An extraordinarily slender galaxy: The NASA/ESA Hubble Space Telescope has imaged a striking galaxy called NGC 4452, which appears to lie exactly edge-on as seen from Earth. The result is an extraordinary picture of billions of stars observed from an unusual angle. The bright nucleus can be seen at the centre, along with the very thin disc that looks like a straight line from our unusual viewing position. To complete the picture, a hazy halo of stars on the periphery of the galaxy makes it seem to glow.NGC 4452 was first seen by William Herschel in 1784 with his 47 cm telescope in England. He described the object as a bright nebula, small and very much elongated. The new Hubble image shows just how elongated this unusual object really is.Galaxies are like star cities, and typically contain many billions of stars. The American astronomer Edwin Hubble, after whom the Hubble Space Telescope is named, was the first person to prove that there are other galaxies beyond our own by measuring their distances. This work, done in the 1920s, forever changed our view of the Universe.Galaxies also belong to collections that are called galaxy clusters. NGC 4452 is part of the Virgo Cluster, so-called because many of its members appear in the constellation of Virgo (the Maiden). This enormous grouping is approximately 60 million light-years distant and contains around 2000 galaxies. It is thought that the Local Group of galaxies, to which our own Milky Way belongs, is on the fringes of the Virgo Cluster, and at some point in the far future the Local Group may be pulled slowly into the Virgo Cluster by the force of gravity. Large numbers of much more remote, faint galaxies, far beyond NGC 4452 and the Virgo Cluster, appear in the background of this image.This picture of NGC 4452 was created from images taken using the Wide Field Channel on Hubble’s Advanced Camera for Surveys. This picture was made from images through blue (F475W, coloured blue) and near-infrared (F850LP, coloured red) filters. The exposures times were 750 s and 1210 s respectively. The field of view extends over 2.6 arcminutes.

Name: NGC 4452
Type: Local Universe : Galaxy : Type : Lenticular
Category: Galaxies
Constellation: Virgo
Distance: 8 million light years
Release date: 8 November 2010, 10:00
Credit: ESA/Hubble & NASA

Hubble witnesses the crafting of a celestial masterpiece: The NASA/ESA Hubble Space Telescope has used its Advanced Camera for Surveys to peer closely at the strange cloud of gas and dust that envelops a star at a late stage in its life, a short-lived phenomenon known as a protoplanetary, or pre-planetary nebula. These fascinating celestial objects give astronomers an opportunity to watch the early stages of planetary nebula formation, as the gas and dust is moulded by high velocity winds — like watching a glassblower at work in his factory. Despite their rather confusing names, these objects are unrelated to planets. The name arose because of the superficial visual similarity between planetary nebulae and the small discs of the outer planets in the Solar System when viewed through a telescope.The protoplanetary nebula shown in this image is known as IRAS 20068+4051 and it is found in the constellation of Cygnus. The shell formed when its progenitor star exhausted its hydrogen fuel for nuclear fusion, causing the outer layers of the star to expand and cool, which created a spherical envelope of gas and dust around the star. The mechanism that drives high velocity winds to then shape this spherical envelope into the intricate structure that we see here is still unclear, which is why continued observation of protoplanetary nebulae is so important. Meanwhile, as the central star continues to evolve, finding new ways to prevent itself from collapsing under its own gravity, it will eventually become hot enough to make the gas glow as a spectacular planetary nebula. These objects emit a broad spectrum of radiation, including visible light, making them great targets for both amateur and professional astronomers.However, protoplanetary nebulae, which often appear smaller and are seen best in infrared light, are much trickier to observe, particularly since water vapour in the Earth’s atmosphere absorbs most infrared wavelengths. But Hubble has exceptionally sharp vision and an unobstructed vantage point in space, making it possible to capture stunning images of these peculiar objects.This picture was created from images taken through yellow (F606W, coloured blue) and near-infrared (F814W, coloured red) filters using the High Resolution Channel of Hubble’s Advanced Camera for Surveys. The exposure times were 1280 s (F606W) and 200 s (F814W) and the field of view spans about 25 arcseconds.

Name: IRAS 20068+4051
Type: Local Universe : Nebula : Type : Planetary
Category: Nebulae
Constellation: Cygnus
Release date: 15 November 2010, 10:00
Credit: ESA/Hubble & NASA

Galactic moths drawn to a bright light: Smaller, dimmer galaxies appear to flit like moths around a radiant street light in this image captured by the NASA/ESA Hubble Space Telescope. The brilliant central object is a supergiant elliptical galaxy, the dominant member of a galaxy cluster with the mouthful of a name MACSJ1423.8+2404. This great swarm of galaxies is located about five billion light-years away in the constellation Boötes (the Herdsman). MACSJ1423.8+2404 and other distant galaxy clusters offer astronomers a peek into the earlier days of our Universe when these colossal groupings were still taking shape. Over the 13.7 billion-year history of the cosmos, such galaxy clusters have emerged as the largest observed gravitationally bound structures. But there is much more than meets the eye when it comes to galaxy clusters — they also hint at the vast majority of the Universe’s substance that we have not yet directly detected. Astronomers study clusters such as MACSJ1423.8+2404 to better understand the influence of dark energy, a mysterious force credited with accelerating the expansion of the Universe and accounting for some 72 percent of the mass of the Universe.The application of what we can see and detect to the study of what we cannot does not end there with MACSJ1423.8+2404 and its ilk. Dark matter, estimated to account for about 23 percent of the mass of the Universe, exists in great quantities in galaxy clusters. The “normal” matter that comprises stars, planets and us trickles in at less than 5 percent.Astronomers observe clusters to study how this dark matter gravitationally gathers visible matter and underpins these vast cosmic metropolises. The galactic moths are drawn to the clusters not by their light, but by the vast unseen reservoir of dark matter. This image was created from images taken using the Wide Field Channel of Hubble’s Advanced Camera for Surveys. The exposures were 75 and 76 minutes respectively, through yellow (F555W) and near-infrared (F814W) filters. The field of view is 3.2 arcminutes across.

Name: MACSJ1423.8+2404
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Bootes
Distance: z=0.545 (redshift)
Release date: 22 November 2010, 10:00
Credit: ESA/Hubble and NASA