Swiss 1.2-metre Leonhard Euler Telescope


Leonhard Euler Telescope
The enclosure of the Leonhard Euler Telescope with the higher situated New Technology Telescope in the background
Alternative namesSwiss 1.2-m Leonhard Euler Telescope Edit this at Wikidata
Named afterLeonhard Euler Edit this on Wikidata
Part ofLa Silla Observatory Edit this on Wikidata
Location(s)Norte Chico in Chile
Coordinates29°15′34″S 70°43′59″W / 29.2594°S 70.7331°W / -29.2594; -70.7331Coordinates: 29°15′34″S 70°43′59″W / 29.2594°S 70.7331°W / -29.2594; -70.7331 Edit this at Wikidata
OrganizationGeneva Observatory Edit this on Wikidata
First light12 April 1998 Edit this on Wikidata
Telescope stylereflecting telescope Edit this on Wikidata
Diameter1.2 m (3 ft 11 in) Edit this at Wikidata
Swiss 1.2-metre Leonhard Euler Telescope is located in Chile
Swiss 1.2-metre Leonhard Euler Telescope
Location of Swiss 1.2-metre Leonhard Euler Telescope
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Leonhard Euler Telescope, or the Swiss EULER Telescope, is a national, fully automatic 1.2-metre (47 in) reflecting telescope, built and operated by the Geneva Observatory. It is located at an altitude of 2,375 m (7,792 ft) at ESO's La Silla Observatory site in the Chilean Norte Chico region, about 460 kilometers north of Santiago de Chile. The telescope, which saw its first light on 12 April 1998, is named after Swiss mathematician Leonhard Paul Euler.[1][2]

The Euler telescope uses the CORALIE instrument to search for exoplanets. In addition, the telescope uses the multi-purpose EulerCam (ecam), a high precision photometry instrument, and a smaller, piggyback mounted telescope, called "Pisco".[2] Its first discovery was a planet in orbit around Gliese 86, determined to be a hot Jupiter with an orbital period of only 15.8 earth days and about four times the mass of Jupiter.[3] Since then, many other exoplanets have been discovered or examined in follow-up observations.

Together with the Mercator Telescope, Euler was part of the Southern Sky extrasolar Planet search Programme, which has discovered numerous extrasolar planets.[4] It has also been frequently employed for follow-up characterization to determine the mass of exoplanets discovered by the Wide Angle Search for Planets, SuperWASP.[5]


The CORALIE spectrograph is an echelle type spectrograph used for astronomy. It is a copy of the ELODIE spectrograph used by Michel Mayor and Didier Queloz to detect the planet orbiting a star . In April 1998 it was built and installed at the Euler Telescope. Later in 2007 it was upgraded by Didier Queloz and his team to increase its performances to support Wide Angle Search for Planets program and Next-Generation Transit Survey. The instrument is optimized to measure Doppler effect on a star's electromagnetic spectrum with great precision to detect the gravitational tug of an exoplanet orbiting around it.[6][7] It also known as "radial velocity" or "wobble" method, is an indirect detection method. The mass of the planet can be estimated from these measurements.

The spectrograph participates in the Southern Sky extrasolar Planet search Programme initiated by Michel Mayor

In 2010 visible camera EulerCam was installed by Didier Queloz. Camera main objective was to measure planet by transit method by supporting ground base program such as Wide Angle Search for Planets . The size of an exoplanet can be estimated using the transit method. By combining the measured size and mass from both methods, it can be determined whether the observed exoplanet is gaseous or rocky.


The resolution of CORALIE is fixed at R = 50,000 with a 3 pixel sampling. The detector CCD is 2k X 2k with a 15 micrometer pixel size.

Discovered exoplanets

First five planetary object discovered using CORALIE are

Planet Announced in Refs
Gliese 86 b 1998 [6]
HD 75289b 1999 [8]
HD 130322 b 1999 [8]
HD 192263b 1999 [9][10]
GJ 3021b 2000 [11]



Timelapse video of Euler and the NTT observing the night sky

See also


  1. ^ "Swiss 1.2-metre Leonhard Euler Telescope". ESO. Retrieved 10 September 2015.
  2. ^ a b "EULER". Exoplanets. Switzerland: Université de Genève. Retrieved 10 September 2015.
  3. ^ Queloz, D.; Mayor, M.; Weber, L.; Blecha, A.; et al. (1999). "A planet orbiting the star Gliese 86". arXiv:astro-ph/9910223.
  4. ^ "Southern Sky extrasolar Planet search Programme".
  5. ^ Queloz, D.; Anderson, D. R.; Collier Cameron, A.; Gillon, M.; et al. (2010). "WASP-8b: a retrograde transiting planet in a multiple system". Astronomy and Astrophysics. 517: L1. arXiv:1006.5089. Bibcode:2010A&A...517L...1Q. doi:10.1051/0004-6361/201014768. S2CID 35774603.
  6. ^ a b Queloz, D.; Mayor, M.; Weber, L.; Blécha, A.; et al. (2000). "The CORALIE survey for southern extra-solar planets. I. A planet orbiting the star Gliese 86". Astronomy and Astrophysics. 354: 99–102. Bibcode:2000A&A...354...99Q.
  7. ^ ESO publication, D. Queloz and M. Mayor, From CORALIE to HARPS, September 2001
  8. ^ a b Udry; Mayor, M.; Naef, D.; Pepe, F.; et al. (2000). "The CORALIE survey for southern extra-solar planets II. The short-period planetary companions to HD 75289 and HD 130322". Astronomy and Astrophysics. 356: 590–598. Bibcode:2000A&A...356..590U.
  9. ^ Santos, N.; Udry, S.; Mayor, M.; Naef, D.; et al. (2003). "The CORALIE survey for southern extra-solar planets XI. The return of the giant planet orbiting HD192263". Astronomy and Astrophysics. 406 (1): 373–381. arXiv:astro-ph/0305434. Bibcode:2003A&A...406..373S. doi:10.1051/0004-6361:20030776. S2CID 16247618.
  10. ^ Santos, N.; Mayor, M.; Naef, D.; Pepe, F.; et al. (2000). "The CORALIE survey for southern extra-solar planets III. A giant planet in orbit around HD 192263". Astronomy and Astrophysics. 356: 599–602. Bibcode:2000A&A...356..599S.
  11. ^ Naef, D.; Mayor, M.; Pepe, F.; Queloz, D.; et al. (2001). "The CORALIE survey for southern extrasolar planets V: 3 new extrasolar planets". Astronomy and Astrophysics. 375 (1): 205–218. arXiv:astro-ph/0106255. Bibcode:2001A&A...375..205N. doi:10.1051/0004-6361:20010841. S2CID 16606841.

External links

  • ESO La Silla 1.2m Leonhard Euler Telescope
  • Southern Sky extrasolar Planet search Programme
  • The CORALIE survey for southern extrasolar planets
  • University of Geneva – The Geneva Observatory
  • /Euler
  • ESO press release: 4 May 2000