Discovery [1] | |
---|---|
Discovered by | A. Massinger |
Discovery site | Heidelberg Obs. |
Discovery date | 15 April 1912 |
Designations | |
(732) Tjilaki | |
Pronunciation | Malay: [tʃiˈlaki] |
Named after | Cilaki River [2] [3] (River in Indonesia) |
A912 HK ·1958 FC 1912 OR | |
Orbital characteristics [4] | |
Epoch 31 May 2020 (JD 2459000.5) | |
Uncertainty parameter 0 | |
Observation arc | 106.66 yr (38,959 d) |
Aphelion | 2.5633 AU |
Perihelion | 2.3490 AU |
2.4561 AU | |
Eccentricity | 0.0436 |
3.85 yr (1,406 d) | |
359.80° | |
0° 15m 21.96s / day | |
Inclination | 10.994° |
173.35° | |
64.900° | |
Physical characteristics | |
12.34±0.01 h [11] | |
Pole ecliptic latitude | |
732 Tjilaki ( prov. designation:A912 HKor1912 OR) is a dark background asteroid, approximately 36 kilometers (22 miles) in diameter, located in the inner region of the asteroid belt. It was discovered by German astronomer Adam Massinger at the Heidelberg Observatory on 15 April 1912, and later named after the Cilaki (Tjilaki) river in Indonesia. [1] [2] The dark D-type asteroid has a rotation period of 12.3 hours. It was an early candidate to be visited by the Rosetta spacecraft which eventually rendezvoused comet 67P/Churyumov–Gerasimenko. [11]
Tjilaki is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. [5] [6] [7] It orbits the Sun in the inner asteroid belt at a distance of 2.3–2.6 AU once every 3 years and 10 months (1,406 days; semi-major axis of 2.46 AU). Its orbit has an eccentricity of 0.04 and an inclination of 11° with respect to the ecliptic. [4] The body's observation arc begins at Heidelberg Observatory on 28 August 1913, or 16 months after its official discovery observation. [1]
This minor planet was named after the Cilaki (Tjilaki) river in West Java, Indonesia. The river rises in the mountains where the city of Malabar (see asteroid 754 Malabar) is located. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ( H 74 ). [2]
In the Phase A study of the Rosetta mission, Tjilaki was considered an alternative visiting target to comet 46P/Wirtanen. [11] However, both candidates were later abandoned in favor of comet 67P/Churyumov–Gerasimenko, which was visited by Rosetta in 2014. The retargeting was necessary as the spacecraft's launch window changed due to a delay caused by the launch failure of the Hot Bird 7 satellite on the maiden flight of the Ariane 5 ECA carrier rocket in 2002.
In both the Tholen- and SMASS-like taxonomic variants of the Small Solar System Objects Spectroscopic Survey (S3OS2), , Tjilaki is a dark D-type asteroid, uncommon in the inner but abundant in the outer asteroid belt as well as among the Jupiter trojan population. [6] [12] Polarimetric observations also determined a D-type. [13] [14]
In February 1996, a rotational lightcurve of Tjilaki was obtained from photometric observations over ten nights by European astronomers using the Dutch 0.9-metre Telescope and the Bochum 0.61-metre Telescope at La Silla Observatory in Chile. Lightcurve analysis gave a rotation period of 12.34±0.01 hours with a brightness variation of 0.19±0.02 magnitude ( U=3− ). [11]
In May 2012, astronomers at the Palomar Transient Factory measured a period of 12.277±0.0048 hours ( U=2 ). [14] [15] Additional observations were made by the TESS-team in January 2019, and by amateur astronomers Axel Martin and Rui Goncalves in May 2020, reporting a concurring period of (12.3286±0.0005) and (12.3216±0.00144) hours with an amplitude of (0.16±0.03) and (0.287±0.004) magnitude, respectively ( U=2/n.a. ). [16] [17]
In 2016, a modeled lightcurve gave a concurring sidereal period of 12.3411±0.0002 hours using data from the Uppsala Asteroid Photometric Catalogue, the Palomar Transient Factory survey, and individual observers, as well as sparse-in-time photometry from the NOFS, the Catalina Sky Survey, and the La Palma surveys ( 950 ). The study also determined two spin axes of (160.0°, 23.0°) and (353.0°, 24.0°) in ecliptic coordinates (λ, β). [18]
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Tjilaki measures (29.791±0.431), (36.49±0.43) and (37.61±1.6) kilometers in diameter and its surface has an albedo of (0.138±0.024), (0.070±0.002) and (0.0655±0.006), respectively. [8] [9] [10] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0763 and a diameter of 37.69 kilometers based on an absolute magnitude of 10.53. [14]
