Massive star exhibits dramatic outbursts

Tribune Newsroom Friday, November 13, 2026 1 minute read

This release features a composite image of a spiral galaxy with a giant, unstable star at its outer edge. Using Chandra, astronomers have discovered the star’s previously hidden companion, which triggers luminous outbursts every 113 days. The spiral galaxy is NGC 4559. Shown at a sharp angle in the composite image, its flat pink and milky blue face tilts toward our upper left. Sitting near the outer edge of the dense spiral, near the center of the frame, is a small group of pink and blue dots. This group is outlined with a white square, enlarged and annotated in supporting images. The smallest pink dot in the square is AT 2016blu, a massive star some 33 times the size of our Sun. For over 15 years astronomers have been watching this star get bright and then dim again in optical light on a regular basis. Chandra’s X-ray observations suggest that a hidden companion object, either a stellar mass black hole or a neutron star, is pulling material from AT 2016blu every 113 days as they orbit one another. This captured material gets so hot that it shines brightly in X-rays. Other pink and blue specks within the white square and enlargement are unresolved stars or star clusters, too distant to be related to the movement of material between AT 2016blu and its hidden but influential neighbor.

Discovery of Unstable Star’s Outbursts

Astronomers utilizing NASA’s Chandra X-ray Observatory have identified the cause behind the frequent outbursts from a massive, unstable star. This finding involves the star AT 2016blu, which is situated in the spiral galaxy NGC 4559, approximately 30 million light-years from Earth.

Details of the Star

AT 2016blu is a particularly large star, with an estimated mass exceeding 33 times that of the Sun. The recent observations have provided significant insights into the behavior of this volatile celestial body.

Significance of the Research

This discovery sheds light on the dynamics of massive stars and their explosive events, contributing to the broader understanding of stellar evolution and the lifecycle of galaxies. The findings were released on November 9, 2026, highlighting advancements in astronomical research.

The image accompanying the announcement combines X-ray data from NASA and the University of Virginia with optical data from the Sloan Digital Sky Survey, showcasing the intricate details of the galaxy and the star’s activities.

Source: NASA