Using 14 years’ worth of Hubble Space Telescope images, astronomers have animated the chaos inside the supersonic jets of newborn stars.

Hubble took still photographs of the jets from 1994 through 2008, and animators used image-morphing models to create seamless videos that put the jets into motion.

“We’r trying to study how stars form. Just by looking at any one process, you don’t get the full picture,” said astronomer Patrick Hartigan of Rice University, who led a study using the new imagery published July 20 in Astrophysical Journal. “It’s very important to understand [the jets], because that’s how our sun formed, and that’s how planetary systems form. And that’s basically how we got here.”

High-speed jets shoot out of distant pulsars, black holes and other objects across the universe, but the closest ones come from newborn stars within the Milky Way some 1,350 light-years away. George Herbig and Guillermo Haro first spotted these nearby jets in the 1950s, lending them the name Herbig-Haro objects. Astronomers have since discovered roughly 400 of them, and more than 100,000 likely exist in the Milky Way alone.

The jets typically appear in pairs and are thought to last no longer than about 100,000 years. Astronomers think the jets originate from a disk of gas and dust around a young star’s equator. When the material spirals onto the stellar surface, the material is flung out of its poles at speeds close to 435,000 mph.

To better understand the dynamics occurring in the jets, Hartigan and his colleagues used computer models to fill in the blanks between Hubble’s photos.

“It’s a lot like the difference between simply, say, looking at picture of … a quarterback throwing a pass versus actually seeing the entire play,” Hartigan said. “[It] really gives you the only way to get true insight into the physics of the dynamics of what’s going on.”

Hartigan and his colleagues used Hubble to zero in on four objects — HH 1, HH 2, HH 34 and HH 47 — over the span of about 14 years. The animations revealed that the jets aren’t constant streams. Rather, young stars shoot them out in clumpy spurts. When faster-traveling clumps impact slower material, they create distinctive bright cones called bow shocks.

Further studies of the imagery, along with the scientific models they help validate, may help astronomers better understand the origins and roles of the jets in forming young stars. A full collection of animations used in the study is available at Hartigan’s home page.

Video: By combining 14 years worth of Hubble imagery, astrophysicists have animated the supersonic jets of gas shooting from newborn stars. (NASA/ESA/P. Hartigan, Rice University/G. Bacon, STScI/M. Kornmesser)

Image: Herbig-Haro objects HH 47 (top), HH 2 (lower right) and HH 34 (lower left). (NASA/ESA/P. Hartigan, Rice University) [high-resolution version available]



Citation: “Fluid Dynamics of Stellar Jets in Real Time: Third Epoch Hubble Space Telescope Images of HH 1, HH 34, and HH 47.” By P. Hartigan, A. Frank, J.M. Foster, B. H. Wilde, M. Douglas, P. A. Rosen, R. F. Coker, B. E. Blue, and J. F. Hansen. The Astrophysical Journal, Vol. 736, No. 29, July 20, 2011. DOI: 10.1088/0004-637X/736/1/29

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