Glowing gas and dark dust in a side-on spiral
The Hubble Space Telescope has produced a sharp image of NGC 4634, a spiral galaxy seen exactly side-on. Its disc is slightly warped by ongoing interactions with a nearby galaxy, and it is crisscrossed by clearly defined dust lanes and bright nebulae.
NGC 4634, which lies around 70 million light-years from Earth in the constellation of Coma Berenices, is one of a pair of interacting galaxies. Its neighbour, NGC 4633, lies just outside the upper right corner of the frame, and is visible in wide-field views of the galaxy. Its subtle effects on NGC 4634 are easy to see to a well-trained eye.
Gravitational interactions pull the neat spiral forms of galaxies out of shape as they get closer to each other, and the disruption to gas clouds triggers vigorous episodes of star formation. While this galaxy’s spiral pattern is not directly visible thanks to our side-on perspective, its disc is slightly warped, and there is clear evidence of star formation.
Along the full length of the galaxy, and scattered around parts of its halo, are bright pink nebulae. Similar to the Orion Nebula in the Milky Way, these are clouds of gas that are gradually coalescing into stars. The powerful radiation from the stars excites the gas and makes it light up, much like a fluorescent sign.
Hubble portrays a dusty spiral galaxy
The Hubble Space Telescope has provided us with another outstanding image of a nearby galaxy. The galaxy NGC 4183, seen here with a beautiful backdrop of distant galaxies and nearby stars. Located about 55 million light-years from the Sun and spanning about eighty thousand light-years, NGC 4183 is a little smaller than the Milky Way.
This galaxy, which belongs to the Ursa Major Group, lies in the northern constellation of Canes Venatici. NGC 4183 is a spiral galaxy with a faint core and an open spiral structure. Unfortunately, this galaxy is viewed edge-on from the Earth, and we cannot fully appreciate its spiral arms. But we can admire its galactic disc.
Dust over the galactic plane is visible as dark intricate filaments that block the visible light from the core of the galaxy. Recent studies suggest that this galaxy may have a bar structure. Galactic bars are thought to act as a mechanism that channels gas from the spiral arms to the centre, enhancing star formation.
A Glimmer from a Dark Cosmic Era
With the combined power of NASA’s Spitzer and Hubble space telescopes, astronomers have spotted what could be the most distant galaxy ever seen. Light from the primordial galaxy traveled approximately 13.2 billion light-years before reaching NASA’s telescopes, shining forth from the so-called cosmic dark ages when the universe was just 3.6 percent of its present age.
Astronomers relied on gravitational lensing to catch sight of the early, distant galaxy. In this phenomenon, predicted by Albert Einstein a century ago, the gravity of foreground objects warps and magnifies the light from background objects.
In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times, bringing the remote object into view.
At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right. In these visible and infrared light images from Hubble, MACS 1149-JD looks like a dim, red speck. The small galaxy’s starlight has been stretched into longer wavelengths, or “redshifted,” by the expansion of the universe.
The far-off galaxy existed within an important era when the universe transformed from a starless expanse during the dark ages to a recognizable cosmos full of galaxies. The discovery of the faint, small galaxy opens a window onto the deepest, remotest epochs of cosmic history.
Angling Saturn
Cassini takes an angled view toward Saturn, showing the southern reaches of the planet with the rings on a dramatic diagonal. The rings cast wide shadows on the planet’s southern hemisphere. The moon Enceladus appears as a small, bright speck in the lower left of the image. The image was taken with the Cassini spacecraft wide-angle camera on June 15, 2012 from a distance of approximately 2.9 million kilometers.
Above Titan’s South
Titan’s south polar vortex seems to float above the moon’s south pole in this Cassini view. The vortex, which is a mass of gas swirling around the south pole high in the moon’s atmosphere, can be seen in the lower right of this view. The moon’s northern hood is also visible in the top left of this view. The image was taken with the Cassini spacecraft narrow-angle camera on July 6, 2012 from a distance of approximately 2.8 million kilometers from Titan.
Atlas V Arc of Light
The Atlas V rocket launched with twin Radiation Belt Storm Probes sent to explore the Van Allen Belts that surround Earth. Astrophotographer Mike Killian took this photo from Cape Canaveral Air Force Station in Florida Aug. 24, 2012.
Endeavour at Edwards AFB
After landing at Edwards Air Force Base in California, the shuttle Endeavour was parked at NASA-Dryden for employees and their families to get up close to the retired orbiter and Shuttle Carrier Aircraft. Photo credit: Walter Scriptunas II/Spaceflight Now
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San Francisco and California wine country - a favourite place on Earth.
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National Geographic Photographer of the Year: Mr. Tall Fox
he’s probably just going through his mid life crisis
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Paintings by Peter Peri
