Post B2mVSy3xNV7sDoVMLA by markmccaughrean@mastodon.social
(DIR) More posts by markmccaughrean@mastodon.social
(DIR) Post #B2mVSFewT8yMVUSlF2 by markmccaughrean@mastodon.social
2026-01-29T12:32:02Z
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Enter the Dragon 🐉🥋Here it is – my new JWST image of the young protostellar outflow system in Cassiopeia called HH288, aka The Dragon Jet.We discovered it in the 1990s & the NASA/ESA/CSA JWST reveals stunning new detail, including several new jets crossing the main dragon 🙂👍This is a 4K version – you can view & download the full 12K image here: https://www.flickr.com/gp/markmccaughrean/944q5814f8For more coverage, see this by @DrCarpineti at: https://www.iflscience.com/dragon-jet-erupts-from-baby-stars-in-stunning-new-jwst-image-82374#Space #SpaceScience #Astronomy #Photography
(DIR) Post #B2mVSKBLebGsX9ehJA by markmccaughrean@mastodon.social
2026-01-29T13:03:23Z
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Some additional technical & scientific information in the thread that follows, mostly cut & paste from the image caption on my Flickr account.But first, a gratuitous video, doing the Ken Burns thing across the scene. No music here, but on my Instagram post, I've used Lalo Schifrin's theme from Bruce Lee's "Enter the Dragon". Super cheesy, but definitely appropriate 🙂Take a listen there, if you're still on that hellsite 😬 https://www.instagram.com/reel/DUGFNWQDBzT/
(DIR) Post #B2mVSOM88SGxTkjMfY by markmccaughrean@mastodon.social
2026-01-29T13:09:42Z
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The image is a near-IR colour composite of the protostellar outflow system HH288, aka The Dragon Jet, made using the NIRCam instrument on NASA/ESA/CSA James Webb Space Telescope. The composite comprises five individual mosaics in the F150W, F200W, F356W, F444W, & F470N filters, spanning the wavelength range 1.3 to 5 microns. Bluer colours are shorter wavelengths; redder are longer. The image is rotated by approximately 50º clockwise from North up, East left, & covers 378 x 259 arcseconds.
(DIR) Post #B2mVSShC05UswEcF3Q by markmccaughrean@mastodon.social
2026-01-29T13:13:07Z
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HH288 lies in galactic plane in the constellation of Cassiopeia at a distance of roughly 2 kiloparsecs or 6500 light years from Earth. The nickname comes from the hopefully-obvious resemblance to a Chinese dragon, or loong / 龍 / 龙 / 🐉.The main horizontal flow comprising "the dragon", with its head & flames to the left & tail to the right, spans roughly 3 parsecs or 9.8 light years.
(DIR) Post #B2mVSXKglBT1Jt7qAi by markmccaughrean@mastodon.social
2026-01-29T13:14:41Z
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The red, orange, & yellow emission is mostly due to emission lines of shock-heated molecular hydrogen, although there is some additional emission from carbon monoxide.The more diffuse yellow-orange glow around the waist of "the dragon" is likely reflection nebulosity from the central protostars driving the main flow. The wider blue & green glow in the image is likely a mixture of reflection nebulosity & emission from polycyclic aromatic hydrocarbons associated with dust in the region.
(DIR) Post #B2mVScD4cvLYRibKUq by markmccaughrean@mastodon.social
2026-01-29T13:15:40Z
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The gas in the main flow is moving at speeds of 100-200 km/sec from its protostar, which is thought to be significantly more massive than the Sun, & likely less than a million years old.However, there are at least two other outflows seen associated with "the dragon", one linear running from lower left to upper right, & another more chaotic from lower right to upper right. Close inspection shows perhaps another two or three newly-discovered small flows as well.
(DIR) Post #B2mVSi4moeHadklnPc by markmccaughrean@mastodon.social
2026-01-29T13:17:30Z
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Also obvious is the small cluster of young embedded stars towards the bottom edge of the image, which also appear to be ejecting jets of molecular hydrogen gas. For obvious reasons, I'm calling this "the dragon's egg" 🐲🐣🙂For more information on our original discovery of HH288 & millimetre wavelength studies of it, see this 2001 paper I wrote with Frédéric Gueth & Peter Schilke: https://scixplorer.org/abs/2001A&A...375.1018G/abstract
(DIR) Post #B2mVSnN38ArX3qLx4a by markmccaughrean@mastodon.social
2026-01-29T13:19:05Z
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The original data making up this image were taken by JWST between 26 & 30 January 2025 as part of the Guaranteed Time Observation programme #4548, PI Mark McCaughrean, JWST Interdisciplinary Scientist for star formation. Image credit & copyright:Mark McCaughrean (MPIA) / NASA, ESA, CSA / CC BY-SA 4.0
(DIR) Post #B2mVSsaLk9TLEXc8zw by markmccaughrean@mastodon.social
2026-01-29T13:21:57Z
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And there's more to come: we're currently writing up these JWST data for publication, but we also have new follow-up millimetre & radio observations coming up, using the IRAM 30m dish, the NOEMA interferometer, & the eVLA.That's work being done in collaboration with Peter Schilke, Beth Jones, & Tatiana Rodríguez at the University of Cologne, & will be a great help in disentangling this very complex set of jets & outflows coming from several embedded protostars.
(DIR) Post #B2mVSy3xNV7sDoVMLA by markmccaughrean@mastodon.social
2026-01-29T14:00:13Z
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Oh, & as a brief coda, what looks like a "simple colour image" is, in fact, anything but. There's a lot of noise in the original data, partly due to the NIRCam electronics which struggle when the sky background is very low, & partly due to cosmic rays hitting the detectors.Processing, aligning, & cleaning the five separate large mosaics, plus aligning them accurately, compressing the dynamic range, & colour compositing took about a month of manual work over Christmas. But worthwhile.