Checked content



Some browsers may have trouble displaying this image at full resolution: This image has a large number of pixels and may either not load properly or cause your browser to freeze. Interactive large-image-viewer ( non-Flash)


If you think this file should be featured on Wikimedia Commons as well, feel free to nominate it.
If you have an image of similar quality that can be published under a suitable copyright license, be sure to upload it, tag it, and nominate it.

English: The Whirlpool Galaxy (Spiral Galaxy M51, NGC 5194) is a classic spiral galaxy located in the Canes Venatici constellation.

Out of this whirl: The Whirlpool Galaxy (M51) and companion galaxy

The graceful, winding arms of the majestic spiral galaxy M51 (NGC 5194) appear like a grand spiral staircase sweeping through space. They are actually long lanes of stars and gas laced with dust.

This sharpest-ever image, taken in January 2005 with the Advanced Camera for Surveys aboard the NASA/ESA Hubble Space Telescope, illustrates a spiral galaxy's grand design, from its curving spiral arms, where young stars reside, to its yellowish central core, a home of older stars. The galaxy is nicknamed the Whirlpool because of its swirling structure.

The Whirlpool's most striking feature is its two curving arms, a hallmark of so-called grand-design spiral galaxies. Many spiral galaxies possess numerous, loosely shaped arms that make their spiral structure less pronounced. These arms serve an important purpose in spiral galaxies. They are star-formation factories, compressing hydrogen gas and creating clusters of new stars. In the Whirlpool, the assembly line begins with the dark clouds of gas on the inner edge, then moves to bright pink star-forming regions, and ends with the brilliant blue star clusters along the outer edge.

Some astronomers believe that the Whirlpool's arms are so prominent because of the effects of a close encounter with NGC 5195, the small, yellowish galaxy at the outermost tip of one of the Whirlpool's arms. At first glance, the compact galaxy appears to be tugging on the arm. Hubble's clear view, however, shows that NGC 5195 is passing behind the Whirlpool. The small galaxy has been gliding past the Whirlpool for hundreds of millions of years.

As NGC 5195 drifts by, its gravitational muscle pumps up waves within the Whirlpool's pancake-shaped disk. The waves are like ripples in a pond generated when a rock is thrown in the water. When the waves pass through orbiting gas clouds within the disk, they squeeze the gaseous material along each arm's inner edge. The dark dusty material looks like gathering storm clouds. These dense clouds collapse, creating a wake of star birth, as seen in the bright pink star-forming regions. The largest stars eventually sweep away the dusty cocoons with a torrent of radiation, hurricane-like stellar winds, and shock waves from supernova blasts. Bright blue star clusters emerge from the mayhem, illuminating the Whirlpool's arms like city streetlights.

The Whirlpool is one of astronomy's galactic darlings. Located 31 million light-years away in the constellation Canes Venatici (the Hunting Dogs), the Whirlpool's beautiful face-on view and closeness to Earth allow astronomers to study a classic spiral galaxy's structure and star-forming processes.


NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team STScI/AURA)

About the Image

NASA caption
Id:     heic0506a
Type:   Observation
Release date:   25 April 2005, 06:00
Related releases:       heic0506
Size:   11477 x 7965 px

About the Object

Name:      Messier 51, Whirlpool Galaxy
Type:   • Local Universe : Galaxy : Type : Spiral
• Galaxies Images/Videos
Distance:       25 million light years

Colours & filters

Band       Wavelength      Telescope
Optical B       435 nm  Hubble Space Telescope ACS
Optical V       555 nm  Hubble Space Telescope ACS
Optical H-alpha + Nii   658 nm  Hubble Space Telescope ACS
Infrared I      814 nm  Hubble Space Telescope ACS
Esperanto: NGC 5194 (Messier 51) estas spirala galaksio en konstelacio Ĉashundoj.
日本語: ハッブル宇宙望遠鏡が撮影した 子持ち銀河 ( 渦巻銀河 M51, NGC 5194)
Nederlands: Het Spiraalvormig sterrenstelsel Messier 51 is een typisch voorbeeld van een spiraalvormig sterrenstelsel, het bevind zich in het sterrenbeeld Jachthonden.
Date January 2005
Source ( direct link)
Author NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team STScI/AURA)
( Reusing this file)

w:en:Creative Commons
This file is licensed under the Creative Commons Attribution 3.0 Unported license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).

Desktop wallpaper icon
This English Wikipedia featured picture is fairly large and has an aspect ratio of approximately 8:5, 16:10, or 16:9, making it suitable as a widescreen computer wallpaper.

See the gallery of such images, or the gallery of non-widescreen images.

The following pages on Schools Wikipedia link to this image (list may be incomplete):

Schools Wikipedia and SOS Children

SOS Children has brought Wikipedia to the classroom. SOS Childrens Villages is an international children's charity, providing a good home and loving family to thousands of children who have lost their parents. We also work with communities to help vulnerable families stay together and raise children in the best possible environment. There are many ways to help with SOS Childrens Villages.