Yrjö Väisälä
Encyclopedia
Yrjö Väisälä ˈyrjø ˈʋæisælæ (6 September 1891 – 21 July 1971) was a Finnish
astronomer
and physicist
.
His main contributions were in the field of optics
, but he was also very active in geodetics, astronomy
and optical metrology
. He had even an affectionate nickname of Wizard of Tuorla (Observatory/Optics laboratory), and there is a book with the same title in Finnish describing his works.
His brothers were mathematician Kalle Väisälä and meteorologist Vilho Väisälä
.
Väisälä was also a fervent supporter of Esperanto
, presiding the Internacia Scienca Asocio Esperantista ("International Association of Esperanto Scientists") in 1968.
This allowed the construction of some of the earliest high-quality Schmidt camera
s, in particular a "field-flattened" version known as Schmidt-Väisälä camera
.
Contemporary to Bernhard Schmidt
's design, but unpublished was also Prof. Yrjö Väisälä's identical design which he had mentioned in lecture notes in 1924 with a footnote: "problematic spherical focal surface".
Once he saw Schmidt's publication, he promptly went ahead and "solved" the field flattening problem by placing a doubly convex lens slightly in front of the film holder (back in the 1930s, astronomical films were glass plates.)
The resulting system is known as the Schmidt-Väisälä camera or sometimes as the Väisälä camera. (This solution is not perfect, as images of different colour end up at slightly different places.)
Prof. Väisälä made a small test unit of 7 mirrors in a mosaic on stiff background steel frame, however it proved to be impossible to stabilize as "just adjust and forget" structure, and next time anybody tried it, was with active controls on Multiple Mirror Telescope.
was doing its first precision triangulation chain measurements, and to create long-distance vertices Prof. Väisälä proposed usage of flash-lights on 5 to 10 km (16,404.2 to 32,808.4 ft) altitude balloons, or on some big fireworks rockets. The idea was to measure the exact position of the flash against background stars, and by precisely knowing one camera location, to derive an accurate location for another camera. This required better wide-field cameras than were available, and was discarded.
Later, Prof. Väisälä developed a method to multiply an optical length reference using white light interferometry to precisely determine lengths of baselines used in triangulation chains. Several such baselines were created in Finland for second high-precision triangulation campaign in 1950s and 1960s.
Later GPS made these methods largely obsolete. A Väisälä interferometry baseline is still maintained by the Finnish Geodetic Institute
in Nummela for the calibration of other distance measurement instruments.
Prof. Väisälä also developed excellent tools to measure earth rotational axis position by building so called zenith telescope
s, and in the 1960s Tuorla Observatory was in the top rank of North Pole position tracking measurements.
In the 1980s radioastronomy was able to replace earth rotation tracking by referring things against "non-moving background" of quasar
s.
For these Zenith Telescopes, Prof. Väisälä made also one of the first experiments at doing mirrors of liquid mercury. (Such mirror needs extremely smooth rotational speeds which were achieved in the late 1990s.)
he built was used at the University of Turku
for searching asteroid
s and comet
s. His research group discovered 7 comets and 807 asteroids.
For this rather massive photographic survey work, Prof. Väisälä developed also a protocol of taking two exposures on same plate some 2–3 hours apart and offsetting those images slightly. Any dot-pairs that differed from background were moving, and deserved follow-up photos. This method halved the film consumption compared to method of "blink comparing"
, where plates get single exposures, and are compared by rapidly showing first and second exposures to human operator. (Blink-comparing was used to find e.g. Pluto
.)
Notably, Yrjö Väisälä discovered the periodic comets 40P/Väisälä and 139P/Väisälä-Oterma
(the latter was co-discovered with Liisi Oterma
and at first classified as asteroid 1939 TN).
The University of Turku
Astronomy department is known as VISPA: Väisälä Institute for Space Physics and Astronomy (http://www.astro.utu.fi/) in honour of its founder.
The crater
Väisälä
on the Moon
is named after him, and so are the asteroid
s 1573 Väisälä
and 2804 Yrjö
.
was named. For this reason the Palomar Mountain Observatory in California has never had an asteroid bearing its name – the rules for naming asteroids state that the names have to differ from each other with more than one letter.
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
.
His main contributions were in the field of optics
Optics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
, but he was also very active in geodetics, astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
and optical metrology
Metrology
Metrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement. The word comes from Greek μέτρον , "measure" + "λόγος" , amongst others meaning "speech, oration, discourse, quote, study, calculation, reason"...
. He had even an affectionate nickname of Wizard of Tuorla (Observatory/Optics laboratory), and there is a book with the same title in Finnish describing his works.
