B. E. Morgado
A5012234014- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Space Exploration and Technology
- Astronomy and Astrophysical Research
- Geomagnetism and Paleomagnetism Studies
- Geology and Paleoclimatology Research
- Historical Astronomy and Related Studies
- Ionosphere and magnetosphere dynamics
- Mathematics and Applications
- Geological and Geochemical Analysis
- Aviation History and Innovations
- Astronomical and nuclear sciences
- Atmospheric and Environmental Gas Dynamics
- Geological and Geophysical Studies
- Advanced Mathematical Theories and Applications
- Geometry and complex manifolds
- Calibration and Measurement Techniques
- Geometric and Algebraic Topology
Laboratório Interinstitucional de e-Astronomia
2018-2025
Valongo Observatory
2015-2025
Universidade Federal do Rio de Janeiro
2014-2025
National Observatory
2016-2024
Délégation Paris 7
2020-2022
Sorbonne Paris Cité
2020-2022
Université Paris Sciences et Lettres
2020-2022
Université de Versailles Saint-Quentin-en-Yvelines
2020-2022
Sorbonne Université
2020-2022
Université Paris Cité
2020-2022
Abstract The physical and orbital parameters of trans-Neptunian objects provide valuable information about the solar system’s formation evolution. In particular, characterization binaries provides insights into mechanisms that may be playing a role at such large distances from Sun. Studies show two distinct populations, (38628) Huya occupies an intermediate position between unequal-sized those with components roughly equal sizes. this work, we predicted observed three stellar occultation...
Jupiter Trojans preserve primitive formation characteristics owing to their collisionless, stable orbits. Determination of shapes and size-frequency distribution helps constrain the collisional evolution parent population, which also originated Kuiper Belt. We started a programme find precise sizes/shapes for Trojans, combining stellar occultations Database Asteroid Models from Inversion Techniques (DAMIT) three-dimensional shape models. report results Diomedes, by fitting its unit...
Quaoar is a classical Trans-Neptunian Object (TNO) with an area equivalent diameter of 1,100 km and orbital semi-major axis 43.3 astronomical units. Based on stellar occultations observed between 2018 2021, inhomogeneous ring (Q1R, Quaoar's first ring) was detected around this body. Aims. A new occultation by August 9th, 2022 aiming to improve shape models the physical parameters Q1R while searching for additional material Methods. The provided nine effective chords across Quaoar, pinning...
Comets offer valuable insights into the early Solar System's conditions and processes. Stellar occultations enable detailed study of cometary nuclei typically hidden by their coma. Observing star's light passing through coma helps infer dust's optical depth near nucleus determine dust opacity detection limits. 29P/Schwassmann-Wachmann 1, a Centaur with diameter approximately 60 km, lies in region transitioning from Centaurs to Jupiter-family comets. Our presents first-ever observed...
In 2013, a stellar occultation revealed the presence of ring system around Centaur Chariklo, marking first discovery such feature on small body. Subsequent observations indicated that main exhibits not only radial density variations but also changes in width depending longitude. this study, we propose method to determine longitude (within an inertial reference frame) and orbital radius each point detected during occultations. addition, provide descriptive analysis ring’s identify combination...
We were able to accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on December 15, 2022. The Kottamia Astronomical Observatory in Egypt did not detect solid body, but we found three extinction features light curve that had symmetrical counterparts with respect central time occultation. One is broad shallow, whereas other two are sharper, maximum ∼25% at achieved spatial resolution 19 km per data point. From Wise Israel, detected caused main...
The stellar occultation technique provides competitive accuracy in determining the sizes, shapes, astrometry, etc., of occulting body, comparable to in-situ observations by spacecraft. With increase number known Solar System objects expected from LSST, highly precise astrometric catalogues, such as Gaia, and improvement ephemerides, occultations will become more common with a higher chords each observation. In context Big Data era, we developed SORA, an open-source python library reduce...
The physical and orbital parameters of Trans-Neptunian Objects (TNOs) provide valuable information about the Solar System's formation evolution. In particular, characterization binaries provides insights into mechanisms that may be playing a role at such large distances from Sun. Studies show two distinct populations, (38628) Huya occupies an intermediate position between unequal-size those with components roughly equal sizes. this work, we predicted observed three stellar occultation events...
The Square Kilometre Array (SKA) Observatory is gearing up the formal construction of its two radio interferometers in Australia and South Africa after end design pre-construction phases. Agile methodologies, Cloud native Computing technologies DevOps software ideas are influencing compute infrastructures that will be key to reduce operational costs SKA while improving control monitoring antennas ancillary systems, Correlators, HPC facilities or related data centre tiered systems. These...
We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo's size shape, the ring reflectivity. consider four possible models for Chariklo (sphere, Maclaurin spheroid, tri-axial ellipsoid Jacobi ellipsoid) we a Bayesian approach estimate corresponding parameters. The spherical model has radius $R=129\pm3$ km. equatorial polar radii $a=b=143^{+3}_{-6}$ km $c=96^{+14}_{-4}$ km, respectively, with density $970^{+300}_{-180}$ kg m$^{-3}$. ellipsoidal semiaxes...
