Venus and the Pleiades
Credit: Jerry Lodriguss
Visible as a small, sparkling hook in the dark sky, this beautiful object is known as SDSS J082354.96+280621.6, or J082354.96 for short. It is a starburst galaxy, so named because of the incredibly (and unusually) high rate of star formation occurring within it.
One way in which astronomers probe the nature and structure of galaxies like this is by observing the behaviour of their dust and gas components; in particular, the Lyman-alpha emission. This occurs when electrons within a hydrogen atom fall from a higher energy level to a lower one, emitting light as they do so. This emission is interesting because this light leaves its host galaxy only after extensive scattering in the nearby gas — meaning that this light can be used as a pretty direct probe of what a galaxy is made up of.
(via scinerds)Source: spacetelescope.org
Galaxies can take many forms — elliptical blobs, swirling spiral arms, bulges, and discs are all known components of the wide range of galaxies we have observed using telescopes like the NASA/ESA Hubble Space Telescope. However, some of the more intriguing objects in the sky around us include ring galaxies like the one pictured above — Zw II 28.
Ring galaxies are mysterious objects. They are thought to form when one galaxy slices through the disc of another, larger, one — as galaxies are mostly empty space, this collision is not as aggressive or as destructive as one might imagine. The likelihood of two stars physically colliding is minimal, and it is instead the gravitational effects of the two galaxies that causes the disruption.
This disruption upsets the material in both galaxies, causing it to redistribute to form a dense central core, encircled by bright stars. All this commotion causes clouds of gas and dust to collapse and triggers new periods of intense star formation in the outer ring, which is thus full of hot, young, blue stars and regions that are actively giving rise to new stars.
The sparkling pink and purple loop of Zw II 28 is not a typical ring galaxy due to its lack of a visible central companion. For many years it was thought to be a lone circle on the sky, but observations using Hubble have shown that there may be a possible companion lurking just inside the ring, where the loop appears to double back on itself. The galaxy has a knotty, swirling ring structure, with some areas appearing much brighter than others.
The Hubble Space Telescope has been looking deep into the Cosmos for over two decades returning over a million observations of planets, exoplanets, nebulae, galaxies and clusters of galaxies. The mission has surpassed our wildest expectations, but some of the most intricately beautiful views of the Universe have been released only recently — sometimes in collaboration with other observatories.
(via n-a-s-a)Source: news.discovery.com
Amazing glowing nebulas resembling cosmic candy take center stage in a group of new photos unveiled today (Oct 10) by the science team behind NASA’s Chandra X-ray Observatory.
The pictures are part of a survey the Chandra space telescope is making of nearby planetary nebulas, which are formed when dying stars push off their outer gaseous layers. The first stage of this survey, which includes Chandra observations of 21 of these nebulas, has now been released. Chandra also released a video of the surveyed nebulas.
Chandra observes the universe in short-wavelength X-ray light. This data, shown in pink, was combined with optical imagery from the Hubble Space Telescope, shown in red, green and blue. The four nebulas pictured above are the Cat’s Eye nebula (NGC 6543), as well as NGC 7662, NGC 7009 and NGC 6826.
Black Holes of the Universe
1. Here Comes the Warm Jets
Combining observations done with ESO’s Very Large Telescope and NASA’s Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. The black hole blows a huge bubble of hot gas, 1000 light-years
2. Radio Waves
This artist’s concept shows a galaxy with a supermassive black hole at its core. The black hole is shooting out jets of radio waves. New research led by theoretical astrophysicist David Garofalo of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., sug
3. Eat to the Beat
Artist’s schematic impression of the distortion of space-time by a supermassive black hole at the center of a galaxy. The black hole will swallow dark matter at a rate which depends on its mass and on the amount of dark matter around it.
4. Portrait of the Quasar as a Young Black Hole
Illustration of a young black hole, such as the two distant dust-free quasars spotted recently by the Spitzer Space Telescope.
5. Beware of the Blob
This illustration shows what one of the galaxies inside a blob might look like, with the spiral arms of the galaxy in yellow and white, and two-sided outflow powered by the supermassive black hole buried inside shown in bright yellow.
Science is too cool for words.
(via scinerds)Source: space.com
Image: Artist’s impression of gravitational waves from two orbiting black holes. Credit: K. Thorne (Caltech) and T. Carnahan (NASA GSFC)
Because black holes are impossible to see, one of scientists’ best hopes to study them is to look for the ripples in space-time, called gravitational waves, that they are thought to create.
Gravitational waves would be distortions propagating through space and time caused by violent events such as the collision of two black holes. They were first predicted by Einstein’s general theory of relativity; however, scientists have yet to find one.
That could change when the latest version of a gravitational wave-hunting facility gets up and running. The Laser Interferometer Gravitational Wave Observatory (LIGO) is actually a pair of observatories, in Louisiana and Washington state, that began operating in 2002. Newly sensitized detectors are being added to both.
Distance: 5,000,000 Light Years
On visual inspection M94 appears to be a series of ring like structures. As one of the closest starburst-ringed galaxies it possesses one of the highest optical surface brightness nuclei known.
At its center is a 1400 light year stellar bar which has been an important influence on the overall morphology of the galaxy. Surrounding the central bar is an inner stellar disk with a radius of about 2300 light years. Further out at a radius of about 3500 light years is an almost perfectly circular starburst ring.
Remnants of an exploded supernova appear as ghostly wisps in this skywatching photo of the Veil Nebula.
Avid astrophotographers Bob and Janice Fera took this spectacular photo on September 2011 from Mike Sherick’s Sagrada Observatory in Las Cruces, New Mexico.
Left behind by the explosion of a massive star, the veil nebula is one of the largest and most spectacular supernova remnants in the sky.
Some 1500 light-years away from Earth, the wispy clouds of heated and ionized dust make up what is known as the Veil of Witch’s Broom Nebula. The source star of the nebula exploded more than 5,000 years ago. The nebula lies in the constellation Cygnus.