ESOcast 46: Catching Light — Special 50th anniversary episode #6

ESOcast 46 is the sixth special episode of this series. It describes how state-of-the-art cameras and spectrographs help ESO’s powerful telescopes collect and analyse the faint light from the distant Universe. Without these instruments, ESO’s eyes on the sky would be blind.

Today’s astronomical images are very different from those from the 1960s. Back then, astronomers used large photographic glass plates, which were not very sensitive and hard to handle. Nowadays, ESO’s telescopes use some of the largest and most sensitive electronic detectors in the world. They catch almost every cosmic photon and recover almost every possible bit of information. For instance, the VLT Survey Telescope’s camera — OmegaCAM — has 32 detectors, which team up to produce spectacular images of the Universe, each with an impressive 268 million pixels.

But astronomy is not only about taking breathtaking images. Astronomers are always after as much information as possible so they need to dissect the starlight into its component colours to study its composition. Spectroscopy is one of the most powerful tools in astronomy and ESO’s telescopes also have some of the world’s most powerful spectrographs, such as the powerful X-shooter at the Very Large Telescope. Spectroscopy allows astronomers to infer important properties of the stars, such as the chemical elements they contain, their temperatures, motions, and even their ages. Moreover, they can study the atmospheres of exoplanets orbiting distant stars or newborn galaxies at the edge of observable Universe.

Watch this episode to discover more about ESO’s state-of-the-art astronomical instruments.


More episodes of the ESOcast are also available.

Find out how to view and contribute subtitles for the ESOcast in multiple languages, or translate this video on dotSUB.


An ESO production

Directed by: Lars Lindberg Christensen
Art Direction, Production Design: Martin Kornmesser
Producer: Herbert Zodet
Written by: Govert Schilling
3D animations and graphics: Martin Kornmesser & Luis Calçada
Editing: Martin Kornmesser
Cinematography: Herbert Zodet & Peter Rixner
Sound engineer: Cristian Larrea
Audio Mastering: Peter Rixner
Host & Lead Scientist: Dr J (Dr Joe Liske, ESO)
Narration: Sara Mendes da Costa
Soundtrack & Sound Effects: movetwo — Axel Kornmesser & Markus Löffler & zero-project (
Proof reading: Anne Rhodes
Technical support: Lars Holm Nielsen, Raquel Yumi Shida & Mathias Andre
DVD Authoring: Andre Roquette
Executive producer: Lars Lindberg Christensen

Footage and photos:
Christoph Malin (
Babak Tafreshi/TWAN
Stéphane Guisard (
José Francisco Salgado (
Alexandre Santerne
Nick Risinger (
Martin Kornmesser
Herbert Zodet
J. Dommaget/J. Boulon/J. Doornenbal/W. Schlosser/F.K. Edmondson/A. Blaauw/Rademakers/R. Holder
Daniel Crouch/Rare Books (
Getty Images
Royal Astronomical Society/Science Photo Library
Jay M. Pasachoff
Chris de Coning/South African Library/Warner-Madear
Africana Museum/Warner
Leiden University
G. Brammer
Mauricio Anton/Science Library
NASA/Spitzer Science Center/R. Hurt
VISTA/J. Emerson
Digitized Sky Survey 2
MPE/S. Gillessen/M. Schartmann
Rainer Lenzen/MPIA Heidelberg
West-Eastern Divan Orchestra in Berlin by KolBerlin
Davide De Martin
Cambridge Astronomical Survey Unit
IDA/Danish 1.5 m/R. Gendler and C. Thöne
Mario Nonino, Piero Rosati and the ESO GOODS Team
The NASA/ESA Hubble Space Telescope
Matthias Maercker
Igor Chekalin
Hans-Hermann  Heyer
Edmund Janssen
Luis Calçada
Scott Kardel
Tom Jarrett,
Kevin Govender
Sergey Stepanenko
T. Preibisch
R. Fosbury (ST-ECF)
OmegaCen/Astro-WISE/Kapteyn Institute
A. Fujii
J.-B. Le Bouquin et al.
D. Coe (STScI)/J. Merten (Heidelberg/Bologna)
Gemini Observatory/NRC/AURA/Christian Marois et al.
M. Janson
Jean-Luc Beuzit
IAC (SMM) and ESPRESSO consortium
T.M. Brown (STScI)
World Wide Telescope


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About the Video

Release date:1 August 2012, 15:00
Related announcements:ann12053
Duration:10m 56s

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Type:• X - ESOcast



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