A5045746237- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Isotope Analysis in Ecology
- Space Exploration and Technology
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Spacecraft and Cryogenic Technologies
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- Advanced materials and composites
- Methane Hydrates and Related Phenomena
- Metal Alloys Wear and Properties
- Aluminum Alloys Composites Properties
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Nuclear physics research studies
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Distributed and Parallel Computing Systems
- Radiomics and Machine Learning in Medical Imaging
Universidade de Brasília
2015-2024
Ferespe (Portugal)
2019-2022
Queen's University Belfast
2010-2021
University of Coimbra
2006-2021
Institute of Astrophysics and Space Sciences
2021
Max Planck Society
2015-2018
Max Planck Institute for Astronomy
2018
Max Planck Institute for Solar System Research
2014-2016
Comet (Switzerland)
2015-2016
University Center of Brasília
2015
Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but mechanism is not understood. We show main growth asteroids can result gas drag-assisted accretion chondrules. largest planetesimals a population with characteristic radius 100 km undergo runaway within ~3 My, forming planetary embryos up to Mars's size along...
We perform hydrodynamical simulations of the accretion pebbles and rocks onto protoplanets a few hundred kilometres in radius, including two-way drag force coupling between particles protoplanetary disc gas. Particle streams interacting with gas far out within Hill sphere protoplanet spiral into prograde circumplanetary disc. Material is accreted due to stirring by turbulent surroundings. speculate that trend for rotation among largest asteroids primordial 10%-50% their mass from during...
Transneptunian objects (TNOs) are bodies populating the Kuiper Belt and they believed to retain most pristine least altered material of solar system. The Herschel Open Time Key Program entitled "TNOs Cool: A survey trans-Neptunian region" has been awarded 373 h investigate albedo, size distribution thermal properties TNOs Centaurs. Here we focus on brightest targets observed by both PACS SPIRE multiband photometers: dwarf planet Haumea, six (Huya, Orcus, Quaoar, Salacia, 2002 UX25, TC302),...
Abstract The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013–2017 with the Canada–France–Hawaii Telescope, surveyed 155 deg 2 of sky to depths m r = 24.1–25.2. We present 838 outer solar system discoveries that are entirely free ephemeris bias. This increases inventory trans-Neptunian objects (TNOs) accurately known orbits by nearly 50%. Each minor planet has 20–60 Gaia /Pan-STARRS-calibrated astrometric measurements made over 2–5 oppositions, which allows...
We analyze albedo data obtained using the Herschel Space Observatory that reveal existence of two distinct types surface among midsized trans-Neptunian objects. A color–albedo diagram shows large clusters objects, one redder and higher another darker more neutrally colored. Crucially, all objects in our sample located dynamically stable orbits within classical Kuiper Belt region beyond are confined to bright red group, implying a compositional link. Those believed have formed further from...
The recent discovery by Pan-STARRS1 of 1I/2017 U1 (`Oumuamua), on an unbound and hyperbolic orbit, offers a rare opportunity to explore the planetary formation processes other stars, effect interstellar environment planetesimal surface. 1I/`Oumuamua's close encounter with inner Solar System in 2017 October was unique chance make observations matching those used characterize small-body populations our own System. We present near-simultaneous g$^\prime$, r$^\prime$, J photometry colors...
We present models of the shapes four Kuiper Belt objects (KBOs) and Jovian Trojan asteroid (624) Hektor as ellipsoidal figures equilibrium Roche binaries. Our simulations select those whose light curves best match measured rotational data. The best-fit shapes, combined with knowledge spin period objects, provide estimates bulk densities these objects. find that KBOs (20000) Varuna 2003 EL61 are well matched by Jacobi triaxial ellipsoid 992 2551 kg m-3, respectively. KBO 2001 QG298 described...
ABSTRACT Although the majority of Centaurs are thought to have originated in scattered disk, with high-inclination members coming from Oort cloud, origin component trans-Neptunian objects (TNOs) remains uncertain. We report discovery a retrograde TNO, which we nickname “Niku,” detected by Pan-STARRS 1 Outer Solar System Survey. Our numerical integrations show that orbital dynamics Niku very similar 2008 KV 42 (Drac), half-life ∼500 Myr. Comparing TNOs and ( q > 10 au, < 100 i 60°),...