His brothers were mathematician Kalle Väisälä and meteorologist Vilho Väisälä
Vilho Väisälä
Vilho Väisälä was a Finnish meteorologist and physicist, and founder of Vaisala.After graduation in mathematics in 1912, Väisälä worked for the Finnish Meteorological Institute in aerological measurements, specializing in the research of the higher troposphere...
.
Väisälä was also a fervent supporter of Esperanto
Esperanto
is the most widely spoken constructed international auxiliary language. Its name derives from Doktoro Esperanto , the pseudonym under which L. L. Zamenhof published the first book detailing Esperanto, the Unua Libro, in 1887...
, presiding the Internacia Scienca Asocio Esperantista ("International Association of Esperanto Scientists") in 1968.
Optician
He developed several methods for measuring the quality of optical elements, as well as a lot of practical methods of manufacturing said elements.This allowed the construction of some of the earliest high-quality Schmidt camera
Schmidt camera
A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. Other similar designs are the Wright Camera and Lurie-Houghton telescope....
s, in particular a "field-flattened" version known as Schmidt-Väisälä camera
Schmidt-Väisälä camera
The Schmidt-Väisälä camera is a type of astronomical telescope intended for wide-field photographic work. It was designed by Yrjö Väisälä.-Invention and design:...
.
Contemporary to Bernhard Schmidt
Bernhard Schmidt
Bernhard Woldemar Schmidt was a German optician. In 1930 he invented the Schmidt telescope which corrected for the optical errors of spherical aberration, coma, and astigmatism, making possible for the first time the construction of very large, wide-angled reflective cameras of short exposure time...
's design, but unpublished was also Prof. Yrjö Väisälä's identical design which he had mentioned in lecture notes in 1924 with a footnote: "problematic spherical focal surface".
Once he saw Schmidt's publication, he promptly went ahead and "solved" the field flattening problem by placing a doubly convex lens slightly in front of the film holder (back in the 1930s, astronomical films were glass plates.)
The resulting system is known as the Schmidt-Väisälä camera or sometimes as the Väisälä camera. (This solution is not perfect, as images of different colour end up at slightly different places.)
Prof. Väisälä made a small test unit of 7 mirrors in a mosaic on stiff background steel frame, however it proved to be impossible to stabilize as "just adjust and forget" structure, and next time anybody tried it, was with active controls on Multiple Mirror Telescope.
Geodesy
In the 1920s and 1930s FinlandFinland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
was doing its first precision triangulation chain measurements, and to create long-distance vertices Prof. Väisälä proposed usage of flash-lights on 5 to 10 km (16,404.2 to 32,808.4 ft) altitude balloons, or on some big fireworks rockets. The idea was to measure the exact position of the flash against background stars, and by precisely knowing one camera location, to derive an accurate location for another camera. This required better wide-field cameras than were available, and was discarded.
Later, Prof. Väisälä developed a method to multiply an optical length reference using white light interferometry to precisely determine lengths of baselines used in triangulation chains. Several such baselines were created in Finland for second high-precision triangulation campaign in 1950s and 1960s.
Later GPS made these methods largely obsolete. A Väisälä interferometry baseline is still maintained by the Finnish Geodetic Institute
Finnish Geodetic Institute
The Finnish Geodetic Institute is a Finnish research institute specializing in geodesy and geospatial information science and technology. It is located in Masala, Kirkkonummi.-History:...
in Nummela for the calibration of other distance measurement instruments.
Prof. Väisälä also developed excellent tools to measure earth rotational axis position by building so called zenith telescope
Zenith telescope
A zenith telescope is a type of telescope that is designed to point straight up at or near the zenith. They are used for precision measurement of star positions, to simplify telescope construction, or both....
s, and in the 1960s Tuorla Observatory was in the top rank of North Pole position tracking measurements.
In the 1980s radioastronomy was able to replace earth rotation tracking by referring things against "non-moving background" of quasar
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
s.
For these Zenith Telescopes, Prof. Väisälä made also one of the first experiments at doing mirrors of liquid mercury. (Such mirror needs extremely smooth rotational speeds which were achieved in the late 1990s.)
Astronomer
The big Schmidt-Väisälä telescopeSchmidt-Väisälä camera
The Schmidt-Väisälä camera is a type of astronomical telescope intended for wide-field photographic work. It was designed by Yrjö Väisälä.-Invention and design:...
he built was used at the University of Turku
University of Turku
The University of Turku , located in Turku in southwestern Finland, is the second largest university in the country as measured by student enrollment, after University of Helsinki. It was established in 1920 and also has faculties at Rauma, Pori and Salo...
for searching asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s and comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s. His research group discovered 7 comets and 807 asteroids.
