Discovery | |
---|---|
Discovered by | J. Palisa |
Discovery site | Vienna Observatory |
Discovery date | 21 October 1911 |
Designations | |
(723) Hammonia | |
Pronunciation | /hæˈmoʊniə/ |
Named after | Hamburg |
1911 NB | |
Orbital characteristics [1] | |
Epoch 31 July 2016 (JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 113.17 yr (41337 d) |
Aphelion | 3.1540 AU (471.83 Gm) |
Perihelion | 2.8324 AU (423.72 Gm) |
2.9932 AU (447.78 Gm) | |
Eccentricity | 0.053719 |
5.18 yr (1891.5 d) | |
71.167° | |
0° 11m 25.188s / day | |
Inclination | 4.9954° |
163.351° | |
246.398° | |
Physical characteristics | |
Mean radius | 17.84±0.7 km |
5.436 h (0.2265 d) | |
0.1829±0.015 | |
10.0 | |
723 Hammonia is a minor planet orbiting the Sun. It was discovered in 1911 and is named after the city of Hamburg. [2] Although the name alludes to Hamburg it was discovered in Vienna. [3] (Vienna is the capital of Austria)
The asteroid was discovered by the noted and prolific astronomer Johann Palisa. [4] He worked from Pola early in his career and later from Vienna observatories. [5] The same night he discovered Hammonia, he also discovered 724 Hapag and 725 Amanda. [6] He discovered dozens and dozens of asteroids between 1874 and 1923, ranging from 136 Austria to 1073 Gellivara. [7]
As seen from a certain area on Earth, 723 Hammonia occulted the star 3UC149-190572 on June 3, 2013. [8]
In 2014 it was noted to have a high-albedo and amorphous Mg pyroxenes was suggested as a possible reason for this. [9]
Mathilde is an asteroid in the intermediate asteroid belt, approximately 50 kilometers in diameter, that was discovered by Austrian astronomer Johann Palisa at Vienna Observatory on 12 November 1885. It has a relatively elliptical orbit that requires more than four years to circle the Sun. This tumbling asteroid has an unusually slow rate of rotation, requiring 17.4 days to complete a 360° revolution about its axis. It is a primitive C-type asteroid, which means the surface has a high proportion of carbon; giving it a dark surface that reflects only 4% of the light that falls on it.
719 Albert, provisional designation 1911 MT, is a stony asteroid, approximately 2.5 kilometers in diameter, classified as a near-Earth object of the Amor group of asteroids. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 3 October 1911, and subsequently a lost minor planet for 89 years. The asteroid was named in memory of Albert Salomon Anselm von Rothschild, an Austrian philanthropist and banker. Albert was the second Amor asteroid discovered, the first being 433 Eros.
Abundantia is a stony main belt asteroid. It was discovered by Johann Palisa on 1 November 1875, from the Austrian Naval Observatory in Pula. The name was chosen by Edmund Weiss of the Vienna Observatory; although the name refers to Abundantia, a Roman goddess of luck, it was also chosen to celebrate the increasing numbers of asteroids that were being discovered in the 1870s.
Hedda is a sizeable Main belt asteroid. It is a C-type asteroid, meaning it is primitive in composition and dark in colour. This asteroid was discovered by Johann Palisa on October 17, 1879, in Pola and was named after Hedwig Winnecke, wife of astronomer Friedrich A. T. Winnecke.
Stephania is a dark background asteroid from the inner regions of the asteroid belt, approximately 32 km (20 mi) in diameter. It was discovered on 19 May 1881, by Austrian astronomer Johann Palisa at the Vienna Observatory. The C-type asteroid has a rotation period of 18.2 hours. It was named after Princess Stéphanie of Belgium.
