Related papers: Sodium and Potassium Linewidths as an Atmospheric …

The exosphere, the tenuous collisionless cloud of gas surrounding Mercury is still a poorly known object because it is the result of many various interactions between the surface, the interplanetary medium (Solar wind, photons and…

The alkali metal sodium (Na) is one of the most commonly detected chemical species in the upper atmospheres of giant exoplanets. In this work we conducted a homogeneous survey of Na in a diverse sample of ten highly irradiated giant…

A complete reassessment of the HST observations of the transits of the extrasolar planet HD209458b has provided a transmission spectrum of the atmosphere over a wide range of wavelengths. Analysis of the NaI absorption line profile has…

The lunar sodium tail extends long distances due to radiation pressure on sodium atoms in the lunar exosphere. Our earlier observations measured the average radial velocity of sodium atoms moving down the lunar tail beyond Earth (i.e., near…

This study investigates the escape of Mercury's sodium-group ions (Na+-group, including ions with m/q from 21 to 30 amu/e) and their dependence on true anomaly angle (TAA), i.e., Mercury's orbital phase around the Sun, using measurements…

Hydrostatic equilibrium is an excellent approximation for the dense layers of planetary atmospheres where it has been canonically used to interpret transmission spectra of exoplanets. Here we exploit the ability of high-resolution…

The link between the surface temperature of Mercury and the exosphere sodium content has been investigated. Observations show that, along the orbit of Mercury, two maxima of total Na content are present: one at aphelion and one at…

Transit observations in the MgI line of HD209458b revealed signatures of neutral magnesium escaping the upper atmosphere of the planet, while no atmospheric absorption was found in the MgII doublet. Here we present a 3D particle model of…

Atmospheric properties of exoplanets can be constrained with transit spectroscopy. The signature of atomic sodium NaI, known to be present above the clouds, is a powerful probe of the upper atmosphere, where it can be best detected and…

During primary transits, the spectral signatures of an exoplanet atmosphere can be measured using transmission spectroscopy. The goal of this work is to accurately measure the atomspheric sodium absorption light curve in HD189733b,…

High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high altitude absorption e.g. from resonant sodium (Na…

We present a theory for interpreting the sodium lines detected in transmission spectra of exoplanetary atmospheres. Previous analyses employed the isothermal approximation and dealt only with the transit radius. By recognising the…

We present a dimensionless index that quantifies the degree of cloudiness of the atmosphere of a transiting exoplanet. Our cloudiness index is based on measuring the transit radii associated with the line center and wing of the sodium or…

MESSENGER observations suggest a magma ocean formed on proto-Mercury, during which evaporation of metals and outgassing of C- and H-bearing volatiles produced an early atmosphere. Atmospheric escape subsequently occurred by plasma heating,…

Sodium and potassium signatures in transiting exoplanets can be challenging to isolate from the stellar absorption lines. Here, these challenges are discussed in the framework of Solar System observations, and transits of Mercury in…

We report measurements of the Stark shifts and Stark widths of sodium spectral lines corresponding to nS-3P and mD-3P transitions. Measurements have been made on AC driven high pressure NaHg and NaCd discharges. Electron density has been…

On 21 March 2013 high-resolution slit spectrographs of comet C/2011 L4 (Panstarrs), at the heliocentric distance r = 0.46 Astronomical Units (AU), were obtained at the Osservatorio Astronomico Campo dei Fiori, Italy. Emission lines of…

High-resolution transmission spectroscopy is a method for understanding the chemical and physical properties of upper exoplanetary atmospheres. Due to large absorption cross-sections, resonance lines of atomic sodium D-lines (at 5889.95…

Sodium (Na) is a moderately volatile element in the lunar exosphere, released from the surface through thermal and non-thermal processes. We present a combined analysis of Chandrayaan-2 CLASS surface Na abundance, LADEE-UVS exospheric…

High-resolution optical spectroscopy is a powerful tool to characterise exoplanetary atmospheres from the ground. The sodium D lines, with their large cross sections, are especially suited to study the upper layers of atmospheres in this…