Somewhere in the southern constellation Chamaeleon, a star that has not finished forming is firing a jet of gas into space at hundreds of kilometres per second. Where that jet slams into the surrounding cloud, the gas is shocked into a glowing, rippling arc. In 2025 the James Webb Space Telescope photographed it in extraordinary detail, and the result looks less like a science image and more like a brushstroke. That arc has a name: Herbig-Haro 49/50.
Herbig-Haro objects are star formation caught in the act. This guide explains what they are, where the name comes from, why they visibly change over just a few years, and how Webb and Hubble capture them. Along the way we will look at four famous examples, all of which Skylit Studio prints as deep sky wall art.
What Are Herbig-Haro Objects?
A Herbig-Haro object is a patch of glowing gas created when a jet from a newborn star crashes into the gas and dust around it. The star itself, called a protostar, is still gathering material from a spinning disc. As that material falls inwards, magnetic fields channel some of it out again along the disc's axis, launching two narrow jets in opposite directions.
When those fast jets hit slower gas, they create shock waves, much like the bow wave of a speedboat. The shocked gas heats up and glows as it cools. That glow, often shaped like a bow, a knot or a chain of beads, is what astronomers call a Herbig-Haro object.
Herbig-Haro Objects at a Glance
- What they are: shock fronts where a young star's jet hits surrounding gas
- Where they are found: star-forming clouds, such as those in Orion, Perseus, Serpens and Chamaeleon
- How fast the jets move: typically hundreds of kilometres per second
- How many are known: well over a thousand have now been catalogued with HH numbers
- How long they last: a brief phase in a star's life, measured in thousands to tens of thousands of years
Who Were Herbig and Haro?
The objects are named after two astronomers who studied them independently around the turn of the 1950s. George Herbig, working at Lick Observatory in California, and Guillermo Haro, working at the Tonantzintla Observatory in Mexico, each recorded small, faint nebulae with unusual spectra close to young stars. Herbig published in 1951 and Haro in 1952.
They were not the first to see one. The American astronomer Sherburne Wesley Burnham had noticed a small nebula near the young star T Tauri back in 1890. But Herbig and Haro were the first to recognise these patches as a distinct class of object, and the Armenian astronomer Viktor Ambartsumian later gave them the joint name that stuck. It took until the 1980s for astronomers to confirm that jets from hidden protostars power them.
A Herbig-Haro object is the signature of a star being born, written in shocked gas rather than starlight.
Objects That Change Within a Lifetime
Most of what we see in the night sky looks the same for thousands of years. Herbig-Haro objects are an exception. Because their jets move so quickly, and many lie only a few hundred light-years away, their knots and bow shocks shift noticeably within a few years.
Astronomers used Hubble to prove it. By comparing images of several Herbig-Haro jets taken over roughly 14 years, a team led by Patrick Hartigan of Rice University stitched together time-lapse movies showing knots of gas racing outwards and bow shocks brightening and fading as they ploughed into denser material.
That also explains why these jets often look clumpy. Young stars feed in bursts, and each burst fires a fresh pulse down the jet, leaving a string of knots with the newest closest to the star: a fossil record of its growing pains.
How Webb and Hubble Photograph Them
Hubble: Visible Light
Hubble sees mostly visible light, and Herbig-Haro objects shine brightly at particular visible wavelengths, especially the red glow of hydrogen and ionised sulphur. That is why Hubble's classic images of jets such as HH 47 and HH 34 look so crisp. The limitation is dust: protostars sit deep inside dense clouds that visible light cannot escape, so Hubble often sees only the sections of a jet that have punched out into the open.
Webb: Infrared Light
Webb works in infrared. Its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) detect longer wavelengths that pass through dust far more easily. Webb is especially sensitive to the glow of molecular hydrogen, which lights up when a jet shocks the cold gas around it. In Webb images, those shocks usually show up as red, orange or pink streaks.
Infrared light is invisible to our eyes, so every Webb picture is translated into colour. Each filter is assigned a visible colour, usually blue for the shortest wavelengths and red for the longest, so the colours map real data. If you enjoy that idea of turning measurements into a picture, our guide to galaxy maps and cosmic cartography explores it further.
The two telescopes complement each other. Hubble's view of the Orion Nebula captures a region packed with jets and bow shocks in visible light, while Webb's infrared eye reveals the outflows still buried in their birth clouds.
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Four Famous Examples Captured by Webb
Herbig-Haro 49/50: The Jet With a Galaxy at Its Tip
HH 49/50 sits in the Chamaeleon I cloud, about 625 light-years away. NASA's Spitzer Space Telescope photographed it in 2006 and nicknamed it the Cosmic Tornado. Webb's 2025 view, combining NIRCam and MIRI, resolves it into layered arcs of shocked gas, driven by a protostar that most likely sits just outside the lower right corner of the frame.
The real surprise is at the tip of the outflow: a spiral galaxy, glowing with a blue central bulge and reddish clumps of star formation in its arms. It is a chance alignment: the galaxy lies far beyond our own Milky Way, vastly more distant than the jet and unrelated to it. Our Herbig-Haro 49/50 print keeps that composition in full, foreground shock and background galaxy together.
