Results 81 to 90 of about 54,240 (242)

Overlapping Open Clusters NGC 1750 and NGC 1758 behind the Taurus Dark Clouds. II. CCD Photometry in the Vilnius System

Open Astronomy, 2003
Seven-color photometry in the Vilnius system has been obtained for 420 stars down to V = 16 mag in the area containing the overlapping open clusters NGC 1750 and NGC 1758 in Taurus.
Straižys V., Kazlauskas A., Černiauskas A., Boyle R. P., Vrba F. J., Philip A. G. Davis, Laugalys V., Černis K., Smriglio F.   +8 more
doaj   +1 more source

From Anti‐Van't Hoff Le Bel Molecules of C6NH to Astronomically Relevant and Experimentally Known and Unknown Carbenes

ChemPhysChem, Volume 26, Issue 20, October 15, 2025.
Molecules with a planar tetracoordinate carbon atom serve as reactive intermediates for carbenes. While isomer 2 has been identified in the laboratory, isomer 5 remains elusive to date. Here, four stationary points with a planar tetracoordinate carbon (ptC) atom that are considered as anti‐van't Hoff Le Bel molecules have been computationally ...
Shilpa Shajan, Devipriya Sivadasan, Krishnan Thirumoorthy, Venkatesan S. Thimmakondu   +3 more
wiley   +1 more source

Nearby Supernova and Cloud Crossing Effects on the Orbits of Small Bodies in the Solar System

The Astrophysical Journal Letters
Supernova (SN) blasts envelop many surrounding stellar systems, transferring kinetic energy to small bodies in the systems. Geologic evidence from ^60 Fe points to recent nearby SN activity within the past several Myr.
Leeanne Smith, Jesse A. Miller, Brian D. Fields   +2 more
doaj   +1 more source

UV–Vis Spectra of Carbonic Acid: Rationalizing Experimental Redshifts between Monomer and Bulk based on (H2CO3)n Calculations

ChemPhysChem, Volume 26, Issue 18, September 19, 2025.
In bulk carbonic acid (e.g., in interstellar icy dust grains) cluster formation produces two distinct UV‐Vis spectral features redshifted by ≈2 eV (25 nm) and by ≈5 eV (80 nm) compared to gas phase single molecule carbonic acid 's adiabatic ionization energy. Theory and experiment were used to investigate the origin of these shifts.
Dennis F. Dinu, Bastian Klein, Chaojiang Zhang, Radu A. Talmazan, Thomas Loerting, Hinrich Grothe, Ralf I. Kaiser, Maren Podewitz   +7 more
wiley   +1 more source

Plasma Production by Laser Ablation of Heavy Metals

Contributions to Plasma Physics, Volume 65, Issue 7, August 2025.
ABSTRACT An Nd:YAG focused laser operating at 1064 nm, 3 ns pulse width, 360 mJ pulse energy, is employed to irradiate heavy metals, such as Ta, W, Pt, Au, and Pb. The in‐vacuum irradiation produces an expanding plasma at the target surface which has high density, temperature, and kinetic energy of emitted ions. Ions have a velocity of the order of 104 
L. Torrisi, M. Cutroneo, A. Torrisi
wiley   +1 more source

Theoretical Calculations for the Acidity of Cyanopolyynes HC2n+1N (n = 0–5) in Gas and Aqueous Phases Using Ab initio Methods

ARO-The Scientific Journal of Koya University, 2019
Cyanopolyynes have been found in the interstellar medium, cold dust cloud Taurus Molecular Cloud-1, and the Titan’s atmosphere. Theoretical calculations are carried out to predict gas and aqueous phase acidities of a series of cyanopolyynes acids.
Hassan H. Abdallah
doaj   +1 more source

The Spectral Energy Distribution of Self-gravitating Interstellar Clouds I. Spheres

, 2007
We derive the spectral energy distribution (SED) of dusty, isothermal, self gravitating, stable and spherical clouds externally heated by the ambient interstellar radiation field.
Bernard J. P., Bernard J. P., Bonnor W. B., Boulanger F., Chlewicki G., Ebert R., Gail H.-P., Jörg Fischera, Laureijs R. J., Lehtinen K., Lehtinen K., Lehtinen K., Lemke D., Mathis J. S., Mattila K., Michael A. Dopita, Ossenkopf V., Padoan P.   +17 more
core   +1 more source

Observations of the Local Interstellar Cloud [PDF]

International Astronomical Union Colloquium, 1997
AbstractConstraints on the ambient (circumsolar) interstellar medium can be derived from observations of interstellar neutrals or their derivatives in the heliosphere. New results have been recently obtained which, when combined with optical and UV observations of the nearby stars (HST-GHRS, EUVE), remove long-standing contradictions and allow us to ...
openaire   +1 more source

The Effect of an Inert Solid Reservoir on Molecular Abundances in Dense Interstellar Clouds

Open Astronomy, 2012
The question, what is the role of freeze-out of chemical species in determining the molecular abundances in the interstellar gas is a matter of debate.
Kalvāns Juris, Shmeld Ivar
doaj   +1 more source

The 2200 A bump and the UV extinction curve

, 2012
The 2200 A bump is a major figure of interstellar extinction. Extinction curves with no bump however exist and are, with no exception, linear from the near-infrared down to 2500 A at least, often over all the visible-UV spectrum.
Bondar, Bradley, Cardelli, Cecchi-Pestellini, Divan, Désert, Fitzpatrick, Gordon, Herbig, Li, Li, Mulas, Nandy, Papoular, Savage, Schalén, Seaton, Steglich, Wegner, Whitford, Wickramasinghe, Wu, Yastrebov, Zagury, Zagury, Zagury, Zagury, Zagury, Zagury, Zagury, Zagury, Zagury, Zagury, Zonca   +33 more
core   +1 more source