ﻻ يوجد ملخص باللغة العربية
A stellar occultation by the large trans-Neptunian object (90482) Orcus was predicted to occur on 2017 March 07. Observations were made at five sites in North and South America. High-speed, visible-wavelength images were taken at all sites, in addition to simultaneous K-band images at one location. Solid-body occultations were observed from two sites. Post-event reconstruction suggested an occultation of two different stars observed from two different sites. Follow-up, speckle imaging at Gemini Observatory revealed a second star, which verified that the occulting body in both cases was Orcus` satellite, Vanth. The two single-chord detections, with an anomalously large timing delay in one chord, have lengths of 291+/-125 km and 434.4+/-2.4 km. The observations, combined with a non-detection at a nearby site, allow a tight constraint of 443+/-10 km to be placed on Vanth`s size (assuming it is spherical). A 3-{sigma} upper limit of 1-4 {mu}bar (depending on constituent) is found for a global Vanth atmosphere. The immersion and emersion profiles are slightly different, with atmospheric constraints 40 percent higher on immersion than on emersion. No rings or other material were detected within ten thousand kms of Vanth, and beyond 8010 km from Orcus, to the tightest optical depth limit of approximately 0.1 at 5 km scale. The occultation probed as close as 5040 km from Orcus, placing an optical depth limit of approximately 0.3 at 5 km scale on any encircling material at that distance.
Context. We study the surface properties of transneptunian populations of Solar-system bodies. Aims. We investigate the surface characteristics of the dwarf planet (136472) Makemake and the resonant object (90482) Orcus. Methods. Using the FORS2 inst
Plutos atmospheric profiles (temperature and pressure) have been studied for decades from stellar occultation lightcurves. In this paper, we look at recent Pluto Global Climate Model (GCM) results (3D temperature, pressure, and density fields) from B
We present results from the first recorded stellar occultation by the large trans-Neptunian object (174567) Varda that was observed on September 10$^{rm th}$, 2018. Varda belongs to the high-inclination dynamically excited population, and has a satel
A stellar occultation by the extreme large-perihelion trans-Neptunian object (541132) Lele={a}k={u}honua (also known by the provisional designation of 2015 TG387) was predicted by the Lucky Star project and observed with the Research and Education Co
We report observations of a stellar occultation by the classical Kuiper belt object (50000) Quaoar occurred on 28 June 2019. A single-chord high-cadence (2 Hz) photometry dataset was obtained with the Tomo-e Gozen CMOS camera mounted on the 1.05 m Sc