'Pumpkin Stars' Spin So Fast They Resemble Pumpkins

Thanks to NASA's Swift and Kepler efforts, researchers have discovered a type of star dubbed a 'pumpkin star' due to its rapid spinning and the shape it appears to have as a result. Chief among the newly found stars is the KSw 71, a giant orange star that completes a rotation in only 5.5 days. In addition, this massive 'pumpkin' star is 10 times the size of the sun with x-ray emissions great than 4,000 times the sun's solar maximum.

The star doesn't really look like a pumpkin, of course, instead resembling one mostly due to its orange color and its seemingly "squashed" shape — the visual appearance is caused by its extreme spinning. Researchers describe the stars as rare and credit the Kepler mission for ultimately uncovering them. It appears that for now at least, 18 of these pumpkin stars have been discovered.

The stars' temperatures span a range that is slightly cooler to slightly hotter than the sun, and whose sizes mostly range from about 3 to about 10.5 times larger than the sun. Though 18 have been identified, researchers estimate there are about 160 pumpkin stars in the Kepler region where these were found.

A close binary system in which two giant stars merged may be the cause of these huge, fast 'pumpkins,' but the exact cause isn't clear at this time. These stars likely had disks at one point that have since dissipated, a short process in terms of space, but one that still takes millions of years. This phase of development — the spinning, that is — is considered brief, relatively speaking, making it a lucky find for astronomers.

SOURCE: Science Daily