Way back in 2006, the Spitzer Space Telescope (SST) took an infrared look at a strange object called Herbig-Haro 49/50. It’s a jet flowing away from a hot young star. The Spitzer image showed a fuzzy blob at the end of the jet. Was it part of the jet, or something more distant? Recently, the James Webb Space Telescope (JWST) focused its infrared eye on the same object and sent home a fantastic snapshot of this cosmic tornado. It also answered the question about the blob: it turns out to be a distant galaxy, itself bursting with hot young stars
Herbig-Haro 49/50 is what’s known as a “protostellar outflow”. Astronomers George Herbig and Guillermo Haro independently characterized these nebulous-looking patches of light as the result of star formation back in the 20th century. HH objects usually pop up in star-forming regions, often around single newly forming stars. These jets extend light-years out from their parent stars and they only last a few tens of thousands of years as the star forms. The ghostly-looking “tornado” shape is a result of the superheated jets of plasma colliding with clouds of gas and dust in the nearby interstellar medium. Astronomers currently know of about a thousand or so of these HH objects in the Milky Way Galaxy.
This object and other HH objects like it can change quickly over a few years. That gives astronomers a chance to track the action and velocity of the jets as they plow through nearby clouds of gas and dust. We can see them in visible light, but many of their details are best seen in infrared views such as those provided by the Hubble Space Telescope, SST, and JWST.
About the HH 49/50 Object
This “cosmic tornado” lies about 600 light-years away from Earth in the Chamaeleon I Cloud complex stellar nursery. Astronomers are interested in this region because it’s forming many stars similar to the Sun. Our own Solar System could have formed in a s stellar creche just like this one.
The central region of the Chamaeleon I star-forming region where HH 49/50 resides. Credit: NASA, ESA, CSA, and M. Zamani (ESA/Webb); Science: F. Sun (Steward Observatory), Z. Smith (Open University), and the Ice Age ERS Team.
HH 49/50’s jet is speeding away from the protostar at speeds of up to 300 kilometers per second. JWST looked at it with its Near Infrared Camera and its Mid-Infrared Instrument. Those allowed it to track the glow of molecular hydrogen, carbon dioxide, and heated dust grains in the material in the jets. If you look closely at the jets, you’ll see what looks like semi-circular arcs and clumps of material. They’re likely being carved out as the jet streams out from a star called Cedarblad 110 IRS4, which lies about 1.5 light-years away from the jet seen in the image. It’s a Class 1 protostar, which means it could be anywhere from a few tens of thousands of years old to almost a million. Most of them have protostellar disks surrounding them, places where future planets could form.
The details provided by JWST of the arcs in HH 49/50 allow astronomers to pinpoint the jet’s source. It’s very likely streaming from the poles of the protostar, although not every arc points back in the same direction. For example, there is an interesting outcrop feature (at the top right of the main outflow) which could be another chance superposition of a different outflow, related to the slow precession of the intermittent jet source. Alternatively, this feature could be a result of the main outflow breaking apart.
About that Galaxy
In the Spitzer image, the object at the upper tip of HH 49/50 was just too fuzzy to understand. In the JWST image, it’s very clear that this object is a distant galaxy. It just happens to be in a very cool alignment with the HH object. The galaxy is a face-on spiral with a prominent central bulge populated by older stars. Those red-colored clumpy areas in the spiral arms are warm clouds of dust, studded with newly forming stars. In a few thousand years, the growing cloud of material pushed away by the HH object’s jet will cover up the galaxy (from our point of view).
That’s not the only galaxy we can see in the JWST image. There are dozens of very distant galaxies that form the backdrop to HH 49/50 and its “tip of the jet” galaxy. There are spirals, ellipticals, and irregulars all in the same view.
For More Information
Webb Unmasks True Nature of the Cosmic Tornado
Cosmic Tornado