For this rather massive photographic survey work, Prof. Väisälä developed also a protocol of taking two exposures on same plate some 2–3 hours apart and offsetting those images slightly. Any dot-pairs that differed from background were moving, and deserved follow-up photos. This method halved the film consumption compared to method of "blink comparing"
Blink comparator
A blink comparator was a viewing apparatus used by astronomers to find differences between two photographs of the night sky shot using optical telescopes such as astrographs. It permitted rapidly switching from viewing one photograph to viewing the other, "blinking" back and forth between the two...
, where plates get single exposures, and are compared by rapidly showing first and second exposures to human operator. (Blink-comparing was used to find e.g. Pluto
Pluto
Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
.)
Notably, Yrjö Väisälä discovered the periodic comets 40P/Väisälä and 139P/Väisälä-Oterma
139P/Väisälä-Oterma
139P/Väisälä-Oterma is a periodic comet in our solar system. When it as discovered in 1939 it was not recognized as a comet and designated as asteroid 1939 TN.- External links :*...
(the latter was co-discovered with Liisi Oterma
Liisi Oterma
Liisi Oterma was a Finnish astronomer, the first woman to get a Ph.D. degree in astronomy in Finland.She discovered or co-discovered some comets, including periodic comets 38P/Stephan-Oterma and 39P/Oterma, and quite a number of asteroids. The asteroid 1529 Oterma was named in her honour.-...
and at first classified as asteroid 1939 TN).
The University of Turku
Turku
Turku is a city situated on the southwest coast of Finland at the mouth of the Aura River. It is located in the region of Finland Proper. It is believed that Turku came into existence during the end of the 13th century which makes it the oldest city in Finland...
Astronomy department is known as VISPA: Väisälä Institute for Space Physics and Astronomy (http://www.astro.utu.fi/) in honour of its founder.
The crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
Väisälä
Väisälä (crater)
Väisälä is a tiny lunar crater located on a rise in the Oceanus Procellarum. Sharing the same continental island are the brilliant crater Aristarchus to the south-southeast and Herodotus to the south-southwest. Väisälä lies just to the west of the Rupes Toscanelli fault line, and the Rimae...
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him, and so are the asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s 1573 Väisälä
1573 Väisälä
1573 Väisälä is a main belt asteroid with an orbital period of 1333.4672727 days . The asteroid was discovered on October 27, 1949, and is named after the Finnish astronomer Yrjö Väisälä.-References:...
and 2804 Yrjö
2804 Yrjö
2804 Yrjö is a main belt asteroid with an orbital period of 1913.5995962 days . The asteroid was discovered on April 19, 1941.-References:...
.
Asteroids discovered
Yrjö Väisälä discovered 128 asteroids. He used to name them with the names of his personal friends that had birthdays. One of them was the professor Matti Palomaa, after whom an asteroid 1548 Palomaa1548 Palomaa
1548 Palomaa is a main-belt asteroid discovered on March 26, 1935 by Y. Vaisala at Turku.- External links :*...
was named. For this reason the Palomar Mountain Observatory in California has never had an asteroid bearing its name – the rules for naming asteroids state that the names have to differ from each other with more than one letter.
| 1391 Carelia 1391 Carelia 1391 Carelia is a main belt asteroid with a perihelion of 2.1183552 AU. It has an eccentricity of 0.1674461 and an orbital period of 1484.2736262 days . It has an average orbital speed of 18.66764903 km/s and an inclination of 7.58649°.... |
1398 Donnera 1398 Donnera 1398 Donnera is a main-belt asteroid discovered on August 26, 1936 by Yrjö Väisälä at University of Turku.- External links :*... |
1405 Sibelius 1405 Sibelius 1405 Sibelius is a main-belt asteroid discovered on September 12, 1936 by Y. Vaisala at Turku.- External links :*... |
