A Giant of Astronomy and a Quantum of Solace

Cerro Paranal, the 2600m high mountain in the Chilean Atacama Desert that hosts ESO's Very Large Telescope, will be the stage for scenes in the next James Bond movie, "Quantum of Solace".
Looking akin to Mars, with its red sand and lack of vegetation, the Atacama Desert is thought to be the driest place on Earth. Cerro Paranal is home to ESO's Very Large Telescope (VLT), which, with its array of four giant 8.2-m individual telescopes, is the world's most advanced optical observatory. The high-altitude site and extreme dryness make excellent conditions for astronomical observations.

"We needed a unique site for a unique set of telescopes, and we found it at Paranal," said Andreas Kaufer, ESO's Paranal Director. "We are very excited that the Bond production team have also chosen this location."

The excellent astronomical conditions at Paranal come at a price, however. In this forbidding desert environment, virtually nothing can grow outside. The humidity drops below 10%, there are intense ultraviolet rays from the sun, and the high altitude leaves people short of breath. Living in this extremely isolated place feels like visiting another planet.

To make it possible for people to live and work here, a hotel or "Residencia" was built in the base camp, allowing them to escape from the arid outside environment. Here, returning from long shifts at the VLT and other installations on the mountain, they can breathe moist air and relax, sheltered from the harsh conditions outside. The Residencia's award-winning design, including an enclosed tropical garden and pool under a futuristic domed roof, gives its interior a feeling of open space within the protective walls - this is a true "haven in the desert".

It is this unique building that serves as the backdrop for the James Bond filming.

QUANTUM OF SOLACE producer, Michael G. Wilson said: "The Residencia of Paranal Observatory caught the attention of our director, Marc Forster and production designer, Dennis Gassner, both for its exceptional design and its remote location in the Atacama desert. It is a true oasis and the perfect hide-out for Dominic Greene, our villain, whom 007 is tracking in our new James Bond film."

In addition to the shooting at the Residencia, further action will take place at the Paranal airstrip.

The film crew present on Paranal includes Englishman Daniel Craig, taking again the role of James Bond, French actor Mathieu Amalric, leading lady Olga Kurylenko, from the Ukraine, as well as acclaimed Mexican actors, Joaquin Cosio and Jesus Ochoa. This cast from across Europe and Latin America mirrors the international staff that works for ESO at Paranal.

After leaving Paranal at the end of the week, the film crew will shoot in other locations close to Antofagasta. Other sequences have been filmed in Panama and, following the Chilean locations, the unit will be travelling to Italy and Austria before returning to Pinewood Studios near London in May.

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Light echoes whisper the distance to a star

Astronomers calibrate the distance scale of the Universe

Taking advantage of the presence of light echoes, a team of astronomers have used an ESO telescope to measure, at the 1% precision level, the distance of a Cepheid - a class of variable stars that constitutes one of the first steps in the cosmic distance ladder.

"Our measurements with ESO's New Technology Telescope at La Silla allow us to obtain the most accurate distance to a Cepheid," says Pierre Kervella, lead-author of the paper reporting the result.

Cepheids [1] are pulsating stars that have been used as distance indicators since almost a hundred years. The new accurate measurement is important as, contrary to many others, it is purely geometrical and does not rely on hypotheses about the physics at play in the stars themselves.

The team of astronomers studied RS Pup, a bright Cepheid star located towards the constellation of Puppis ('the Stern') and easily visible with binoculars. RS Pup varies in brightness by almost a factor of five every 41.4 days. It is 10 times more massive than the Sun, 200 times larger, and on average 15 000 times more luminous.

RS Pup is the only Cepheid to be embedded in a large nebula [2], which is made of very fine dust that reflects some of the light emitted by the star.

Because the luminosity of the star changes in a very distinctive pattern, the presence of the nebula allows the astronomers to see light echoes and use them to measure the distance of the star.

"The light that travelled from the star to a dust grain and then to the telescope arrives a bit later than the light that comes directly from the star to the telescope," explains Kervella. "As a consequence, if we measure the brightness of a particular, isolated dust blob in the nebula, we will obtain a brightness curve that has the same shape as the variation of the Cepheid, but shifted in time."

This delay is called a 'light echo', by analogy with the more traditional echo, the reflection of sound by, for example, the bottom of a well.

By monitoring the evolution of the brightness of the blobs in the nebula, the astronomers can derive their distance from the star: it is simply the measured delay in time, multiplied by the velocity of light (300 000 km/s). Knowing this distance and the apparent separation on the sky between the star and the blob, one can compute the distance of RS Pup.

From the observations of the echoes on several nebular features, the distance of RS Pup was found to be 6500 light years, plus or minus 90 light years.

"Knowing the distance to a Cepheid star with such an accuracy proves crucial to the calibration of the period-luminosity relation of this class of stars," says Kervella. "This relation is indeed at the basis of the distance determination of galaxies using Cepheids."

RS Pup is thus distant by about a quarter of the distance between the Sun and the Centre of the Milky Way. RS Pup is located within the Galactic plane, in a very populated region of our Galaxy.

Notes

[1]: Cepheids are rare and very luminous pulsating stars whose luminosity varies in a very regular way. They are named after the star Delta Cephei in the constellation of Cepheus, the first known variable star of this particular type and bright enough to be easily seen with the unaided eye. Almost a century ago, in 1912, American astronomer Henrietta Leavitt published a relation between the intrinsic brightness and the pulsation period of Cepheids, the longer periods corresponding to the brighter stars. This relation still plays today a central role in the extragalactic distance scale.

[2]: The nebula around RS Pup was discovered in 1961 by Swedish astronomer Bengt Westerlund, who later became ESO Director in Chile (1970-74).

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