Results 31 to 40 of about 2,119 (235)

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

Extending the ALMA Census of Circumstellar Disks in the Upper Scorpius OB Association

The Astrophysical Journal
We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 7 continuum (340 GHz) and carbon monoxide (CO) J = 3–2 observations for an extended sample of disks in the Upper Scorpius OB Association (Upper Sco, age ∼10 Myr).
John M. Carpenter, Taran L. Esplin, Kevin L. Luhman, Eric E. Mamajek, Sean M. Andrews   +4 more
doaj   +1 more source

Scattered Radiation of Protoplanetary Disks

Universe, 2022
Scattered radiation of circumstellar (CS) dust plays an important role in the physics of young stars. Its observational manifestations are various but more often they are connected with the appearance of intrinsic polarization in young stars and their CS
Vladimir P. Grinin, Larisa V. Tambovtseva   +1 more
doaj   +1 more source

Debris Disks Can Contaminate Mid-infrared Exoplanet Spectra: Evidence for a Circumstellar Debris Disk around Exoplanet Host WASP-39

The Astrophysical Journal Letters
The signal from a transiting planet can be diluted by astrophysical contamination. In the case of circumstellar debris disks, this contamination could start in the mid-infrared and vary as a function of wavelength, which would then change the observed ...
Laura Flagg, Alycia J. Weinberger, Taylor J. Bell, Luis Welbanks, Giuseppe Morello, Diana Powell, Jacob L. Bean, Jasmina Blecic, Nicolas Crouzet, Peter Gao, Julie Inglis, James Kirk, Mercedes López-Morales, Karan Molaverdikhani, Nikolay Nikolov, Apurva V. Oza, Benjamin V. Rackham, Seth Redfield, Shang-Min Tsai, Ray Jayawardhana, Laura Kreidberg, Matthew C. Nixon, Kevin B. Stevenson, Jake D. Turner   +23 more
doaj   +1 more source

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

Vertical Structure of Gas and Dust in Four Debris Disks

The Astrophysical Journal
We present high-spectral-resolution M -band spectra from iSHELL on NASA’s Infrared Telescope Facility along the line of sight to the debris disk host star HD 32297. We also present a Gemini Planet Imager H -band polarimetric image of the HD 131488 debris
Kadin Worthen, Christine H. Chen, Sean D. Brittain, Cicero X. Lu, Isabel Rebollido, Aoife Brennan, Luca Matrà, Carl Melis, Timoteo Delgado, Aki Roberge, Johan Mazoyer   +10 more
doaj   +1 more source

Circumstellar Disks and Star Formation [PDF]

Highlights of Astronomy, 1992
Results from the IRAS satellite showed that many pre-main sequence stars exhibited unexpectedly large fluxes in the infrared spectral region. Several studies have shown that the simplest and most satisfying explanation of this excess emission is that it arises in optically-thick, dusty, circumstellar disks (Rucinski 1985; Adams, Lada, and Shu 1987 ...
L. Hartmann, M. Gomez, S.J. Kenyon
openaire   +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

MIRI MRS Observations of β Pictoris. I. The Inner Dust, the Planet, and the Gas

The Astrophysical Journal
We present JWST MIRI Medium Resolution Spectrograph (MRS) observations of the β Pictoris system. We detect an infrared excess from the central unresolved point source from 5 to 7.5 μ m which is indicative of dust within the inner ∼7 au of the system.
Kadin Worthen, Christine H. Chen, David R. Law, Cicero X. Lu, Kielan Hoch, Yiwei Chai, G. C. Sloan, B. A. Sargent, Jens Kammerer, Dean C. Hines, Isabel Rebollido, William Balmer, Marshall D. Perrin, Dan M. Watson, Laurent Pueyo, Julien H. Girard, Carey M. Lisse, Christopher C. Stark   +17 more
doaj   +1 more source

Modelling and interpretation of SEDs*

EPJ Web of Conferences, 2015
Circumstellar disks are mostly detected by larger continuum fluxes in the infrared to mm spectral regions as compared to naked stars (a flux excess).
Woitke Peter
doaj   +1 more source