NGC 1333: A Nursery Full of Outflows
NGC 1333 is a reflection nebula in the Perseus molecular cloud, roughly 1,000 light-years away, and it is one of the busiest stellar nurseries near the Sun. It is home to the famous HH 7 to 11 chain of Herbig-Haro objects, and many more outflows criss-cross the cloud. ESA chose Webb's NIRCam view of the region as its Picture of the Month in August 2024. Webb sees through the dust to pick out young stars, brown dwarfs and the red and pink shock fronts of jets. Our NGC 1333 Perseus print shows the full scene.
The Serpens Nebula: Jets in Formation
In 2024 Webb revealed something astronomers had theorised about but never seen so clearly. In the upper left of its image of the Serpens Nebula, about 1,300 light-years away, a group of protostellar outflows all point in the same direction, like rain driven at the same angle by the wind. NASA described the bright red clumpy streaks as shocks where jets hit the surrounding gas, the same physics that creates a Herbig-Haro object. The alignment suggests the stars inherited their spin from the cloud they formed in. You can see it on our Serpens Nebula print.
Lynds 483: An Hourglass Made by Two Stars
Lynds 483 lies about 650 light-years away in the constellation Serpens. In a 2025 NIRCam image, Webb showed two protostars at its centre, hidden within a dark disc, blowing out jets that have shaped an hourglass of glowing gas over tens of thousands of years. NASA highlighted the twisting shock fronts where newer ejections collide with older, slower material. The Lynds 483 print captures its orange, blue and purple layers.
Spotting Jets in Other Webb Images
In Webb's 2022 view of the Pillars of Creation, NASA pointed out the wavy, lava-like red lines at the edges of some pillars: ejections from stars still forming inside the gas and dust.
From Telescope to Wall
Every image in this article started as raw telescope data, processed by teams at NASA, ESA, the Canadian Space Agency (for Webb) and the Space Telescope Science Institute into the published images. Each print credits them.
Skylit Studio prepares those released images for large-format printing, then prints and frames them in Manchester. Each Deep Sky print comes unframed or in a black, white, natural or dark brown frame. The composition on your wall is the one the scientists released, distant galaxy and all in the case of HH 49/50.
A print like this suits anyone who loves astronomy or simply striking images, and it carries a hopeful message: these are pictures of beginnings.
Where to Look Tonight
You will not see a Herbig-Haro object with the naked eye, but you can see where they live. Orion rises in the east during the mid-evening in late autumn and is well placed in the small hours, and by December it is high in the south by late evening. Just below Orion's Belt, the Orion Nebula appears as a misty smudge in the Sword, and inside it Hubble has photographed dozens of jets and bow shocks from young stars. HH 1 and HH 2, two of the first Herbig-Haro objects ever catalogued, also lie in Orion.
Our guide to finding Orion from the UK walks you through it, and the Night Sky Explorer shows exactly where it sits above your town tonight. For more naked-eye targets, see what you can see in the UK night sky with no equipment. And if a particular night matters to you, a personalised star map records the stars above a chosen place and date.
Frequently Asked Questions
What is a Herbig-Haro object in simple terms?
It is a glowing patch of gas created when a jet from a very young star crashes into the surrounding cloud. The collision produces shock waves that heat the gas, which then glows. Herbig-Haro objects mark places where stars are forming right now.
Why are they called Herbig-Haro objects?
They are named after George Herbig of Lick Observatory and Guillermo Haro of Mexico's Tonantzintla Observatory, who studied them independently and published their findings in 1951 and 1952. Viktor Ambartsumian later gave them the combined name.
Can I see a Herbig-Haro object through a telescope at home?
Most are too faint to see by eye through a typical backyard telescope, although astrophotographers using long exposures can capture some of the brighter ones. Their home regions, such as the Orion Nebula, are easy to find with binoculars from the UK during autumn and winter.
Is the spiral galaxy in the HH 49/50 image connected to the jet?
No. It is a chance alignment. The jet is inside our own Milky Way, about 625 light-years away, while the galaxy is far more distant, well beyond our galaxy. From our viewpoint, it simply happens to appear at the tip of the outflow.
Why does Webb show more jets than Hubble?
Webb observes in infrared light, which passes through the dust that surrounds newborn stars, and it is very sensitive to glowing molecular hydrogen. Hubble mainly sees visible light, which dust blocks, so it captures the parts of jets that have broken out of their clouds. Together the two telescopes give a fuller picture.
Are the colours in Webb images real?
Webb's infrared light is invisible to human eyes, so image processors assign visible colours to each filter, usually blue for shorter wavelengths and red for longer ones. The colours represent real measurements, translated into a range our eyes can see.
Bring a Newborn Star Home
Herbig-Haro objects are proof that the universe is still building stars, and Webb and Hubble have given us ringside seats. From the galaxy-tipped jet of HH 49/50 to the hourglass of Lynds 483, each image is a moment of creation caught in light. Skylit Studio prints them so that moment can hang on your wall.
