Exoplanets at a discount

Fig. 1: An image of Beta Pic's companion taken with the apodising phase plate on VLT/NaCo, after processing. The light from the central star was blocked out (in processing). Credit: ESO

ResearchBlogging.org
Astronomers have many ways of spotting exoplanets round far away stars – but getting a direct look at them, especially with ground-based telescopes, remains a difficult job. With a planet emitting very little light of its own, and appearing to us essentially on top of the host star, its radiation is completely drowned in the image of the star. Catching those few photons and separating them from the flood of light from the star requires some clever observational tricks. To do this with ground-based telescopes, we at the very least need adaptive optics, to prevent the atmosphere from creating a blurry mess and  keep the image nice and sharp, and often some sort of mask that will block out as much as possible of the stellar light. But an upgrade to one of ESO’s near-infrared workhorse imager NaCo on VLT’s 4th Unit Telescope has just made it a whole lot easier.

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First steps in direct exoplanet spectroscopy

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)

ResearchBlogging.org

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.

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Laser guide stars as magnetometers

ResearchBlogging.orgIn 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.

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How not to shoot down aircraft in the name of science


ResearchBlogging.org
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.
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What other people see

Sometimes 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.
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