the star that has exploded six times and defies all theories

Key Points:

• The supernova iPTF14hls, first observed in 2014, defied expectations by erupting multiple times over roughly 1,000 days, with brightness peaking at least five times and maintaining a steady temperature around 5,000 to 6,000 Kelvin.
• Archival images revealed a previous explosion at the same location in 1954, indicating the star has exploded six times since then and is estimated to be at least 50 times more massive than the Sun.
• The debris from iPTF14hls expands at a rate six times slower than any known supernova, suggesting an unusually slow explosion process.
• Scientists have proposed various hypotheses, including antimatter burning, pulsational pair-instability supernova, and an evolving magnetar, but none fully explain the star's unique behavior.
• After fading into a remnant nebula in 2018, the site of iPTF14hls continues to be monitored by the Hubble Space Telescope for further study.