Results 31 to 40 of about 25,802 (223)

Dust-forming molecules in VY Canis Majoris (and Betelgeuse)

, 2013
The formation of inorganic dust in circumstellar environments of evolved stars is poorly understood. Spectra of molecules thought to be most important for the nucleation, i.e.
Brunken, S., Gottlieb, C. A., Kaminski, T., McCarthy, M. C., Menten, K. M., Muller, H. S. P., Patel, N. A., Schmidt, M. R., Winters, J. M., Young, K. H.   +9 more
core   +1 more source

A Coronagraphic Pilot Study of the Circumstellar Environments around Red Supergiants: CD -31°4916’s Dust Morphology

The Astronomical Journal
Many mechanisms have been proposed to contribute to massive-star mass loss, but in general little is known about the physics involved. Studies of circumstellar environments around massive stars might help to determine which mechanisms are the most common.
Jamie R. Lomax, Emily M. Levesque, John P. Wisniewski, John H. Debes   +3 more
doaj   +1 more source

Composite grains: Application to circumstellar dust

Atti della Accademia Peloritana dei Pericolanti : Classe di Scienze Fisiche, Matematiche e Naturali, 2011
Using the discrete dipole approximation (DDA) we calculate the absorption efficiency of the composite grain, made up of a host silicate spheroid and inclusions of graphite, in the spectral region 5.0-25.0μm.
D. B. Vaidya, R. Gupta
doaj   +1 more source

SN 2020uem: a Possible Thermonuclear Explosion within a Dense Circumstellar Medium. I. The Nature of Type IIn/Ia-CSM SNe from Photometry and Spectroscopy

The Astrophysical Journal, 2023
We have performed intensive follow-up observations of a Type IIn/Ia-CSM supernova (SN IIn/Ia-CSM), 2020uem, with photometry, spectroscopy, and polarimetry. In this paper, we report on the results of our observations focusing on optical/near-infrared (NIR)
Kohki Uno, Keiichi Maeda, Takashi Nagao, Tatsuya Nakaoka, Kentaro Motohara, Akito Tajitsu, Masahiro Konishi, Shuhei Koyama, Hidenori Takahashi, Masaomi Tanaka, Hanindyo Kuncarayakti, Miho Kawabata, Masayuki Yamanaka, Kentaro Aoki, Keisuke Isogai, Kenta Taguchi, Mao Ogawa, Koji S. Kawabata, Yuzuru Yoshii, Takashi Miyata, Ryo Imazawa   +20 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

Near-infrared Integral-field Spectroscopy of the Wind Forming Region of CW Leo

The Astronomical Journal
The circumstellar envelope of the carbon star CW Leo exhibited various unexpected changes in recent optical imaging observations. We have performed a follow-up observation using the Near-infrared Integral-Field Spectrograph (NIFS) equipped on the Gemini ...
Hyosun Kim, Youichi Ohyama, Ho-Gyu Lee, Ji Hoon Kim   +3 more
doaj   +1 more source

Interrelationships between interstellar and interplanetary grains [PDF]

, 1986
The relationship between solar system dust (SSD) and interstellar dust particles (ISMD) is being reconsidered because of the discovery of isotopic anomalies in meteorites.
Clayton, D. D.
core   +2 more sources

MODELS OF CIRCUMSTELLAR MASERS IN BIPOLAR OUTFLOWS

Odessa Astronomical Publications, 2017
Sources of molecular maser radio emission in envelopes of late-type variable stars (red giants and supergiants) are considered. Radio and optical data on asymmetry of mass loss process in red giants are briefly reviewed.
G. M. Rudnitskij
doaj   +1 more source

Dust Around T Tauri Stars [PDF]

Journal of Astronomy and Space Sciences, 2011
To reproduce the multiple broad peaks and the fine spectral features in the spectral energy distributions (SEDs) of T Tauri stars, we model dust around T Tauri stars using a radiative transfer model for multiple isothermal circumstellar dust shells. We
Kyung-Won Suh, Young-Joo Kwon
doaj   +1 more source

First direct detection of large polycyclic aromatic hydrocarbons on asteroid (162173) Ryugu samples: An interstellar heritage

Natural Sciences, Volume 4, Issue 4, October 2024.
Large free aromatic species, with up to 61 carbon atoms, were detected in grains of the Ryugu carbonaceous asteroid using ultra‐sensitive two‐step laser mass spectrometry. This discovery confirms the presence of large polycyclic aromatic hydrocarbons in the interstellar medium and provides new information on the formation and evolution of organic ...
Hassan Sabbah, Ghylaine Quitté, Karine Demyk, Christine Joblin   +3 more
wiley   +1 more source