Related papers: 15NH3 in the atmosphere of a cool brown dwarf
The search for signs of life on other worlds has largely focused on terrestrial planets. Recent work, however, argues that life could exist in the atmospheres of temperate sub-Neptunes. Here, we evaluate the usefulness of carbon dioxide…
H$_3^+$ emission is the dominant cooling mechanism in Jupiter's thermosphere and a useful probe of temperature and ion densities. The H$_3^+$ ion is predicted to form in the thermospheres of close-in `hot Jupiters' where its emission would…
We present a model for lightning shock induced chemistry that can be applied to atmospheres of arbitrary H/C/N/O chemistry, hence for extrasolar planets and brown dwarfs. The model couples hydrodynamics and the STAND2015 kinetic gas-phase…
Planets form from the same cloud of molecular gas and dust as their host stars. Confirming if planetary bodies acquire the same refractory element composition as their natal disc during formation, and how efficiently volatile elements are…
Interferometric observations of the atmosphere of Titan were performed with the Submillimeter Array on two nights in February 2004 to investigate the global average vertical distributions of several molecular species above the tropopause.…
Motivated by recent spectroscopic evidence for carbon-rich atmospheres on some transiting exoplanets, we investigate the influence of the C/O ratio on the chemistry, composition, and spectra of extrasolar giant planets both from a…
With a temperature of $\sim 285$ K WISE0855 is the coldest brown dwarf observed so far. Using the James Webb Space Telescope (JWST) we obtained observations that allow us to characterize WISE0855s atmosphere focusing on vertical variation…
The elemental and isotopic abundances of volatiles like carbon, oxygen, and nitrogen may trace a planet's formation location relative to H$_2$O, CO$_2$, CO, NH$_3$, and N$_2$ "snowlines", or the distance from the star at which these…
The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes, hence atmospheres. We discuss contemporary…
We determine the carbon isotopic ratios in the atmospheres of some evolved stars in both globular clusters and the disk of our Galaxy. Analysis of 12CO and 13CO bands at 2.3 micron was carried out using fits to observed spectra of red…
A planetary atmosphere is the outer gas layer of a planet. Besides its scientific significance among the first and most accessible planetary layers observed from space, it is closely connected with planetary formation and evolution, surface…
Brown dwarfs and giant gas extrasolar planets have cold atmospheres with a rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral…
The abundance ratio of $^{14}$N$/^{15}$N is, in principle, a powerful tool for tracing stellar nucleosynthesis. This work aims to measure and analyze ($^{14}$N/$^{15}$N)$\times$($^{13}$C/$^{12}$C) and $^{14}$N$/^{15}$N abundance ratios in…
It has been proposed that the distinct formation and evolution of exoplanets and brown dwarfs may affect the chemical and isotopic content of their atmospheres. Recent work has indeed shown differences in the $^{12}$C/$^{13}$C isotope…
Elements heavier than hydrogen and helium, collectively termed metals, were created inside stars and dispersed through space at the final stages of stellar evolution. The relative amounts of different isotopes (variants of the same element…
Gas-giant planets emit a large fraction of their light in the mid-infrared ($\gtrsim$3$\mu$m), where photometry and spectroscopy are critical to our understanding of the bulk properties of extrasolar planets. Of particular importance are…
Samples of pristine Solar System material found in meteorites and interplanetary dust particles are highly enriched in (15)N. Conspicuous nitrogen isotopic anomalies have also been measured in comets, and the (14)N/(15)N abundance ratio of…
The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have concluded that the…
We present the results of the Infrared Space Observatory Short Wavelength Spectrometer (ISO-SWS) observations of Jupiter related to ammonia. We focus on two spectral regions; the first one (the 10-micron region), probes atmospheric levels…
The Texas Echelon cross Echelle Spectrograph (TEXES), mounted on NASA's Infrared Telescope Facility (IRTF), was used to map mid-infrared ammonia absorption features on both Jupiter and Saturn in February 2013. Ammonia is the principle…