Barred Spiral Galaxy: Definition, Facts, Characteristics
A barred spiral galaxy is a distinct type of spiral galaxy characterized by a central bar-shaped structure composed of stars. Barred spiral galaxies possess features including their overall structure, the prominent central bar, and characteristics that set them apart from other galaxy types. These galaxies exhibit facts related to their formation, evolution, and distribution in the universe. Learn about barred spiral galaxies’ size, shape, composition, and prevalence among observed galaxies.
Barred spiral galaxies account for 60-70% of spiral galaxies in the universe. The central bar structure funnels gas and dust towards the galaxy’s center, triggering star formation. Bars in these galaxies extend 10,000 to 15,000 light-years in length. Barred spiral galaxies contain supermassive black holes at their centers, with masses millions to billions of times that of the Sun.
Barred spiral galaxies feature a central bar composed of packed stars. Spiral arms extend from the ends of the bar, creating patterns in the galactic disk. The bar structure influences star and gas movement, causing inward and outward orbits. Bars channel matter towards galactic centers, enhancing star formation and building up bulges over time.
Barred spirals have a bar-shaped concentration of stars at their centers, while regular spirals lack this feature. Arm configuration varies between galaxy types. Spiral galaxies exhibit arms winding around nuclei in continuous curves. Barred spiral galaxies have arms extending from bar ends, appearing different from regular spiral arms.
NGC 1300 is an example of a barred spiral galaxy, located 61 million light-years away in the Eridanus constellation. Messier 77 (M77) showcases barred spiral structure, situated 47 million light-years away in the Cetus constellation. The Milky Way is classified as a barred spiral galaxy, featuring a bar-shaped structure and spiral arms. The Magellanic Cloud (LMC) is classified as a dwarf barred spiral galaxy, with a bar length of 10,000 light-years.
What is a barred spiral galaxy?
Barred spiral galaxies feature a central bar-shaped structure composed of stars, gas, and dust. Spiral galaxies consist of a central bulge and disk with spiral arms. Bars funnel gas and dust towards the center, triggering star formation. Stars and gas move in complex circular and radial motions. 60-70% of local universe spiral galaxies are barred.
The bar is the defining characteristic of barred spiral galaxies. Spiral arms emerge from the ends of this central bar, creating the galaxy’s shape. The disk of barred spiral galaxies surrounds the central bulge and bar, containing most of the galaxy’s matter. Barred spiral galaxies have a galactic center containing a bar, bulge, and supermassive black hole.
Barred spiral galaxy formation involves gravitational collapse of gas and dust in the early universe. The bar in barred spiral galaxies acts as a density wave driving star formation and gas inflow. Barred spiral galaxies have rates of star formation in the bar and spiral arms. Barred spiral galaxies are classified into subtypes SBa, SBb, and SBc based on bar prominence and arm tightness.
What are fun facts about barred spiral galaxies?
Barred spiral galaxies comprise up to 70% of all spiral galaxies. Stars in the central bar are packed and older. Bars trigger star formation by compressing gas and dust in the galaxy’s disk. Barred spirals contain amounts of gas and dust. The central bulge makes up a portion of the galaxy’s total mass.
Fun facts about barred spiral galaxies are listed below.
- Barred spiral galaxies exist in abundance: They account for 60-70% of all spiral galaxies.
- The Milky Way’s classification: It is a confirmed barred spiral galaxy through observations and simulations.
- Structure of barred spiral galaxies: Central bars with arms connecting at the ends create a spiral pattern.
- Effects of bars on motions: Bars influence the movement of stars and gas, causing inward and outward orbits.
- Bars act as funnels: They channel gas and stars towards the galactic center, enhancing star formation.
- Formation of bulges: Bars build bulges by funneling matter towards the center over time.
- Feeding supermassive black holes: Bars direct matter to the core, fueling black hole growth.
- Stellar composition of bars: They contain numerous older stars, densely packed.
- Central black holes: Barred spiral galaxies have black holes millions or billions of times the sun’s mass.
- Systems of interaction: Barred spiral galaxies show dynamic movement and interaction within their components.
What are the characteristics of a barred spiral galaxy?
Barred spiral galaxies feature a central bar structure containing stars, gas, and dust. Spiral arms extend from the bar’s ends, hosting regions of star formation. The bar drives material towards the centre, fueling star formation and supermassive black hole growth. Spiral arms contain many young stars and are either tightly or loosely wound.
The characteristics of a barred spiral galaxy are outlined below.
- The central bar: The central bar contains the galaxy’s nucleus and often a supermassive black hole. The central bar funnels gas and dust toward the galaxy’s center, driving increased star formation in these regions.
- Spiral arms: Spiral arms of barred spiral galaxies connect to the ends of the central bar. These arms do not lead directly to the center but extend from the bar’s endpoints.
- Unique orbital patterns: Stars and gas follow twisted, radial orbits within the bar due to its gravitational influence. Radial orbits occur due to the bar’s gravitational influence, creating dynamics throughout the galaxy.
- Prevalence of barred spiral galaxies: Barred spiral galaxies are common. Two-thirds of all spiral galaxies, including the Milky Way, are classified as barred spirals, affecting their appearance and evolution.
What is the difference between a spiral and a barred spiral galaxy?
Spiral galaxies and barred spiral galaxies differ in their central structure. Barred spirals contain a bar-shaped concentration of stars at their centre. Regular spirals lack this bar feature. Barred spirals have looser spiral arms surrounding the central bar. The bar affects star formation and galaxy evolution in barred spirals.
