DTM staff member, Alycia Weinberger, along with a team of scientists from UCLA and the Gemini Observatory, have discovered dusty debris around an essentially dead star where gravity and radiation should have long ago removed any sign of dust. This finding may provide insights into our own solar system’s eventual demise several billion years from now.

The team’s results are based on mid-infrared observations made with the Gemini 8-m Frederick C. Gillett Telescope in Hawaii in May. These observations reveal a surprisingly high abundance of dust orbiting an ancient stellar ember named GD 362.

GD 362 is a white dwarf star. It represents the end-state of stellar evolution for stars like the Sun and more massive stars, such as this one’s progenitor, which had an original mass about seven times that of the Sun’s. After undergoing nuclear reactions for millions of years, GD 362’s core ran out of fuel and could no longer create enough heat to counterbalance the inward push of gravity. After a short period of instability and mass loss, the star collapsed into a white-hot mass, the remains of which have been cooling ever since. On the basis of its cooling rate, astronomers estimate that between two and five billion years have passed since the death of GD 362. This long time interval would explain why there is no sign of a shell of glowing gas, known as a planetary nebula, from the explulsion of material as the star died. During its thermonuclear decline, GD 362 experienced an extensive period of mass loss, dropping from a mass of about seven solar masses, to a smaller, one-solar-mass shadow of its former self.

The Gemini’s unique observations were made with the MICHELLE mid-infrared spectograph on the Gemini North telescope on Mauna Kea, Hawaii. Describing the research team’s discoveries, Weinberger concludes: “These data were phenomenal. Observing this star was a thrill! We were able to find the remnants of a planetary system around this star only because of Gemini’s tremendous sensitivity in the mid-infrared. Usually you need a spacecraft to do this well.”

To view the project’s full results, which will appear in an upcoming issue of the Astrophysical Journal, click here.