Fermilab team discovers star

Artist rendering of Dwarf star. Photo: NASA/JPL-Caltech

Fermilab scientists Douglas Tucker of SCD and William Wester of PPD, visiting Professor J Allyn Smith from Austin Peay State University, and interns Samuel Wyatt and Mees Fix identified a cataclysmic variable star while looking for white dwarf stars as part of [the commissioning phase for] the Dark Energy Survey.

“They’re not unusual, but they’re really interesting scientifically,” says Smith. “[This type of star] is the progenitor of a Type I supernova,” although this particular star won’t explode for millions of years.

Cataclysmic variable stars are actually a set of two stars, one white dwarf and one normal. The super-dense dwarf draws matter away from the companion star, which forms an accretion disk around the star. When matter falls into the star or when the disk becomes very dense and heated, it emits radiation.

Fix made the actual discovery, when he noticed these emissions while analyzing the star’s spectroscopy. He brought the results to the group, who recognized the emissions pattern as one belonging to a cataclysmic variable star.

Although it appeared in sky surveys dating back to the 1950s, no one had previously identified this object as a cataclysmic variable star.

“It took a young summer student to clean up the spectra that we recorded to identify it,” said Wester.

While the star can’t be used as a part of the Dark Energy Survey, the team plans to do further research to discover more about this phenomenon.

This article first appeared in the August issue of Computing Bits.