Nowadays, treatment of metastatic breast cancer (MBC) has been enriched with novel therapeutical strategies. Metronomic chemotherapy (mCHT) is a continuous and frequent administration of chemotherapy ...at a lower dose and so whit less toxicity. Thus, this strategy could be attractive for elderly MBC patients. Aim of this analysis is to provide insights into mCHT's activity in a real-life setting of elderly MBC patients. Data of patients ≥ 75 years old included in VICTOR-6 study were analyzed. VICTOR-6 is a multicentre, Italian, retrospective study, which collected data on mCHT in MBC patients treated between 2011 and 2016. A total of 112 patients were included. At the beginning of mCHT, median age was 81 years (75-98) and in 33% of the patients mCHT was the first line choice. Overall Response Rate (ORR) and Disease Control Rate (DCR) were 27.9% and 79.3%, respectively. Median PFS ranged between 7.6 and 9.1 months, OS between 14.1 and 18.5 months. The most relevant toxicity was the hematological one (24.1%); severe toxicity (grade 3-4) ranged from 0.9% for skin toxicity up to 8% for hematologic one. This is a large study about mCHT in elderly MBC patients, providing insights to be further investigated in this subgroup of frail patients.
ABSTRACT
Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterization of the planetary system orbiting the late G dwarf TOI-561. After the identification of three ...transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm−3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.
State-of-the-art radial-velocity (RV) exoplanet searches are currently limited by RV signals arising from stellar magnetic activity. We analyze solar observations acquired over a 3 yr period during ...the decline of Carrington Cycle 24 to test models of RV variation of Sun-like stars. A purpose-built solar telescope at the High Accuracy Radial-velocity Planet Searcher for the Northern hemisphere (HARPS-N) provides disk-integrated solar spectra, from which we extract RVs and log R HK ′ . The Solar Dynamics Observatory (SDO) provides disk-resolved images of magnetic activity. The Solar Radiation and Climate Experiment (SORCE) provides near-continuous solar photometry, analogous to a Kepler light curve. We verify that the SORCE photometry and HARPS-N log R HK ′ correlate strongly with the SDO-derived magnetic filling factor, while the HARPS-N RV variations do not. To explain this discrepancy, we test existing models of RV variations. We estimate the contributions of the suppression of convective blueshift and the rotational imbalance due to brightness inhomogeneities to the observed HARPS-N RVs. We investigate the time variation of these contributions over several rotation periods, and how these contributions depend on the area of active regions. We find that magnetic active regions smaller than 60 Mm2 do not significantly suppress convective blueshift. Our area-dependent model reduces the amplitude of activity-induced RV variations by a factor of two. The present study highlights the need to identify a proxy that correlates specifically with large, bright magnetic regions on the surfaces of exoplanet-hosting stars.
To understand the formation and evolution of solar-type stars in the solar neighborhood, we need to measure their stellar parameters to high accuracy. We present a catalogue of accurate stellar ...parameters for 451 stars that represent the HARPS Guaranteed Time Observations (GTO) "high precision" sample. Spectroscopic stellar parameters were measured using high signal-to-noise (S / N) spectra acquired with the HARPS spectrograph. The spectroscopic analysis was completed assuming LTE with a grid of Kurucz atmosphere models and the recent ARES code for measuring line equivalent widths. We show that our results agree well with those ones presented in the literature (for stars in common). We present a useful calibration for the effective temperature as a function of the index color B-V and Fe/H. We use our results to study the metallicity-planet correlation, namely for very low mass planets. The results presented here suggest that in contrast to their jovian couterparts, neptune-like planets do not form preferentially around metal- rich stars. The ratio of jupiter-to-neptunes is also an increasing function of stellar metallicity. These results are discussed in the context of the core-accretion model for planet formation.
We report on new transit photometry for the super-Earth 55 Cnc e obtained with Warm Spitzer/IRAC at 4.5 μm. An individual analysis of these new data leads to a planet radius of ...\hbox{$2.21_{-0.16}^{+0.15}$}2.21-0.16+0.15 R⊕, which agrees well with the values previously derived from the MOST and Spitzer transit discovery data. A global analysis of both Spitzer transit time-series improves the precision on the radius of the planet at 4.5 μm to 2.20 ± 0.12 R⊕. We also performed an independent analysis of the MOST data, paying particular attention to the influence of the systematic effects of instrumental origin on the derived parameters and errors by including them in a global model instead of performing a preliminary detrending-filtering processing. We deduce an optical planet radius of 2.04 ± 0.15 R⊕ from this reanalysis of MOST data, which is consistent with the previous MOST result and with our Spitzer infrared radius. Assuming the achromaticity of the transit depth, we performed a global analysis combining Spitzer and MOST data that results in a planet radius of 2.17 ± 0.10 R⊕ (13 820 ± 620 km). These results point to 55 Cnc e having a gaseous envelope overlying a rocky nucleus, in agreement with previous works. A plausible composition for the envelope is water which would be in super-critical form given the equilibrium temperature of the planet.
