Messier 82, also known as the Cigar Galaxy, is a starburst galaxy about 12 million light-years away in the constellation Ursa Major. Starburst galaxies undergo extremely high rates of star formation and are thought to represent a particular phase in a galaxy’s evolution. Because of its excessive star birth, M82 is five times brighter than our own Milky Way galaxy.
This image, from the Mount Lemmon SkyCenter, required a 28-hour exposure using the 32-inch Schulman telescope.
Image: Adam Block/Mount Lemmon SkyCenter/University of Arizona [high-resolution]
Billions of Earthlike Planets Crowd Milky Way?
Nearly every star in the Milky Way (pictured) has its own Earthlike planet, astronomers say.
Twin Explosions In Gigantic Dusty Potato Crisp
The beautiful edge-on spiral galaxy NGC 3190 with tightly wound arms and a warped shape that makes it resemble a gigantic potato crisp, as seen by ESO’s Very Large Telescope. Supernova SN 2002bo is found in between the ‘V’ of the dust lanes in the south-western part of NGC 3190. SN 2002cv is obscured by a large amount of dust and is therefore not visible. Its position is however indicated on the above image
A Milky Way look-alike, NGC 6744
This picture of the nearby galaxy NGC 6744 was taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla. The large spiral galaxy is similar to the Milky Way, making this image look like a picture postcard of our own galaxy sent from extragalactic space. The picture was created from exposures taken through four different filters that passed blue, yellow-green, red light, and the glow coming from hydrogen gas. These are shown in this picture as blue, green, orange and red, respectively.
Star Streams of Sagittarius Dwarf Galaxy
Credit: Amanda Smith, Institute of Astronomy, University of Cambridge
Artist’s concept of the four tails of the Sagittarius dwarf galaxy (orange clump on left of the image) orbiting the Milky Way. The bright yellow circle to the right of the Milky Way’s center is our sun (not to scale). We can see the Sagittarius galaxy’s star tails stretching across the sky.
Artist impression of the submillimeter galaxy LESS J0332 observed the ALMA at the 5000-meter altitude plateau. [Credit: NAOJ]
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter.
2. NGC 1300, an example of a barred spiral galaxy.
3. The Antennae Galaxies are undergoing a collision that will result in their eventual merger.
4. Galactic Center of the Milky Way
The Andromeda Galaxy (/ænˈdrɒmədə/) is a spiral galaxy approximately 2.5 million light-years (2.4×1019 km) from Earthin the Andromeda constellation. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. The Andromeda Galaxy is the nearest spiral galaxy to our galaxy (Milky Way), but not the closest galaxy overall.
In the image
4. Stars in the Andromeda Galaxy’s disc.
Near collision creates a bridge of gas between Andromeda and another galaxy
Astronomers have confirmed that a bridge of hydrogen gas is streaming between the giant Andromeda Galaxy and its smaller neighbor, the Triangulum Galaxy. The connection is likely the result of a cosmological close call between the two, a discovery that will help scientists better understand the evolution of galaxies.
This discovery was actually made in 2004 by using the Westerbrook Synthesis Radio Telescope in the Netherlands, but it was strongly disputed by some scientists who questioned the findings on technical grounds. But now, astronomers working out of the National Radio Astronomy Observatory (NRAO) have confirmed that a bridge of gas between the two galaxies does indeed exist. By using the highly sensitive Green Bank Telescope (GBT), these astronomers were able to conduct a more thorough analysis that revealed six dense clumps of gas in the stream.
Once these clumps of gas were confirmed to exist, the astronomers faced the more challenging task of confirming that they were connected between Andromeda and Triangulum. Further investigations showed that the clumps share roughly the same velocity with respect to Earth, suggesting that they are in fact part of a bridge between the two galaxies.
The astronomers speculate that the bridge is the result of the two galaxies passing close to each other. Gravitational forces resulted in a “tidal tail” in which gas was pulled into intergalactic space as lengthy streams. The near collision, it is thought, must have happened billions of years ago because neither galaxy seems to show any evidence of the encounter today.
The two galaxies, also known as M31 and M33 respectively, are about 2.6 and 3 million light-years from Earth and are members of our own Local Group of galaxies, an exclusive club that contains about 30 others.
Another challenge for the astronomers was the tenuous nature of the gas and its extremely faint radio emissions. Most radio telescopes wouldn’t be able to to pick up the trace, which is why the GBT proved indispensable to this study. The astronomers hope to continue to use GBT to learn more about this unique phenomenon and get a better sense of the orbital history of the galaxies.
Eurekalert. Images via National Radio Astronomy Observatory.
The Galaxy Evolution
1. Rainbow of Galaxies
This image of the Cartwheel galaxy shows multi-wavelength observations from several NASA missions, including the Galaxy Evolution Explorer, whose data is seen in blue. The Hubble Space Telescope is in green, the Spitzer Space Telescope is in red and the Chandra X-ray Observatory is in purple.
2. Jellyfish Galaxy
Wispy tendrils of hot dust and gas glow brightly in this ultraviolet image of the Cygnus Loop nebula.
3. Plowing Through the Depths of Space
GALEX captured a second runaway star, similar to Mira, also speeding through the cosmos.
4. Dissecting a Galaxy
By combining ultraviolet data from the Galaxy Evolution Explorer with infrared observations from the Spitzer Space Telescope, astronomers get a clearer picture of the various components of a galaxy.
Weird Galaxy Glows Bright in Amazing Telescope
The strange galaxy Centaurus A is pictured in a new image from the European Southern Observatory. The image was produced by the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile. [Full Story]
Credit: ESA/Hubble & NASA Wedneday, May 23, 2012
Galaxy NGC 891 lies approximately 30 million light-years away from Earth in the constellation of Andromeda. This Hubble Space Telescope photo shows the galaxy’s northern half, with the central bulge outside the image on the bottom left. Filaments of dust and gas clearly extend outwards from the plane of the galaxy into the galaxy halo over hundreds of light-years, unlike our own Milky Way. — Tom Chao
An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using data from NASA’s Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in X-rays as a million suns radiate at all wavelengths.
Researchers used Chandra to discover a new ultraluminous X-ray source, or ULX. These objects give off more X-rays than most binary systems, in which a companion star orbits the remains of a collapsed star. These collapsed stars form either a dense core called a neutron star or a black hole. The extra X-ray emission suggests ULXs contain black holes that might be much more massive than the ones found elsewhere in our galaxy.