C. Jacques
A5089711502- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Planetary Science and Exploration
- Astronomical Observations and Instrumentation
- Historical Astronomy and Related Studies
- Isotope Analysis in Ecology
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Maritime and Coastal Archaeology
- Law, logistics, and international trade
- Classical Antiquity Studies
- Geophysics and Gravity Measurements
- SAS software applications and methods
- Scientific Research and Discoveries
- Historical, Religious, and Philosophical Studies
- Pacific and Southeast Asian Studies
- Classical Philosophy and Thought
- Geology and Paleoclimatology Research
- Mineralogy and Gemology Studies
National Observatory
2019-2022
Companhia Energética de Minas Gerais (Brazil)
2006-2013
We present results derived from the first multi-chord stellar occultations by transneptunian object (50000) Quaoar, observed on 2011 May 4 and 2012 February 17, a single-chord occultation October 15. If timing of five chords obtained in were correct, then Quaoar would possess topographic features (crater or mountain) that be too large for body this mass. An alternative model consists applying time shifts to some account possible errors. Satisfactory elliptical fits are possible, yielding an...
Abstract We present the results of a fourth planetary defense exercise, focused this time on small near-Earth asteroid (NEA) 2023 DZ2 and conducted during its close approach to Earth in March. The International Asteroid Warning Network (IAWN), with support from NASA's Planetary Defense Coordination Office (PDCO), has been coordinating observational campaigns since 2017 test operational readiness global capabilities. last campaign NEA Apophis, an outcome that exercise was need for short burst...
Abstract We describe results of a planetary defense exercise conducted during the close approach to Earth by near-Earth asteroid (99942) Apophis 2020 December–2021 March. The community has been conducting observational campaigns since 2017 test operational readiness global capabilities. These community-led exercises were carried out with support NASA’s Planetary Defense Coordination Office and International Asteroid Warning Network. campaign is third in our series exercises. goal this was...
Context.
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...
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)...
We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by plutino object (84922) 2003 VS2. From 2013 2014 we obtained accurate astrometric positions for object, while occultation on November 7, parameters best-fitting ellipse to limb body at time occultation. also short-term photometry data order derive its rotational phase during The light curve a peak-to-peak amplitude 0.141 ± 0.009 mag. This allows us...
We report the results of two multi-chord stellar occultations by dwarf planet (1) Ceres that were observed from Brazil on 2010 August 17, and USA 2013 October 25. Four positive detections obtained for occultation, nine occultation. Elliptical models adjusted to chords obtain Ceres' size shape. Two limb fitting solutions studied each event. The first one is a nominal solution with an indeterminate polar aspect angle. second was constrained pole coordinates as given Drummond et al. Assuming...
Abstract The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for second observing campaign to test the timing accuracy astrometric observation. With 82 participating stations, International Asteroid Warning Network collected 1046 observations around time approach. Compared previous targeting 2019 XS, some individual observers were able significantly improve their reported observation times. In particular, U.S. surveys achieved...
Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, provide characteristics of occulting object its vicinity. Aims. Using between 2017 2020, our aim is constrain physical parameters rings. We also determine structure rings, obtain precise astrometrical positions Chariklo. Methods. predicted organised several...