First steps in direct exoplanet spectroscopy January 16, 2010
Posted by sarah in: new astronomy . 2comments
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.
Laser guide stars as magnetometers December 25, 2009
Posted by sarah in: astronomy, geology, science . 1 comment so far
In a nice piece of cross-pollination between disciplines, scientists have proposed a new method for measuring the Earth’s magnetic field strength using technology developed for ground-based observational astronomy. As it turns out, the laser guide stars astronomers use to sense the turbulence high up in the atmosphere can be used as cheap and efficient magnetometers.
How not to shoot down aircraft in the name of science November 3, 2009
Posted by sarah in: astronomy, new astronomy, science . 2comments
Astronomers and air travel maintained a peaceful coexistence for over a century. That is, until astronomers started firing powerful lasers into the atmosphere -sky dwellers, human or otherwise, are no big fan of those. Bodies like the Federal Aviation Administration and US Space Command have imposed restrictions on the use of the high-powered lasers astronomers now routinely fire into the atmosphere to assist with their observations, to prevent anything or anyone flying across the sky from potential harm from the lasers. While astronomical lasers aren’t powerful enough to physically damage an airplane, they could easily injure pilots or passengers, and damage sensitive imaging equipment on Earth-observing satellites.
Last week scientists from the University of California at San Diego reported on their work to develop an integrated aircraft warning system for astronomical telescopes, that gives accurate warnings about approaching aircraft and helps minimise the observatory downtime due to passing planes.
(more…)
What other people see September 29, 2009
Posted by sarah in: science . Add a commentSometimes it’s useful to try and imagine other people’s points of view. Literally! In this video, Pablo Artal, Professor of Physics at the University of Murcia in Spain, gives a nice demo of what certain eye defects, like myopia or cataracts, do to a person’s vision.
(more…)
Putting astronomy to work March 10, 2009
Posted by sarah in: science . 1 comment so farWe astronomers often get asked about the point of our research. Why do we care about galaxies, about dark matter and dark energy? It happens at the best of times, but in these economic climes even more so – see my previous post. Phil Plait made a great video telling us exactly why astronomy, and scientific research in general, matters a great deal to everyone – even to those who think it is far removed from their beds. Watch it here.
This week’s issue of the Economist has the Technology Quarterly, where new technological developments are highlighted, and as usual it contains some really interesting stuff. One story in particular put a big smile on my face, as it’s applying astronomy research that I myself have worked on in the past, albeit indirectly, to a hugely relevant issue, both economically and environmentally: scientists in San Diego are using astronomical wavefront sensing technologies to determine when and how much fields need to be irrigated. Many modern telescopes use a technique called adaptive optics to remove the blurring effects of the turbulence in the atmosphere – the effect that causes the familiar twinkling of stars in the sky, from the light as it enters the instrument. By measuring the distortions in real time, several hundreds of times per second during every exposure, and feeding the information to a thin flexible mirror, the light can literally be bent back into shape. The process of measuring the blur of the light is called wavefront sensing.