ABSTRACT We report the discovery of three new transiting hot Jupiters by WASP-South together with the TRAPPIST photometer and the Euler/CORALIE spectrograph. WASP-74b orbits a star of V = 9.7, making ...it one of the brighter systems accessible to southern telescopes. It is a 0.95MJup planet with a moderately bloated radius of 1.5 in a 2 day orbit around a slightly evolved F9 star. WASP-83b is a Saturn-mass planet at 0.3 with a radius of 1.0 . It is in a 5 day orbit around a fainter (V = 12.9) G8 star. WASP-89b is a 6 MJup planet in a 3 day orbit with an eccentricity of e = 0.2. It is thus similar to massive, eccentric planets such as XO-3b and HAT-P-2b, except that those planets orbit F stars whereas WASP-89 is a K star. The V = 13.1 host star is magnetically active, showing a rotation period of 20.2 days, while star spots are visible in the transits. There are indications that the planet's orbit is aligned with the stellar spin. WASP-89 is a good target for an extensive study of transits of star spots.
Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with ...time, making it hard to distinguish between models. The obliquity of an orbit with respect to the stellar rotation axis is thought to be more stable than other parameters such as eccentricity. Most planets, to date, appear aligned with the stellar rotation axis; the few misaligned planets so far detected are massive (\textgreater2 M-J). Aims. Our goal is to measure the degree of alignment between planetary orbits and stellar spin axes, to search for potential correlations with eccentricity or other planetary parameters and to measure long term radial velocity variability indicating the presence of other bodies in the system. Methods. For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle beta between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We used a combined analysis of photometry and radial velocities, fitting model parameters with the Markov Chain Monte Carlo method. After obtaining beta we attempt to statistically determine the stribution of the real spin-orbit angle psi. Results. We found that three of our targets have beta above 90 degrees: WASP-2b: beta = 153 degrees(+11)(-15), WASP-15b: beta = 139.6 degrees(+5.2)(-4.3) and WASP-17b: beta = 148.5 degrees(+5.1)(-4.2); the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0 degrees. We find no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All six orbits are close to circular, with only one firm detection of eccentricity e = 0.00848(-0.00095)(+0.00085) in WASP-18b. No long-term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of beta and our six and transforming them into a distribution of psi we find that between about 45 and 85% of hot Jupiters have psi \textgreater 30 degrees. Conclusions. Most hot Jupiters are misaligned, with a large variety of spin-orbit angles. We find observations and predictions using the Kozai mechanism match well. If these observational facts are confirmed in the future, we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration. At present, standard disc migration cannot explain the observations without invoking at least another additional process.
We present new measurements of the projected spin-orbit angle lambda for six WASP hot Jupiters, four of which are new to the literature (WASP-61, -62, -76, and -78), and two of which are new analyses ...of previously measured systems using new data (WASP-71, and -79). We use three different models based on two different techniques: radial velocity measurements of the Rossiter-McLaughlin effect, and Doppler tomography. Our comparison of the different models reveals that they produce projected stellar rotation velocities (v sin I sub( s)) measurements often in disagreement with each other and with estimates obtained from spectral line broadening. The Boue model for the Rossiter-McLaughlin effect consistently underestimates the value of v sin I sub( s) compared to the Hirano model. Although v sin I sub( s) differed, the effect on lambda was small for our sample, with all three methods producing values in agreement with each other. Using Doppler tomography, we find that WASP-61 b ( lambda =4 degree . 0 +...), WASP-71 b ( lambda =-1 degree . 9 +...), and WASP-78 b ( lambda = -6. degree 4 plus or minus 5.9) are aligned. WASP-62 b ( lambda =19 degree . 4 +...) is found to be slightly misaligned, while WASP-79 b ( lambda =-95 degree .2 +...) is confirmed to be strongly misaligned and has a retrograde orbit. We explore a range of possibilities for the orbit of WASP-76 b, finding that the orbit is likely to be strongly misaligned in the positive lambda direction. (ProQuest: ... denotes formulae/symbols omitted.)
The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from ...which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only ∼0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 MJup), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 106, as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.
Abstract
The time-variable velocity fields of solar-type stars limit the precision of radial-velocity determinations of their planets’ masses, obstructing detection of Earth twins. Since 2015 July, ...we have been monitoring disc-integrated sunlight in daytime using a purpose-built solar telescope and fibre feed to the HARPS-N stellar radial-velocity spectrometer. We present and analyse the solar radial-velocity measurements and cross-correlation function (CCF) parameters obtained in the first 3 yr of observation, interpreting them in the context of spatially resolved solar observations. We describe a Bayesian mixture-model approach to automated data-quality monitoring. We provide dynamical and daily differential-extinction corrections to place the radial velocities in the heliocentric reference frame, and the CCF shape parameters in the sidereal frame. We achieve a photon-noise-limited radial-velocity precision better than 0.43 m s−1 per 5-min observation. The day-to-day precision is limited by zero-point calibration uncertainty with an RMS scatter of about 0.4 m s−1. We find significant signals from granulation and solar activity. Within a day, granulation noise dominates, with an amplitude of about 0.4 m s−1 and an autocorrelation half-life of 15 min. On longer time-scales, activity dominates. Sunspot groups broaden the CCF as they cross the solar disc. Facular regions temporarily reduce the intrinsic asymmetry of the CCF. The radial-velocity increase that accompanies an active-region passage has a typical amplitude of 5 m s−1 and is correlated with the line asymmetry, but leads it by 3 d. Spectral line-shape variability thus shows promise as a proxy for recovering the true radial velocity.
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