Inside Euler’s Head Or how to see a telescope through the walls of its dome

As night was falling over ESO’s La Silla Observatory in Chile on 20 December 2009, the sky was not yet dark enough for the telescopes to start observations. But conditions were perfect to perform a clever trick with the dome of the Swiss 1.2-metre Leonhard Euler Telescope: allowing us to peer inside with this photograph apparently taken through the dome.

This image is a 75-second exposure taken while the slit of the Euler telescope’s dome was performing half a rotation at full speed. Through the ghostly blur of the moving dome walls, the telescope is clearly visible. A dim light was switched on in the interior of the building especially for the purpose of this photo.

The picture was taken by Malte Tewes, a young astronomer from the École Polytechnique Fédérale de Lausanne in Switzerland, who had just finished a two-week observing run at the telescope on the evening in question. The next observer, Amaury Triaud, and the telescope’s technician, Vincent Mégevand (both pictured), were on site so they could operate the dome from the inside while Malte took the photograph from outside.

The road that leads to ESO’s nearby 3.6-metre telescope is visible lined by a chain of lights to the left of the image. In addition to the 3.6-metre telescope, the New Technology Telescope, and the MPG/ESO 2.2-metre telescope, La Silla Observatory also hosts several national and project telescopes that are not operated by ESO. The Euler telescope, named after the famous Swiss mathematician Leonhard Euler, is one of them.
eso.org

Highlights of the MAGIC Telescopes

Juan Cortina for the MAGIC Collaboration

Spectrum of electrons and positrons measured with MAGIC, along with other measurements from instruments on orbit, balloons and IACTs. MAGIC extends the spectrum produced by IACTs down to 100 GeV


The MAGIC two 17 meter diameter Very High Energy (VHE) gamma-ray telescopes have now operated for two years in stereoscopic mode.
The performance of the instrument has been evaluated: the integral sensitivity for an energy above 300 GeV is 0.76% crab units (10% Crab units differential sensitivity below 100 GeV) and the analysis threshold energy is 50 GeV.
Highlights of the last two years of observations are the measurement of the Crab Nebula spectrum from ~50 GeV to ~50 TeV; the detection of the Crab pulsar up to an energy of 400 GeV, with energy spectra measured for both P1 and P2; the discovery of two new radiogalaxies at VHE (NGC 1275 and IC-310); the absence of an energy cutoff and the discovery of fast variability in the quasars 3C 279 and PKS 1222+21; the discovery at VHE and the characterization of numerous blazars; upper limits to the VHE emission of the Perseus cluster of galaxies and to Dark Matter annihilation in dwarf Spheroidals and the measurement of the electron+positron spectrum between 100 GeV and 3 TeV.
MAGIC is currently undergoing a major upgrade of the readout and trigger electronics, and of the camera of the first telescope……..
Read more: http://arxiv.org

Telescope to spot aliens

World’s largest eye on the sky to join quest for signs of ET

The device will be built in the Chilean desert in a dome the size of a stadium

Housed in a dome almost the size of Big Ben and containing a mirror nearly half the length of a football pitch, it wasn’t exactly rocket science for astronomers to find a name for this telescope.
And, sure enough, they came up with the European Extremely Large Telescope – just about the only routine thing about the world’s largest and most powerful ‘eye on the sky’.
Astronomers reckon it may finally shed light on whether there really is life somewhere out there by helping them find Earth-like rocky worlds that are home to other beings.

And British scientists might be among the first to find out – as their work is crucial to the project.
Key instruments for the telescope will be developed thanks to £3.5million funding from the Science and Technology Facilities Council.
The device in the Atacama Desert, Chile, will be built in a dome that covers an area the size of a stadium…… Continue reading Telescope to spot aliens

Laser Meets Lightning

On Thursday 18 August, the sky above the Allgäu Public Observatory in southwestern Bavaria was an amazing sight, with the night lit up by two very different phenomena: one an example of advanced technology, and the other of nature’s dramatic power.

As ESO tested the new Wendelstein laser guide star unit by shooting a powerful laser beam into the atmosphere, one of the region’s intense summer thunderstorms was approaching — a very visual demonstration of why ESO’s telescopes are in Chile, and not in Germany. Heavy grey clouds threw down bolts of lightning as Martin Kornmesser, visual artist for the ESO outreach department, took timelapse photographs of the test for ESOcast 34. With purely coincidental timing this photograph was snapped just as lightning flashed, resulting in a breathtaking image that looks like a scene from a science fiction movie. Although the storm was still far from the observatory, the lightning appears to clash with the laser beam in the sky.

