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)
Shape matters in black hole growth January 31, 2010
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Fig. 1 (from Schawinski et al., 2010)
Active galaxies have gone by many names: active galactic nuclei, quasars, QSOs, Seyfert galaxies, radio galaxies. Astronomers used to think these were all distinct types of objects, unified by the observation of large amounts of energy emerging from a compact region at the centre of the galaxy. These days, despite a great variety in observational characteristics, active galaxies’ engines are generally thought to be driven by a single mechanism, the accretion of material onto a supermassive central black hole.
In a paper published to the Arxiv last week, Kevin Schawinski and collaborators have used Galaxy Zoo classifications of local Universe galaxies to show that active elliptical galaxies are markedly different from those with a more disk-like or spiral shapes, adding morphology as an additional factor to consider in our model of active galaxies.
First steps in direct exoplanet spectroscopy January 16, 2010
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Top: Image of star HR8799 and its exoplanet HR8799c (ESO/M.Janson). Bottom: The spectrum as recorded by the NACO detector, prior to extraction ; the vertical direction is spatial, horizontal is spectral (M. Janson et al, 2010)
Astronomers collaborating from both sides of the Atlantic have obtained the first direct spectrum of an exoplanet. The news here is mainly that they managed to record the spectrum and separate it reliably from that of the host star. Their short letter in ApJ, posted to astro-ph yesterday, doesn’t delve deeply into the implications of what they found but focuses more on the way they obtained, processed and analysed their data to separate the planet’s signature from that of the star.
Behind the Webb January 1, 2010
Posted by sarah in: new astronomy . Add a commentFirst of all – best wishes for the new year to you all!
Working on an instrument for James Webb Space Telescope I regularly receive emails from NASA when the telescope features in the media or new images are released. Recently I discovered that there’s a new site for JWST called webbtelescope.org – in the style of hubblesite.org – and it contains a couple of episodes of a relatively new video podcast series called Behind the Webb. The first episode was about the detectors for MIRI, the mid-infrared instrument whose testing and calibration I work on. As the components that actually transform the incoming photons from the teelscope into a digital signal that we can see, record, process and interpret, the detectors are the heart of the instrument – and this episode is a nice intro to how it all works. Watch it below via YouTube or go to the original page (whose embed code doesn’t seem to work).
Oh My Herschel December 17, 2009
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Herschel stares into Aquila
Scientists have gathered in Madrid this week to discuss for the first time the data they have received from the new infrared telescope Herschel that was launched in May of this year. Some fantastic images have been produced as part of the first observing programmes, like the one above of an active star forming region in the constellation Aquila. The region was known as a ‘dark cloud’ – meaning that dust was blocking any visible or near-infrared radiation coming from its interior. Until Herschel came along, and switched on the lights. Observing at longer infrared wavelengths, the telescope is sensitive to radiation from cooler and dusty material, allowing it to peer into the cloud’s interior. The image, created from data from two of Herschel’s images, PACS and SPIRE, shows up to 700 dense pockets of cold and dusty material that may eventually condense into stars; around 100 of them have progressed to the protostellar stage where they begin to resemble a young forming star.
ESA has launched a new site to showcase the Herschel images. A little sparsely populated so far, but the first postings are very promising indeed.
Image credit: ESA and the SPIRE & PACS consortia, Ph. André (CEA Saclay) for the Gould’s Belt Key Programme Consortia
