PIA21088 - Supernova SN 2014C (Optical and X-Ray)

NGC 7331, also known as Caldwell 30, is an

unbarred spiral galaxy An unbarred spiral galaxyAstronomy Pictures(accessed 18 April 2010) is a type of spiral galaxy without a central bar, or one that is not a barred spiral galaxy. It is designated with an SA in the galaxy morphological classification scheme. Ba ...

about away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Pegasus Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as hor ...

. It was discovered by

William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline H ...

in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the

NGC 7331 Group NGC 7331 Group is a visual grouping of galaxies in the constellation Pegasus. Spiral galaxy NGC 7331 is a foreground galaxy in the same field as the collection, which is also called the ''Deer Lick Group''. It contains four other members, affe ...

of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300-350 million light years. The galaxy appears similar in size and structure to the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

, and is sometimes referred to as "the Milky Way's twin". However, discoveries in the 2000s regarding the structure of the Milky Way may call this similarity into doubt, particularly because the latter is now believed to be a barred spiral, compared to the unbarred status of NGC 7331. In spiral galaxies the central bulge typically co-rotates with the disk but the bulge in the galaxy NGC 7331 is rotating in the opposite direction to the rest of the disk. In both visible light and infrared photos of the NGC 7331, the core of the galaxy appears to be slightly off-center, with one side of the disk appearing to extend further away from the core than the opposite side. Multiple

supernova A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...

events have been observed in this galaxy. SN 1959D, a Type IIL supernova, was the first supernova identified within NGC 7331. The supernova was discovered by

Milton Humason Milton La Salle Humason (August 19, 1891 – June 18, 1972) was an American astronomer. He was born in Dodge Center, Minnesota. Biography Humason dropped out of school and had no formal education past the age of 14. Because he loved the m ...

and H. S. Gates in a survey at

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

. More recent supernovae are SN 2013bu and SN 2014C, the latter of which underwent an unusual "metamorphosis" from a hydrogen-poor Type Ib to a hydrogen-rich Type IIn over the course of a year . A 1903 photographic plate from

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owne ...

shows a magnitude 16.6 candidate transient that may have also been a supernova. __NOTOC__

References

External links

*
Calar Alto Observatory
– NGC 7331

– "A Galaxy So Inclined"
SST
– "Morphology of Our Galaxy's 'Twin'"

at the astro-photography site of Mr. T. Yoshida

at W. Kloehr Astrophotography *

– NGC 7331 {{DEFAULTSORT:Ngc 7331 NGC 7331 Group Unbarred spiral galaxies Pegasus (constellation) 7331 12113 69327 030b Astronomical objects discovered in 1784

See also

References

External links