1406 Komppa 1406 Komppa 1406 Komppa is a main-belt asteroid discovered on September 13, 1936 by Y. Vaisala at Turku.- External links :*... |
1407 Lindelöf 1407 Lindelöf 1407 Lindelöf is a main belt asteroid with an orbital period of 1676.6949325 days .The asteroid was discovered on November 21, 1936.-References:... |
| 1421 Esperanto 1421 Esperanto 1421 Esperanto is a main belt asteroid discovered on March 18, 1936 by the Finnish astronomer Yrjö Väisälä at Iso-Heikkilä Observatory in Turku, Finland. It measures 43.31km in diameter.... |
1424 Sundmania 1424 Sundmania 1424 Sundmania is a main-belt asteroid discovered on January 9, 1937 by Yrjö Väisälä at Turku.- External links :*... |
1446 Sillanpää 1446 Sillanpää 1446 Sillanpää is a main belt asteroid with an orbital period of 1229.4888810 days . The asteroid was discovered on January 26, 1938.-References:... |
1447 Utra 1447 Utra 1447 Utra is a main-belt asteroid discovered on January 26, 1938 by Y. Vaisala at Turku.- External links :*... |
1448 Lindbladia 1448 Lindbladia 1448 Lindbladia is a main-belt asteroid discovered on February 16, 1938 by Y. Vaisala at Turku.- External links :*... |
| 1449 Virtanen 1449 Virtanen 1449 Virtanen is a main belt asteroid with an orbital period of 1210.0044377 days . It was discovered on February 20, 1938 by Yrjö Väisälä at Iso-Heikkilä Observatory in Turku, Finland. It is named after the Finnish chemist Artturi Ilmari Virtanen.-References:... |
1450 Raimonda 1450 Raimonda 1450 Raimonda is a main-belt asteroid discovered on February 20, 1938 by Y. Vaisala at Turku.- External links :*... |
1451 Granö 1451 Granö 1451 Granö is a main belt asteroid with an orbital period of 1194.1311242 days .The asteroid was discovered on February 22, 1938.-References:... |
1453 Fennia 1453 Fennia 1453 Fennia is an inner main belt asteroid. It was discovered on March 8, 1938 by the Finnish astronomer Yrjö Väisälä at Iso-Heikkilä Observatory in Turku, Finland. The asteroid's name is the Latin word for Finland.... |
1454 Kalevala 1454 Kalevala 1454 Kalevala is a main-belt asteroid discovered on February 16, 1936 by Yrjö Väisälä at Turku.- External links :*... |
| 1460 Haltia 1460 Haltia 1460 Haltia is a main-belt asteroid discovered on November 24, 1937 by Vaisala, Y. at Turku.- External links :*... |
1462 Zamenhof 1462 Zamenhof Zamenhof is a main belt asteroid, which was discovered by the Finnish astronomer and physicist Yrjö Väisälä on February 6, 1938. It has a diameter of 25.82 km and geometric albedo of 0.1268.... |
1463 Nordenmarkia 1463 Nordenmarkia 1463 Nordenmarkia is a main-belt asteroid discovered on February 6, 1938 by Y. Vaisala at Turku.- External links :*... |
1471 Tornio 1471 Tornio 1471 Tornio is a main-belt asteroid discovered on September 16, 1938 by Y. Vaisala at Turku.- External links :*... |
1472 Muonio 1472 Muonio 1472 Muonio is a main-belt asteroid discovered on October 18, 1938 by Y. Vaisala at Turku.- External links :*... |
| 1473 Ounas 1473 Ounas 1473 Ounas is a main-belt asteroid discovered on October 22, 1938 by Y. Vaisala at Turku.- External links :*... |
1477 Bonsdorffia 1477 Bonsdorffia 1477 Bonsdorffia is a main-belt asteroid discovered on February 6, 1938 by Vaisala, Y. at Turku.- External links :*... |
1478 Vihuri 1478 Vihuri 1478 Vihuri is a main belt asteroid with an orbital period of 1414.2465144 days . The asteroid was discovered on February 6, 1938.-References:... |
1479 Inkeri 1479 Inkeri 1479 Inkeri is a main-belt asteroid discovered on February 16, 1938 by Vaisala, Y. at Turku.- External links :*... |
1480 Aunus 1480 Aunus 1480 Aunus is a main-belt asteroid discovered on February 18, 1938 by Vaisala, Y. at Turku.- External links :*... |
| 1483 Hakoila 1483 Hakoila 1483 Hakoila is a main-belt asteroid discovered on February 24, 1938 by Vaisala, Y. at Turku.- External links :*... |
1488 Aura 1488 Aura 1488 Aura is a main-belt asteroid discovered on December 15, 1938 by Vaisala, Y. at Turku.- External links :*... |
