A stellar sprinkler

This Picture of the Week shows the young stellar object 244-440 in the Orion Nebula observed with ESO’s Very Large Telescope (VLT) –– the sharpest image ever taken of this object. That wiggly magenta structure is a jet of matter launched close to the star, but why does it have that shape?

Very young stars are often surrounded by discs of material falling towards the star. Some of this material can be expelled into powerful jets perpendicularly to the disc. The S-shaped jet of 244-440 suggests that what lurks at the center of this object isn’t one but two stars orbiting each other. This orbital motion periodically changes the orientation of the jet, similar to a water sprinkler. Another possibility is that the strong radiation from the other stars in the Orion cloud could be altering the shape of the jet.

These observations, presented in a new paper led by Andrew Kirwan at Maynooth University in Ireland, were taken with the Multi Unit Spectroscopic Explorer (MUSE) instrument at ESO’s VLT in Chile. Red, green and blue colours show the distribution of iron, nitrogen and oxygen respectively. But this is just a small fraction of all the data gathered by MUSE, which actually takes thousands of images at different colours or wavelengths simultaneously. This allows astronomers to study not only the distribution of many different chemical elements but also how they move.

Moreover, MUSE is installed at the VLT’s Unit Telescope 4, which is equipped with an advanced adaptive optics facility that corrects atmospheric turbulence, delivering images sharper than Hubble’s. These new observations will therefore allow astronomers to study with unprecedented detail how stars are born in massive clouds like Orion.