Faint galaxy with popping pink features: The NASA/ESA Hubble Space Telescope has imaged a region of space containing the intriguing object IC 2574. Pink bubbles blown by supernova explosions abound in this faint galaxy. The colour of these shells comes from hydrogen gas irradiated by newborn stars. The formation of the stars was triggered by shock waves from earlier supernova detonations that compressed material together. IC 2574 is commonly known as Coddington's Nebula after the American astronomer Edwin Coddington, who discovered it in 1898. Astronomers classify IC 2574 as a dwarf irregular galaxy due to its relatively small size and lack of organisation or structure. These galaxies are thought to resemble some of the earliest that formed in the Universe. Dwarf irregular galaxies thus serve as useful "living fossils" for studying the evolution of more complex galaxy types such as our home, the Milky Way, with its central bar and spiral arms. The expanding shells in IC 2574 are of particular interest to astronomers as they reveal how supernova-driven explosions ignite round after round of star formation. The constellation containing IC 2574 is Ursa Major (The Great Bear). IC 2574 is located about 12 million light-years away, belonging to the Messier 81 group of galaxies. This group is named after the most prominent galaxy in its midst, the big, bright and accordingly well-studied spiral galaxy Messier 81. This picture was produced with Hubble’s Advanced Camera for Surveys, and covers a field of view of around 3.3 by 3.3 arcminutes.

Name: IC 2574
Type: Local Universe : Galaxy : Type : IrregularLocal Universe : Galaxy : Size : Dwarf
Category: Galaxies
Constellation: Ursa Major
Distance: 13 million light years
Release date: 26 December 2011, 10:00
Credit: ESA/Hubble & NASA

Smoke without fire: a different view of the cigar galaxy: This image shows the most detailed view ever of the core of Messier 82 (M 82), also known as the Cigar Galaxy. Rich with dust, young stars and glowing gas, M 82 is both unusually bright and relatively close to Earth. The starburst galaxy is located around 12 million light-years away in the constellation of Ursa Major (The Great Bear). This is not the first time Hubble has imaged the Cigar Galaxy. Previous images (for example heic0604) show a galaxy ablaze with stars. Yet this image looks quite unlike them, and is dominated instead by glowing gas and dust, with the stars almost invisible. Why such a difference? The new image is more detailed than previous Hubble observations – in fact, it is the most detailed image ever made of this galaxy. But the reason it looks so dramatically different is down to the choices astronomers make when designing their observations. Hubble’s cameras do not see in colour: they are sensitive to a broad range of wavelengths which they image only in greyscale. Colour pictures can be constructed by passing the light through different coloured filters and combining the resulting images, but the choice of filters makes a big difference to the end result. Using filters which allow through relatively broad bands of colours, similar to those our eyes see, results in natural-looking colours and bright stars, as starlight shines brightly across the spectrum. Using filters transparent only to the wavelengths emitted by specific chemical elements, as in this image, isolates the light from glowing gas clouds, while blocking out much of the starlight. This explains why the stars appear faint in this image, and why the dust lanes are sharply silhouetted against the brightly glowing gas clouds. The image shows the light emitted by sulphur (shown in red), visible and ultraviolet light from oxygen (shown green and blue, respectively), and light from hydrogen (cyan). The field of view is approximately 2.7 by 2.7 arcminutes.

Name: Cigar Galaxy, M 82, M82, Messier 82
Type: Local Universe : Galaxy : Activity : Starburst
Category: Galaxies
Constellation: Ursa Major
Distance: 12 million light years
Release date: 2 January 2012, 10:00
Credit: ESA/Hubble & NASA

Hubble spots a busy barred spiral: This  classic shot of a galaxy in the constellation of Ursa Major was taken  by the NASA/ESA Hubble Space Telescope. NGC 3259 is a bright barred  spiral galaxy located approximately 110 million light-years from Earth. Being  a fully-formed active galaxy, its bright central bulge hosts a  supermassive black hole, whose huge appetite for matter explains the  high luminosity of the galaxy’s core: as it devours its surroundings,  the black hole emits intense radiation across the whole electromagnetic  spectrum, including in visible light. The  beautiful spiral arms of the galaxy are not left out either as they  contain dark lanes of dust and gas, ideal spawning grounds for stars.  These bright, young, hot stars appear in rich clusters in the galaxy’s  arms and are what gives the galaxy its blueish hue. Interestingly,  the galaxy has a small companion (visible to the left of the image), a  much smaller galaxy that may be orbiting NGC 3259. In the background,  numerous distant galaxies can be seen, easily identifiable by their  elliptical shapes. They are visible here mainly in infrared light, which  is shown in red in this image.

Name: NGC 3259
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Ursa Major
Distance: 120 million light years
Release date: 9 January 2012, 10:00
Credit: ESA/Hubble & NASA

Core of Messier 100 in super high res: Messier 100 is a perfect example of a grand design spiral galaxy, a type of galaxy with prominent and very well-defined spiral arms. These dusty structures swirl around the galaxy’s nucleus, and are marked by a flurry of star formation activity that dots Messier 100 with bright blue, high-mass stars. This image from the NASA/ESA Hubble Space Telescope, the most detailed made to date, shows the bright core of the galaxy and the innermost parts of its spiral arms. Messier 100 has an active galactic nucleus — a bright region at the galaxy’s core caused by a supermassive black hole that is actively swallowing material, which radiates brightly as it falls inwards. The galaxy’s spiral arms also host smaller black holes, including the youngest ever observed in our cosmic neighbourhood, the result of a supernova observed in 1979. Messier 100 is located in the direction of the constellation of Coma Berenices, about 50 million light-years distant. The galaxy became famous in the early 1990s with the release of two images of the object taken with Hubble before and after a major repair to the telescope, which illustrated the dramatic improvement in Hubble’s observations. This image, taken with the high resolution channel of Hubble’s Advanced Camera for Surveys demonstrates the continued evolution of Hubble’s capabilities over two decades in orbit. This image, like all high resolution channel images, has a relatively small field of view: only around 25 by 25 arcseconds.

Name: M 100, Messier 100
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Coma Berenices
Distance: 50 million light years
Release date: 16 January 2012, 10:00
Credit: ESA/Hubble & NASA