Laser guide stars are artificial stars created 90 kilometres up in the Earth’s atmosphere using a laser beam. Measurements of this artificial star can be used to correct for the blurring effect of the atmosphere in astronomical observations — a technique known as adaptive optics. The Wendelstein laser guide star unit is a new design, combining the laser with the small telescope used to launch it in a single modular unit, which can then be placed onto larger telescopes.

The laser in this photograph is a powerful one, with a 20-watt beam, but the power in a bolt of lightning peaks at a trillion (one million million) watts, albeit for just a fraction of a second! Shortly after this picture was taken the storm reached the observatory, forcing operations to close for the night. While we may have the ability to harness advanced technology for devices such as laser guide stars, we are still subject to the forces of nature, not least among them the weather!
http://www.eso.org/public/images/potw1136a/

Fermi catalogue update shows ‘violent Universe’ changes

The catalogue that lists the most violent neighbourhoods in the Universe has been updated.

Fermi spotted that the Crab Nebula, once thought to be constant, flares violently with gamma rays

The Fermi space telescope captures gamma rays – the highest-energy light in nature, which hints at the cosmos’ most extreme conditions and processes.

The second Fermi catalogue represents a full two years of data, improving on the first edition’s 11 months.

It lists 1,873 gamma-ray sources; some 589 remain unidentified and could represent entirely new cosmic objects.

Dave Thompson, a Nasa astrophysicist who co-led the catalogue’s production, told BBC News that the effort was more than just an expanded list.

“The new catalogue is a new data set,” he said. “We’ve reanalysed all the data, reduced our background, developed new methods of analysis. We’re convinced that not only is this quantitatively a better catalogue – it’s qualitatively a better catalogue.”

It is also a snapshot from a slowly unfolding film of the Universe’s most extreme environments.

“It’s very important to understand that the gamma-ray sky is not static, it’s changing all the time,” explained Steven Ritz, deputy principal investigator for the Fermi mission’s Large-Area Telescope….. Continue reading Fermi catalogue update shows ‘violent Universe’ changes

NASA’s Hubble Makes One Millionth Science Observation

NASA’s Hubble Space Telescope crossed another milestone in its space odyssey of exploration and discovery. On Monday, July 4, the Earth-orbiting observatory logged its one millionth science observation during a search for water in an exoplanet’s atmosphere 1,000 light-years away.

“For 21 years Hubble has been the premier space science observatory, astounding us with deeply beautiful imagery and enabling ground-breaking science across a wide spectrum of astronomical disciplines,” said NASA Administrator Charles Bolden. He piloted the space shuttle mission that carried Hubble to orbit. “The fact that Hubble met this milestone while studying a faraway planet is a remarkable reminder of its strength and legacy.”

Although Hubble is best known for its stunning imagery of the cosmos, the millionth observation is a spectroscopic measurement, where light is divided into its component colors. These color patterns can reveal the chemical composition of cosmic sources.

Hubble’s millionth exposure is of the planet HAT-P-7b, a gas giant planet larger than Jupiter orbiting a star hotter than our sun. HAT-P-7b, also known as Kepler 2b, has been studied by NASA’s planet-hunting Kepler observatory after it was discovered by ground-based observations. Hubble now is being used to analyze the chemical composition of the planet’s atmosphere.

This is an artist's concept of that planet, HAT-P-7b. It is a "hot Jupiter" class planet orbiting a star that is much hotter than our sun. Hubble Space Telescope's millionth science observation was trained on this planet to look for the presence of water vapor and to study the planet's atmospheric structure via spectroscopy.

“We are looking for the spectral signature of water vapor. This is an extremely precise observation and it will take months of analysis before we have an answer,” said Drake Deming of the University of Maryland and NASA’s Goddard Space Flight Center in Greenbelt, Md. “Hubble demonstrated it is ideally suited for characterizing the atmospheres of exoplanets, and we are excited to see what this latest targeted world will reveal.”…. Continue reading NASA’s Hubble Makes One Millionth Science Observation