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| Discovery of Supernova 2012ha, the bright spot in the image at the edge of a galaxy in the Virgo Cluster, was confirmed by a spectrogram obtained with the Hobby-Eberly Telescope at McDonald Observatory. The Central Bureau for Astronomical Telegrams of the International Astronomical Union officially designated the Type 1a discovery as Supernova 2012ha [Credit: HET] |
The exploding star is in a relatively empty portion of the sky labeled "anonymous" in the faint constellation Canes Venatici. Home to a handful of galaxies, Canes Venatici is near the constellation Ursa Major, best known for the Big Dipper.
A second supernova discovered Nov. 20 exploded about 230 million years ago, said Ferrante, who made the initial observation. That exploding star is in one of the many galaxies of the Virgo constellation.
Both supernovae were spotted with the Robotic Optical Transient Search Experiment's robotic telescope ROTSE3b, which is now operated by SMU graduate students. ROTSE3b is at the McDonald Observatory in the Davis Mountains of West Texas near Fort Davis.
The supernova that exploded about 450 million years ago is officially designated Supernova 2013X. It occurred when life on Earth consisted of creatures in the seas and oceans and along coastlines. Following naming conventions for supernova, Supernova 2013X was nicknamed "Everest" by Govinda Dhungana, an SMU graduate student who participated in the discovery.
The supernova that exploded about 230 million years ago is officially designated Supernova 2012ha. The light from that explosion has been en route to Earth since the Triassic geologic period, when dinosaurs roamed the planet. "That's fairly recent as these explosions go," Ferrante said. Dhungana gave the nickname "Sherpa" to Supernova 2012ha.
Type 1a supernovae help measure cosmic distances
Everest and Sherpa are two of about 200 supernovae discovered worldwide in a given year. Before telescopes, supernovae observations were rare -- sometimes only several every few centuries, according to the scientists.
"Everest and Sherpa aren't noteworthy for being the youngest, oldest, closest, furthest or biggest supernovae ever observed," Ferrante said. "But both, like other supernovae of their kind, are important because they provide us with information for further science."
Everest and Sherpa are Type 1a supernovae, the result of white dwarf explosions, said Robert Kehoe, physics professor and leader of the SMU astronomy team in the SMU Department of Physics.
The scientists explain that a white dwarf is a dying star that has burned up all its energy. It is about as massive as Earth's sun. It's core is about the size of Earth. The core is dense, however, and one teaspoon of it weighs as much as Mount Everest, Kehoe said.