Young Stars Blast a Hole in Space


There is a black patch of space in NGC 1999, and for years astronomers have thought it was just a dense cloud of gas and dust, blocking light from passing through. But the Herschel infrared space telescope – which has the ability to peer into these dense clouds — has made an unexpected discovery. This black patch is actually a hole that has been blown in the side of the nebula by the jets and winds of gas from the young stellar objects in this region of space. “No-one has ever seen a hole like this,” said Tom Megeath, of the University of Toledo in the USA. “It’s as surprising as knowing you have worms tunneling under your lawn, but finding one morning that they have created a huge, yawning pit.”

Any previous descriptions of NCG 1999 said that the ominous dark cloud in the center was actually a condensation of cold molecular gas and dust so thick and dense that it blocks light. And astronomers had no reason to believe otherwise, until Herschel’s powerful infrared eyes took a look from space.

A Hubble image of NCG 1999 showing the dark patch. Credit: Hubble Heritage Team (STScI) and NASA

When Herschel looked in the direction of this nebula to study nearby young stars, the cloud continued to look black. But, that should not be the case. Herschel’s infrared eyes are designed to see into such clouds. Either the cloud was immensely dense or something was wrong.

Investigating further using ground-based telescopes, astronomers found the same story however they looked: this patch looks black not because it is a dense pocket of gas but because it is truly empty. Something has blown a hole right through the cloud.

Stars are born in dense clouds of dust and gas. Although jets and winds of gas have been seen coming from young stars in the past, it has always been a mystery exactly how a star uses these to blow away its surroundings and emerge from its birth cloud. With Herschel, this may be the first time we can see this process.

The astronomers think that the hole must have been opened when the narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas that forms NGC 1999. The powerful radiation from a nearby mature star may also have helped to clear the hole. Whatever the precise chain of events, it could be an important glimpse into the way newborn stars disperse their birth clouds.

Source: ESA

3 Replies to “Young Stars Blast a Hole in Space”

  1. “Something has blown a hole right through the cloud.”

    Got to be mag. fields…. but how and why? ISM meets local bi-polar HH tauri-like outburst?

  2. Aqua, at the risk of straying into EU territory I agree and I believe mag fields play a much larger part in cosmology than they are given credit for.

  3. Well, first of all, this has nothing to do with Cosmology. We do not talk about the Big Bang here. Just to make that clear.

    Second, magnetic fields have a lot of credit. Physicists and astronomers know of their importance. A lot of phenomena would be impossible without magnetic fields.
    Jets are the example of this story. These are collimated tubes of magnetic fields leaving the star (in this case) on its rotational axis. Through these bipolar tubes particles flow away from the (young) star.
    This is a very important process for the star to grow. In order to accrete matter the material in the disk surrounding the star must get rid of its angular momentum, which is very complicated. However, magnetic fields and jets help! They can basically transport away the angular momentum helping the material in the disk to fall onto the star.

    This is, indeed, the story of TTauri stars, very young stars that do not even burn hydrogen in their core. The jets are not as energetic as their counterparts of Quasars; but the process is the same. In the case of young stars we see the jets as Herbig-Haro-objects.

    As a side note, a friend of mine is working on the deepest picture ever taken of the Orion Nebula and searches especially for these things: disks and Herbig-Haro-objects. He has found over 300 so far. So, the story is backed up and seems quite real.

    So, by saying that it were jets that created the hole, we name all the ingredients necessary to do it: Young stars accreting matter, shooting out magnetic fields in a very collimated form. It’s not really necessary to name all these ingredients all the time again, I think……

    This is written just to clear things up and to avoid a starting mess….

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