NASA’s Galaxy Evolution Explorer has discovered baby galaxies forming in our relative neighborhood, casting doubt on the theory that only small galaxies were forming this long after the Big Bang. These new galaxies are called ultraviolet luminous galaxies, and they’re only 2-4 billion light-years away. They could be as young as 100 million to one billion years old. The Galaxy Evolution Explorer surveyed thousands of galaxies before finding these few dozen ultraviolet-bright ones, which are teeming in new star formation.
The Subaru telescope captured this image of a dusty planetary nebula surrounding a star similar to our own Sun at the end of its life. Located 5,000 light-years away from Earth in the constellation of Cygnus, the nebula is very similar to the more famous Ring Nebula. When they reach the end of their lives, stars like our own Sun shed layers of gas and dust which pile up around the star, and are pushed outward. In this nebula, the material has reached a distance of 100 times the size of our Solar System.
As the year winds down, observers in the Northern Hemisphere may notice the days growing steadily shorter; while observers in the Southern Hemisphere notice the days getting longer. In addition, in the north the days are getting colder and in the south the days are getting warmer. All this happens while Earth is moving toward a point in its orbit known as the Winter Solstice. But what is the Solstice anyway?
Astronomers working with the European Southern Observatory took a series of images of the Tarantula Nebula (aka 30 Doradus), which is one of the most impressive objects in the Southern sky. Located 170,000 light-years away in the constellation of Doradus, the Tarantula Nebula got its name because the various patches of gas and dust look like the legs of a spider emanating from the central “body” of young hot stars. The gas is mainly just protons and neutrons which are kept apart by energetic radiation coming off the stars in the area.
The early Universe was much dustier than astronomers were expecting, according to new data gathered by the Spitzer Space Telescope. This leads to the question, how did it get so dusty so early? Regular stars take billions of years before they star giving off large amounts of dust. But massive stars can form quickly and then explode as supernovae within 10 million years. The problem is that these explosions produce enormous amounts of hot dust, but very little cold dust, which is the kind found in the early Universe. So, the mystery continues.
Astronomers from the Harvard-Smithsonian Center for Astrophysics believe it’s possible that our own Sun could have stolen some material from other stars billions of years ago. They came to this conclusion while trying to understand the orbit of Sedna, which takes 10,000 years to go around the Sun, in a highly elliptical orbit far beyond the Kuiper Belt. When our Sun was younger than 200 million years old, it could have swept past another star, disrupting the Kuiper Belt, and trading large objects (like Sedna) with each other.
IRAS ? The Infrared Astronomical Satellite ? was launched in 1983 and was the first spacecraft to map the entire sky recording over 350,000 sources, and there were some early surprises in the data too. The bright star Vega in the constellation of Lyra was seen to have a cool accretion disk of a primordial Vega [solar] system in the process of formation. A decade later, astronomers discovered another larger accretion disk of dusty material, this time around the star Formalhaut in the constellation of the Southern Fish, and many more have followed since. Thereafter a new astronomical study was created with to examine primordial accretion disks around other stars. Here Richard Pearson talks to astronomer Michiel Min about stellar planetary systems.
Astronomers at the European Southern Observatory’s Paranal Observatory took this image of galaxy NGC 6118, located 80 million light-years away. A supernova was discovered exploding just north of the galaxy’s centre on August 1, 2004. Astronomers now believe that it is a Type 1b or 1c, which means that it probably arose in a binary star system; a massive star whose hydrogen envelope was siphoned off by its stellar partner before it exploded.
Japanese researchers using the Subaru Telescope have found a large galaxy caught in the act of consuming a smaller companion galaxy. It’s a messy eater; there’s a wispy trail of stars over 500,000 light-years long, which is the longest astronomers have ever seen. Examples of this kind of galactic destruction are hard to find because the consumed are usually dim dwarf galaxies. We have only indirect evidence of digested galaxies in our own Milky Way, like groups of stars traveling in an unusual trajectory.