A particular star shows spectral lines of the lithium isotope ⁶Li. What conclusion do astronomers draw from this observation? A) The star has vaporized one of its planets that spiraled in too close to the star because the star's own ⁶Li was destroyed by nuclear reactions long ago. B) The star has not yet begun nuclear reactions in its core because these reactions destroy ⁶Li. C) Planets must be orbiting around the star because only planets show ⁶Li spectral lines. D) The star is composed of pristine (unmodified) material from the Big Bang because ⁶Li has been destroyed in material that has been processed in stars and expelled back into space.

Question

Quizplus · Accepted Answer

The presence of ⁶Li in the star's spectrum suggests that it has acquired this isotope from an external source, such as a vaporized planet, because ⁶Li is typically destroyed in stars through nuclear reactions.

A Particular Star Shows Spectral Lines of the Lithium Isotope