1492 Oppolzer 1492 Oppolzer 1492 Oppolzer is a main-belt asteroid discovered on March 23, 1938 by Y. Vaisala at Turku.- External links :*... |
1494 Savo 1494 Savo 1494 Savo is a main-belt asteroid discovered on September 16, 1938 by Y. Vaisala at Turku.Named after Savonia, region of Finland.- External links :*... |
1495 Helsinki 1495 Helsinki 1495 Helsinki is a main-belt asteroid discovered on September 21, 1938 by Yrjö Väisälä at Turku.- External links :*... |
| 1496 Turku 1496 Turku 1496 Turku is a main-belt asteroid discovered on September 22, 1938 by Y. Vaisala at Turku.- External links :*... |
1497 Tampere 1497 Tampere 1497 Tampere is a main-belt asteroid discovered on September 22, 1938 by Y. Vaisala at Turku.- External links :*... |
1498 Lahti 1498 Lahti 1498 Lahti is a main-belt asteroid discovered on September 16, 1938 by Y. Vaisala at Turku.- External links :... |
1499 Pori 1499 Pori 1499 Pori is a main-belt asteroid discovered on October 16, 1938 by Y. Väisälä at Turku, and is named after the city of Pori, Finland.- External links :*... |
1500 Jyväskylä 1500 Jyväskylä 1500 Jyväskylä is a small Main belt asteroid.It was discovered by Y. Väisälä on October 16, 1938, and is named after the town of Jyväskylä, Finland.Little is known about this asteroid.- External links :*... |
| 1503 Kuopio 1503 Kuopio 1503 Kuopio is a main-belt asteroid discovered on December 15, 1938 by Yrjö Väisälä at Turku.- External links :*... |
1518 Rovaniemi 1518 Rovaniemi 1518 Rovaniemi is a main-belt asteroid discovered on October 15, 1938 by Y. Vaisala at Turku.- External links :*... |
1519 Kajaani 1519 Kajaani 1519 Kajaani is a main-belt asteroid discovered on October 15, 1938, by Y. Vaisala at Turku.- External links :*... |
1520 Imatra 1520 Imatra 1520 Imatra is a main-belt asteroid discovered on October 22, 1938 by Vaisala, Y. at Turku.- External links :*... |
1521 Seinäjoki 1521 Seinäjoki 1521 Seinäjoki is a main belt asteroid with an orbital period of 1755.3497820 days . The asteroid was discovered on October 22, 1938.-References:... |
| 1523 Pieksämäki 1523 Pieksämäki 1523 Pieksämäki is a main belt asteroid with an orbital period of 1225.7458519 days . The asteroid was discovered on January 18, 1939.-References:... |
1524 Joensuu 1524 Joensuu 1524 Joensuu is a main-belt asteroid discovered on September 18, 1939 by Y. Vaisala at Turku.- External links :*... |
1525 Savonlinna 1525 Savonlinna 1525 Savonlinna is a main-belt asteroid discovered on September 18, 1939 by Y. Vaisala at Turku.- External links :*... |
1526 Mikkeli 1526 Mikkeli 1526 Mikkeli is a main-belt asteroid discovered on October 7, 1939 by Y. Vaisala at Turku.- External links :*... |
1527 Malmquista 1527 Malmquista 1527 Malmquista is a main-belt asteroid discovered on October 18, 1939 by Y. Vaisala at Turku. It is named for the Swedish astronomer Gunnar Malmquist.- External links :*... |
| 1529 Oterma 1529 Oterma 1529 Oterma is an outer main-belt asteroid discovered on January 26, 1938 by Y. Väisälä at Turku. It was named after Liisi Oterma.- External links :*... |
1530 Rantaseppä 1530 Rantaseppä 1530 Rantaseppä is a main belt asteroid with an orbital period of 1231.1780240 days . The asteroid was discovered on 16 September 1938.- References :... |
1532 Inari 1532 Inari 1532 Inari is a main-belt asteroid discovered on September 16, 1938 by Vaisala, Y. at Turku.- External links :*... |
1533 Saimaa 1533 Saimaa 1533 Saimaa is a main-belt asteroid discovered on January 19, 1939 by Y. Vaisala at Turku.- External links :*... |
1534 Näsi 1534 Näsi 1534 Näsi is a main belt asteroid with an orbital period of 1649.3803209 days .The asteroid was discovered on January 20, 1939.-References:... |
| 1535 Päijänne 1535 Päijänne 1535 Päijänne is a main belt asteroid with an orbital period of 2057.4959234 days . The asteroid was discovered on September 9, 1939.-References:... |
1536 Pielinen 1536 Pielinen 1536 Pielinen is a main-belt asteroid discovered on September 18, 1939 by Y. Vaisala at Turku.- References :... |
