The spiral galaxy NGC 925 reveals cosmic pyrotechnics in its spiral arms where bursts
of star formation are taking place in the red, glowing clouds scattered throughout it. Credit: KPNO/NOIRLab/NSF/AURA — Acknowledgements: PI: M T. Patterson
(New Mexico State University) — Image processing: Travis Rector
(University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
This archival image from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, captures a snapshot of some cosmic pyrotechnics — the asymmetric spiral arms of the galaxy NGC 925, which host dazzling bursts of star formation. This stunning image is only one example of the spectacular firework displays that astronomy has to offer.
If you’re looking for fireworks for the US celebration of the Fourth of July, then look no further than the world of astronomy. The cosmic firework at the center of this image, the spiral galaxy NGC 925, resembles a vast pinwheel, with a bright central bar and swirling spiral arms. The red bursts strewn throughout NGC 925 are eruptions of star formation, which can be traced by observing conspicuous hydrogen-alpha emission.
NGC 925 lies about 20 million light-years from Earth in the direction of the constellation of Triangulum (The Triangle), and at first glance, it resembles a classic, ordered spiral galaxy. However, closer inspection reveals a subtle asymmetry — the galaxy is slightly lopsided. The spiral arm which appears at the top of this image is prominent and well-defined, but the lower half of the galaxy is more disordered and “fluffy.” This strange lopsidedness and the sparkly fireworks may be a result of the galaxy’s turbulent history, past interactions with other galaxies having distorted and disturbed NGC 925. Interactions like these are also likely to have sparked star formation during the history of this galaxy. ...
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
<<The Catherine wheel or pinwheel is a type of firework consisting either of a powder-filled spiral tube, or an angled rocket mounted with a pin through its center. When ignited, the energy of the fireworks not only create sparks and flame, but cause the wheel to quickly rotate, making the display much more spectacular. The physics of the process are those of an aeolipile. The firework is named after Saint Catherine of Alexandria who, according to Christian tradition, was condemned to death by “breaking on the wheel”. When she touched the wheel it miraculously flew to pieces.
The largest Catherine wheel ever made was designed by the Lily Fireworks Factory of Mqabba, Malta. The Catherine wheel had a diameter of 32 m, and was lit on 18 June 2011, the eve of the annual feast of Our Lady of the Lilies. In Malta, Catherine wheels are a traditional fixture during every village 'festa'. Some villages even hold competitions on the eve of the parish feast, while others display the vast work of one firework. Entrants display a variety of moving shapes and include various colours year after year as the technology progresses. These displays are only a small part of the firework catalogue planned throughout the week preceding the feast and on the feast day itself. The Catherine wheel displays typically end with the burning of what is called 'the carpet': the largest Catherine wheel in the display on the night.>>
