NGC 3938 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 ...
in the
Ursa Major
Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa ...
constellation. It was discovered on 6 February 1788 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 ...
. It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is roughly 67,000
light years
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
in diameter.
It is approximately 43 million light years away from
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
.
[ NGC 3938 is classified as type Sc under the ]Hubble sequence
The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a tun ...
, a loosely wound spiral galaxy with a smaller and dimmer bulge.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 ...
e have been identified within NGC 3938. SN 2005ay is a type II supernova
A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo this ...
that was discovered on 27 March 2005 and had a magnitude of 15.6. SN 2017ein is a type Ic supernova
Type Ib and Type Ic supernovae are categories of supernovae that are caused by the stellar core collapse of massive stars. These stars have shed or been stripped of their outer envelope of hydrogen, and, when compared to the spectrum ...
that was discovered on 25 May 2017 and peaked at magnitude 14.9. Images taken before the explosion point to a progenitor mass between ~47-48, if it was in a single star system, and ~60-80, if it was in a binary star
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...
system.[ SN 2022xlp is a type Ia supernova that was discovered on 13 October 2022 by Koichi Itagaki.
]
Gallery
Artist's impression of progenitor star to a type Ic supernova.jpg, Artist's impression of progenitor star to a type Ic supernova in NGC 3938.Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project began in 2000 a ...
References
External links
*
Ursa Major (constellation)
Unbarred spiral galaxies
3938
17880206
Ursa Major Cluster
037229
{{Spiral-galaxy-stub