Results 11 to 20 of about 60,044 (291)
The Astrophysical Journal, 2023 We present the first isotopic abundances of both ^13 CO and C ^18 O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions.
David R. Coria +5 more
doaj +1 more source
The Astrophysical Journal Letters, 2023 GN-z11 is an unusually luminous high-redshift galaxy that was recently observed to have strong nitrogen lines while at the same time lacking traditional signatures of active galactic nucleus activity.
Chris Nagele, Hideyuki Umeda
doaj +1 more source
Frontiers in Astronomy and Space Sciences, 2021 Among presolar grains, oxide ones are made of oxygen, aluminum, and a small fraction of magnesium, produced by the 26Al decay. The largest part of presolar oxide grains belong to the so-called group 1 and 2, which have been suggested to form in Red Giant
S. Palmerini +11 more
doaj +1 more source
Isotopic Composition of Solar Wind Calcium: First in Situ Measurement by CELIAS/MTOF on Board SOHO [PDF]
, 1997 We present first results on the Ca isotopic abundances derived from the high resolution Mass Time-of-Flight (MTOF) spectrometer of the charge, element, and isotope analysis system (CELIAS) experiment on board the Solar and Heliospheric Observatory (SOHO).
A. B. Galvin +16 more
core +3 more sources
The cosmic-ray contribution to galactic abundances of the light elements: Interpretation of GCR LiBeB abundance measurements from ACE/CRIS [PDF]
, 2001 Inelastic collisions between the galactic cosmic rays (GCRs) and the interstellar medium (ISM) are responsible for producing essentially all of the light elements Li, Be, and B (LiBeB) observed in the cosmic rays.
Binns, W. R. +14 more
core +1 more source
Cold Deuterium Fractionation in the Nearest Planet-forming Disk
The Astrophysical Journal, 2023 Deuterium fractionation provides a window into the thermal history of volatiles in the solar system and protoplanetary disks. While evidence of active molecular deuteration has been observed toward a handful of disks, it remains unclear whether this ...
Carlos E. Romero-Mirza +9 more
doaj +1 more source
Cno Abundances Of Hydrogen-Deficient Carbon And R Coronae Borealis Stars: A View Of The Nucleosynthesis In A White Dwarf Merger [PDF]
, 2009 We present high-resolution (R similar to 50,000) observations of near-IR transitions of CO and CN of the five known hydrogen-deficient carbon (HdC) stars and four R Coronae Borealis (RCB) stars.
Eriksson, Kiell +3 more
core +1 more source
Sm and Gd Isotopic Shifts in Eucrites and Implications for Their Cosmic-Ray Exposure History
The Astrophysical Journal, 2023 The isotopic compositions of Sm and Gd in eight eucrites—five from a desert, Dar al Gani (DaG) 380, DaG 391, DaG 411, DaG 443, and DaG 480, and three from nondesert areas, Juvinas, Millibillillie, and Stannern—were determined to understand the cosmic-ray
Takaharu Saito +2 more
doaj +1 more source
Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints [PDF]
, 2015 Context. The availability of asteroseismic constraints for a large sample of red giant stars from the CoRoT and Kepler missions paves the way for various statistical studies of the seismic properties of stellar populations. Aims.
Baglin, A. +19 more
core +5 more sources
Oxygen isotopic ratios in cool R Coronae Borealis stars [PDF]
, 2010 We investigate the relationship between R Coronae Borealis (RCB) stars and hydrogen-deficient carbon (HdC) stars by measuring precise 16O/18O ratios for five cool RCB stars.
Alvarez +17 more
core +3 more sources