Astronomy & Astrophysics (A&A)
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Astronomy & Astrophysics is an international Journal that publishes papers on all aspects of astronomy and astrophysics (theoretical, observational, and instrumental) independently of the techniques used to obtain the results.
Astronomy & Astrophysics (A&A)
23h ago
Vol. 684
5. Galactic structure, stellar clusters and populations
Observed kinematics of the Milky Way nuclear stellar disk region by M. Zoccali, A. Rojas-Arriagada, E. Valenti, R. Contreras Ramos, A. Valenzuela-Navarro, C. Salvo-Guajardo 2024, A&A, 684, A214
Zooming into the central regions of the Milky Way unravels a great deal of structures, though often obscured by large extinction. These comprise the Galactic bulge at the kiloparsec scale, down to stellar and gaseous components with a 100 pc extent, as also seen in other galaxies. In past works, a flat, stellar disk with a 150 pc radi ..read more
Astronomy & Astrophysics (A&A)
23h ago
Vol. 684
10. Planets and planetary systems
AFM-IR nanospectroscopy of nanoglobule-like particles in Ryugu samples returned by the Hayabusa2 mission by Jérémie Mathurin, Laure Bejach, Emmanuel Dartois, et al. 2024, A&A, 684, A198
Vibrational spectroscopy is a powerful tool to investigate the chemical structure of organic matter and minerals in meteorites, micrometeorites, and return samples from space missions. "Classic" infrared microspectrocopy (µ-FTIR) is, however, diffraction limited to spatial resolutions of a few microns. Infrared photothermal nanospectrocopy (AFM-IR), which combine ..read more
Astronomy & Astrophysics (A&A)
3w ago
Vol. 684
10. Planets and planetary systems
Thermal tides in neutrally stratified atmospheres: Revisiting the Earth's Precambrian rotational equilibrium by Mohammad Farhat, Pierre Auclair-Desrotour, Gwenaël Boué, Russell Deitrick, Jacques Laskar 2024, A&A, 684, A49
The climatic history of the Earth is scarcely constrained. A key element to model is the length of the day, which was likely shorter in the past than it is now. The variation in the length of the day is a consequence of the Earth's spin variation, resulting from different torques involving the Earth, the Sun, the Moon, the atmos ..read more
Astronomy & Astrophysics (A&A)
3w ago
Vol. 683
2. Astrophysical processes
The nature of the X-ray filaments around bow shock pulsar wind nebulae by Barbara Olmi, Elena Amato, Rino Bandiera, Pasquale Blasi 2024, A&A, 683, L1
When a pulsar moves across the interstellar medium, it is likely to release energetic leptons. In some cases, they become visible as a linear, filamentary structure emitting X-rays. These structures could be as long as 15 pc, as in the Lighthouse Nebula, but with a very small cross section (1-10% of the length). In this Letter, Olmi and collaborators suggest that the X-ray emission of these filaments can b ..read more
Astronomy & Astrophysics (A&A)
1M ago
Vol. 681
10. Planets and planetary systems
Formation of flattened planetesimals by gravitational collapse of rotating pebble clouds by Sebastian Lorek, Anders Johansen 2024, A&A, 681, A38 In their study, Lorek & Johansen delve into the fascinating process of how a kilometer-sized planetesimal might form from a rotating cloud of pebbles. They used a Monte Carlo method to simulate this complex process and find that when pebble clouds that rotate slowly collapse under their own gravity, they can form shapes such as flattened ellipsoids. This finding provides insights into the unique shap ..read more
Astronomy & Astrophysics (A&A)
1M ago
Vol. 682
6. Interstellar and circumstellar matter
eROSITA studies of the Carina nebula by Manami Sasaki, Jan Robrade, G.H. Martin Krause, R. Jonathan Knies, Kisetsu Tsuge, Gerd Pühlhofer, Andrew Strong 2024, A&A, 682, A172
Whatever might be wanted to study feedback processes and the symbiosis of stars and interstellar clouds can be found in the Carina nebula. This star-forming region harbors a broad range of massive stars, including the ever-popular luminous blue variable (and multiple interacting wind system) eta Carina. The region and its core clusters have been subject to continuing mu ..read more
Astronomy & Astrophysics (A&A)
2M ago
Vol. 682
6. Interstellar and circumstellar matter
eROSITA studies of the Carina nebula by Manami Sasaki, Jan Robrade, G.H. Martin Krause, R. Jonathan Knies, Kisetsu Tsuge, Gerd Pühlhofer, Andrew Strong 2024, A&A, 682, A172
Whatever might be wanted to study feedback processes and the symbiosis of stars and interstellar clouds can be found in the Carina nebula. This star-forming region harbors a broad range of massive stars, including the ever-popular luminous blue variable (and multiple interacting wind system) eta Carina. The region and its core clusters have been subject to continuing m ..read more
Astronomy & Astrophysics (A&A)
2M ago
Vol. 682
7. Stellar structure and evolution
PSR J0210+5845: Ultra-wide binary pulsar with a B6 V main sequence star companion by E. van der Wateren, C. G. Bassa, G. H. Janssen, I. V. Yanes-Rizo, J. Casares, G. Nelemans, W. B. Stappers, C. M. Tan 2024, A&A, 682, A178
A neutron star forms in the explosion of a massive star as a supernova. When the exploding star is part of a binary system, the binary usually gets disrupted. In favorable conditions (e.g., asymmetries in the supernova explosion), however, the binary system can survive, leaving a newborn neutron star orbiting a massive compani ..read more
Astronomy & Astrophysics (A&A)
2M ago
Vol. 682
12. Atomic, molecular, and nuclear data
The UMIST database for astrochemistry 2022 by T. J. Millar, C. Walsh, M. Van de Sande, A. J. Markwick 2024, A&A, 682, A109
Detailed astrochemical models are necessary for interpreting the observations of interstellar and circumstellar molecules. They depend on the values of the rate coefficients of individual chemical reactions, and these need to be continuously updated to reflect advances in experimental and theoretical estimates. In this volume, Tom Millar and collaborators present the sixth release of the UMIST Database for Astrochemistr ..read more
Astronomy & Astrophysics (A&A)
2M ago
Vol. 682
10. Planets and planetary systems
Secular change in the spin states of asteroids due to radiation and gravitation torques. New detections and updates of the YORP effect by J. Durech, D. Vokrouhlicky, P. Pravec, et al. 2024, A&A, 682, A93
The motion of near-Earth asteroids is significantly influenced by non-gravitational forces, specifically thermal torques resulting from the proximity to the Sun. These effects are known as the Yarkovsky effect for orbital dynamics and the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect when impacting the object's rotation. The latter effect i ..read more