Unbarred spiral galaxy
Encyclopedia
An unbarred spiral galaxy is a type of spiral galaxy
Spiral galaxy
A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...

 without a central bar, or one that is not a barred spiral galaxy
Barred spiral galaxy
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in approximately two-thirds of all spiral galaxies...

. It is designated with an SA in the galaxy morphological classification scheme.

The Sombrero Galaxy
Sombrero Galaxy
The Sombrero Galaxy is an unbarred spiral galaxy in the constellation Virgo located 28 million light years from earth. It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its inclined disk. The dark dust lane and the bulge give this galaxy the appearance of a...

 is an unbarred spiral galaxy.

Barless spiral galaxies are one of three general types of spiral galaxies under the de Vaucouleurs system classification system, the other two being intermediate spiral galaxy
Intermediate spiral galaxy
An intermediate spiral galaxy is a galaxy that is in between the classifications of a barred spiral galaxy and an unbarred spiral galaxy. It is designated as SAB in the galaxy morphological classification scheme.-Grades:...

 and barred spiral galaxy. Under the Hubble tuning fork, it is one of two general types of spiral galaxy, the other being barred spirals.

Grades

Example Type Image Information Notes
SA0- SA0- is a type of lenticular galaxy
Lenticular galaxy
A lenticular galaxy is a type of galaxy which is intermediate between an elliptical galaxy and a spiral galaxy in galaxy morphological classification schemes. Lenticular galaxies are disk galaxies which have used up or lost most of their interstellar matter and therefore have very little ongoing...

SA0 SA0 is a type of lenticular galaxy
Lenticular galaxy
A lenticular galaxy is a type of galaxy which is intermediate between an elliptical galaxy and a spiral galaxy in galaxy morphological classification schemes. Lenticular galaxies are disk galaxies which have used up or lost most of their interstellar matter and therefore have very little ongoing...

SA0+ SA0+ is a type of lenticular galaxy
Lenticular galaxy
A lenticular galaxy is a type of galaxy which is intermediate between an elliptical galaxy and a spiral galaxy in galaxy morphological classification schemes. Lenticular galaxies are disk galaxies which have used up or lost most of their interstellar matter and therefore have very little ongoing...

NGC 3593
NGC 3593
NGC 3593 is a spiral galaxy located in the constellation Leo. It is frequently but not consistently identified as a member of the Leo Triplet group.-External links:*...

SA0/a SA0/a can also be considered a type of unbarred lenticular galaxy
Unbarred lenticular galaxy
An unbarred lenticular galaxy is a lenticular version of an unbarred spiral galaxy. They have the Hubble type of SA0An example of this is the Galaxy AM 0644-741. For other examples see :Category:Unbarred lenticular galaxies....

NGC 3593 is actually an "SA(s)0/a"
NGC 3169
NGC 3169
NGC 3169 is a spiral galaxy in the constellation Sextans. The galaxy is gravitationally distorted by nearby galaxy NGC 3166. Supernova burst SN 2003cg has been observed in 2003.-External links:***...

SAa NGC 3169 is actually an "SA(s)a pec"
Messier 81
Messier 81
Messier 81 is a spiral galaxy about 12 million light-years away in the constellation Ursa Major. Due to its proximity to Earth, large size and active galactic nucleus Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a spiral galaxy about 12 million light-years away in the constellation Ursa...

SAab M81 is actually an "SA(s)ab"
Messier 88
Messier 88
Messier 88 is a spiral galaxy about 47 million light-years away in the constellation Coma Berenices. It was discovered by Charles Messier in 1781.-Properties:...

SAb M88 is actually an "SA(rs)b"
NGC 3949
NGC 3949
NGC 3949 is an unbarred spiral galaxy in the constellation Ursa Major. It is believed to be approximately 50 million light-years away from the earth.-Supernova:The type II supernova SN 2000db is the only supernova that has been observed within NGC 3949....

SAbc NGC 3949 is actually an "SA(s)bc"
NGC 4414
NGC 4414
NGC 4414 is an unbarred spiral galaxy about 62 million light-years away in the constellation Coma Berenices. It is a flocculent galaxy, with short segments of spiral structure but without the dramatic well-defined spiral arms of a grand design spiral...

SAc NGC 4414 is actually an "SA(rs)c"
Triangulum Galaxy
Triangulum Galaxy
The Triangulum Galaxy is a spiral galaxy approximately 3 million light years from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101...

SAcd Triangulum is actually an "SA(s)cd"
NGC 300
NGC 300
NGC 300 is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between us and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group...

SAd NGC 300 is actually an "SA(s)d"
NGC 45
NGC 45
NGC 45 is a barred spiral galaxy in the constellation of Cetus. It was discovered on 11 November 1835 by the English astronomer John Herschel. In the sky, it is located near the magnitude 6.8 star HD 941.-External links:...

SAdm SAdm can also be considered a type of unbarred Magellanic spiral NGC 45 is actually an "SA(s)dm"
NGC 4395
NGC 4395
NGC 4395 is a low surface brightness spiral galaxy with a halo that is about 8′ in diameter. It has several wide areas of greater brightness running northwest to southeast. The one furthest southeast is the brightest...

SAm SAm is a type of Magellanic spiral
Magellanic spiral
Magellanic spiral galaxies are galaxies which are classified as the type Sm . They are galaxies with one spiral arm, and are named after their prototype, the Large Magellanic Cloud, an SBm galaxy....

(Sm)
NGC 4395 is actually an "SA(s)m"
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