To the ancient Greeks the sky was crammed with mythological figures. Few resembled the people or animals they were supposed to portray. But the Greeks were gifted essay-test-takers who could fill in the blanks with the best of them, and they knew observers could always recognize a star’s brilliance. So a man named Hipparchus who lived on Rhodes devised a scheme for sorting out star brightness. Tune in to hear how his system, still in use today, assigned each star one of six different magnitudes.
Strange Universe: The Magnitude of the Problem 3/12/23
![The irregular spiral galaxy NGC 5486 hangs against a background of dim, distant galaxies in this image from the NASA/ESA Hubble Space Telescope. The tenuous disc of the galaxy is threaded through with pink wisps of star formation, which stand out from the diffuse glow of the galaxy’s bright core. While this particular galaxy has indistinct, meandering spiral arms it lies close to the much larger Pinwheel Galaxy, one of the best known examples of ‘grand design’ spiral galaxies with prominent and well-defined spiral arms. In 2006 Hubble captured an image of the Pinwheel Galaxy which was — at the time — the largest and most detailed photo of a spiral galaxy ever taken with Hubble. NGC 5486 lies 110 million light-years from Earth in the constellation Ursa Major. Constellations are not only patterns of bright stars, but also a system that astronomers use to divide the sky into regions. There are 88 of these regions, and each has an associated constellation depicting a mythological figure, an animal, or even an item of scientific equipment. This strange celestial menagerie contains everything from Ursa Major’s great bear to a toucan, a sea monster, a telescope, and even a painter's easel! This observation comes from a selection of Hubble images exploring the detritus left behind by Type II supernovae. As massive stars reach the end of their lives they cast off huge amounts of gas and dust before ending their lives in titanic supernova explosions. NGC 5486 hosted a supernova in 2004, and astronomers used the keen vision of Hubble’s Advanced Camera for Surveys to explore the aftermath in the hopes of learning more about these explosive events. [Image description: A spiral galaxy. It is irregularly-shaped and its spiral arms are difficult to distinguish. The edges are faint and the core has a pale glow. It is dotted with small, wispy, pink regions where stars are forming. A few stars and small galaxies in warm colours are visible around it.] Link Hubble spies](https://npr.brightspotcdn.com/dims4/default/d3c5d9b/2147483647/strip/true/crop/1041x641+0+5/resize/880x542!/quality/90/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2F88%2F1c%2F38e4b10844e581e6f33747d31ed1%2Fesa-hubble-nasa-c.%20Kilpatrick.jpg)
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— Hubble spies a meandering spiral
The irregular spiral galaxy NGC 5486 hangs against a background of dim, distant galaxies in this image from the NASA/ESA Hubble Space Telescope. The tenuous disc of the galaxy is threaded through with pink wisps of star formation, which stand out from the diffuse glow of the galaxy’s bright core. While this particular galaxy has indistinct, meandering spiral arms it lies close to the much larger Pinwheel Galaxy, one of the best known examples of ‘grand design’ spiral galaxies with prominent and well-defined spiral arms. In 2006 Hubble captured an image of the Pinwheel Galaxy which was — at the time — the largest and most detailed photo of a spiral galaxy ever taken with Hubble. NGC 5486 lies 110 million light-years from Earth in the constellation Ursa Major. Constellations are not only patterns of bright stars, but also a system that astronomers use to divide the sky into regions. There are 88 of these regions, and each has an associated constellation depicting a mythological figure, an animal, or even an item of scientific equipment. This strange celestial menagerie contains everything from Ursa Major’s great bear to a toucan, a sea monster, a telescope, and even a painter's easel! This observation comes from a selection of Hubble images exploring the detritus left behind by Type II supernovae. As massive stars reach the end of their lives they cast off huge amounts of gas and dust before ending their lives in titanic supernova explosions. NGC 5486 hosted a supernova in 2004, and astronomers used the keen vision of Hubble’s Advanced Camera for Surveys to explore the aftermath in the hopes of learning more about these explosive events. [Image description: A spiral galaxy. It is irregularly-shaped and its spiral arms are difficult to distinguish. The edges are faint and the core has a pale glow. It is dotted with small, wispy, pink regions where stars are forming. A few stars and small galaxies in warm colours are visible around it.] Link Hubble spies
ESA/Hubble & NASA, C. Kilpatrick / ESA/Hubble
