299 citations · 1.3k across the 39 of their papers we have counts for
33 papers · 1 filter
Constraints on Triton atmospheric evolution from occultations: 1989-2022
B. Sicardy, A. Tej, A. R. Gomes-Junior +49
Context - Around the year 2000, Triton's south pole experienced an extreme summer solstice that occurs every about 650 years, when the subsolar latitude reached about 50°. Bracketi…
Physical properties of Centaur (60558) 174P/Echeclus from stellar occultations
C. L. Pereira, F. Braga-Ribas, B. Sicardy +42
The Centaur (60558) Echeclus was discovered on March 03, 2000, orbiting between the orbits of Jupiter and Uranus. After exhibiting frequent outbursts, it also received a comet desi…
Kilometer-precise (UII) Umbriel physical properties from the multichord stellar occultation on 2020 September 21
M. Assafin, S. Santos-Filho, B. E. Morgado +39
We report the results of the stellar occultation by (UII) Umbriel on September 21st, 2020. The shadow crossed the USA and Canada, and 19 positive chords were obtained. A limb param…
A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS measured from stellar occultations
F. L. Rommel, F. Braga-Ribas, J. L. Ortiz +201
This work aims at constraining the size, shape, and geometric albedo of the dwarf planet candidate 2002 MS4 through the analysis of nine stellar occultation events. Using multichor…
Constraints on (2060) Chiron's size, shape, and surrounding material from the November 2018 and September 2019 stellar occultations
Felipe Braga-Ribas, C. L. Pereira, B. Sicardy +24
After the discovery of rings around the largest known Centaur object, (10199) Chariklo, we carried out observation campaigns of stellar occultations produced by the second-largest…
The changing material around (2060) Chiron from an occultation on 2022 December 15
J. L. Ortiz, C. L. Pereira, B. Sicardy +30
We could accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on 2022 December 15. The Kottamia Astronomical Observatory in Egypt d…
The two rings of (50000) Quaoar
C. L. Pereira, B. Sicardy, B. E. Morgado +66
Quaoar is a classical Trans-Neptunian Object (TNO) with an area equivalent diameter of 1,100 km and an orbital semi-major axis of 43.3 astronomical units. Based on stellar occultat…
The multichord stellar occultation by the centaur Bienor on January 11, 2019
E. Fernández-Valenzuela, N. Morales, M. Vara-Lubiano +42
Within our program of physical characterization of trans-Neptunian objects and centaurs, we predicted a stellar occultation by the centaur (54598) Bienor to occur on January 11, 20…
Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
P. Santos-Sanz, J. L. Ortiz, B. Sicardy +85
Within our international program to obtain accurate physical properties of trans-Neptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya of the star Gai…
Constraints on the structure and seasonal variations of Triton's atmosphere from the 5 October 2017 stellar occultation and previous observations
J. Marques Oliveira, B. Sicardy, A. R. Gomes-Júnior +234
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 from this event, 42 of…
Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020
B. E. Morgado, B. Sicardy, F. Braga-Ribas +78
The Centaur (10199) Chariklo has the first rings system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow the de…
The 2017 May 20 stellar occultation by the elongated centaur (95626) 2002 GZ
P. Santos-Sanz, J. L. Ortiz, B. Sicardy +56
We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (m= 14.0 mag) by the centaur 2002 GZ for 2017 May 20$^{\rm th}…
Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs
F. L. Rommel, F. Braga-Ribas, J. Desmars +66
Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, and their physical properties have invaluable information for evolutionary theories. Ste…
A multi-chord stellar occultation by the large trans-Neptunian object (174567) Varda
D. Souami, F. Braga-Ribas, B. Sicardy +41
We present results from the first recorded stellar occultation by the large trans-Neptunian object (174567) Varda that was observed on September 10, 2018. Varda belongs…
The 2014-2015 Brazilian Mutual Phenomena campaign for the Jovian satellites and improved results for the 2009 events
B. Morgado, R. Vieira-Martins, M. Assafin +15
Progress in astrometry and orbital modelling of planetary moons in the last decade enabled better determinations of their orbits. These studies need accurate positions spread over…
First stellar occultation by the Galilean moon Europa and upcoming events between 2019 and 2021
B. Morgado, G. Benedetti-Rossi, A. R. Gomes-Júnior +21
Context. Bright stellar positions are now known with an uncertainty below 1 mas thanks to Gaia DR2. Between 2019-2020, the Galactic plane will be the background of Jupiter. The den…
Pluto's ephemeris from ground-based stellar occultations (1988-2016)
J. Desmars, E. Meza, B. Sicardy +13
From 1988 to 2016, several stellar occultations have been observed to characterize Pluto's atmosphere and its evolution (Meza et al, 2019). From each stellar occultation, an accura…
Pluto's lower atmosphere and pressure evolution from ground-based stellar occultations, 1988-2016
E. Meza, B. Sicardy, M. Assafin +167
Context. Pluto's tenuous nitrogen (N2) atmosphere undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has been recently (July 2015) observed by th…
The future of stellar occultations by distant solar system bodies: perspectives from the Gaia astrometry and the deep sky surveys
Julio Camargo, Josselin Desmars, Felipe Braga-Ribas +5
Distant objects in the solar system are crucial to better understand the history and evolution of its outskirts. The stellar occultation technique allows the determination of their…
APPROX -- Mutual approximations between the Galilean moons. The 2016-2018 observational campaign
B. Morgado, R. Vieira-Martins, M. Assafin +23
The technique of mutual approximations accurately gives the central instant at the maximum apparent approximation of two moving natural satellites in the sky plane. This can be use…
Size and shape of Chariklo from multi-epoch stellar occultations
R Leiva, B Sicardy, J I B Camargo +28
We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo's size and shape, and the ring reflectivity. We consider four possible models for Ch…
The structure of Chariklo's rings from stellar occultations
D. Bérard, B. Sicardy, J. I. B. Camargo +79
Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this disc…
Study of the plutino object (208996) 2003 AZ84 from stellar occultations: size, shape and topographic features
A. Dias-Oliveira, B. Sicardy, J. L. Ortiz +60
We present results derived from four stellar occultations by the plutino object (208996) 2003~AZ, detected at January 8, 2011 (single-chord event), February 3, 2012 (multi-c…
Results from a triple chord stellar occultation and far-infrared photometry of the trans-Neptunian object (229762) 2007 UK126
Karsten Schindler, Jürgen Wolf, Jerry Bardecker +8
A stellar occultation by a trans-Neptunian object (TNO) provides an opportunity to probe its size and shape. Very few occultations by TNOs have been sampled simultaneously from mul…