ALMA/NAOJ: Retreating Snow Line Reveals Organic Molecules

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Retreating Snow Line Reveals Organic Molecules around Young Star
ALMA | NAOJ | NRAO | ESO | 2019 Feb 04

False-color image of V883 Ori taken with ALMA. The distribution of dust is shown in orange and the distribution of methanol, an organic molecule, is shown in blue. Credit: ALMA (ESO/NAOJ/NRAO), Lee et al.

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Astronomers using ALMA have detected various complex organic molecules around the young star V883 Ori. A sudden outburst from this star is releasing molecules from the icy compounds in the planet forming disk. The chemical composition of the disk is similar to that of comets in the modern Solar System. Sensitive ALMA observations enable astronomers to reconstruct the evolution of organic molecules from the birth of the Solar System to the objects we see today.

The research team led by Jeong-Eun Lee (Kyung Hee University, Korea) used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect complex organic molecules including methanol (CH₃OH), acetone (CH₃COCH₃), acetaldehyde (CH₃CHO), methyl formate (CH₃OCHO), and acetonitrile (CH₃CN). This is the first time that acetone was unambiguously detected in a planet forming region or protoplanetary disk.

Various molecules are frozen in ice around micrometer-sized dust particles in protoplanetary disks. V883 Ori’s sudden flare-up is heating the disk and sublimating the ice, which releases the molecules into gas. The region in a disk where the temperature reaches the sublimation temperature of the molecules is called the “snow line.” The radii of snow lines are about a few astronomical units (au) around normal young stars, however, they are enlarged almost 10 times around bursting stars. ...

The Ice Composition in the Disk Around V883 Ori Revealed by Its Stellar Outburst ~ Jeong-Eun Lee et al

• Nature Astronomy (online 04 Feb 2019) DOI: 10.1038/s41550-018-0680-0
  arXiv.org > astro-ph > arXiv:1809.00353 > 02 Sep 2018

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<<The Thing from Another World (1951) concerns a U.S. Air Force crew and scientists who find a crashed flying saucer and a humanoid body frozen nearby in the Arctic ice. Returning to their remote research outpost with the body in a block of ice, they are forced to defend themselves against this malevolent, plant-based alien when it is accidentally revived. The film was partly shot in Glacier National Park and interior sets built at a Los Angeles ice storage plant.>>

Dr. Arthur Carrington: Captain, when you find what you're looking for, remember it's a stranger in a strange land. The only crimes involved were those committed against it. It awoke from a block of ice, was attacked by dogs, shot by frightened man. All I want is a chance to communicate with it.

Hendry: Doctor you can do anything you want with it provided it's locked up in a safe place.

"Scotty": An intellectual carrot. The mind boggles. Captain, we catch up with our pal give me a chance to get a picture before somebody makes a salad of 'em eh?

Hendry: Sure Scotty.