The Scutum–Centaurus Arm, also known as Scutum-Crux arm, is a long, diffuse curving streamer of

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

s, gas and dust that spirals outward from the proximate end of 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 ey ...

's central

bar Bar or BAR may refer to: Food and drink * Bar (establishment), selling alcoholic beverages * Candy bar * Chocolate bar Science and technology * Bar (river morphology), a deposit of sediment * Bar (tropical cyclone), a layer of cloud * Bar (un ...

. The Milky Way has been posited since the 1950s to have four

spiral arm Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Sagittarius Sagittarius ( ) may refer to: *Sagittarius (constellation) *Sagittarius (astrology), a sign of the Zodiac Ships *''SuperStar Sagittarius'', a cruise ship * USS ''Sagittarius'' (AKN-2), a World War II US Navy cargo ship Music *Sagittarius (ban ...

and Norma arms. In January 2014, a 12-year study into the distribution and lifespan of massive stars and a 2013-reporting study of the distribution of masers and open clusters both found corroboratory, though would not state irrefutable, evidence for four principal spiral arms. The Scutum–Centaurus Arm lies between the minor Carina–Sagittarius Arm and the major

Perseus Arm The Perseus Arm is one of two major spiral arms of the Milky Way galaxy. The second major arm is called the Scutum–Centaurus Arm. The Perseus Arm begins from the distal end of the long Milky Way central bar. Previously thought to be 13,000 lig ...

. The Scutum–Centaurus Arm starts near the core as the ''Scutum Arm'', then gradually turns into the ''Centaurus Arm''. The region where the Scutum–Centaurus Arm connects to the bar of the galaxy is rich in

star-forming region Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars. As a branch of astronomy, star formation includes ...

s and

open clusters An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...

. In 2006 a large cluster of new stars containing 14

red supergiant Red supergiants (RSGs) are stars with a supergiant luminosity class ( Yerkes class I) of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antar ...

stars was discovered there and named

RSGC1 RSGC1 (''Red Supergiant Cluster 1'') is a young massive open cluster in the Milky Way galaxy. It was discovered in 2006 in the data generated by several infrared surveys, named for the unprecedented number of red supergiant members. The clust ...

. In 2007 a cluster of approximately 50,000 newly formed stars named RSGC2 was located only a few hundred light years from RSGC1. It is thought to be less than 20 million years old and contains 26 red supergiant stars, the largest grouping of such stars known. Other clusters in this region include

RSGC3 RSGC3 (''Red Supergiant Cluster 3'') is a young massive open cluster belonging to the Milky Way galaxy. It was discovered in 2010 in the GLIMPSE survey data. The cluster is located in the constellation Scutum at the distance of about 7 ...

and

Alicante 8 Alicante 8, also known as RSGC4, (''Red Supergiant Cluster 4'') is a young massive open cluster belonging to the Milky Way galaxy. It was discovered in 2010 in the 2MASS survey data. As of 2010, the only members of the cluster that are currentl ...

References

{{DEFAULTSORT:Scutum-Centaurus Arm Milky Way arms Galactic astronomy Spiral galaxies

See also

References