science & techESA/Hubble2024 · Gemini constellation

A white dwarf stealing matter from a partner star explodes 650 million light-years away

the gist

Hubble has imaged the galaxy LEDA 22057, about 650 million light-years away in Gemini, where a supernova called SN 2024PI appears as a pale blue dot near the core. It was discovered in January 2024 by an automated survey that scans the northern sky every two days. This is a Type Ia supernova, which requires a white dwarf, the dense remnant of a star with less than about eight times the Sun's mass. A white dwarf can explode only if it is in a binary system and pulls material from a companion until it becomes too massive to support itself. The resulting runaway fusion destroys it in a blast visible across many galaxies.

so what

Type Ia supernovae are bright and fairly uniform, which is why astronomers use them to measure distances across the universe. Understanding how they start explains a key tool of modern cosmology.

fun fact

The Sun will eventually become a white dwarf, about five billion years from now.

ESA/Hubble · CC BY 4.0

Image: ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)