The solar system started to form about 4.56 Gyr ago and despite the long intervening time span, there still exist several clues its formation. three major sources for this information are meteorites, present structure planet-forming systems around young stars. In introduction we give an overview of current understanding formation from all these different research fields. This includes question lifetime protoplanetary disc, stages planet formation, their duration, relative importance. We...
We report the discovery, tracking and detection circumstances for 85 trans-Neptunian objects (TNOs) from first 42 deg$^{2}$ of Outer Solar System Origins Survey (OSSOS). This ongoing $r$-band survey uses 0.9 field-of-view MegaPrime camera on 3.6 m Canada-France-Hawaii Telescope. Our orbital elements these TNOs are precise to a fractional semi-major axis uncertainty $<0.1\%$. achieve this precision in just two oppositions, as compared normal 3-5 via dense observing cadence innovative...
We report new light curves and phase functions for nine Jupiter-family comets (JFCs). They were observed in the period 2004–2015 with various ground telescopes as part of Survey Ensemble Physical Properties Cometary Nuclei well during devoted observing campaigns. add to this a review properties 35 JFCs previously published rotation properties. The photometric time series obtained Bessel R, Harris R SDSS r΄ filters absolutely calibrated using stars from Pan-STARRS survey. This specially...
This study evaluated clinical features of individuals with long COVID (5–8 months after diagnosis) who reported sleep and memory problems (62 cases) compared to those without (52 controls). Both groups had a similar mean age (41 vs. 39 years). Around 86% the participants were non-hospitalized at time infection, none them vaccinated that point. Subsequently, both cases controls received vaccine; however, vaccination rates differed significantly between (30.7% 51.0%). Cases symptoms acute...
Over one thousand objects have so far been discovered orbiting beyond Neptune. These trans-Neptunian (TNOs) represent the primitive remnants of planetesimal disk from which planets formed and are perhaps analogous to unseen dust parent-bodies in debris disks observed around other main-sequence stars. The dynamical physical properties these bodies provide unique important constraints on formation evolution models Solar System. While architecture this region (also known as Kuiper Belt) is...
Comet 133P/Elst–Pizarro is the first known and currently best-characterized member of main-belt comets, a recently identified class objects that exhibit cometary activity but which are dynamically indistinguishable from asteroids. We report here on results multiyear monitoring campaign 2003 to 2008, present observations return in 2007. find pattern consistent with seasonal modulation. Additionally, recomputation phase function parameters using data 133P was inactive yields new IAU HR= 15.49...
Comets are remnants of the icy planetesimals that formed beyond ice line in Solar Nebula. Growing from micrometre-sized dust and particles to km-sized objects is, however, difficult because growth barriers time scale constraints. The gravitational collapse pebble clouds through streaming instability may provide a suitable mechanism for comet formation. We study collisional compression cm-sized porous ice/dust-mixed pebbles collapsing clouds. For this, we developed collision model consisting...
Context. Comet formation by gravitational instability requires aggregates that trigger the streaming and cluster in pebble-clouds. These form as mixtures of dust ice from (sub-)micrometre-sized grains via coagulation solar nebula. Aim. We investigate growth monomer grains. are interested properties these aggregates: whether they might instability, how compare to pebbles found on comets, what implications for comet collapsing Methods. used Monte Carlo simulations study through locally...
Main belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was discovered to exhibit comet-like activity by the Pan-STARRS1 survey telescope using automated point-spread-function analyses performed PS1's Moving Object Processing System. Deep follow-up observations show both a short (\sim 10") antisolar dust tail and longer 60") trail aligned with object's orbit plane, similar morphology observed for another main-belt comet, P/2010 R2 (La Sagra), other well-established comets,...
Ever since the very first photometric studies of Centaurs and Kuiper belt objects (KBOs) their visible color distribution has been controversial. This controversy triggered to a prolific debate on origin surface colors these distant icy solar system. Two scenarios have proposed interpret explain large variability colors, hence composition. Are mainly primordial directly related formation region, or are they result evolution processes? To date, no mechanism found that successfully explains...