NASA’s Chandra Finds Source of Star’s Mysterious Outbursts
Edmonds Using NASA’s Chandra X-ray Observatory, astronomers have discovered what is triggering repeated outbursts from a giant, unstable star.
Key points
- “This star’s behavior was confusing at first because it kept acting like a supernova, but clearly it’s not because it keeps surviving these outbursts about three times a year,” said co-author Núria Torres-Albà, also of the University of Virginia.
- The bottom-left image shows NASA’s Chandra X-ray data obtained in 2001 and 2002, before AT 2016blu’s first observed outburst in 2012, and the bottom-right image shows Chandra data obtained between March 24 and March 27, 2026.
- So, we needed to plan the Chandra X-ray observations carefully to be simultaneous with an optical outburst.” Chandra data from March 2026 revealed that AT 2016blu was at least 100 times brighter in X-rays than in Chandra data from 2001 to 2002, which is before the outbursts began.
“To understand the cause of these eruptions, we realized we needed X-ray data, timed so that we’d observe the star when it was in an outburst.” The team used Chandra because it is the only X-ray telescope with sharp enough vision to distinguish AT 2016blu from another nearby bright X-ray source.
Additional details
- A composite NASA Chandra X-ray and Sloan Digital Sky Survey (SDSS) optical image of the galaxy NGC 4559 located about 30 million light-years from Earth.
- A new study, published Monday in the latest issue of The Astrophysical Journal, details the discovery of a previously hidden companion object that keeps pulling material away from the massive star every 113 days as they orbit one another.
- “For 15 years, astronomers have been watching this star get really bright and then dim again on a regular basis,” said Mojgan Aghakhanloo of the University of Virginia in Charlottesville, who led this study.
- The top-left image shows optical data obtained March 14, 2026, by the Katzman Automatic Imaging Telescope (KAIT), when AT 2016blu was in quiescence, or not in outburst, and the top-right image shows KAIT data from March 25, 2026, when the source was in outburst.
- However, unlike in a supernova explosion, the star is not destroyed, so AT 2016blu is also referred to as a “supernova impostor.” Between 2012 and 2026, astronomers detected at least 27 bursts of optical light, or light in wavelengths that are visible to our eyes, from AT 2016blu roughly every 113 days.
How this summary was made: extractive summary — built from the sources' own reporting. It is drawn only from the reporting of the sources listed below — read the originals for full detail. How we summarize →
Advertisement
Every article behind this summary — 1 article from 1 outlet
Get stories like this in your inbox.
Subscribe — it's freeOne free email at 6am — your topics, deduplicated, five minutes. No account, no paywall.