Not a planet, still interesting February 7, 2010
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Despite Mike Brown’s best efforts, Pluto is not dead (yet). These cool new images of the tiny non-planet taken with the Hubble Space Telescope show that it is by no means a boring lump of icy rock. When comparing these images, taken in 2002-2003, to a previous set dating back to 1994, scientists noticed some striking changes. This would suggest that Pluto, just like many bodies in the solar system, shows seasonal activity and all kinds of interesting chemistry as it moves along its looong orbit around the Sun.
Image: NASA, ESA, and M. Buie (Southwest Research Institute)
Puffing up elliptical galaxies October 3, 2009
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Elliptical galaxies are the boring uncles of the galaxy family: they’re amorphous blobby things, ubiquitous in the Universe, that contain a fairly uniform population of old, red stars. Without the interstellar gas and dust that is needed to harbour pretty sites of star formation, they are supremely unphotogenic. But they have far more going on beneath their featureless surface: the complex dynamics inside many ellipticals show evidence of a turbulent past and, with many of the most massive known galaxies in our local Universe being ellipticals, they clearly play an important role in galaxies’ evolution.
Studies seem to suggest that high-redshift elliptical galaxies are more compact than their present-day counterparts (figure from Glazebrook, 2009)
Observational surveys of elliptical galaxies at high redshift have in recent years revealed a further interesting fact: ellipticals at high redshift appear to be much smaller in size than those in our local Universe, but have about the same mass and density of stars. In a recent ApJ paper, Ivana Damjanov of the University of Toronto and collaborators describe how a sample of elliptical galaxies at redshifts 1 to 2 looked 2-3 times smaller than those in the local Universe. The first surprise lies in that they evolve at all between redshift 2 and 0. In our current understanding of galaxy formation and evolution, ellipticals are the “red and dead” endpoints of evolution.
Revamped Hubble breaks new ground September 13, 2009
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Going, going, gone? Candidate z~7-8 galaxies, seen to "drop out" in the z filter around 1 micron (adapted from Oesch et al., 2009)
Quick on the heels of NASA’s showcasing of the first images taken by a reborn Hubble Space Telescope come a pair of papers posted to astro-ph showing a glimpse of Hubble’s potential new power. These papers, by a collaboration of US, Swiss and Dutch astronomers, report the detection of galaxies using Hubble’s new optical/infrared camera WFC3 out to staggeringly high redshifts of 8-9. If confirmed, this shows that Hubble can now detect radiation from galaxies when the Universe was just a few hundred million years old. The first anything at those distances was spotted just a few months ago, when satellite SWIFT caught a gamma-ray burst that was confirmed to have erupted at redshift of 8.2.
Hubble lives, long live Hubble! September 9, 2009
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Following months of commissioning and calibrating Hubble’s new instruments installed during the servicing mission earlier this year, NASA today released the first set of images from the revamped observatory. Each of the images show one of the gourmet pieces of the visible Universe, like the group of interacting galaxies known as Stephan’s Quintet, above. The image is a composite made up of many from different filters all taken with the new wide-field camera, WFC3. Brilliant!
For the full set of images released today, hop over here.
Image:NASA, ESA, and the Hubble SM4 ERO Team
Welcome back Atlantis, good luck Frank! May 26, 2009
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Welcome back Atlantis
After a fascinating 13-day mission to the Hubble Space Telescope, Space Shuttle Atlantis and its crew touched down safely at Edwards Air Force Base on Sunday 24 May. Welcome home Atlantis! The mission to repair and upgrade Hubble was closely followed by space and astronomy enthusiasts around the world (yup that includes me), thanks to the great coverage on NASA TV.
A welcoming ceremony is taking place today at 4 pm Central Time, watch it live here.
I’m delighted the astronauts got the job done and Hubble is ready for its final stint. Unfortunately I had to miss the landing as I was on a little jaunt around Britain to attend some meetings and catch up with friends and family.
Great also to have Mike Massimino back on live twitter, telling us all about the weirdness of being back on Earth.
Good luck Frank!
Three astronauts will take off from the Baikonur cosmodrome tomorrow for the International Space Station. Representing the European Space Agency is Belgian Frank De Winne, who will also become the first European commander of the ISS during his 6-month stay. Good luck Frank!
Read more about the mission here. Watch a Q&A session with him on ESA’s YouTube channel here.
Image: G. Blevins/LA Daily News
