Enclosure of the 2.2-meter telescope at Calar Alto Observatory | |||||||||||
| Alternative names | Spanish Astronomical Centre in Andalusia | ||||||||||
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| Organization | Institute of Astrophysics of Andalusia (IAA-CSIC) Council of Andalusia | ||||||||||
| Observatory code | 493 | ||||||||||
| Location | Almería,Spain | ||||||||||
| Coordinates | 37°13′25″N2°32′46″W / 37.22361°N 2.54611°W /37.22361; -2.54611 | ||||||||||
| Altitude | 2,168 m (7,113 ft) | ||||||||||
| Website | www | ||||||||||
| Telescopes | |||||||||||
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| see§ List of discovered minor planets |
TheCalar Alto Observatory (Centro Astronómico Hispano en Andalucía or "Spanish Astronomical Centre in Andalusia") is anastronomicalobservatory located inAlmería province inSpain onCalar Alto, a 2,168-meter-high (7,113 ft) mountain in theSierra de Los Filabres subrange of theSierra Nevada.[2]
Until 2018, Calar Alto was owned and operated jointly by the GermanMax Planck Institute for Astronomy in Heidelberg, and the SpanishInstitute of Astrophysics of Andalusia (IAA-CSIC) inGranada. It was named the "German–Spanish Astronomical Centre" (in Spanish,Centro Astronómico Hispano-Alemán (CAHA); in German,Deutsch-Spanisches Astronomisches Zentrum). In 2019, theCouncil of Andalusia takes over the German partner, sharing the observatory with theSpanish National Research Council through its head institute, IAA-CSIC.
Calar Alto telescopes are used for a broad range of observations, from objects in theSolar System[2] to cosmology (theAlhambra andCALIFA surveys), including the search for exoplanets (theCARMENES survey).
The 3.5-meter telescope is the second-largest telescope in mainland Europe after the 4-meterEastern Anatolian Observatory telescope,[3] though there are three larger telescopes on the Spanish island ofLa Palma at theRoque de los Muchachos Observatory. The minor planet189202 Calar Alto, discovered byFelix Hormuth atStarkenburg Observatory in 2003, was named in honor of the observatory site.[2]
The observatory was proposed in 1970 and officially opened in July 1975 with the commissioning of its 1.23-metre (48 in) telescope. The facility developed through German–Spanish cooperation in astronomy, and over time four additional telescopes were brought into operation. TheSchmidt telescope was moved to Calar Alto in 1976 from theHamburg Observatory at Bergedorf, where it had been completed in 1954. The observatory hosted the finish ofStage 11 of the2017 Vuelta a España cycling race (the stage was won byMiguel Ángel López), having previously hosted stage finishes in2004 (won by eventual race championRoberto Heras) and2006 (won byIgor Antón).Calar Alto was climbed on Stage 9 of the Vuelta (AUG 2021).
The Calar Alto Observatory is located inAlmería province inSpain onCalar Alto, a 2,168-meter-high (7,113 ft) mountain in theSierra de Los Filabres subrange of theSierra Nevada.

According to theKöppen climate classification, the Calar Alto Observatory has aMediterranean climate (Csa/Csb) with strong influences of ahumid continental climate (Dsa/Dsb), with hot summers and cold winters. Calar Alto has one of the most continental climates in Spain: both the temperatures of 40 °C (104 °F), which is very close to the hottest temperature ever recorded in the province of Almería (after theTabernas Desert), and −20 °C (−4 °F), which is the coldest temperature ever recorded in the province of Almería, both of which are recorded here. Precipitation is higher during winter, and lower during summer.
There are 4 main telescopes on site: a 3.5-meter (138-inch), 2.2 m (87 in), and a 1.23 m (48 in) telescope, and an 80 cm (31 in) Schmidt reflector.The 3.5-meter is the largest telescope on European soil with anequatorial mount.There is also a 1.52 m (60 in) telescope that is owned and operated by theSpanish National Observatory and a robotic telescope operated by theSpanish Astrobiology Center (CAB).
The CALIFA survey (Calar Alto Legacy Integral Field Area survey) is an astronomical project to map 600 galaxies with imaging spectroscopy (integral field spectroscopy (IFS)).[4]
The CARMENES survey (Calar Alto high-Resolution search for M-dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) is a project to examine approximately 300 M-dwarf stars for signs of exoplanets with the CARMENES instrument on Calar Alto's 3.5m telescope. Operating since 2016, it aims to find Earth-sized exoplanets around 2M🜨 (Earth masses) usingDoppler spectroscopy (also called the radial velocity method).[5][6]
Close to a hundredminor planets have been discovered at Calar Alto by astronomersLuboš Kohoutek,Kurt Birkle,Ulrich Hopp,Johann Baur,Krisztián Sárneczky,Gyula Szabó,Felix Hormuth andHermann Boehnhardt. In addition, theMinor Planet Center, directly credits "Calar Alto" with the discovery of the following minor planets:[1]
| important; height: 205px; | ||
|---|---|---|
| (63429) 2001 MH5 | 21 June 2001 | list |
| (94223) 2001 BU53 | 17 January 2001 | list |
| (99258) 2001 MF5 | 21 June 2001 | list |
| 124143 Joséluiscorral | 21 June 2001 | list |
| 213269 Angelbarbero | 20 June 2001 | list |
| (247170) 2001 BY10 | 16 January 2001 | list |
| (250482) 2004 DF79 | 18 February 2004 | list |