SN 2004et

SN 2004et is a bright Type II-P^[1] supernova that occurred in the spiral galaxy NGC 6946 (The Fireworks Galaxy^[2]), about 22 million light years away from Earth.^[3] The star that made the supernova was falsely identified to be a yellow supergiant but was then identified to be a type red supergiant of 13.8 solar masses. SN 2004et showed some rebrightening about 1,000 days after the initial supernova probably due to ejecta of circumstellar material or thermal echo.^[4][5] SN 2004et was one of the most luminous Type II-P supernovae ever recorded and characterized.^[6]

SN 2004et

Locations of SN 004et and SN 2017eaw in the Fireworks Galaxy, known for having many supernovas
Event type	Supernova
Type II-P
Date	c. 22 million years ago (discovered 2004)
Instrument	Spitzer Space Telescope
Constellation	Cygnus
Right ascension	20:35:25.330
Declination	+60:07:17.6
Epoch	J2000.0
Distance	c. 22 million ly
Host	Fireworks Galaxy
Progenitor	Red supergiant c. 13.8 solar masses
Peak apparent magnitude	20.89
Other designations	SN 2004et
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Discovery

SN 200et was discovered in 2004 and observed until 2009 by using the Spitzer InfarRed Array Camera,^[7] a ultra sensitive infrared space telescope that is used to study planets, stars, asteroids, comets, and galaxies.^[8]