Related papers: Cassini imaging search rules out rings around Rhea
The review is devoted to a discussion of new (and often unexpected) aspects of the old problem of elastic light scattering by small metal particles, whose size is comparable to or smaller than the thickness of the skin layer. The main focus…
The accurate determination of Saturn's gravitational coefficients by Cassini could provide tighter constrains on Saturn's internal structure. Also, occultation measurements provide important information on the planetary shape which is often…
In our solar system, the presence of rings is exclusive to the gas giants, but is this the case for all planetary systems? In principle, it seems that rocky exoplanets could also have rings, which could be searched for by studying their…
Photometry from the Helios and STEREO spacecraft revealed regions of enhanced sky surface-brightness suggesting a narrow circumsolar ring of dust associated with Venus's orbit. We model this phenomenon by integrating the orbits of…
Solar system bodies that lack a significant atmosphere and significant internal magnetic fields, such as the Moon and asteroids, have been considered as passive absorbers of the solar wind. However, ion observations near the Moon by the…
A search for infrared ring nebulae associated with regions of ionized hydrogen has been carried out. The New GPS Very Large Array survey at 20 cm forms the basis of the search, together with observations obtained with the Spitzer Space…
We present a survey of six low to moderate redshift quasars with Chandra and XMM-Newton. The primary goal is to search for the narrow X-ray absorption lines produced by highly ionized metals in the Warm-Hot Intergalactic Medium. All the…
Needle-like metallic particles have been suggested to explain a wide variety of astrophysical phenomena, ranging from the mid-infrared interstellar extinction to the thermalization of starlight to generate the cosmic microwave background.…
The images of Sagittarius A$^*$ recently released by the Event Horizon Telescope collaboration have been accompanied [Ap.J.Lett.\,{\bf 930\,\#2}\,(2022)\,L17] by an analysis of the constraints on the possible absence of a trapping horizon,…
Using the Advanced CCD Imaging Spectrometer (ACIS), the Chandra X-ray Observatory (CXO) observed the Saturnian system for one rotation of the planet (~37 ks) on 20 January, 2004, and again on 26-27 January, 2004. In this letter we report…
Spitzer and Caltech Submillimeter Observatory (CSO) images and spectrophotometry of epsilon Eridani at wavelengths from 3.5 to 350 um reveal new details of its bright debris disk. The 350 um map confirms the presence of a ring at r = 11-28…
The exact nature of eta Carinae is still an open issue. In this paper we assume a binary system to explain the strong X-ray emission, but we also take into account that, near periastron and because of the highly eccentric orbit, the wind…
We analyze far-infrared (10-650 cm$^{-1}$) emissivity spectra of Saturn's main rings obtained by the Cassini Composite Infrared Spectrometer (CIRS). In modeling of the spectra, the single scattering albedos of regolith grains are calculated…
Context: Observation of star occultations is a powerful tool to determine shapes and sizes of asteroids. This is key information necessary for studying the evolution of the asteroid belt and to calibrate indirect methods of size…
We present thermal infrared images of the bipolar nebula surrounding eta Carinae at six wavelengths from 4.8 to 24.5 microns. These were obtained with the MIRAC3 camera system at the Magellan Observatory. Our images reveal new intricate…
A wide variety of solar system bodies are now known to radiate in the soft x-ray energy (<5 keV) regime. These include planets (Earth, Jupiter, Venus, Saturn, Mars): bodies having thick atmospheres, with or without intrinsic magnetic field;…
Recent ALMA observations have revealed that a large fraction of protoplanetary discs contain bright rings at (sub)millimeter wavelengths. Dust trapping induced by pressure maxima in the gas disc is a popular explanation for these rings.…
Unlike hot Jupiters or other gas giants, super-Earths are expected to have a wide variety of compositions, ranging from terrestrial bodies like our own to more gaseous planets like Neptune. Observations of transiting systems, which allow us…
A recent occultation measurement of the dwarf planet Haumea (Ortiz et al. 2017) revealed an elongated shape with the longest axis comparable to Pluto's mean diameter. The chords also indicate a ring around Haumea's equatorial plane, where…
A stellar occultation of Gaia DR3 2646598228351156352 by the Centaur (2060) Chiron was observed from the South African Astronomical Observatory on 2018 November 28 UT. Here we present a positive detection of material surrounding Chiron from…