SN 2013fs is a

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

, located in the

spiral galaxy Spiral galaxies form a galaxy morphological classification, class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''

NGC 7610 NGC 7610 is a spiral galaxy in the constellation Pegasus. Discovered by Andrew Ainslie Common in August 1880, it was accidentally "rediscovered" by him the same month, and later given the designation NGC 7616. Supernova One supernova has been ...

, discovered by the

Intermediate Palomar Transient Factory The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...

sky survey at

Palomar Observatory The Palomar Observatory is an astronomical research observatory in the Palomar Mountains of San Diego County, California, United States. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

on 6 October 2013 (and originally named iPTF 13dqy). It was discovered approximately three hours from explosion (first light) and was observed in

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

and

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

wavelengths, among others, within several hours. Optical spectra were obtained beginning at six hours from explosion, making these the earliest such detailed observations ever made of a supernova. The supernova was also independently discovered by

Kōichi Itagaki is an amateur astronomer based in Yamagata, the capital city of Yamagata Prefecture in the Tōhoku region of northern Honshu island, Japan. He is responsible for discovering many comets, and over 170 supernovae.red supergiant Red supergiants (RSGs) are stars with a supergiant luminosity class ( Yerkes class I) and a stellar classification K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelg ...

with a mass 10 times the mass of the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

, an effective temperature of 3,500 K, a radius 607 times the size of the Sun, and no more than a few million years old when it exploded. The star was surrounded by a relatively dense shell of gas shed by the star within the year before it exploded. Radiation emitted by the supernova explosion illuminated this shell, which had a mass of approximately one-thousandth the mass of the Sun, and its outer fringe was about five times the distance of

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

from the Sun.

References

External links

Light curves and spectra
on th
Open Supernova Catalog
20131006 Supernovae Pegasus (constellation) {{var-star-stub