Galactic bar paradox resolved in cosmic dance

New light has been shed on a mysterious and long-standing conundrum at the very heart of our galaxy. The new work offers a potential solution to the so-called "Galactic bar paradox," whereby different observations produce ...

Classifying galaxies with artificial intelligence

Astronomers have applied artificial intelligence (AI) to ultra-wide field-of-view images of the distant Universe captured by the Subaru Telescope, and have achieved a very high accuracy for finding and classifying spiral ...

Image: Barred spiral galaxy NGC 4907

The barred spiral galaxy known as NGC 4907 shows its starry face from 270 million light-years away to anyone who can see it from the Northern Hemisphere. This is a new image from the NASA/ESA Hubble Space Telescope of the ...

Image: Hubble snaps ghostly galaxy

A notable feature of most spiral galaxies is the multitude of arching spiral arms that seemingly spin out from the galaxy's center. In this image, taken with the NASA/ESA Hubble Space Telescope, the stunning silvery-blue ...

Image: Hubble sees sculpted galaxy

Captured by the NASA/ESA Hubble Space Telescope, this image shows NGC 7513, a barred spiral galaxy. Located approximately 60 million light-years away, NGC 7513 lies within the Sculptor constellation in the Southern Hemisphere.

Image: Snapshot of cosmic pyrotechnics

If you're looking for fireworks for the U.S. celebration of Independence Day, then look no further than the world of astronomy. The cosmic firework at the center of this image, the spiral galaxy NGC 925, resembles a vast ...

Image: Hubble spots feathered spiral

The spiral pattern shown by the galaxy in this image from the NASA/ESA Hubble Space Telescope is striking because of its delicate, feathery nature. These "flocculent" spiral arms indicate that the recent history of star formation ...

Image: Hubble captures galaxy on edge

The galaxy known as NGC 5907 stretches wide across this image. Appearing as an elongated line of stars and dark dust, the galaxy is categorized as a spiral galaxy just like our own Milky Way. In this new image from the NASA/ESA ...

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Spiral galaxy

A spiral galaxy is a galaxy belonging to one of the three main classes 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 the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.

Spiral galaxies are named for the (usually two-armed) spiral structures that extend from the center into the disk. The spiral arms are sites of ongoing star formation and are brighter than the surrounding disk because of the young, hot OB stars that inhabit them. Roughly half of all spirals are observed to have an additional component in the form of a bar-like structure, extending from the central bulge, at the ends of which the spiral arms begin. Our own Milky Way has been recently (in the 1990s) been confirmed to be a barred spiral, although the bar itself is difficult to observe from our position within the Galactic disk. The most convincing evidence for its existence comes from a recent survey, performed by the Spitzer Space Telescope, of stars in the Galactic center.

Together with irregulars, spiral galaxies make up approximately 60% of galaxies in the local Universe. They are mostly found in low-density regions and are rare in the centers of galaxy clusters.

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