White Dwarfs in Death Spiral Could Unravel Century-Old Mystery
White dwarfs are the collapsed corpses of stars like our Sun that ran out of fuel. Now, astronomers have found a pair of binary white dwarfs orbiting each other once every seven minutes, the fastest orbit ever found for this type of system. Known as ZTF J1539+5027 (or J1539), this pair of stellar corpses could help unlock the secrets of gravitational waves — mysterious ripples in space time first proposed by Albert Einstein in 1915.
Every clear night, the Zwicky Transient Facility (ZTF), operated by Caltech at the 48-inch telescope at Mount Palomar, searches for celestial objects which move, blink, or vary in brightness. Promising candidates are then forwarded to the Kitt Peak National Observatory in Arizona, where they are studied in more detail. The 2.1 meter telescope at Kitt Peak was equipped with a new instrument, the Electron Multiplying Demonstrator (KPED) to quickly identify varying brightness levels seen from stars.
“As the dimmer star passes in front of the brighter one, it blocks most of the light, resulting in the seven-minute blinking pattern we see in the ZTF data,” Caltech graduate student Kevin Burdge explained.
The J1539 system is so small, the pair would fit inside of the planet Saturn. The pair is found 8,000 light years from Earth, seen in the constellation of Boötes…
