Description

Geographical position 

Institute of Astronomy (former Astronomical Observatory of the University of Latvia),
Raina blvd 19, LV-1050 Riga, Latvia

Location 

Latitude 56.950645 N, longitude 24.116041 E. Elevation ??? m above mean sea level.

IAU observatory code 

-

Description of (scientific/cultural/natural) heritage 

Founding of Riga Observatory

On October 18, 1922, the Astronomical Cabinet, which had existed since 1921, was renamed the "Astronomical Observatory" by the University Council and this date is considered the official founding day of the observatory.

The Riga Polytechnic, founded in 1862, got an impressive historistic building at 19 Raini boulevard (1866 to 1869), planned by professor Gustavus Hilbig and erected by the architect Hess. Latvia was part of the Russian Empire (1721 to 1918).

The astronomical tower (completed in 1869), which was especially designed for the Polytechnic building, belongs now to the main building of the University of Latvia (1919). Today also the Museum of the University of Latvia (LUM) is located there. 

The astronomical tower had served for astronomy for more than 150 years. In the 19th century, the refracting telescope in the tower was used for scientific observations. In the first half of the 20th century, practical work in the tower was still carried out by students. Since 1986, the Astronomical Tower has been operating as a public observatory.

Fields of Research of Riga Astronomers

A weather service was set up in the Astronomical Observatory and the necessary instruments and clocks were purchased. 
Timekeeping played an important role. The exact time was determined for both scientific and purely practical reasons -- the Astronomical Observatory reported the correct time to the post and telegraph office, and several clocks in Riga worked in coordination with the observatory's clocks.

A traditional field of research for university astronomers was the study of the orbits of small planets. As early as 1933, the small planet studied by the astronomer Karlis Stein was given the name "Latvija". In 1971, a small planet was given the name "Riga".
In recognition of the astronomers' achievements, four more minor planets bear their names. They are "Dirikis", "Steins", "Balodis" and "Agita". One minor planet is named after the astronomer Stanislav Vasilevski, who emigrated from Latvia. In total, there are nine celestial bodies orbiting the solar system whose names are associated with Latvia.

Starting with the "International Year of Geophysics" (1957-1958) and prompted by the launch of the first artificial Earth satellite, a station was set up for visual and later for photographic observation of satellites. This was followed by laser location of satellites, since 1987 with the ZMP laser rangefinder with a lens diameter of 105cm.

Also astrophysical studies started in Riga Observatory; in addition, the new Riekstukalns Observatorija (85m high) in Baldones near Riga was created (1957). 
Astronomers studied the spectra of red giants, especially of carbon stars, and analyzed the chemical composition of their atmospheres. For these spectrophotometric studies two telescopes with a mirror diameter of 55cm were acquired.

In 1966, a Schmidt telescope with a mirror diameter of 120cm and a correction plate of 80cm started operating as the largest telescope in Latvia. It serves for wide field photographs of the sky, and for obtaining stellar spectra. 

In 1967, the Radio Astrophysics Observatory was officially established. 
In 1997, by merging the Radio Astrophysics Observatory and the Astronomical Observatory of the University of Latvia, the Institute of Astronomy of the University of Latvia was established.

History 

Instruments of the Astronomical Observatory of Riga University

• 9.7-cm-Achromatic Fraunhofer Refractor (f=1.37m), Fraunhofer of Munich (1873)
• 11-cm-Refractor (f=1.65m), Heyde of Dresden (1921)
  
  
• 80cm/120cm-Schmidt telescope (1966) 
  started operating in Baldone
  
  
• Two 55-cm-Reflecting telescopes - 
  installed to observe changes in stellar brightness, especially more than 3,000 carbon stars were observed.
  
  
• ZMP laser rangefinder with a lens diameter of 105cm
  
  
• Radio telescope RT-10 with a diameter of 10m (1972)
  
  
• Radio telescopes of 32m and 16m diameter (1996) --
  one of the largest radio telescopes in Europe. 
  It can be used as a component of a long-baseline radio interferometer. In 1999, the first observations of extragalactic objects were made in this mode. 

Directors of the Astronomical Observatory of Riga University

• ....

Fridrihs Canders and Latvian Astronomy Collection of the LU Museum

The collection consists of two parts - the collection of the history of Latvian astronomy and the part of the collection dedicated to Fridrich Cander and space exploration with a total number of about 5,000 items.

In 2019, when the LU Institute of Astronomy moved to the House of Science on Jelgava Street, the LU Museum also received the observatory rooms, where the original Weather Service clocks were located. After the repair of the premises, restoration of furniture and exhibits, on October 19, 2022, exactly 100 years after the founding of the Astronomical Observatory of the University of Latvia, these premises open their doors to visitors again, only now as an exposition of the Museum of the University of Latvia.

The collection of Latvian astronomy shows ancient and modern astronomical instruments, books, star charts, and meteorites. 
There are also observation records, as well as the archives of individual astronomers, such as Professor Fritz Blumbach, Professor Karls Stein, the Latvian Astronomical Society, as well as documents and photos of its leader Matis Dirikis, astronomer Leonidas Rozes, astronomer Andrejs Alksnis and Irenas Pundure. 

