Mysterious Blue Ring Nebula Reveals Secrets of Binary Stars

James Maynard
Nov 19 · 3 min read

The Blue Ring Nebula holds answers to mysteries of binaries — as well as posing a few questions of its own.

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The Blue Ring Nebula seen in a NASA image. An expanding cloud of hydrogen gas is shown in blue, and shock waves from the merger event can be seen in red. Image credit: NASA/JPL-Caltech/M. Seibert (Carnegie Institution for Science)/K. Hoadley (Caltech)/GALEX Team

In 2004, the Galaxy Evolution Explorer, an orbiting space telescope scanning distant groups of galaxies, found a bizarre object. Among other oddities, this body appeared to be blue, despite giving off no visible light. Careful observations showed the presence of a pair of rings within the body, earning it the moniker of the Blue Ring Nebula.

Sixteen years of studying this rare object found it to be a ring of hydrogen gas, surrounding a what looks like an ordinary star. However, the properties of this object suggest the star at the center of this object is, itself, the product of the merger of a pair of stars. This discovery of TYC 2597–735-1 could open up a new era of understanding the nature of binary star systems.

“We were in the middle of observing one night, with a new spectrograph that we had recently built, when we received a message from our colleagues about a peculiar object composed of a nebulous gas expanding rapidly away from a central star. How did it form? What are the properties of the central star? We were immediately excited to help solve the mystery!” Guðmundur Stefánsson of Princeton University stated.

A look at how the Blue Ring Nebula formed. One of the two leading edges of the eruption are shown in magenta, while gas and other material is seen as blue. The gas is only visible where layers overlap. Video credit: NASA/JPL-Caltech/R-Hurt

Unlike our own Sun, most stars in the Milky Way are found in binary systems, dancing with another star around their common center of gravity.

“Stellar mergers are a brief but common phase in the evolution of binary star systems. These events have many astrophysical implications; for example, they may lead to the creation of atypical stars… Although a handful of stellar mergers have been observed directly, the central remnants of these events were shrouded by an opaque shell of dust and molecules, making it impossible to observe their final state,” researchers wrote in an article in Nature detailing the study.

In systems where stars are close enough can result in a collision between the stars, merging the bodies together into one massive star.

“Purple haze all in my brain… Lately things, they don’t seem the same
Acting funny, but I don’t know why… ‘Scuse me while I kiss the sky”

Purple Haze, Jimi Hendrix

Orbital energy once present in the former stars results in the ejection of large quantities of material from the newly-formed body.

“When neutron stars collide, all hell breaks loose. They start producing a tremendous amount of visible light, and also gamma rays, X-rays, radio waves,” describes Frans Pretorius, physics professor at Princeton.

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The trio of telescopes responsible for our discoveries concerning the Blue Ring Nebula: (l-r) The Keck Telescope, Galaxy Evolution Explorer, and the Hobby-Eberly Telescope. Image credits: (l-r) Keck Observatory, NASA/GALEX Team, McDonald Observatory.

Astronomers went to work studying the Blue Ring Nebula, using a pair of 10-meter telescopes — the HIRES optical spectrograph at the Keck Telescope in Hawaii, and the near-infrared Habitable-zone Planet Finder attached to the Hobby-Eberly Telescope in Texas.

Analysis revealed TYC 2597–735–1 is the product of a stellar merger which took place thousands of years ago.

The Blue Ring Nebula offers astronomers a unique target to study — a composite star caught still settling down from its birth in a cathartic stellar merger.

James Maynard is the founder and publisher of The Cosmic Companion. He is a New England native turned desert rat in Tucson, where he lives with his lovely wife, Nicole, and Max the Cat.

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The Cosmic Companion

Exploring the wonders of the Cosmos, one mystery at a time

James Maynard

Written by

Writing about space since I was 10, still not Carl Sagan. Weekly video show, podcast, comics, more: www.thecosmiccompanion.net

The Cosmic Companion

Exploring the wonders of the Cosmos, one mystery at a time

James Maynard

Written by

Writing about space since I was 10, still not Carl Sagan. Weekly video show, podcast, comics, more: www.thecosmiccompanion.net

The Cosmic Companion

Exploring the wonders of the Cosmos, one mystery at a time

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