1541 Estonia 1541 Estonia 1541 Estonia is a main-belt asteroid discovered on February 12, 1939 by Vaisala, Y. at Turku. It was named after the country of Estonia.- External links :*... |
1542 Schalén 1542 Schalén 1542 Schalén is a main belt asteroid with an orbital period of 1991.3244631 days . The asteroid was discovered on August 26, 1941.-References:... |
1548 Palomaa 1548 Palomaa 1548 Palomaa is a main-belt asteroid discovered on March 26, 1935 by Y. Vaisala at Turku.- External links :*... |
| 1549 Mikko 1549 Mikko 1549 Mikko is a main-belt asteroid discovered on April 2, 1937 by Y. Vaisala at Turku.- External links :*... |
1551 Argelander 1551 Argelander 1551 Argelander is a main belt asteroid discovered on February 24, 1938 by Yrjö Väisälä at the Iso-Heikkilä Observatory in Turku, Finland. It is named after Friedrich Wilhelm Argelander, a 19th century head of the observatory at Turku.- External links :*... |
1552 Bessel 1552 Bessel 1552 Bessel is a Main Belt asteroid.It was discovered on February 24, 1938 by Yrjö Väisälä at Turku, Finland. It was named in honor of the German astronomer Friedrich Wilhelm Bessel.... |
1567 Alikoski 1567 Alikoski 1567 Alikoski is an outer main belt asteroid discovered on April 22, 1941 by Yrjö Väisälä at Turku. It is named after Finnish astronomer Heikki A. Alikoski.- External links :*... |
1631 Kopff 1631 Kopff 1631 Kopff is a main-belt asteroid discovered on October 11, 1936 by Y. Vaisala at Turku. The asteroid was named in memory of August Kopff.- External links :*... |
| 1646 Rosseland 1646 Rosseland 1646 Rosseland is a main-belt asteroid discovered on January 19, 1939 by Y. Vaisala at Turku.- External links :*... |
1656 Suomi 1656 Suomi 1656 Suomi is a Mars-crossing asteroid discovered on March 11, 1942 by Y. Vaisala at Turku.- External links :*... |
1659 Punkaharju 1659 Punkaharju 1659 Punkaharju is a main-belt asteroid discovered on December 28, 1940 by Yrjö Väisälä at Turku. It is named after the municipality of Punkaharju, Finland.- External links :*... |
1677 Tycho Brahe 1677 Tycho Brahe 1677 Tycho Brahe is an asteroid in the main asteroid belt, of the group . It is named for the pre-telescopic era astronomer Tycho Brahe .- See also :*Asteroids list... |
1678 Hveen 1678 Hveen 1678 Hveen is a main-belt asteroid discovered on December 28, 1940 by Vaisala, Y. at Turku.- External links :*... |
| 1696 Nurmela 1696 Nurmela 1696 Nurmela is a main-belt asteroid discovered on March 18, 1939 by Y. Vaisala at Turku.- External links :*... |
1699 Honkasalo 1699 Honkasalo 1699 Honkasalo is a main-belt asteroid discovered on August 26, 1941 by Y. Vaisala at Turku.- External links :*... |
1723 Klemola 1723 Klemola 1723 Klemola is a main-belt asteroid discovered on March 18, 1936 by Y. Vaisala at Turku.- External links :*... |
1740 Paavo Nurmi 1740 Paavo Nurmi 1740 Paavo Nurmi is a minor planet. It was discovered by Y. Vaisala on October 18, 1939 in Turku, Finland. It is named for famed Finnish distance runner Paavo Nurmi, who won nine Olympic gold medals.-External links:*... |
1757 Porvoo 1757 Porvoo 1757 Porvoo is a main-belt asteroid discovered on March 17, 1939 by Y. Vaisala at Turku.- External links :*... |
| 1883 Rimito 1883 Rimito 1883 Rimito is a main-belt asteroid discovered on December 4, 1942 by Y. Vaisala at Turku.- External links :*... |
1928 Summa 1928 Summa 1928 Summa is a main-belt asteroid discovered on September 21, 1938 by Y. Vaisala at Turku.- External links :*... |
1929 Kollaa 1929 Kollaa 1929 Kollaa is a main-belt asteroid discovered on January 20, 1939 by Yrjö Väisälä at Turku, Finland. It is named after the Kollaa River in Karelia, the focal point on the Winter War.- External links :*... |
1947 Iso-Heikkilä 1947 Iso-Heikkilä 1947 Iso-Heikkilä is a main belt asteroid with an orbital period of 2045.9444096 days . The asteroid was discovered on March 4, 1935 by Yrjö Väisälä.-References:... |
2020 Ukko 2020 Ukko 2020 Ukko is a main-belt asteroid discovered on March 18, 1936 by Y. Vaisala at Turku.- External links :*... |
| 2067 Aksnes 2067 Aksnes 2067 Aksnes is an outer main belt asteroid discovered on February 23, 1936 by Yrjö Väisälä at Turku.- External links :*... |
