NASA telescope identifies companion driving eruptions of massive star AT 2016blu
The discovery of a black hole or neutron star explains why the star survived 27 bursts of light that mimicked supernovas.
Astronomers have identified a compact cosmic companion as the cause of repeated eruptions from a massive star in the NGC 4559 spiral galaxy, according to a Times of India report. The star, named AT 2016blu, is located approximately 30 million light-years from Earth and has a mass at least 33 times that of the Sun.
The star belongs to a class of hot, massive stars called luminous blue variables. Between 2012 and 2026, the star underwent at least 27 visible light bursts, appearing roughly every 113 days. These events resembled supernovas but did not destroy the star, leading astronomers to label them 'supernova impostors'.
Using the NASA Chandra X-ray Observatory, researchers detected X-ray emissions during a March 2026 outburst that were at least 100 times brighter than levels recorded in 2001 and 2002. The data suggests the star is in an elongated orbit with a black hole or a neutron star.
Mojgan Aghakhanloo of the University of Virginia, who led the study, said astronomers had watched the star brighten and dim regularly for 15 years. The study, published in The Astrophysical Journal, explains that the compact companion captures material from the massive star during close encounters, heating it to produce X-rays and visible light.
The findings suggest that some ultra-luminous X-ray sources may be connected to massive stars interacting with compact objects. The research may also help scientists understand why certain stars undergo dramatic changes before dying in supernova explosions.