This document details the first public data release of the HARPS radial velocities catalog. This data release aims to provide the astronomical community with a catalog of radial velocities obtained ...with spectroscopic observations acquired from 2003 to 2023 with the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrograph installed at the ESO 3.6m telescope in La Silla Observatory (Chile), and spanning wavelengths from 3800 to 6900 Angstrom. The catalog comprises 289843 observations of 6488 unique astronomical objects. Radial velocities reported in this catalog are obtained using the HARPS pipeline, with a typical precision of 0.5 m/s, which is essential for the search and validation of exoplanets. Additionally, independent radial velocities measured on the H\(\alpha\) spectral line are included, with a typical error of around 300 m/s suitable for various astrophysical applications where high precision is not critical. This catalog includes 282294 radial velocities obtained through the HARPS pipeline and 288972 derived from the H\(_\alpha\) line, collectively forming a time-series dataset that provides a historical record of measurements for each object. Further, each object has been cross-referenced with the SIMBAD astronomical database to ensure accurate identification, enabling users to locate and verify objects with existing records in astronomical literature. Information provided for each object includes: astrometric parameters (coordinates, parallaxes, proper motions, radial velocities), photometric parameters (apparent magnitudes in the visible and near-infrared), spectral types and object classifications.
Lunar Occultations with Aqueye+ and Iqueye Zampieri, Luca; Richichi, Andrea; Naletto, Giampiero ...
The Astronomical journal,
11/2019, Letnik:
158, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We report the first-time use of the Aqueye+ and Iqueye instruments to record lunar occultation events. High time resolution recordings in different filters have been acquired for several occultations ...taken from 2016 January through 2018 January with Aqueye+ at the Copernicus telescope and Iqueye at the Galileo telescope in Asiago, Italy. Light curves with different time bins were calculated in post-processing and analyzed using a least-square model-dependent method. A total of nine occultation light curves were recorded, including one star for which we could measure for the first time the size of the chromosphere ( Psc) and one binary star for which discrepant previous determinations existed in the literature (SAO 92922). A disappearance of Alf Tau shows an angular diameter in good agreement with literature values. The other stars were found to be unresolved, at the milliarcsecond level. We discuss the unique properties of Aqueye+ and Iqueye for these kind of observations, namely the simultaneous measurement in up to four different filters thanks to pupil splitting, and the unprecedented time resolution well exceeding the microsecond level. This latter makes Aqueye+ and Iqueye suitable to observe not just occultations by the Moon, but also much faster events such as, e.g., occultations by artificial screens in low orbits. We provide an outlook of future possible observations in this context.
Abstract
We describe a large simulation of the stars to be observed by the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). The simulation is based on the
TRILEGAL
code, which ...resorts to large databases of stellar evolutionary tracks, synthetic spectra, and pulsation models, added to simple prescriptions for the stellar density and star formation histories of the main structures of the Galaxy, to generate mock stellar samples through a population synthesis approach. The main bodies of the Magellanic Clouds are also included. A complete simulation is provided for single stars, down to the
r
= 27.5 mag depth of the coadded Wide–Fast–Deep survey images. A second simulation is provided for a fraction of the binaries, including the interacting ones, as derived with the
BinaPSE
module of
TRILEGAL
. We illustrate the main properties and numbers derived from these simulations, including: comparisons with real star counts; the expected numbers of Cepheids, long-period variables, and eclipsing binaries; the crowding limits as a function of seeing and filter; the star-to-galaxy ratios. Complete catalogs are accessible through the NOIRLab Astro Data Lab, while the stellar density maps are incorporated in the LSST metrics analysis framework.
Abstract
TOI-2202 b is a transiting warm Jovian-mass planet with an orbital period of
P
= 11.91 days identified from the Full Frame Images data of five different sectors of the TESS mission. Ten TESS ...transits of TOI-2202 b combined with three follow-up light curves obtained with the CHAT robotic telescope show strong transit timing variations (TTVs) with an amplitude of about 1.2 hr. Radial velocity follow-up with FEROS, HARPS, and PFS confirms the planetary nature of the transiting candidate (
a
b
= 0.096 ± 0.001 au,
m
b
= 0.98 ± 0.06
M
Jup
), and a dynamical analysis of RVs, transit data, and TTVs points to an outer Saturn-mass companion (
a
c
= 0.155 ± 0.002 au,
m
c
= 0.37 ± 0.10
M
Jup
) near the 2:1 mean motion resonance. Our stellar modeling indicates that TOI-2202 is an early K-type star with a mass of 0.82
M
⊙
, a radius of 0.79
R
⊙
, and solar-like metallicity. The TOI-2202 system is very interesting because of the two warm Jovian-mass planets near the 2:1 mean motion resonance, which is a rare configuration, and their formation and dynamical evolution are still not well understood.
