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Explanation: Far away, long ago, a star exploded. Supernova 1994D, visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526. Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae. In fact, the light emitted during the weeks after its explosion caused it to be given the familiar designation of a Type Ia supernova. If all Type 1a supernovae have the same intrinsic brightness, then the dimmer a supernova appears, the farther away it must be. By calibrating a precise brightness-distance relation, astronomers are able to estimate not only the expansion rate of the universe (parameterized by the Hubble Constant), but also the geometry of the universe we live in (parameterized by Omega and Lambda). The large number and great distances to supernovae measured in 1998 have been interpreted as indicating that we live in a previously unexpected universe.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: cosmology - universe - supernova
Publications with words: cosmology - universe - supernova
See also:
- APOD: 2024 December 1 Á Cosmic Latte: The Average Color of the Universe
- APOD: 2024 October 20 Á Dark Matter in a Simulated Universe
- APOD: 2024 July 1 Á Time Spiral
- APOD: 2023 December 31 Á Illustris: A Simulation of the Universe
- APOD: 2023 October 11 Á NGC 1097: Spiral Galaxy with Supernova
- APOD: 2023 July 9 Á Doomed Star Eta Carinae
- APOD: 2023 July 5 Á A Map of the Observable Universe