Highlight in the collection is a nicely restored star globe of 80cm in diameter, purchased in 1935, placed in a metal tripod. It depicts the brightest stars connected by lines, mythological constellation figures, the Milky Way, a grid of coordinates and the most important lines of the celestial sphere. 

Besides the Weather Service room, there is the Time Service room, presented with clocks, chronometers and chronographs, switchboards, commutators and measuring instruments.

Friedrich Arturowitsch Zander / Fridrihs Canders (1887--1933), one of the early rocket pioneers, was born in Riga, studied at the Riga Polytechnic Institute. In Moscow, he was engaged in the design of jet engines and the calculation of interplanetary trajectories. Under his leadership, the first rocket with a liquid-propellant engine "GIRD-X" was created, which was successfully tested in 1933, a few months after the death of the inventor.
Canders proposed important ideas in cosmonautics: the use of unnecessary parts of the rocket body as fuel, the winged rocket, "solar sails", and gliding landing.
The Museum shows the dreams and scientific achievements in space flight of Fridrihs Canders: the GIRD X rocket, the OR-1 jet engine, and the interplanetary rocket-plane project. 

State of preservation 

The main building of the University of Latvia, founded in 1919, at Raina boulevard 19 is an architectural monument of national importance (1869), and the building is also located in the territory of the "Historical Center of Riga" urban construction monument of national importance and UNESCO World Cultural and Natural Heritage. 
In the current situation, the building's enclosing structures have low thermal resistance, constructive wear and tear and increased air infiltration, resulting in CO₂ emissions in the environment. The project is planned to be implemented until 2028. 

Comparison with related/similar sites 

cf. Lohrmann-Observatory, Dresden, Germany and Greifswald Observatory

Threats or potential threats 

no threats

Present use 

The main building of the University of Latvia houses the Museum of the University of Latvia (LUM). 
The Astronomical Tower is used as Public Observatory.

Astronomical relevance today 

In 1997, by merging the Radio Astrophysics Observatory and the Astronomical Observatory of the University of Latvia, the Institute of Astronomy of the University of Latvia was established.

History:

• 1957 - First satellite observations in Riga, Astronomical Observatory University of Latvia
• 1957 - First observatory building near Baldone, one year later becomes Astrophysical Observatory
  1966 - 0.8-m/1.2-m-Schmidt telescope, made by Carl Zeiss of Jena, installed at Baldone Observatory
• 1972 - Radio Astronomy with regular observations of the Sun (radio radiation, analyze the changes, and record flares) in the Baldones Radioastrophysics Observatory
• 1987 - Regular satellite laser ranging measurements starts in Riga
• 1997 - Astronomical Institute of University of Latvia was founded by merging Astronomical Observatory of University of Latvia and Baldone's Astrophysics Observatory of Latvian Academy of Sciences
• 1996 - Ventspils International Radio Astronomy Center 
  in Irbeni in the Ventspils region (32m and 16m diameter radio telescopes)

See also: 

• Observatory of the Riga Polytechnical Institute (RPI) *1862 (until 1915) 
• LU Institute of Astronomy (former Astronomical Observatory of the University of Latvia), Raina blvd 19, LV-1050 Riga, Latvia.
  In 2019, the LU Institute of Astronomy moved to the "House of Science", Jelgavas 4, LV 1003 Riga, Latvia
• Astrophysical Observatory, University of Latvia, Riga-Baldone, Latvia (IAU code 069, 56°46'27'' N, 24°24'26'' E)
• Astronomy Observatory Riga, Kandavas Street 2, Riga, Latvia?
• Observatory of the Navigation School in Mangali (Magnushof) Riga (Transit instrument with impersonal micrometer, two Riefler clocks, one with vacuum, an astronomical sidereal time clock made by Knoblich, two modern writing chronographs, several chronometers)

References

Bibliography (books and published articles) 

• Schagger, A.: Die Universitäts Sternwarte zu Riga, Lettland. In: Publications de l'Observatoire Astronomique de l'Université de Lettonie à Riga, Nr. 1 (1932), p. 1-34.
  
  
• Vilks, Ilgonis: Decades Long Science Communication at Institute of Astronomy Based on High Level Science, 2015 (https://fotonikalv.files.wordpress.com/2015/05/vilks_foton). 
  
  
• Vilks, Ilgonis: private communication (June 2024).
  
  
• Vilks, Ilgonis: Astronomija Latvija 20. gadsimta. Riga: Latvijas Universitate 2024. 
   

Links to external sites 

• Institute of Astronomy (IA), University of Latvia,  Riga, Latvia
• Baldones observatorija, Astrophysical Observatory, Riga, Latvia
• Riga Observatory, Latvia (Wikimapia)
• Astrophysical Observatory, University of Latvia, Riga, Latvia (Wikimapia)
• Museum of the University of Latvia, 19 Raina Boulevard, Riga
• Riga Stradins University - RSU History Museum, Riga, Latvia, 16 Dzirciema iela
• LU Muzeja virtuala izstade, Aug 30, 2019
• Astronomija Latvija