Results 51 to 60 of about 584 (186)
GalaxiesWe report new medium-resolution spectroscopy covering the wavelength range from 0.6 to 2.4 μm, as well as multi-epoch, multi-wavelength photometry, of the Class I high-mass embedded young stellar object Mol 12 (IRAS 05373+2349). It is embedded (AV≃12) in
Mauricio Tapia +3 more
doaj +1 more source
Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin +11 more
wiley +1 more source
On the Circumstellar Matter Distribution around Herbig Ae/Be Stars
The Astrophysical Journal, 1997 The spectral energy distributions (SEDs) observed in Herbig Ae/Be stars are critically analyzed in connection with a spherically symmetric model for matter distribution around the central objects. The possibility that the dusty component is described by an MRN-DL mixture (see the work of Mathis, Rumpl, and Nordsiek; Draine and Lee) and is constituted ...
PEZZUTO S. +2 more
openaire +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
The Astronomical JournalThe carrier of the 21 μ m emission feature discovered in a handful of protoplanetary nebulae (PPNe) is one of the most intriguing enigmas in circumstellar chemistry.
Jian-Jie Qiu +9 more
doaj +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 +2 more
wiley +1 more source
The Astrophysical Journal LettersWe report C, N, Si, and Al–Mg isotope data for 39 presolar X silicon carbide (SiC) and four silicon nitride grains—a group of presolar grains that condensed in the remnants of core-collapse Type II supernovae (CCSNe)—isolated from the Murchison meteorite.
Nan Liu +5 more
doaj +1 more source
The Effect of Viscosity on the Temperature of Ae Star Disks
GalaxiesThis study explores the impact of viscous heating on decretion disks around Classical Ae (CAe) stars, with a focus on modeling the disk’s thermal structure.
R. Anusha, T. A. A. Sigut
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
Magnetically controlled circumstellar matter in the helium-strong stars
The Astrophysical Journal, 1990 This paper reports the observation and interpretation of the ultraviolet spectrum variations of nine helium-strong stars: HD 36485, 37017, 37479, 37776, 58260, 60344, 64740, 96446, and 133518. A unified model is developed to account for the observed correlation among three stellar properties: the line profile characteristics of the C IV and Si IV ...
Steven N. Shore, Douglas N. Brown
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