2091 Sampo 2091 Sampo 2091 Sampo is a main-belt asteroid discovered on April 26, 1941 by Y. Vaisala at Turku.- External links :*... |
2096 Väinö 2096 Väinö 2096 Väinö is a main belt asteroid with an orbital period of 1395.9245208 days . The asteroid was discovered on October 18, 1939.-References:... |
2194 Arpola 2194 Arpola 2194 Arpola is a main-belt asteroid discovered on April 3, 1940 by Vaisala, Y. at Turku.- External links :*... |
2204 Lyyli 2204 Lyyli 2204 Lyyli is a Mars-crossing asteroid discovered on March 3, 1943 by Y. Vaisala at Turku.- External links :*... |
| 2243 Lönnrot 2243 Lönnrot 2243 Lönnrot is a main belt asteroid with an orbital period of 1231.4595638 days .The asteroid was discovered on September 25, 1941.-References:... |
2258 Viipuri 2258 Viipuri 2258 Viipuri is a main belt asteroid with an orbital period of 1614.0961528 days . The asteroid was discovered on October 7, 1939.-References:... |
2292 Seili 2292 Seili 2292 Seili is a main-belt asteroid discovered on September 7, 1942 by Y. Vaisala at Turku.- External links :*... |
2299 Hanko 2299 Hanko 2299 Hanko is a main-belt asteroid discovered on September 25, 1941, by Vaisala, Y. at Turku. It is named after Hanko, the southernmost town in southern Finland.- External links :... |
2333 Porthan 2333 Porthan 2333 Porthan is a main-belt asteroid discovered on 3 March 1943 by Y. Vaisala at Turku.- External links :*... |
| 2379 Heiskanen 2379 Heiskanen 2379 Heiskanen is a main-belt asteroid discovered on September 21, 1941 by Vaisala, Y. at Turku.- External links :*... |
2397 Lappajärvi 2397 Lappajärvi 2397 Lappajärvi is a main belt asteroid with an orbital period of 1978.6650442 days .The asteroid was discovered on February 22, 1938.-References:... |
2454 Olaus Magnus 2454 Olaus Magnus 2454 Olaus Magnus is a main-belt asteroid discovered on September 21, 1941 by Y. Vaisala at Turku.- External links :*... |
2464 Nordenskiöld 2464 Nordenskiöld 2464 Nordenskiöld is a main belt asteroid with an orbital period of 2059.0149135 days .The asteroid was discovered on January 19, 1939.-References:... |
2479 Sodankylä 2479 Sodankylä 2479 Sodankylä is a main belt asteroid with an orbital period of 1348.1409642 days . The asteroid was discovered on February 6, 1942.-References:... |
| 2486 Metsähovi 2486 Metsähovi 2486 Metsähovi is a main belt asteroid with an orbital period of 1248.1792618 days .The asteroid was discovered on March 22, 1939.-References:... |
2502 Nummela 2502 Nummela 2502 Nummela is a main-belt asteroid discovered on March 3, 1943 by Yrjö Väisälä at Turku.- External links :*... |
2512 Tavastia 2512 Tavastia 2512 Tavastia is a main-belt asteroid discovered on April 3, 1940 by Aust Redmin at Turku.- External links :*... |
2535 Hämeenlinna 2535 Hämeenlinna 2535 Hämeenlinna is a main belt asteroid with an orbital period of 1223.9388569 days .The asteroid was discovered on February 17, 1939.-References:... |
2638 Gadolin 2638 Gadolin 2638 Gadolin is a main-belt asteroid discovered on September 19, 1939 by Vaisala, Y. at Turku.- External links :*... |
| 2639 Planman 2639 Planman 2639 Planman is a main-belt asteroid discovered on April 9, 1940 by Y. Vaisala at Turku.- External links :*... |
2678 Aavasaksa 2678 Aavasaksa 2678 Aavasaksa is a main-belt asteroid discovered on February 24, 1938 by Yrjö Väisälä at Turku. It is named after the Aavasaksa hill in Ylitornio, Finland.... |
2679 Kittisvaara 2679 Kittisvaara 2679 Kittisvaara is a main-belt asteroid discovered on October 7, 1939 by Yrjö Väisälä at Turku.- External links :*... |
2690 Ristiina 2690 Ristiina 2690 Ristiina is a main-belt asteroid discovered on February 24, 1938 by Y. Vaisala at Turku.- External links :*... |
2715 Mielikki 2715 Mielikki 2715 Mielikki is a main-belt asteroid discovered on October 22, 1938 by Y. Vaisala at Turku.- External links :*... |
| 2716 Tuulikki 2716 Tuulikki 2716 Tuulikki is a main-belt asteroid discovered on October 7, 1939 by Y. Vaisala at Turku.- External links :*... |
