Related Experiment Video
Updated: Aug 4, 2026

High Precision Zinc Isotopic Measurements Applied to Mouse Organs
Published on: May 22, 2015
Neutron-Capture Element Abundances in the Globular Cluster M15
Abstract:
High-resolution, high signal-to-noise ratio, blue-violet spectra of three red giant branch tip stars in M15 have been obtained with the Keck I High-Resolution Echelle Spectrograph. These spectra have been analyzed to determine the abundances of several neutron-capture elements, including the radioactive chronometer element thorium. There are two principal results of this study. First, the abundances of the heavier (Z>/=56) elements for each of the three stars is well matched by a scaled solar system r-process abundance distribution. Second, a weighted mean-observed Th/Eu ratio for the stars implies an age for the neutron-capture material in M15 stars of 14+/-3 Gyr, in reasonable agreement with other recent age estimates for Galactic globular clusters.
More Related Videos
Related Concept Videos
Electron Configuration of Multielectron Atoms
Atomic Radii and Effective Nuclear Charge
Nuclear Stability
To hold positively charged protons together in the...
Nuclear Transmutation
Atomic Nuclei: Nuclear Magnetic Moment
Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...

