C/2017 K2 (Pan-STARRS) is an Oort cloud comet discovered in May 2017. Ground observations have revealed that this long-period comet was active at heliocentric distance of 35 au. At such a distance, activity cannot be driven by the sublimation or the exothermic crystallization of water ice. We assume that the activity of comet C/2017 K2 may be

En los últimos años, el descubrimiento de exoplanetas ha incrementado exponencialmente. Actualmente, se conocen más de 5000 planetas extrasolares y para 77 de ellos se han detectado señales atmosféricas utilizando observaciones de baja y alta resolución espectral. Una de las maneras más efectivas de estudiar las atmósferas exoplanetarias está

Mid-infrared (mid-IR) observations are powerful in identifying heavily obscured active galactic nuclei (AGN) that have weak emission in other wavelengths. Data from the Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope provides an excellent opportunity to perform such studies. We take advantage of the MIRI imaging data from the

Planetary nebulae (PNs) consist of an ionized envelope surrounding a hot central star (CSPN) that emits mostly at ultraviolet (UV) wavelengths. UV observations, therefore, provide important information on both the CSPN and the nebula. We have matched the PNs in the Hong Kong/Australian Astronomical Observatory/Strasbourg Hα catalog with the Galaxy

The composition of comets hold clues about the early stages of the formation and evolution of the Solar System. Being the brightest comet observed in the northern hemisphere since the passage of comet C/1995 O1 (Hale-Bopp) in 1997, comet C/2020 F3 (NEOWISE) represents an interesting target for studying its coma composition and the chemical

We analyse the molecular and atomic emission lines of 71 bright Herschel-selected galaxies between redshifts 1.4 and 4.6 detected by the Atacama Large Millimeter/submillimeter Array. These lines include a total of 156 CO, [C I], and H 2O emission lines. For 46 galaxies, we detect two transitions of CO lines, and for these galaxies we find gas