A dazzling new image offers a rare look at the violent birth of a new star. The photo gives a finely detailed view of two high-velocity jets of material streaming away from the newborn fireball in opposite directions. The image is the product of combined radio observations by the European Space Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA) in Chile and those of the shorter wavelength visible light from the ESO’s New Technology Telescope (NTT). The new addition to our cosmos, located some 1400 light years from Earth in the southern constellation of Vela (The Sails), is called Herbig-Haro 46/47.
Infant stars emerge in a violent conflagration as they spew forth material at speeds as mind-bogglingly high as one million kilometers per hour. As this material slams into the surrounding hot, ionized carbon monoxide molecules, it produces a glow and creates what is known as a Herbig-Haro object. By observing the glow, astronomers have discovered that the jets streaming away from the new star are even more energetic than previously thought, the ESO said in a news release.
The new image shows two jets coming from the newborn star, one coming towards Earth and one moving away. According to the ESO, the receding jet was nearly invisible in earlier pictures in visible light because dust clouds surrounding the star obscured the view. The photos also reveal a previously unknown jet streaming in a completely different direction.
ALMA, which astronomers have been using to study Herbig-Haro 46/47 even before the array was completed and the telescope still under construction, has both provided considerably sharper images than other observatories and allowed scientists to measure the speed at which the glowing star-stuff is traveling through space, the ESO said.
“ALMA’s exquisite sensitivity allows the detection of previously unseen features in this source, like this very fast outflow. It also seems to be a textbook example of a simple model where the molecular outflow is generated by a wide-angle wind from the young star,” said team leader and first author of the new study, Hector Arce of Yale University.
It only took five hours of ALMA observation time to obtain the images, the ESO said, adding that it would have taken other telescopes ten time longer to get pictures of similar quality. Co-author Stuartt Corder of the Joint ALMA Observatory in Chile described the detail in the Herbig-Haro 46/47 images as “stunning.” Even more wonderful, he said, is that ALMA is still in its early days and in the future will be able to provide even better images than these in a much shorter time.
According to the ESO, the sensitivity and sharpness of ALMA’s observations allowed the team to discover a previously unknown outflow component that appears to originate from a lower-mass companion to the infant star. This secondary outflow, which is seen at nearly right angles to the principal object, seems to be making a hole in the surrounding cloud.
Because ALMA has made it possible to see features in a star’s outflow in much greater detail than before, there surely will be many amazing discoveries to be made with the telescope’s full array, Arce said. “ALMA will certainly revolutionize the field of star formation,” he observed.
The study will appear in the Astrophysical Journal.