Examinando por Autor "Andrews, J."

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Acceso Abierto
All-sky visible and near infrared space astrometry
(Springer Link, 2021-03-11) Hobbs, D.; Brown, Anthony; Hog, E.; Jordi, C.; Kawata, D.; Tanga, P.; Klioner, S. A.; Sozzetti, A.; Wyrzykowski, L.; Walton, N.; Vallenari, A.; Makarov, V.; Rybizki, J.; Jiménez Esteban, F. M.; Caballero, J. A.; McMillan, P. J.; Secrest, N.; Mor, R.; Andrews, Jeff J.; Zwitter, T.; Chiappini, C.; Fynbo, J. P. U.; Ting, Y. S.; Hestroffer, D.; Lindegren, L.; McArthur, B.; Gouda, N.; Moore, A.; González, O. A.; Vaccari, M.; Hobbs, D. [0000-0002-2696-1366]; Brown, A. [0000-0002-7419-9679]; Sozzetti, A. [0000-0002-7504-365X]; Secrest, N. [0000-0002-4902-8077]
The era of all-sky space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or milliarcsec per year) accuracy level. Hipparcos has now been superseded by the results of the Gaia mission. The second Gaia data release contained astrometric data for almost 1.7 billion sources with tens of microarcsec (or microarcsec per year) accuracy in a vast volume of the Milky Way and future data releases will further improve on this. Gaia has just completed its nominal 5-year mission (July 2019), but is expected to continue in operations for an extended period of an additional 5 years through to mid 2024. Its final catalogue to be released ∼ 2027, will provide astrometry for ∼ 2 billion sources, with astrometric precisions reaching 10 microarcsec. Why is accurate astrometry so important? The answer is that it provides fundamental data which underpin much of modern observational astronomy as will be detailed in this White Paper. All-sky visible and Near-InfraRed (NIR) astrometry with a wavelength cutoff in the K-band is not just focused on a single or small number of key science cases. Instead, it is extremely broad, answering key science questions in nearly every branch of astronomy while also providing a dense and accurate visible-NIR reference frame needed for future astronomy facilities.
Acceso Abierto
Generic Entry Probe Program (GEPP) – an international initiative promoting the development of European descent modules dedicated to the in situ
(EGU General Assembly, 2024-05-13) Mousis, O.; Ambrosi, R.; André, N.; Andrews, J.; Apéstigue, Víctor; Atkinson, D.; Arruego, Ignacio; Blanc, M.; Boithias, H.; Bolton, S.; Bousquet, P.; Canup, R.; Cavalié, T.; Freeman, A.; Faye, F.; Ferri, F.; Glein, C.; Guelhan, A.; Hartogh, P.; Loehle, S.; Hue, V.; Lebreton, J. P.; Lemaistre, S.; Mooij, E.; Pichon, T.; Pinaud, G.; Steuer, D.; Toledo, D.; Rauer, H.; Vorburger, A.; Wurz, P.
The international consortium GEPP has been set to conceptualize probe designs with appropriate payloads that would remain within the typical budget allocated for ESA M-class missions (currently 500 M€). The aims of the consortium are i) to conceptualize a line of generic planetary entry probes that could be targeted to the giant planets with very few modifications, ii) to make the international science community, ESA and its member states, conscious that there is an opportunity to supply a series of entry probes as part of future international collaborations, for example as part of the future NASA flagship mission towards Uranus (Uranus Orbiter Probe) or to any future NASA-led mission to the outer planets for an affordable budget, and iii) to demonstrate that an M-class budget could even fund several entry probes with well-prioritized science objectives. The model payload capabilities of each concept will be defined according to a carefully-designed science traceability matrix. Two extreme concepts shall be investigated by the GEPP Consortium, namely a highly capable parachute-descent probe including a typical payload of 30 kg of scientific instruments down to 10 bars, and a smaller parachute-descent probe designed to address top priority science objectives with selected key measurements that would address the ESA Cosmic Vision 2050 science objectives. This presentation will detail the scientific objectives for each entry probe design, as well as the content, organization and planning of the study, which is assumed to be completed by the end of 2025.