A new photograph from the Spitzer Space Telescope shows how supernova remnant Cassiopeia A evolved over time. The original star contained 15 to 20 times the mass of our Sun, and was made up of concentric shells of elements. The lightest elements, like hydrogen, were in the outermost shell, while the heaviest elements sunk to the centre. The shells of the exploded material match up quite well with the original layers in the star before it detonated as a supernova.

Press release

New images taken with Hubble’s Advanced Camera for Surveys (ACS) in November 2005 and September 2006 show the evolution of the light echo around the star V838 in the constellation of Monoceros.
Hubble’s Latest Views of Light Echo from Star V838 Monocerotis

Astronomers have discovered two of the most distant galaxies ever seen, when the Universe was only 700 million years old. The galaxies were first discovered as part of the Hubble Space Telescope’s Deep Field Survey, which looked into the distant Universe. Astronomers then did follow-on observations with the Spitzer Space Telescope to confirm their distance and age. The galaxies are between 50-300 million years old, and have only 1% of the mass of our own Milky Way.

Astronomers weigh 200-million-year-old baby galaxies

In 1054 A.D., Chinese astronomers recorded the temporary brightening of a star in the constellation Taurus. Nearly 1000 years later, we look into the same region and see the exploded remnants of a dead star: the Crab Nebula. A new composite photograph of the Crab Nebula was made by merging images from Hubble, the Chandra X-Ray Observatory, and the Spitzer Space Telescope. It shows only a hail of high-energy particles and expanding debris cloud that once was a massive star.
http://chandra.harvard.edu/photo/2006/crab/

Zooming in on a nearby young star called HD 141569A, astronomers using the Subaru telescope on Mauna Kea, Hawaii, discovered a hole in a disk of gas and dust encircling the star. The existence of this large gap, which is about the size of the orbit of Saturn, supports the theory that this young star ended its infancy abruptly by ionizing and pushing away the gas in the disk from which it was born.
http://subarutelescope.org/Pressrelease/2006/10/23/index.html

Astronomers using NASA’s Spitzer Space Telescope have recently identified two quasars, or supermassive black holes, that may be on the verge of a colossal cosmic “belch”.
http://www.spitzer.caltech.edu/news/866-feature06-34-Belching-Black-Holes

Imagine trying to understand how a football game works based on just a few fuzzy snapshots of the game in play. Astronomers have faced this challenge when it comes to understanding the dynamics of the beehive swarm of stars in the globular star clusters that orbit our Milky Way Galaxy. Now, NASA’s Hubble Space Telescope has provided astronomers with the best observational evidence to date that globular clusters sort out stars according to their mass, governed by a gravitational billiard ball game between stars.
http://hubblesite.org/newscenter/archive/releases/2006/33/full/

Using the near infrared integral field spectrograph CIRPASS at Gemini South, Ruben Diaz and an international team of astronomers have discovered a previously unknown hidden mass concentration that looks like a second nucleus in the starburst galaxy M83.

http://www.gemini.edu/node/205

A two-decade-long riddle about the bizarre shape of the Milky Way’s nearest spiral-shaped galaxy, Andromeda, has been solved, suggests a new study. Instead of having the flat plane and outflung arms that are the hallmarks of a mature spiral galaxy, Andromeda has a warped plane and several rather chaotic, overlapping outer rings. The reason, according to an international team of astronomers, is that Andromeda suffered a head-on collision with a smaller galaxy some 210 million years ago. The evidence comes from infrared images taken by NASA’s Spitzer Space Telescope. They show a previously hidden, tilted second ring that protrudes from the heart of the galaxy. This ring is likely to be the shockwave of gas and dust from a colossal collision. The theory has been put to the test in a computer simulation. It suggests a dwarf galaxy called M32 probably drove straight into the heart of Andromeda.
Article

Images

A new Hubble image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies. As the two galaxies smash together, thousand of millions of stars are born, mostly in groups and clusters of stars.

http://hubblesite.org/newscenter/archive/releases/2006/46/image/a/

http://www.esa.int/esaCP/SEM5T4O7BTE_index_1.html