Context. Pluto's tenuous nitrogen (N2) atmosphere undergoes strong seasonal effects due to high obliquity and orbital eccentricity, has been recently (July 2015) observed by the New Horizons spacecraft. Goals are (i) construct a well calibrated record of evolution surface pressure on Pluto (ii) constrain structure lower using central flash in 2015. Method: eleven stellar occultations between 2002 2016 used retrieve atmospheric profiles (density, pressure, temperature) $\sim$5 km $\sim$380...
After the discovery of rings around largest known Centaur object, (10199) Chariklo, we carried out observation campaigns stellar occultations produced by second-largest (2060) Chiron, to better characterize its physical properties and presence material on surroundings. We predicted successfully observed two Chiron. These observations were used constrain size shape fitting elliptical limbs with equivalent surface radii in agreement radiometric measurements. Constraints Chiron are reported for...
A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves this event, 42 of which yielded a central flash detection. aimed at constraining Triton's atmospheric structure seasonal variations its pressure since Voyager 2 epoch (1989). also shape lower atmosphere analysis. used Abel inversions direct ray-tracing code to provide density, pressure, temperature profiles in altitude range $\sim$8 km...
Context. In about 2000, the south pole of Triton experienced an extreme summer solstice that occurs every ∼650 years, when subsolar latitude reached 50°S. Bracketing this epoch, a few occultations probed atmosphere in 1989, 1995, 1997, 2008, and 2017. A recent ground-based stellar occultation observed on 6 October 2022 provides new measurement atmospheric pressure Triton. This is presented here. Aims. The goal to constrain volatile transport models (VTMs) atmosphere. basically vapor...
Context. The physical characterization of trans-Neptunian objects is essential for improving our understanding the formation and evolution Solar System. Stellar occultation a ground-based technique that can be successfully used to determine some TNOs’ fundamental properties with high precision, such as size shape. Aims. This work aimed at constraining size, shape, geometric albedo dwarf planet candidate (307261) 2002 MS 4 through analysis nine stellar events. Using multichord detection, we...
The irregular satellites of the giant planets are believed to have been captured during evolution solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from how were captured. best way obtain these parameters observations in situ by spacecrafts or stellar occultations objects. Both techniques demand that orbits well known. We aimed good astrometric positions improve ephemeris. identified reduced several three...
Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, their physical properties have invaluable information for evolutionary theories. Stellar occultation is a ground-based method studying these small bodies has presented exciting results. These observations can provide precise profiles the involved body, allowing an accurate determination its size shape. The goal to show that even single-chord detections TNOs allow us measure milliarcsecond astrometric...
Within our international program to obtain accurate physical properties of trans-Neptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya star Gaia DR2 4352760586390566400 (mG = 11.5 mag.) for March 18, 2019. After an extensive observational campaign, updated prediction and it turned out be favorable central Europe. Therefore, mobilized half hundred professional amateur astronomers, was finally detected from 21 telescopes located at 18 sites. This makes event one...
During the 2014–2015 mutual events season, Institut de Mécanique Céleste et Calcul des Éphémérides (IMCCE), Paris, France, and Sternberg Astronomical Institute (SAI), Moscow, Russia, led an international observation campaign to record ground-based photometric observations of Galilean moon occultations eclipses. We focused on processing complete data base compute new accurate astrometric positions. used our method derive positions from light curves events. developed model eclipses, while...
Typically we can deliver astrometric positions of natural satellites with errors in the 50–150 mas range. Apparent distances from mutual phenomena, have much smaller errors, less than 10 mas. However, this method only be applied during equinox planets. We developed a that provide accurate data for – approximations. The when any two pass close by each other apparent sky plane. fundamental parameter is central instant t0 passage reach minimum. Galilean moons. All observations were made 0.6 m...
Abstract A stellar occultation occurs when a Solar System object passes in front of star for an observer. This technique allows the sizes and shapes occulting body to be determined with kilometer precision. In addition, this constrains body’s positions, albedos, densities, so on. context Galilean moons, these events can provide their best ground-based astrometry, uncertainties order 1 mas (∼3 km at Jupiter’s distance during opposition). We organized campaigns successfully observed by Io (JI)...
ABSTRACT Recording a stellar occultation is one powerful method that gives direct information about the physical properties of occulting Solar system object. In order to obtain reliable and accurate results, simultaneous observations from different locations across-track projected path are great importance. However, organizing all observing stations, aggregating, analysing data time-consuming not easy. We have developed web portal named Occultation Portal (OP) manage those observation...
Context . From 1988 to 2016, several stellar occultations have been observed characterise Pluto’s atmosphere and its evolution. each occultation, an accurate astrometric position of Pluto at the observation epoch is derived. These positions mainly depend on occulted star precision timing. Aims We present 19 derived from 2016. Using Gaia DR2 for stars, accuracy these estimated 2−10 mas, depending circumstances. positions, we derive updated ephemeris system barycentre using NIMA code. Methods...