Pages

Sunday, September 21, 2025

LL Pegasi Binary Star System: A Celestial Spiral with a Twist | ALMA & Hubble

LL Pegasi Binary Star System: A Celestial Spiral with a Twist | ALMA & Hubble

The Atacama Large Millimeter/submillimeter Array (ALMA) captured this remarkable image of a binary star system, where two stars—LL Pegasi and its companion—are locked in a stellar waltz, orbiting around their common center of gravity. The old star LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula, and the distinct spiral shape is the imprint made by the stars orbiting in this gas.
A composition of the ALMA and Hubble data.

Although it looks like the pattern of a shell on the beach, this intriguing spiral is in fact astronomical in nature. The Atacama Large Millimeter/submillimeter Array (ALMA) has captured a remarkable image of a binary star system, where two stars—LL Pegasi and its companion—are locked in a stellar waltz, orbiting around their common center of gravity. The old star LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula, and the distinct spiral shape is the imprint made by the stars orbiting in this gas.

The spiral spans light-years and winds around with extraordinary regularity. Based on the expansion rate of the spiralling gas, astronomers estimate that a new “layer” appears every 800 years—approximately the same time it takes for the two stars to complete one orbit around each other.

LL Pegasi was first highlighted about ten years ago when the NASA/European Space Agency Hubble Space Telescope obtained a picture of the almost-perfect spiral structure. This was the first time a spiral pattern had been found in material surrounding an old star. Now, ALMA’s observations, showing one “cross-section”, have added an extra dimension to reveal the exquisitely-ordered 3D geometry of the spiral pattern.


Credit: ALMA (ESO/NAOJ/NRAO)/H. Kim et al.
Release Date: March 6, 2017

#NASA #ESA #Astronomy #Science #Space #Hubble #Stars #LLPegasi #Nebulae #PlanetaryNebulae #IRAS231661655 #Pegasus #Constellations #MilkyWayGalaxy #Universe #HST #HubbleSpaceTelescope #GSFC #STScI #UnitedStates #ESO #ALMA #RadioAstronomy #Europe #STEM #Education

No comments:

Post a Comment