Results 51 to 60 of about 25,802 (223)

Radiative Pressure on Fractal Dust Grains in Oxygen-rich AGB Stars

The Astrophysical Journal
There is still considerable debate on the exact composition of grains formed in the outflows of O-rich, asymptotic giant branch stars. Estimates of the expected condensation distances based on radiative transfer calculations show that iron-free silicates
Frank T. Ferguson, Joseph A. Nuth, John A. Paquette   +2 more
doaj   +1 more source

A STUDY OF MASS LOSS AND DUST FORMATION NEAR HOT STARS

Odessa Astronomical Publications, 2016
At present dust formation is well studied only near cool stars, whose surface temperatures are close to those of dust sublimation. Hot stars need to supply large amounts of circumstellar material to allow dust formation around them.
K. S. Kuratov, A. S. Miroshnichenko, A. V. Kusakin, N. Sh. Alimgazinova, A. Zh. Nuryzbaeva, A. B. Manapbaeva, A. K. Kuratova   +6 more
doaj   +1 more source

Morphological Properties of PPNs: Mid-IR and HST Imaging Surveys

, 2000
We will review our mid-infrared and HST imaging surveys of the circumstellar dust shells of proto-planetary nebulae. While optical imaging indirectly probes the dust distribution via dust-scattered starlight, mid-IR imaging directly maps the distribution
B Zuckerman, H Habing, Hrivnak, I Iben Jr, Meixner, S Kwok, SR Trammel   +6 more
core   +2 more sources

Commentary on the role of polyoxometalates in nature cybernetic loop

Natural Sciences, Volume 4, Issue 2-3, June-July 2024.
Polyoxometalates (POMs) are both synthetic and naturally occurring coordination compounds. In the biosphere, POMs can participate in many different life‐determining geochemical and biological processes. Future interdisciplinary research on POMs may reveal their potential for prebiotic and abiotic chemistry, as well as for the development of artificial ...
Kirill Yu. Monakhov
wiley   +1 more source

Infrared Signatures of Disrupted Minor Planets at White Dwarfs

, 2009
Spitzer Space Observatory IRAC and MIPS photometric observations are presented for 20 white dwarfs with T < 20,000 K and metal-contaminated photospheres.
B. Zuckerman, Becklin, Brinkworth, Chen, Chiang, Dahn, Debes, Debes, Desharnais, Dufour, Farihi, Farihi, Farihi, Farihi, Farihi, Fazio, Fixsen, Friedrich, Friedrich, Giclas, Gänsicke, Gänsicke, Hansen, Hoard, Holberg, Holberg, Holberg, Ida, J. Farihi, Jura, Jura, Jura, Jura, Jura, Jura, Kawka, Kawka, Kilic, Kilic, Kilic, Kilic, Lepine, Liebert, Liebert, M. Jura, Marleau, McCook, McCook, Monet, Mullally, Napiwotzki, Perryman, Reach, Rieke, Salim, Skrutskie, von Hippel, Vrba, Zuckerman, Zuckerman, Zuckerman   +60 more
core   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux, Markus Mugrauer, Richard Bischoff   +2 more
wiley   +1 more source

AC Her: Evidence of the First Polar Circumbinary Planet

The Astrophysical Journal Letters, 2023
We examine the geometry of the post–asymptotic giant branch (AGB) star binary AC Her and its circumbinary disk. We show that the observations describe a binary orbit that is perpendicular to the disk with an angular momentum vector that is within 9° of ...
Rebecca G. Martin, Stephen H. Lubow, David Vallet, Narsireddy Anugu, Douglas R. Gies   +4 more
doaj   +1 more source

Limitations of the modified blackbody fit method for determining molecular cloud properties

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract Achieving a comprehensive understanding of the star and planet formation process is one of the fundamental tasks of astrophysics, requiring detailed knowledge of the physical conditions during the different phases of this process. During the earliest stages, that is, concerning physical processes in molecular clouds and filaments, the column ...
Niko Zielinski, Sebastian Wolf
wiley   +1 more source

The Type II SN 2025pht in NGC 1637: A Red Supergiant with Carbon-rich Circumstellar Dust as the First JWST Detection of a Supernova Progenitor Star

The Astrophysical Journal Letters
We present follow-up imaging and spectroscopy and pre-explosion imaging of SN 2025pht located in NGC 1637 at 12 Mpc. Our spectroscopy shows that SN 2025pht is a Type II supernova (SN) with broad lines of hydrogen and with minimal line-of-sight extinction
Charles D. Kilpatrick, Aswin Suresh, Kyle W. Davis, Maria R. Drout, Ryan J. Foley, Alexander Gagliano, Wynn V. Jacobson-Galán, Ravjit Kaur, Kirsty Taggart, Jason Vazquez   +9 more
doaj   +1 more source

A Search for Infrared Emission from Core-Collapse Supernovae at the Transitional Phase

, 2012
Most of the observational studies of supernova (SN) explosions are limited to early phases (< a few yr after the explosion) of extragalactic SNe and observations of SN remnants (> 100 yr) in our Galaxy or very nearby galaxies.
Andrews, Artyukhina, Baars, Bode, Bouchet, Bouchet, Cherchneff, Chu, Chugai, Dale, Dopita, Draine, Dwek, Dwek, Dwek, Dwek, Edoh, Fox, Fox, Fox, Freedman, Gordon, Graham, Hidehiro Kaneda, Hideo Matsuhara, Hines, Immler, Immler, Itsuki Sakon, Kaneda, Keiichi Maeda, Ko Arimatsu, Kotak, Kozasa, Lenz, Liszt, Lorente, Masaomi Tanaka, Meikle, Meikle, Meikle, Mezger, Montes, Murakami, Méndez, Nozawa, Nozawa, Nozawa, Nozawa, Onaka, Petre, Rho, Rho, Rieke, Ryo Ohsawa, Sakon, Schlegel, Schlegel, Schlegel, Schlegel, Schoniger, Seok, Sibthorpe, Skrutskie, Smith, Smith, Smith, Soria, Sugerman, Swinyard, Takashi Onaka, Takaya Nozawa, Takehiko Wada, van Dyk, Werner, Williams   +75 more
core   +1 more source