Results 71 to 80 of about 411,596 (264)

JWST Imaging of the Closest Globular Clusters—V. The White Dwarfs Cooling Sequence of M4

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT We combine infrared (IR) observations collected by the James Webb Space Telescope with optical deep images by the Hubble Space Telescope taken ~20 years earlier to compute proper‐motion membership for the globular cluster (GC) M4 (NGC 6121) along its entire white dwarf (WD) cooling sequence (CS).
Luigi R. Bedin, Mattia Libralato, Maurizio Salaris, Domenico Nardiello, Michele Scalco, Massimo Griggio, Jay Anderson, Pierre Bergeron, Andrea Bellini, Roman Gerasimov, Adam J. Burgasser, Daniel Apai   +11 more
wiley   +1 more source

A GLIMPSE into the Nature of Galactic Mid-IR Excesses

, 2008
We investigate the nature of the mid-IR excess for 31 intermediate-mass stars that exhibit an 8 micron excess in either the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire or the Mid-Course Space Experiment using high resolution optical spectra ...
Andrillat A., Ashok N. M., B. Uzpen, Boehm T., Brocklehurst M., Brosche P., C. Thom, Carroll J. A., Catala C., Catala C., D. R. Semler, Dachs J., Finkenzeller U., Finkenzeller U., H. A. Kobulnicky, Israel F. P., Jaschek C., Jaschek C., Jaschek M., Jaschek M., Jenniskens P., Kozok J. R., Monet D. G., Pogodin M. A., Royer F., Seidensticker K. J., Siess L., T. Bensby, The P. S., Viallefond F., Viallefond F., Viallefond F., Westin T. N. G., Wright A. E.   +33 more
core   +1 more source

A YOUNG PROTOPLANET CANDIDATE EMBEDDED IN THE CIRCUMSTELLAR DISK OF HD 100546 [PDF]

, 2013
We present high-contrast observations of the circumstellar environment of the Herbig Ae/Be star HD 100546. The final 3.8 μm image reveals an emission source at a projected separation of 0.″48 ± 0.″04 (corresponding to ∼47 ± 4 AU) at a position angle of 8.
S. Quanz, A. Amara, M. Meyer, M. Kenworthy, M. Kasper, Julien H. Girard   +5 more
semanticscholar   +1 more source

XMM‐Newton Observations of the Peculiar Be X‐Ray Binary A0538‐66

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT A0538‐66 is a neutron star/Be x‐ray binary located in the Large Magellanic Cloud and, since its discovery in the 70s, it showed a peculiar behavior that makes it a unique object in the high‐mass x‐ray binaries scene: the extremely eccentric orbit (e=0.72$$ e=0.72 $$), the short spin period of the neutron star (P=69$$ P=69 $$ ms), the episodes ...
Michela Rigoselli, Caterina Tresoldi, Lorenzo Ducci, Sandro Mereghetti   +3 more
wiley   +1 more source

Angular Momentum Transport in Binary Star Formation: The Enhancement of Magnetorotational Instability and Role of Outflows

The Astrophysical Journal
The formation of binary stars is highly influenced by magnetic fields, which play a crucial role in transporting angular momentum. We conducted 3D numerical simulations of binary star accretion via a circumbinary disk, taking into account a magnetic ...
Tomoaki Matsumoto
doaj   +1 more source

Angular Momentum Exchange by Gravitational Torques and Infall in the Circumbinary Disk of the Protostellar System L1551 NE [PDF]

, 2014
We report the ALMA observation of the Class I binary protostellar system L1551 NE in the 0.9-mm continuum, C18O (3-2), and 13CO (3-2) lines at a ~1.6 times higher resolution and a ~6 times higher sensitivity than those of our previous SMA observations ...
Hanawa, Tomoyuki, Ho, Paul T. P., Lim, Jeremy, Matsumoto, Tomoaki, Saigo, Kazuya, Saito, Masao, Takakuwa, Shigehisa   +6 more
core   +2 more sources

Toward an efficient second‐order method for computing the surface gravitational potential on spherical‐polar meshes

Astronomische Nachrichten, Volume 345, Issue 8, October 2024.
Abstract Astrophysical accretion discs that carry a significant mass compared with their central object are subject to the effect of self‐gravity. In the context of circumstellar discs, this can, for instance, cause fragmentation of the disc gas, and—under suitable conditions—lead to the direct formation of gas‐giant planets.
Oliver Gressel, Udo Ziegler
wiley   +1 more source

Revisiting the Chemical Composition of WD 1145+017: Impact of Circumstellar Disk Contamination on Photospheric Abundances

The Astrophysical Journal
We performed a chemical analysis of the asteroid-bearing white dwarf WD 1145+017 using optical and ultraviolet spectroscopic data from 25 epochs between 2015 and 2023.
Érika Le Bourdais, Patrick Dufour, Siyi Xu   +2 more
doaj   +1 more source

Linking Circumstellar Disk Lifetimes to the Rotational Evolution of Low-mass Stars

The Astrophysical Journal, 2023
The high-energy radiation emitted by young stars can have a strong influence on their rotational evolution at later stages. This is because internal photoevaporation is one of the major drivers of the dispersal of circumstellar disks, which surround all ...
K. Monsch, J. J. Drake, C. Garraffo, G. Picogna, B. Ercolano   +4 more
doaj   +1 more source

Optical and Near-Infrared Monitoring of Gamma-ray Binaries Hosting Be Stars

Universe, 2021
Optical and near-infrared observations are compiled for the three gamma-ray binaries hosting Be stars: PSR B1259−63, LSI+61 303, and HESS J0632+057. The emissions from the Be disk are considered to vary according to the changes in its structure, some of ...
Yuki Moritani, Akiko Kawachi
doaj   +1 more source