Stunning New Images from Ball: The Spectropolarimetric High-Contrast Exoplanet Research Instrument on ESO’s Very Large Telescope (VLT) Showcase the Intricate Interactions of Gas and Dust Ejected by the Dual Stars in the AFGL 4106 System.

“Before a star reaches the end of its life cycle, it expels massive amounts of gas and dust that contribute to the formation of a growing nebula,” stated Dr. Gabriel Tomassini from the Côte d’Azur Observatory and colleagues.

“The massive stars in the AFGL 4106 system are in advanced but distinct stages of their lifecycle, with one having shed enough mass to form a surrounding dusty envelope.”

In their recent study, the authors meticulously map this cosmic debris to identify the characteristics of AFGL 4106’s central star.

“Imaging objects near a bright star presents significant challenges due to the star’s overwhelming brightness. In fact, the central star appears black as its brilliance saturates the image detectors,” noted the researchers.

“Fortunately, the VLT’s SPHERE instrument excels at managing significant light contrasts, enabling detailed observation of both the luminous stars and their darker surrounding nebulae for the first time.”

“It also corrects for atmospheric turbulence, providing remarkably clear images.”

The nebula’s unique shape indicates that the companion star significantly affects the gas outflow from the dying star, introducing asymmetry and distorting the gas and dust cloud from a perfectly spherical shape.

“Our findings place constraints on the physical properties and evolutionary status of the system,” concluded the astronomers.

“This research enhances our understanding of mass loss processes in massive binary stars and the morphology of nebulae surrounding evolved stars.”

Results from this study are detailed in the journal Astronomy and Astrophysics.

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G. Tomassini et al.. 2026. Characterizing the post-red supergiant binary system AFGL 4106 and its complex nebula with SPHERE/VLT. A&A 706, A5; doi: 10.1051/0004-6361/202557705