On Aug. 20, various news outlets reported that the Atacama Large Millimeter/Submillimeter Array (ALMA) radio telescope in Chile has taken pictures of the formation of a new star in the constellation Vela, 430 parsecs away from Earth.
The young star has been unleashing huge jets of gases such as carbon monoxide and ionized oxygen at speeds of up to 1 million kilometers per hour. These jets collide with protostar material and produce what are known as Herbig-Haro objects. Herbig-Haro objects are patches of nebulosity made by newly formed stars, and are created as the magnetic field of a protostar interacts with the magnetic fields of materials in the thin disk that surrounds it. They have been observed since the late 19th century, but they were only recognized as a distinct type of emission nebula in the 1940s. Such objects typically last on the order of 1,000 years, a small amount of time with respect to stellar evolution.
ALMA was able to detect Herbig-Haro 46/47 as well as another stream of material ejected from the star in the opposite direction. The jets are notable for traveling about four times faster than any previously observed carbon monoxide jets.
"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," explained Héctor Arce of Yale University, the team leader and first author of a study of the new stars that was published in the Astrophysical Journal.
"The detail in the Herbig-Haro 46/47 images is stunning. Perhaps more stunning is the fact that, for these types of observations, we really are still in the early days. In the future ALMA will provide even better images than this in a fraction of the time," added Stuartt Corder of Joint ALMA Observatory, a co-author of the new paper.
“This system is similar to most isolated low-mass stars during their formation and birth. But it is also unusual because the outflow impacts the cloud directly on one side of the young star and escapes out of the cloud on the other. This makes it an excellent system for studying the impact of the stellar winds on the parent cloud from which the young star is formed,” said Diego Mardones of the University of Chile, another co-author of the study.
ALMA's instruments took five hours to get the new results. Photos taken with other telescopes did not catch the second jet stream because dust and gas surrounding the star obscured their views, a limitation which a radio telescope like ALMA can overcome.