The galaxy M104 (NGC 4594) in Virgo. It is an 8th-magnitude spiral of type Sa or Sb with a large nucleus and is seen edge-on, giving the appearance of a Mexican hat. A dark lane of dust runs across its centre. It is about 30 million l.y. away, closer than the Virgo Cluster.
http://www.eso.org/public/images/sombrero/
- sieve element
- sieve of Eratosthenes
- sieve plate column
- sievert
- Sievert, Rolf Maximilian (1896–1966)
- sieve tube
- sieving
- sifting property
- sifting technique
- SIG
- sig
- Siger of Brabant (c.1240–1284)
- sig file
- sight glass
- Sigismund (1368–1437)
- sigma
- sigma algebra
- sigma bond
- sigma electron
- sigma factor
- sigma function
- sigma language
- Sigma Octantis
- sigma particle
- sigma-t density