Observatoire de Paris

2 months ago | aanda.org | Johns Hopkins |Observatoire de Paris |Université PSL

Home All issues Volume 693 (January 2025) A&A, 693 (2025) A315 Full HTML Issue A&A Volume 693, January 2025 Article Number A315 Number of page(s) 9 Section Planets, planetary systems, and small bodies DOI https://doi.org/10.1051/0004-6361/202452695 Published online 29 January 2025 A&A, 693, A315 (2025) First unambiguous detection of ammonia in the atmosphere of a planetary mass companion with JWST/MIRI coronagraphs 1,2,3★, 3, 3, 3, 3, 4, 5,6,7, 8,9, 10, 11, 12, 13, 3, 14, 15, 16, 11, 9, 17,...

Jan 23, 2025 | academic.oup.com | Observatoire de Paris |Université PSL

We analyse the stellar distributions on the [Fe/H]-[Mg/Fe] plane for 11 Milky Way-mass galaxies from the FIRE-2 cosmological baryonic zoom-in simulations. Alpha-element bimodality, in the form of two separate sequences on the [Fe/H]-[Mg/Fe] plane, is not a universal feature of disk galaxies.

Dec 20, 2024 | academic.oup.com | Université de Moncton |Observatoire de Paris |Université Paris Diderot

A group of horizontal-branch stars of particular interest for atomic diffusion (Michaud 1970) are blue horizontal-branch (BHB) stars. This group shows abundance anomalies for higher than 11 500 K (i.e. Glaspey et al. 1989; Behr et al. 1999; Moehler et al. 1999). Grundahl et al. (1999) studied several globular clusters and found that hot BHB stars reveal photometric jumps in the Hertzsprung–Russell (HR) diagram; Ferraro et al. (1998) reported that they also display photometric gaps.

Nov 3, 2024 | link.springer.com | Institut Origines |Aix-Marseille Université |Univ. Bordeaux |Observatoire de Paris

AbstractObservations of the Jovian upper atmosphere at high latitudes in the UV, IR and mm/sub-mm all indicate that the chemical distributions and thermal structure are broadly influenced by auroral particle precipitations. Mid-IR and UV observations have shown that several light hydrocarbons (up to 6 carbon atoms) have altered abundances near Jupiter’s main auroral ovals.

Sep 24, 2024 | academic.oup.com | Observatoire de Paris |Université PSL

The Martian Moon eXploration (MMX) is a sample return mission from the Japanese Space Agency (JAXA) (Kuramoto et al. 2022), scheduled to be originally launched towards the Martian system in 2024 but was recently postponed to 2026. MMX will study the Martian atmosphere, characterize the surface of the Martian satellites Phobos and Deimos using remote sensing observations, delivering a rover to interact with the surface of Phobos and returning Phobos sample to Earth.