In 2004, astronomers using NASA’s Galaxy Evolution Explorer stumbled on an abnormal, ring-formed ‘blue’ nebula and the star at its heart, TYC 2597-735-1. Unique observations of the thing indicate that TYC 2597-735-1 merged with its decrease-mass stellar accomplice much less than 5,000 years within the past and created a bipolar outflow of fabric.
The Blue Ring Nebula is located 6,197 light-years away within the constellation of Hercules. The nebula is 13 light years extensive and contains hydrogen gasoline (blue) expanding from a central star, which is the remnant core of a stellar merger; crimson filaments are shockwave filaments from the merging match. Image credit ranking: NASA / JPL-Caltech / M. Seibert, Carnegie Institution for Science / K. Hoadley, Caltech / GALEX Crew.
“We were within the course of observing one night, with a contemporary spectrograph that we had only within the near previous built, as soon as we received a message from our colleagues a few bizarre object gentle of a nebulous gasoline expanding impulsively a ways from a central star,” said co-creator Dr. Guðmundur Stefánsson, a postdoctoral researcher within the Department of Astrophysical Sciences at Princeton University.
“How did it manufacture? What are the properties of the central star? We were in an instant excited to support clear up the mystery!”
Most stars within the Milky Intention are in binary stellar systems — pairs of stars orbiting every other. If they’re shut sufficient together, such systems can meet their death in a stellar merging match.
To take a look at this hypothesis, Dr. Stefánsson and colleagues seen the Blue Ring Nebula with two diversified spectrographs on sizable ground-based entirely mostly telescopes: the HIRES optical spectrograph on the 10-m Keck Telescope and the near-infrared Habitable-zone Planet Finder on the 10-m Ardour-Eberly Telescope at McDonald Observatory.
“The spectroscopic observations were key in permitting us to note the thing extra, from which we behold that the central star is inflated, and we behold signatures of accretion seemingly from a surrounding disk of debris,” Dr. Stefánsson said.
“Certainly, the spectroscopic details coupled with theoretical modeling reveals that the Blue Ring Nebula is in step with the image of a merging binary star gadget, suggesting that the inwards spiraling accomplice turned into as soon as seemingly a low-mass star,” said lead creator Dr. Keri Hoadley, a postdoctoral researcher within the Cahill Heart for Astrophysics at Caltech.
Even supposing the relics of a few such binary merging events non-public been seen ahead of, all such objects non-public been enshrouded by opaque dust and clouds, obstructing the watch of the properties of the central stellar remnant.
The Blue Ring Nebula is the most attention-grabbing object permitting an unobstructed watch of the central stellar remnant, offering a undeniable window into its properties and yielding clues in regards to the merging direction of.
“The Blue Ring Nebula is uncommon. As such, it is surely thrilling that we were in a attach to search out it, and we’re alive to in regards to the different of finding more such objects within the lengthy bustle,” Dr. Hoadley said.
“In that case, that would allow us to abolish extra insights into the remnants of stellar mergers and the processes that govern them.”
“For somewhat an awfully lengthy time we opinion that perhaps there turned into as soon as a planet several times the mass of Jupiter being torn apart by the star, and that turned into as soon as throwing all that gasoline out of the gadget,” said co-creator Dr. Label Seibert, an astrophysicist at the Carnegie Institution for Science and a member of the GALEX group at Caltech.
“We behold tons of two-star systems that may perhaps perhaps perchance moreover merge in the end, and we maintain we’ve known stars that merged perhaps hundreds and hundreds of years within the past,” said co-creator Dr. Brian Metzger, a researcher within the Department of Physics at Columbia University and the Heart for Computational Astrophysics at Flatiron Institute.
“However we non-public nearly no details on what occurs in between.”
“We maintain there are doubtlessly tons of younger remnants of stellar mergers in our Galaxy, and the Blue Ring Nebula may perhaps perhaps perchance moreover indicate us what they look enjoy so we can name more of them.”
“The merger of two inclined stars explains the seemingly conflicting observations in regards to the central star’s youthful luminosity and ancient chemical makeup,” said co-creator Dr. Andrew McWilliam, an astrophysicist at the Carnegie Institution for Science.
The group’s work turned into as soon as printed within the November 19, 2020 version of the journal Nature.
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K. Hoadley et al. 2020. A blue ring nebula from a stellar merger several thousand years within the past. Nature 587, 387-391; doi: 10.1038/s41586-020-2893-5