2733 Hamina 2733 Hamina 2733 Hamina is a main-belt asteroid discovered on February 22, 1938 by Vaisala, Y. at Turku.- External links :*... |
2737 Kotka 2737 Kotka 2737 Kotka is a main-belt asteroid discovered on February 22, 1938 by Y. Vaisala at Turku.- External links :*... |
2750 Loviisa 2750 Loviisa 2750 Loviisa is a main-belt asteroid discovered on December 30, 1940 by Y. Vaisala at Turku.- External links :*... |
2802 Weisell 2802 Weisell 2802 Weisell is a main-belt asteroid discovered on January 19, 1939 by Y. Vaisala at Turku.- External links :*... |
| 2820 Iisalmi 2820 Iisalmi 2820 Iisalmi is a main-belt asteroid discovered on September 8, 1942 by Vaisala, Y. at Turku.Iisalmi is a town and municipality of Finland.- External links :*... |
2826 Ahti 2826 Ahti 2826 Ahti is an outer main belt asteroid discovered on October 18, 1939 by Yrjö Väisälä at Turku.- External links :*... |
2885 Palva 2885 Palva 2885 Palva is a main-belt asteroid discovered on October 7, 1939 by Yrjö Väisälä at Turku.- External links :*... |
2898 Neuvo 2898 Neuvo 2898 Neuvo is a main-belt asteroid discovered on February 20, 1938 by Yrjö Väisälä at Turku.- External links :*... |
2962 Otto 2962 Otto 2962 Otto is a main-belt asteroid discovered on December 28, 1940 by Y. Vaisala at Turku.- External links :... |
| 2972 Niilo 2972 Niilo 2972 Niilo is a main-belt asteroid discovered on October 7, 1939 by Y. Vaisala at Turku.- External links :*... |
3037 Alku 3037 Alku 3037 Alku is a main belt asteroid discovered on January 17, 1944 by Vaisala, Y. at Turku.- External links :*... |
3099 Hergenrother 3099 Hergenrother 3099 Hergenrother is a main-belt asteroid discovered on April 3, 1940 by Vaisala, Y. at Turku.- External links :*... |
3166 Klondike 3166 Klondike 3166 Klondike is a main-belt asteroid discovered on March 30, 1940 by Y. Vaisala at Turku.- External links :*... |
3212 Agricola 3212 Agricola 3212 Agricola is a main belt asteroid discovered on February 19, 1938 by Vaisala, Y. at Turku.- External links :*... |
| 3223 Forsius 3223 Forsius 3223 Forsius is a main-belt asteroid discovered on September 7, 1942 by Vaisala, Y. at Turku.- External links :*... |
3272 Tillandz 3272 Tillandz 3272 Tillandz is a main-belt asteroid discovered on February 24, 1938 by Y. Vaisala at Turku.- External links :*... |
3281 Maupertuis 3281 Maupertuis 3281 Maupertuis is a main-belt asteroid discovered on February 24, 1938 by Y. Vaisala at Turku. The crater was named for the French mathemetician and astronomer Pierre Louis Maupertuis .- External links :*... |
3522 Becker 3522 Becker 3522 Becker is a main-belt asteroid discovered on September 21, 1941 by Vaisala, Y. at Turku.- External links :*... |
3606 Pohjola 3606 Pohjola 3606 Pohjola is a main-belt asteroid discovered on September 19, 1939 by Y. Vaisala at Turku.- External links :*... |
| 3897 Louhi 3897 Louhi 3897 Louhi is a main-belt asteroid discovered on September 8, 1942 by Y. Vaisala at Turku.- External links :*... |
4181 Kivi 4181 Kivi 4181 Kivi is a main-belt asteroid discovered on February 24, 1938 by Yrjö Väisälä at Turku.- External links :*... |
4266 Waltari 4266 Waltari 4266 Waltari is a main-belt asteroid discovered on December 28, 1940 by Yrjö Väisälä at Turku.- External links :*... |
4512 Sinuhe 4512 Sinuhe 4512 Sinuhe is a main-belt asteroid discovered on January 20, 1939 by Yrjö Väisälä at Turku, Finland.- External links :*... |
5073 Junttura 5073 Junttura 5073 Junttura is a main-belt asteroid discovered on March 3, 1943 by Y. Vaisala at Turku.- External links :*... |
| (5153) 1940 GO (5153) 1940 GO 1940 GO is a main-belt minor planet. It was discovered by Yrjö Väisälä at the University of Turku in Turku, Finland, on April 9, 1940.-External links:*... |
(6073) 1939 UB (6073) 1939 UB 1939 UB is a main-belt minor planet. It was discovered by Yrjö Väisälä at the University of Turku in Turku, Finland, on October 18, 1939.-External links:*... |
6572 Carson 6572 Carson 6572 Carson is a main-belt asteroid discovered on September 22, 1938 by Vaisala, Y. at Turku.- External links :*... |