Results 31 to 40 of about 792,921 (206)

Interstellar C2 molecules in a Taurus dark cloud

open access: yesThe Astrophysical Journal, 1983
Five relatively strong interstellar absorption lines of C2 in the (2-0) Phillips band near 8670 A have been detected toward the heavily reddened, late B star HD 29647, which lies behind a substantial part of one of the darkest regions of the nearest molecular cloud complex, the dark clouds of Taurus.
L. M. Hobbs   +2 more
openaire   +1 more source

The 12C/13C Ratio in Interstellar Dark Clouds [PDF]

open access: yesSymposium - International Astronomical Union, 1980
Since 13C is believed to be produced by non-equilibrium CNO processing in stellar evolution (Truran 1977), measurements of the carbon ratio Rc ≡ [12C] / [13C] in the interstellar medium may provide important information on nucleo-synthesis. Commonly, the ratio (N13/N18)LTE ≡ [13CO/C18O]LTE is measured and from this RLTE ≡ [12CO/13CO]LTE is deduced and ...
W.H. Mccutcheon   +3 more
openaire   +1 more source

The Young Ages of 70 μm Dark Clumps Inferred from Carbon Chain Chemistry

open access: yesThe Astrophysical Journal
The physical conditions of the earliest environment of high-mass star formation are currently poorly understood. To that end, we present observations of the carbon chain molecules HC _5 N, CCS, and HC _7 N in the 22–25 GHz band toward 12 high-mass 70 μ m
Kadin Worthen   +6 more
doaj   +1 more source

The formation of molecular hydrogen in the interstellar medium [PDF]

open access: yes, 2010
H2 is the most abundant molecule in the interstellar medium and forms on the surface of interstellar dust grains. Laboratory studies have been conducted of HD formation on a dust grain analogue, which is a highly-oriented pyrolytic graphite surface ...
Islam, F.
core  

Dark ice chemistry in interstellar clouds [PDF]

open access: yes, 2020
This thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores. Astronomical ice observations are also presented and are
Qasim, D.N.
core  

Cosmogenic 10Be as a Tracer for Recent Heliospheric Encounters With Interstellar Cold Clouds and Nearby Supernovae

open access: yesGeophysical Research Letters, Volume 53, Issue 19, 16 October 2026.
Abstract Recent works suggest there are periods when the Sun encountered massive interstellar cold clouds which compressed the heliosphere to within Earth's orbit, exposing Earth to interstellar galactic cosmic rays and energetic particles of heliospheric origin.
Anna Nica   +4 more
wiley   +1 more source

NIKA2 observations around LBV stars Emission from stars and circumstellar material [PDF]

open access: yesEPJ Web of Conferences, 2020
Luminous Blue Variable (LBV) stars are evolved massive objects, previous to core-collapse supernova. LBVs are characterized by photometric and spectroscopic variability, produced by strong and dense winds, mass-loss events and very intense UV radiation ...
Ricardo Rizzo J.   +2 more
doaj   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

open access: yesJournal of Field Robotics, Volume 43, Issue 7, Page 4475-4514, October 2026.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang   +3 more
wiley   +1 more source

Structure and Fragmentation Scale of a Massive Star-forming Filament in NGC 6334: High-resolution Mid-infrared Absorption Imaging with JWST

open access: yesThe Astrophysical Journal Letters
Dense filaments are believed to be representative of the initial conditions of star formation in molecular clouds. We have used the MIRI instrument on JWST to image the massive filament NGC 6334M at d  ∼ 1.3 kpc with unprecedented resolution and dynamic ...
Philippe André   +6 more
doaj   +1 more source

Molecular Life-Time against Photodissociation in Dark Interstellar Clouds [PDF]

open access: yesSymposium - International Astronomical Union, 1987
Molecules in the interstellar space are exposed to interstellar radiation, so that they are destroyed by photodissociation processes, leading to the production of smaller molecules and ions, which in turn can react with other molecular species. Therefore, dissociation rates and dissociation products are important for the chemistry of interstellar ...
S. Aiello   +4 more
openaire   +1 more source

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