225 Henrietta is a very large outer main-belt asteroid. It was discovered by Austrian astronomer Johann Palisa on April 19, 1882, in Vienna and named after Henrietta, wife of astronomer Pierre J. C. Janssen. The asteroid is orbiting at a distance of 3.39 AU from the Sun with a period of 6.24 years and an eccentricity (ovalness) of 0.26. The orbital plane is inclined at an angle of 20.9° to the plane of the ecliptic. 225 Henrietta belongs to Cybele group of asteroids and is probably in a 4:7 orbital resonance with the planet Jupiter.
Russia is a large Main belt asteroid. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. It was discovered by Johann Palisa on 31 January 1883 in Vienna, who named it after the country of Russia.
Augusta is a main-belt asteroid, discovered on 31 March 1886 by astronomer Johann Palisa at Vienna Observatory, Austria. The stony S-type asteroid measures about 12 kilometers in diameter. It is the first-numbered member of the Augusta family, after which the small Asteroid family and subgroup of the main-belt has been named. Augusta was named after the German–Austrian writer Auguste von Littrow (1819–1890), widow of astronomer Carl Ludwig von Littrow, who was a former director of the Vienna Observatory.
Walpurga is a large Main belt asteroid. It was discovered by Johann Palisa on 3 April 1886 in Vienna and was named after Saint Walburga.
Silesia is a large Main belt asteroid, about 73 kilometers in diameter. It was discovered by Johann Palisa on 5 April 1886 at Vienna Observatory, Austria.
Olga is a large Main belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material.
Chaldaea is a large Main belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material. It was discovered by Johann Palisa on 30 August 1891 in Vienna. It was named in honor of the Chaldeans, considered the founders of astrology.
710 Gertrud is a Themistian asteroid, which means it is a member of the Themis family of asteroids. It was discovered by Austrian astronomer Johann Palisa on 28 February 1911 from Vienna.
716 Berkeley is a background asteroid from the central regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 30 July 1911. The stony S-type asteroid has a rotation period of 15.6 hours and measures approximately 21 kilometers in diameter. It was named after the city of Berkeley, California, where the discoverer's colleague Armin Otto Leuschner (1868–1953) was the director of the local observatory.
722 Frieda is a bright background asteroid and slow rotator from the inner regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 18 October 1911. The stony S-type asteroid has a notably long rotation period of 131.1 hours and measures approximately 9 kilometers in diameter. It was named after Frieda Hillebrand, daughter of Austrian astronomer Karl Hillebrand (1861–1939), and grand-daughter of Edmund Weiss (1837–1917) who had been the director of the discovering observatory.
730 Athanasia is a background asteroid from the inner regions of the asteroid belt, approximately 4.5 kilometers in diameter. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 10 April 1912. The presumed stony S-type asteroid has a rotation period of 5.7 hours and is likely very elongated in shape. It was named Athanasia, the Greek word for "immortality".
794 Irenaea is a dark background asteroid from the outer regions of the asteroid belt. It was discovered on 27 August 1914, by Austrian astronomer Johann Palisa at the Vienna Observatory. The presumed C-type asteroid has a rotation period of 9.1 hours and measures approximately 36 kilometers in diameter. It was likely named after Irene Hillebrand, daughter of Austrian astronomer Edmund Weiss (1837–1917).
803 Picka is a large and dark background asteroid from the outer regions of the asteroid belt. It was discovered on 21 March 1915, by Austrian astronomer Johann Palisa at the Vienna Observatory. The carbonaceous D-type asteroid has a rotation period of 5.1 hours and measures approximately 57 kilometers in diameter. It was named after Czech physician Friedrich Pick (1867–1921).
964 Subamara, is a stony background asteroid from the outer regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 27 October 1921. The S-type asteroid has a rotation period of 6.9 hours. It was named for the observatory's "very bitter" observing conditions due to light pollution.
1073 Gellivara, provisional designation 1923 OW, is a dark Themistian asteroid, approximately 27 kilometers in diameter, located in the outer regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 14 September 1923, and later named after the Swedish town of Gällivare.