Abstract
TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations ...(TTVs). Precise characterization of the planets’ masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial-velocity measurements using HARPS, FEROS, and the Planet Finder Spectrograph break that degeneracy, and an expanded TTV baseline from TESS and an ongoing ground-based transit observing campaign increase the precision of the mass and eccentricity measurements. We determine that TOI-216c is a warm Jupiter, TOI-216b is an eccentric warm Neptune, and that they librate in 2:1 resonance with a moderate libration amplitude of
deg, a small but significant free eccentricity of
for TOI-216b, and a small but significant mutual inclination of 1.°2–3.°9 (95% confidence interval). The libration amplitude, free eccentricity, and mutual inclination imply a disturbance of TOI-216b before or after resonance capture, perhaps by an undetected third planet.
ABSTRACT
HD 21749 is a bright (V = 8.1 mag) K dwarf at 16 pc known to host an inner terrestrial planet HD 21749c as well as an outer sub-Neptune HD 21749b, both delivered by Transiting Exoplanet ...Survey Satellite (TESS). Follow-up spectroscopic observations measured the mass of HD 21749b to be 22.7 ± 2.2 M⊕ with a density of $7.0^{+1.6}_{-1.3}$ g cm−3, making it one of the densest sub-Neptunes. However, the mass measurement was suspected to be influenced by stellar rotation. Here, we present new high-cadence PFS RV data to disentangle the stellar activity signal from the planetary signal. We find that HD 21749 has a similar rotational time-scale as the planet’s orbital period, and the amplitude of the planetary orbital RV signal is estimated to be similar to that of the stellar activity signal. We perform Gaussian process regression on the photometry and RVs from HARPS and PFS to model the stellar activity signal. Our new models reveal that HD 21749b has a radius of 2.86 ± 0.20 R⊕, an orbital period of 35.6133 ± 0.0005 d with a mass of Mb = 20.0 ± 2.7 M⊕ and a density of $4.8^{+2.0}_{-1.4}$ g cm−3 on an eccentric orbit with e = 0.16 ± 0.06, which is consistent with the most recent values published for this system. HD 21749c has an orbital period of 7.7902 ± 0.0006 d, a radius of 1.13 ± 0.10 R⊕, and a 3σ mass upper limit of 3.5 M⊕. Our Monte Carlo simulations confirm that without properly taking stellar activity signals into account, the mass measurement of HD 21749b is likely to arrive at a significantly underestimated error bar.
Este estudio evalúa distintos métodos de seguimiento de la vegetación en función de los siguientes objetivos: 1) forestal, ligado a la evolución de la carga del combustible vegetal mediante ...parámetros estructurales: cobertura y fitovolumen; 2) conservación, relacionados con la composición florística (riqueza y diversidad); 3) tecnológico, relacionado con la utilización de la teledetección para evaluar parámetros estructurales. En concreto, este trabajo compara diferentes métodos de evaluación de campo y los utiliza para validar el método de teledetección (sensores transportados por un dron) en el estudio de la evolución de la vegetación tras la aplicación de las quemas prescritas y del herbivorismo pírico. Se discuten los resultados obtenidos con cada método y se aportan recomendaciones.
In the course of the selection of the scientific themes for the second and third L-class missions of the Cosmic Vision 2015–2025 program of the European Space Agency, the exploration of the ice giant ...planets Uranus and Neptune was defined “a timely milestone, fully appropriate for an L class mission”. Among the proposed scientific themes, we presented the scientific case of exploring both planets and their satellites in the framework of a single L-class mission and proposed a mission scenario that could allow to achieve this result. In this work we present an updated and more complete discussion of the scientific rationale and of the mission concept for a comparative exploration of the ice giant planets Uranus and Neptune and of their satellite systems with twin spacecraft. The first goal of comparatively studying these two similar yet extremely different systems is to shed new light on the ancient past of the Solar System and on the processes that shaped its formation and evolution. This, in turn, would reveal whether the Solar System and the very diverse extrasolar systems discovered so far all share a common origin or if different environments and mechanisms were responsible for their formation. A space mission to the ice giants would also open up the possibility to use Uranus and Neptune as templates in the study of one of the most abundant type of extrasolar planets in the galaxy. Finally, such a mission would allow a detailed study of the interplanetary and gravitational environments at a range of distances from the Sun poorly covered by direct exploration, improving the constraints on the fundamental theories of gravitation and on the behavior of the solar wind and the interplanetary magnetic field.
•The ice giants Uranus and Neptune and their satellites are unexplored and very diverse.•Uranus and Neptune are templates for the most abundant class of exoplanets.•Comparative exploration of ice giants provides information on Solar System formation.•A mission to ice giants allows the study of general relativity and interplanetary medium.•A L-class mission to both planets and their satellites with twin spacecraft is feasible.
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