Orion Star Factory May Be Deadly to Planets

Artist’s concept of two proplyds, or protostars, around a massive O-type star. The nearer proplyd is having its planet-forming dust and gas blasted away by the radiation from the star. The farther one retains its planet-making potential.
Credit: NRAO/AUI/NSF; B. Saxton

 

The Great Orion Nebula not only looks like a giant star factory, but new research suggests it also is a destroyer of young worlds.

New high-frequency radio observations obtained through the radio telescopes at the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile show for the first time that the giant gas cloud, located some 1,400 light-years from Earth, contains hot, young stars embedded in the gas cloud that are blasting away at infant planets and the associated debris surrounding nearby baby stars.

The new data reveal that these newborn stars and their forming planets, ones located within 0.1 light-years (about 600 billion miles) of one of these fast and furious-type stars are doomed to have their blanket of dust and gas blown away in just a few million years. As a consequence, the stellar explosions effectively shut down nearby planetary formation.

The results offer insights into the birth and death of starting solar systems, say astronomers.

“O-type stars, which are really monsters compared to our sun, emit tremendous amounts of ultraviolet radiation, and this can play havoc during the development of young planetary systems,” explained Rita Mann, an astronomer with the National Research Council of Canada in Victoria, British Columbia, and lead author on the new study published in the Astrophysical Journal.

“Using ALMA, we looked at dozens of embryonic stars with planet-forming potential and, for the first time, found clear indications where protoplanetary disks simply vanished under the intense glow of a neighboring massive star.”

Stellar nurseries such as the Orion Nebula are where scores of sunlike stars and their family of planets are born. When these stars die, they explode in a supernova and seed surrounding space with the heavy elements that help kick-start the formation of the next generation of stars. However, before they explode, the massive stars are deadly for young planets.

“Taken together, our investigations with ALMA suggest that extreme [ultraviolet] regions are not just inhospitable, but they’re downright hazardous for planet formation. With enough distance, however, it’s possible to find a much more congenial environment,” said Mann.

“This work is really the tip of the iceberg of what will come out of ALMA; we hope to eventually learn how common solar systems like our own are.”

See for Yourself

Look toward the southern sky on any clear evening and you might notice some of the brightest twinkles belong to one of this season’s hallmark constellations, Orion, the Hunter.

With its distinctive row of three equally brilliant stars representing Orion’s belt, and four surrounding stars marking the shoulders and knees of the giant, this constellation is easily found in the southwestern sky around mid-evening.

Dangling below Orion’s belt, there is a line of fainter stars just visible to the naked eye — a hanging sword. An interesting pattern is made up of two dim stars and what looks to the eye like a fuzzy spot shining between them. This special “gleam” in the sword is a massive star factory 1,400 light-years distant called the Great Orion Nebula. Make sure you check it out with binoculars or a telescope!

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Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.