Results 111 to 120 of about 362,838 (268)

Signatures of exosolar planets in dust debris disks

open access: yes, 2000
We apply our recently elaborated, powerful numerical approach to the high-resolution modeling of the structure and emission of circumstellar dust disks, incorporating all relevant physical processes.
Gorkavyi, Nick N.   +3 more
core   +1 more source

Synthetic Modeling of Polarized Dust Emission in Intermediate-mass Young Stellar Objects. II. Effects of Radiative Torque Disruption on Dust Grains in Protostellar Jets/Outflows

open access: yesThe Astrophysical Journal
One possible explanation for the presence of very large grains (VLGs) larger than 10 μ m in the inner envelope of intermediate-mass Class 0/I young stellar objects is their migration from the protostellar disk via outflows. To assess whether RATD hinders
Nguyen Chau Giang   +4 more
doaj   +1 more source

Are Giant Planets Forming Around HR 4796A? [PDF]

open access: yes, 2003
We have obtained FUSE and HST STIS spectra of HR 4796A, a nearby 8 Myr old main sequence star that possesses a dusty circumstellar disk whose inclination has been constrained from high resolution near-infrared observations to be ~17 deg from edge-on.
Abgrall H.   +6 more
core   +1 more source

Discovery of Volatile Gas in the Giant Impact Disk Around the 150 Myr Old HD 23514

open access: yesThe Astrophysical Journal Letters
We report the discovery of CO _2 gas emission around HD 23514, an F5V star in the ∼150 Myr old Pleiades cluster, hosting one of the rare giant-impact disks with unique mineralogy dominated by silica dust. We show that the dust feature remains stable over
Kate Y. L. Su   +10 more
doaj   +1 more source

A GLIMPSE into the Nature of Galactic Mid-IR Excesses

open access: yes, 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.   +33 more
core   +1 more source

Evidence of V-band polarimetric separation of carbon stars at high Galactic latitude

open access: yes, 2010
Polarization is an important indicator of stellar evolution, especially for stars evolving from red-giant stage to planetary nebulae. However, not much is known about the polarimetric properties of the carbon-enhanced metal-poor (CEMP) stars, although ...
Aoki   +21 more
core   +1 more source

The Morphology of the Asteroidal Dust around White Dwarf Stars: Optical and Near-infrared Pulsations in G29-38

open access: yesThe Astrophysical Journal
More than 36 yr have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class.
Ted von Hippel   +22 more
doaj   +1 more source

The circumstellar envelope of AFGL 4106 [PDF]

open access: yes, 1999
We present new imaging and spectroscopy of the post-red supergiant binary AFGL 4106. Coronographic imaging in H-alpha reveals the shape and extent of the ionized region in the circumstellar envelope (CSE).
Molster, F. J.   +3 more
core   +1 more source

Very Late-time JWST and Keck Spectra of the Oxygen-rich Supernova 1995N

open access: yesThe Astrophysical Journal
We present new JWST/MIRI Medium Resolution Spectroscopy and Keck spectra of SN 1995N obtained in 2022–2023, more than 10,000 days after the supernova (SN) explosion. These spectra are among the latest direct detections of a core-collapse SN, both through
Geoffrey C. Clayton   +45 more
doaj   +1 more source

SPECTROSCOPIC MONITORING OF THE B[E] OBJECTS FSCMA AND MOCAM

open access: yesOdessa Astronomical Publications, 2019
Objects with the B[e] phenomenon exhibit permitted and forbidden emission lines due to the presence of circumstellar ionized gas and large infrared excesses due to processing of the stellar radiation by circumstellar dust.
A. K. Kuratova   +10 more
doaj   +1 more source

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