prograde orbit is favoured (
λ
= 18
°
± 49
°
). The stellar activity of HAT-P-21 indicates a rotation period of 15.88 ± 0.02 days, which allowed us to determine its true misalignment angle
ψ
= 25° ± 16°. Our new analysis of the physical parameters of the five exoplanetary systems returned values compatible with those existing in the literature. Using TESS and the available transit light curves, we reviewed the orbital ephemeris for the five systems and confirmed that the HAT-P-26 system shows transit timing variations, which may tentatively be attributed to the presence of a third body.
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Polymorphisms in the interleukin-28B are important determinants in the spontaneous and drug-induced control of hepatitis C virus infection.
We assessed the association of rs8099917 and rs12979860 ...polymorphisms with spontaneous viral clearance, severity of liver fibrosis, and response to interferon-monotherapy in 245 thalassemia major patients with hepatitis C virus infection.
Ninety-eight patients (40%) had a spontaneous viral clearance while 147 patients (60%) developed a chronic infection. Spontaneous viral clearance was more frequent among patients with the T/T genotype of rs8099917 polymorphism (OR 2.130; P = 0.008) or C/C genotype of rs12979860 polymorphism (OR 2.425; P = 0.001). During observation, 131 patients with chronic infection underwent a liver biopsy; age (OR 1.058; P = 0.01) G/T or G/G genotypes of rs8099917 polymorphism (OR 3.962; P = 0.001), and C/T or T/T genotypes of rs12979860 polymorphism (OR 3.494; P = 0.005) were associated with severe liver fibrosis, independent of liver iron concentration. Finally, T/T genotype of rs8099917 polymorphism (OR 3.014; P = 0.03) or C/C genotype of rs12979860 polymorphism (OR 3.285; P = 0.01), age (OR 0.902; P = 0.001), female gender (OR 3.418; P = 0.01) and 2 or 3 virus C genotypes (OR 4.700; P=0.007) were independently associated with sustained virological response in 114 patients treated with alpha-interferon. Conclusions Polymorphisms in the interleukin-28B are associated with the control of hepatitis C virus infection in thalassemia major patients, and understanding allelic patterns has an important role in determining prognosis and therapeutic management.
Pigmented villonodular synovitis (PVNS) is a rare pre-malignant disease that require aggressive treatment as surgical synovectomy, eventually followed by radiosynovectomy. Nevertheless, the disease ...often reoccurs after these treatments. To determine the safety and efficacy of intra-articular (IA) TNF-a blockade with etanercept (ETN), before extended arthroscopic synovectomy, in severe PVNS of the knee, two patients, (a 26-year-old man with B27+ undifferentiated spondylarthropathy and a 32-year-old femal with seronegative olygoarthritis), affected by diffuse knee PVNS (diagnosis made by histological examination), resistant to IA corticosteroid injections and to repeated arthroscopic synovectomy, were submitted, after protocol approval by human research committee and patient’s written informed consent to intra-articular etanercept (IA-ETN) treatment with a different dosage schedule: 12.5 mg weekly IA-ETN injection for 4 weeks, followed by extended arthroscopic synovectomy and of 25 mg IA-ETN injection for 4 weeks, respectively. Previous DMARDs treatment was continued in stable appropriate doses. Any adverse events were recorded throughout the study. The following parameters were considered as clinical endpoints: 1) Knee Joint Index (KJI: range 0-14); 2) Thompson index (THI: range 0-9) At the study entry and at the end of follow-up, high frequency ultrasound grey scale synovial thickening (US-ST) was also assessed. No adverse events were observed due to IA-ETN and to arthroscopic synovectomy. Marked improvement of knee disease activity over time and sustained functional recover was obtained. US-ST evaluation before treatment initiation and at the end of follow-up confirmed the regression of knee joint synovial proliferation
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