Arm configuration varies between these galaxy types. Spiral galaxies exhibit arms that wind around the nucleus in a continuous curve. Barred spiral galaxies have arms extending from the ends of the bar, through the nucleus, and out into the disk, in a fragmented and irregular manner.
Differences in the central bulge shape distinguish these galaxy types. Spiral galaxies have a spherical or ellipsoidal central bulge. Barred spiral galaxies possess an elongated central bulge, aligned with the central bar.
Two-thirds of spiral galaxies are classified as barred spiral galaxies. All spiral galaxies have spiral arms that wind around the nucleus.
Classification of galaxies is based on these structural differences. Galaxies are categorized as spiral or barred spiral depending on the presence or absence of a central bar and the way the spiral arms connect to the center of the galaxy.
Is the Milky Way a barred spiral galaxy?
The Milky Way is a barred spiral galaxy. Barred spiral galaxies have central bar-shaped structures and spiral arms. The Milky Way’s central bar measures 27,000 light-years long. Four spiral arms named Norma, Scutum-Centaurus, Sagittarius, and Perseus extend from the bar. NASA’s Spitzer Space Telescope and ESA’s Gaia mission confirmed this structure.
The Milky Way’s bar is a key feature of the galaxy’s structure. It is an elongated region 27,000 light-years long and 1,000 light-years wide. The bar contains packed older stars and runs through the center of the galaxy. It plays a role in shaping the galaxy’s evolution and influencing star formation.
The Milky Way’s spiral pattern is characterized by four arms. These arms are named Norma, Scutum-Centaurus, Sagittarius, and Perseus. The spiral arms exhibit increased star density and star formation. They are thought to be density waves that compress gas, triggering the formation of new stars.
The Milky Way type is classified as an SBc-type galaxy in the Hubble sequence. This classification is based on the galaxy’s barred shape, spiral arms, and small central bulge. The Milky Way contains hundreds of billions of stars, remnants, gas, dust, and dark matter. Its structure includes a central bulge, a flat rotating disk, and a halo.
What are examples of barred spiral galaxies?
NGC 1300 and NGC 1365 are known examples of barred spiral galaxies. NGC 1300 resides in the Eridanus constellation with a bar and two spiral arms. NGC 1365 is located in Fornax, featuring a bar. The Milky Way and Hubble’s Galaxy in Ursa Major are barred spiral galaxies with bar-shaped structures and spiral arms.
Examples of barred spiral galaxies are provided in the table below.
| Galaxy Name | Distance (million light-years) | Constellation | Bar Length (kiloparsecs) | Bar Length (light-years) | Central Bulge Diameter (kiloparsecs) | Central Bulge Diameter (light-years) |
| Milky Way | 0.026 | Sagittarius | 8.3 | 27,000 | 2.7 | 8,800 |
| NGC 1300 | 61 | Eridanus | 4.7 | 15,000 | 2.1 | 6,800 |
| Messier 77 (M77) | 47 | Cetus | 2.3 | 7,500 | 1.4 | 4,600 |
| M58 | 68 | Virgo | 4.3 | 14,000 | 2.5 | 8,200 |
| M61 | 60 | Virgo | 2.3 | 7,500 | 1.7 | 5,600 |
| NGC 613 | 67 | Sculptor | 2.2 | 7,200 | 1.3 | 4,300 |
| M91 | 63 | Coma Berenices | 2.1 | 6,800 | 1.2 | 3,900 |
| M109 | 83 | Ursa Major | 4.2 | 13,700 | 2.3 | 7,500 |
| Large Magellanic Cloud (LMC) | 0.163 | Dorado | 2.5 | 8,200 | 1.1 | 3,600 |
| Andromeda Galaxy (M31) | 2.5 | Andromeda | 2.6 | 8,500 | 2.6 | 8,500 |
NGC 1300 represents a barred spiral galaxy. NGC 1300 is located about 61 million light-years away in the constellation of Eridanus. Its bar length is estimated to be 15,000 light-years.
Messier 77 (M77) showcases another barred spiral structure. M77 is situated about 47 million light-years away in the constellation of Cetus. The galaxy features a bar length of around 10,000 light-years.
M58 and M61 are examples of barred spiral galaxies. M58 is located about 68 million light-years away in the constellation of Virgo, with a bar length of 15,000 light-years. M61 is found about 60 million light-years away in the constellation, possessing a bar length of around 10,000 light-years.
NGC 613 demonstrates the characteristics of a barred spiral galaxy. NGC 613 is positioned about 67 million light-years away in the constellation of Sculptor. Its bar extends 10,000 light-years.
M91 and M109 illustrate the diversity of barred spiral galaxies. M91 is located about 63 million light-years away in the constellation of Coma Berenices, with a bar length of around 10,000 light-years. M109 is situated about 83 million light-years away in the constellation of Ursa Major, featuring a bar length of 15,000 light-years.
The Large Magellanic Cloud (LMC) is classified as a dwarf barred spiral galaxy. LMC exhibits a bar structure with a length of 10,000 light-years. The Andromeda Galaxy (M31) is sometimes considered a barred spiral galaxy. Andromeda’s bar length is estimated to be 10,000 light-years.
Barred spiral galaxies possess bars of stars, gas, and dust running through their centers. Disks of spiral arms surround these central bars. Barred spiral galaxies include a range of galaxy types and are found in environments, from isolated regions to galaxy clusters and groups.
