New Image of Messier 101: The Pinwheel

The face-on Pinwheel spiral galaxy is seen at ultraviolet wavelengths in this image taken by ESA’s XMM-Newton space telescope.

Image Credit: ESA/XMM & R. Willatt

Also known as M101, the galaxy lies 21 million light-years away in the constellation Ursa Major. It measures 170 000 light-years across – nearly twice the diameter of our own Milky Way Galaxy – and contains at least a trillion stars. About a billion of these stars could be similar to our own Sun.

Pinwheel Galaxy

The Pinwheel Galaxy, M101, is a spiral galaxy located about 21 million light years away towards the constellation Ursa Major, the Big Dipper or the Great Bear. It is about 170,000 light years across, around 70% the size of our Milky Way. In this image, infrared light is in red, ultraviolet in blue, visible in yellow, and X-rays in purple.

The lopsided shape of the Pinwheel Galaxy is probably the result of an interaction with another galaxy. As a result, waves of high mass and condensed gas spread through the galaxy, compressing clouds of material and stimulating star formation, creating several bright star forming regions called HII regions visible in the arms. Since it is so far away, our view of the galaxy is 21 million years old, as we are still waiting for more recent light to reach us.

Image from NASA, information from NASA and Spitzer.

An archetypal dwarf galaxy

The constellation of Ursa Major (The Great Bear) is home to Messier 101, the Pinwheel Galaxy. M101 is one of the biggest and brightest spiral galaxies in the night sky. Like the Milky Way, Messier 101 is not alone, with smaller dwarf galaxies in its neighbourhood.

NGC 5477, one of these dwarf galaxies in the Messier 101 group, is the subject of this image from the NASA/ESA Hubble Space Telescope. Without obvious structure, but with visible signs of ongoing starbirth, NGC 5477 looks much like an archetypal dwarf irregular galaxy. The bright nebulae that extend across much of the galaxy are clouds of glowing hydrogen gas in which new stars are forming. These glow pinkish red in real life, although the selection of green and infrared filters through which this image was taken makes them appear almost white.

In addition to NGC 5477, the image includes numerous galaxies in the background, including some that are visible right through NGC 5477. This serves as a reminder that galaxies, far from being solid, opaque objects, are actually largely made up of the empty space between their stars.

Image credit: ESA/Hubble & NASA

Astronomy Photo of the Day: 5/8/14 - A Beautiful View of Messier 101

This incredible image, taken by R Jay GaBany, reveals the many colorful layers of the galaxy known as The Pinwheel Galaxy (also known as Messier 101). This celestial feature is an extremely popular galaxy to capture and study, but this has to be one of the most spectacular images ever taken of it.

M101 itself has various interesting features, but perhaps most prominently (at least in this version) is its asymmetrical structure Astronomers posit that its unusual shape is an artifact left behind after the galaxy experienced a close encounter with another galaxy in its past, but the culprit has yet to be identified. Moreover, we can see almost 3,000 starforming regions that cropped up after the gravitational collision.

Another observation that sets this galaxy apart from other spirals like our galaxy is the sheer number of stars contained within. The Pinwheel Galaxy has an estimated one TRILLION stars, while the Milky Way has about 400 billion (meaning, it has merely 1/4th of the stars the Pinwheel Galaxy has), though it’s worth mentioning that the Milky Way is almost less than half its size.

This featured galaxy can be found about 21-million light-years away from Earth in the Ursa Major constellation.

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Image Credit: R Jay GaBany

The galaxy Messier 101 is a swirling spiral of stars, gas, and dust. Messier 101 is nearly twice as wide as our Milky Way galaxy. This infrared view by NASA’s Spitzer Space Telescope reveals the galaxy’s delicate dust lanes as yellow-green filaments. Such dense dust clouds are where new stars can form.

In this image, dust warmed by the light of hot, young stars glows red. The rest of the galaxy’s hundreds of billions of stars are less prominent and form a blue haze. Astronomers can use infrared light to examine the dust clouds where stars are born.

Astronomy Photo of the Day: 2/12/15 — NGC 5474

Meet NGC 5474: a lovely dwarf galaxy — which I hereby propose we call the “Oyster Galaxy’ (it even appears to have a pearl in its center) — found around 21 million light-years from Earth in the Ursa Major constellation.

In an image taken by the Hubble Space Telescope’s ‘Advanced Camera For Surveys’ (ACS), we see this dimulative galaxy, at least by astronomical standards, in unprecedented clarity. Indeed, despite the fact that the galaxy only contains a few billion stars (our galaxy has around 400 billion, while our closest neighbor, the Andromeda galaxy, is known to contain over 1 trillion stars), it still has all the markings — the prominent, well-defined sweeping spiral arms, and the bright central core — of a so-called ‘Grand Design Spiral Galaxy’ (technically, it’s classified as a dwarf spiral galaxy)

Additionally, astronomers know that NGC 5474 isn’t all by its lonesome; it’s actually a member of a well-known galaxy group, called the Messier 101 Group. More famous members include, rather obviously, I might add, Messier 101, along with the extraordinarily beautiful Pinwheel Galaxy.

Messier 101 has definitely been shaped by its companions, so it’s only fair that its influence be exerted on its quaint neighbor, perhaps that’s where many of NGC 5474’s visible distortions, including the offset central core, came from. Gravitational encounters have certainly reinvigorated star formation activity within the galaxy’s confines, creating ripples that propagated from the inside out.

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Image Credit: ESA/Hubble & NASA

Messier 101 - The Pinwheel Galaxy

One of the last entries in the Messier Catalogue, M101 is a massive and visually stunning spiral galaxy. It was discovered in 1781 by Pierre Méchain and then confirmed by Charles Messier. M101 has shown to be a galaxy of significant star formation. Also, there appears to be a stellar mass black hole, 20 to 30 times the mass of our sun, which is consuming matter at a higher rate than our theories suggest it should!

Top: Wide-Field - Anttler

Bottom: Close-Up - ESA/Hubble

The Pinwheel galaxy, officially named Messier 101, is dominated by a mish-mash of spiral arms. The Pinwheel galaxy is located about 27 million light-years away in the constellation Ursa Major. It has one of the highest known gradients of metals (elements heavier than helium) of all nearby galaxies in our universe. In other words, its concentrations of metals are highest at its center, and decline rapidly with distance from the center. This is because stars, which produce metals, are squeezed more tightly into the galaxy’s central quarters.

This Hubble image originally released in 2006 reveals the gigantic Pinwheel galaxy, one of the best known examples of “grand design spirals”, and its supergiant star-forming regions in unprecedented detail. The image is the largest and most detailed photo of a spiral galaxy ever taken with Hubble.

credit: Image: European Space Agency & NASA