#herbig-haro objects

The "V" Chamaeleon Molecular Cloud. Photo © Dongjian Jiang, 19 Sept '25. Photographer's description: "The Chamaeleon Dark Nebula is a prominent star-forming region located in the southern constellation Chamaeleontis, approximately 450-500 light-years from Earth‌. It consists of dense molecular clouds (Chamaeleon I, II, and III) that obscure background starlight, appearing as dark silhouettes against the Milky Way‌. These clouds contain young stars and Herbig-Haro objects, with blue reflection nebulae scattered throughout‌. The region spans several degrees in the sky, equivalent to about 5 light-years at its estimated distance‌." Herbig–Haro (HH) objects are bright patches of nebulosity associated with newborn stars. They are formed when narrow jets of partially ionised gas ejected by stars collide with nearby clouds of gas and dust..." - Wikipedia. AstroBin image of the day 29 Sept '25.

Map of the Perseus molecular cloud - Wikipedia.

Reflection nebulae NGC 6727 and NGC 6726, with Herbig-Haro objects (baby star jets) and other nearby deep space objects, including variable nebula NGC 6729, and IC 4812, all in Corona Australis, the 'Southern Crown.' 1. and 2. Photo and detail by Mark James Ford. 3. Photo by Mark Hanson. 4. Annotated photo by Mark Hanson. 5. Annotated photo by Josep M. Drudis (Astrodrudis).

Rare Shock Waves

South of the large star-forming region known as the Orion Nebula, lies bright blue reflection nebula NGC 1999. At the edge of the Orion molecular cloud complex some 1,500 light-years distant, NGC 1999's illumination is provided by the embedded variable star V380 Orionis. That nebula is marked with a dark sideways T-shape near center in this cosmic vista that spans about 10 light-years. The dark shape was once assumed to be an obscuring dust cloud seen in silhouette against the bright reflection nebula. But recent infrared images indicate the shape is likely a hole blown through the nebula itself by energetic young stars. In fact, this region abounds with energetic young stars producing jets and outflows with luminous shock waves. Cataloged as Herbig-Haro (HH) objects, named for astronomers George Herbig and Guillermo Haro, the shocks look like red gashes in this scene that includes HH1 and HH2 just below NGC 1999. The stellar jets push through the surrounding material at speeds of hundreds of kilometers per second.

Inside the head of this interstellar monster is a star that is slowly destroying it. The monster, actually an inanimate pillar of gas and dust, measures over a light year in length. The star, not itself visible through the opaque dust, is bursting out partly by ejecting energetic beams of particles. Similar epic battles are being waged all over the star-forming Carina Nebula (NGC 3372). The stars will win in the end, destroying their pillars of creation over the next 100,000 years, and resulting in a new open cluster of stars. The pink dots are newly formed stars that have already been freed from their birth monster. The above image is only a small part of a highly detailed panoramic mosaic of the Carina Nebula taken by the Hubble Space Telescope in 2007. The technical name for the stellar jets are Herbig-Haro objects. How a star creates Herbig-Haro jets is an ongoing topic of research, but it likely involves an accretion disk swirling around a central star. A second impressive Herbig-Haro jet is visible across the bottom of a larger image..