Starbirth Visions

Starbirth Art and Science

An image of Herbig-Haro object HH 46/47 is based on observations made at radio wavelengths by ALMA as well as visible-light observations made with the European Southern Observatory’s New Technology Telescope. The ALMA observations (orange and green, lower right) of the newborn star reveal a large energetic jet moving away from us, which in the visible is hidden by dust and gas. To the left (in pink and purple) the visible part of the jet is seen, streaming partly towards us. Courtesy: ESO/ALMA (ESO/NAOJ/NRAO)/H. Arce. Acknowledgements: Bo Reipurth

This image may look like an impressionistic painting of space, but it’s based on actual data taken by the Atacama Large Millimeter/Submillimeter Array (ALMA) and observations in visible light taken with the New Technology Telescope (ESO),  high in the Andes of South America. It a multi-wavelength view that is giving astronomers a whole new view of a starbirth region not far from Earth.

First of all, what is this object?  As the caption says, it’s an image made from data taken during observations of a Herbig-Haro object. These glowing clouds of gas and dust are named after two astronomers named George Herbig and Guillermo Haro, who studied the properties of light they give off. Their work revealed that Herbig-Haro objects occur in starbirth areas where material ejected at really high speeds from newborn stars creates shocks in the surrounding clouds.

It turns out that young stars are really active and can be quite violent as they “grow up”, almost more like rebellious teenagers. They eject material away from themselves at close to a million kilometers per hour (about 640,000 miles per hour) through massive jets. When those jets intersect the surrounding cloud of gas and dust, it heats and energizes the gas, and that causes it to glow.

This particular Herbig-Haro object is actually quite close to us in cosmic terms—only about 1,400 light-years away. In the newly released ALMA image, astronomers can make out two jets. One is headed toward Earth and the other points away from us.  In this image, the jets stream out to the upper left and lower right. The newborn star is at the center of the butterfly-shaped object. Interestingly, the birth cloud for the hot young star doesn’t seem to be symmetrical. You can tell because one jet seems to be slamming into thick areas of cloud while the other jet escapes almost to empty space. In addition, astronomers think there may be a third outflow from the young star, carving its way out from the birth nest.

Radio astronomy (which senses wavelengths of light or radio frequencies commonly known as radio, millimeter, submillimeter, and microwave) allows astronomers to look beyond clouds of gas and dust that can block visible light and hide things from our view. The ALMA installation is an array of multiple sensors that can take very high resolution (sharp) data of distant objects and show us more detail in them. ALMA is only just beginning its “career” as Earth’s latest radio telescope array designed to ferret out naturally occurring signals from active objects in the cosmos.