A supernova is when a huge star explodes. It usually happens when its nuclear fusion cannot hold the core against its own gravity. The core collapses, then there's one final, titanic explosion. This causes the sudden appearance of a "new" bright star, before slowly fading from sight over several weeks or months.
The picture below shows SN 1994D (bright spot on the lower left), a supernova outshining its home galaxy, NGC 4526.
The word 'supernova' was coined by Walter Baade and Fritz Zwicky during 1931 lectures held at The California Institute of Technology, then used publicly in 1933 at a meeting of the American Physical Society.
The supernova SN 1006 first appeared in the constellation Lupus and was widely seen on Earth beginning in the year 1006. It occurred 7,200 light years away. It was, in terms of apparent magnitude, the brightest stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus. The supernova's remnant was not identified until 1965.
A supernova was seen by Chinese, Arab, and possibly Amerindian observers near the star Zeta Tauri in 1054. Chinese astronomers recorded it as a "guest star" on July 4th. For several months it remained bright enough to be seen during the day. Its remnants form the Crab Nebula.
The last supernova observed in our Milky Way galaxy was in the year 1604. The astronomer Johannes Kepler began observing SN 1604 at its peak on October 17, 1604, and continued to make estimates of its brightness until it faded from naked eye view a year later.
Kepler's supernova was so bright, it could even be seen during the day for three weeks.
Picture below shows Johannes Kepler's original drawing from De Stella Nova (1606) depicting the location of the supernova, marked with an N (8 grid squares down, 4 over from the left)
ASASSN-15lh is a superluminous supernova that was detected by the All Sky Automated Survey for SuperNovae (ASAS-SN) in 2015 in the southern constellation Indus. The discovery, confirmed by ASAS-SN group with several other telescopes, was formally described and published on January 15, 2016.
ASASSN-15lh is the most luminous supernova ever detected; at its brightest it was at least 20 times brighter than the whole Milky Way, with an energy hundreds of billions times greater than the Sun.
When a supernova unleashes a gamma ray burst, it releases as much energy in a few seconds as our sun will release in its entire lifetime.
The gamma-ray burst GRB 080319B that was observed on March 19, 2008 broke the record for the farthest object that could be seen by the naked eye. The explosion occurred about 7.5 billion years ago, roughly half the time since the Big Bang.
Supernovas are the source of many of the chemical elements heavier than hydrogen and helium in the universe.
Traces of radioactive iron-60, a strong indicator of supernova debris, is buried in the sea floor right across the Earth.
The picture below shows SN 1994D (bright spot on the lower left), a supernova outshining its home galaxy, NGC 4526.
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| By NASA/ESA, |
The word 'supernova' was coined by Walter Baade and Fritz Zwicky during 1931 lectures held at The California Institute of Technology, then used publicly in 1933 at a meeting of the American Physical Society.
The supernova SN 1006 first appeared in the constellation Lupus and was widely seen on Earth beginning in the year 1006. It occurred 7,200 light years away. It was, in terms of apparent magnitude, the brightest stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus. The supernova's remnant was not identified until 1965.
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| SN 1006 supernova remnant |
A supernova was seen by Chinese, Arab, and possibly Amerindian observers near the star Zeta Tauri in 1054. Chinese astronomers recorded it as a "guest star" on July 4th. For several months it remained bright enough to be seen during the day. Its remnants form the Crab Nebula.
The last supernova observed in our Milky Way galaxy was in the year 1604. The astronomer Johannes Kepler began observing SN 1604 at its peak on October 17, 1604, and continued to make estimates of its brightness until it faded from naked eye view a year later.
Kepler's supernova was so bright, it could even be seen during the day for three weeks.
Picture below shows Johannes Kepler's original drawing from De Stella Nova (1606) depicting the location of the supernova, marked with an N (8 grid squares down, 4 over from the left)
ASASSN-15lh is a superluminous supernova that was detected by the All Sky Automated Survey for SuperNovae (ASAS-SN) in 2015 in the southern constellation Indus. The discovery, confirmed by ASAS-SN group with several other telescopes, was formally described and published on January 15, 2016.
ASASSN-15lh is the most luminous supernova ever detected; at its brightest it was at least 20 times brighter than the whole Milky Way, with an energy hundreds of billions times greater than the Sun.
When a supernova unleashes a gamma ray burst, it releases as much energy in a few seconds as our sun will release in its entire lifetime.
The gamma-ray burst GRB 080319B that was observed on March 19, 2008 broke the record for the farthest object that could be seen by the naked eye. The explosion occurred about 7.5 billion years ago, roughly half the time since the Big Bang.
Supernovas are the source of many of the chemical elements heavier than hydrogen and helium in the universe.
Traces of radioactive iron-60, a strong indicator of supernova debris, is buried in the sea floor right across the Earth.
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