Alternative mean-diameters published by the WISE team include (36.76±11.57 km) and (37.96±9.94 km) with a corresponding albedo of (0.09±0.06) and (0.15±0.05). [6] [14] Two asteroid occultations on 20 June 2005 and on 28 July 2009, gave a best-fit ellipse dimension of (33.6 km × 33.6 km) and (37.7 km × 36.4 km), respectively, each with an intermediate quality rating of 2. [6] These timed observations are taken when the asteroid passes in front of a distant star. [6]
333 Badenia is a large background asteroid, approximately 72 kilometers in diameter, located the outer region of the asteroid belt. It was discovered on 22 August 1892, by astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in southwest Germany. The carbonaceous C-type asteroid has a rotation period of 9.9 hours. It was named after the historical Grand Duchy of Baden that existed until 1918, and where the discovering observatory is located. Badenia was the first asteroid to receive a provisional designation.
406 Erna, provisional designation 1895 CB, is a dark asteroid of the background population in the outer regions of the asteroid belt, approximately 46 kilometers in diameter. It was discovered by French astronomer Auguste Charlois at Nice Observatory on 22 August 1895. The asteroid was presumably named after Erna Bidschof, the granddaughter of Johann Palisa.
731 Sorga is a highly elongated background asteroid from the outer regions of the asteroid belt, approximately 38 kilometers in diameter. It was discovered on 15 April 1912, by German astronomer Adam Massinger at the Heidelberg-Königstuhl State Observatory in southwest Germany. The C-type (CD) and X-type asteroid (Xe) has a rotation period of 8.2 hours. It was named Sorga, meaning "the heavens" in the Indonesian language.
734 Benda is a large background asteroid from the outer regions of the asteroid belt, approximately 70 kilometers in diameter. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 11 October 1912. For its size, the dark X-type asteroid has a relatively short rotation period of 7.1 hours. It was named after the discoverer's wife, Anna Benda.
735 Marghanna is a large carbonaceous background asteroid from the central regions of the asteroid belt, approximately 74 kilometers in diameter. It was discovered on 9 December 1912, by German astronomer Heinrich Vogt at the Heidelberg-Königstuhl State Observatory in southwest Germany. The dark C-type asteroid (Ch) has a rotation period of 20.6 hours and is rather regular in shape. It was named after Margarete Vogt and after Hanna, the mother and a relative of the discoverer, respectively.
779 Nina is a large background asteroid, approximately 80 kilometers in diameter, located in the central region of the asteroid belt. It was discovered on 25 January 1914, by Russian astronomer Grigory Neujmin(1886-1946) at the Simeiz Observatory on the Crimean peninsula. The metallic X-type asteroid with an intermediate albedo has a rotation period of 11.2 hours. It was named after the discoverer's sister, Nina Neujmina (Tsentilovich) (1889–1971).
834 Burnhamia is a large background asteroid, approximately 61 kilometers in diameter, that is located in the outer region of the asteroid belt. It was discovered on 20 September 1916, by German astronomer Max Wolf at the Heidelberg Observatory in southwest Germany. The X-type asteroid (GS) has a rotation period of 13.9 hours. It was named after American astronomer Sherburne Wesley Burnham (1838–1921).
849 Ara is a large, metallic background asteroid, approximately 80 kilometers in diameter, that is located in the outer region of the asteroid belt. It was discovered on 9 February 1912, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. The M-type asteroid has a short rotation period of 4.1 hours and is likely elongated in shape. It was named after the American Relief Administration (ARA) for the help given during the Russian famine of 1921–22.
968 Petunia, is a stony asteroid of the Itha family, approximately 28 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 24 November 1921, by astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. The bright S-type asteroid has a long rotation period of 61.3 hours. It was named after the genus of flowering plants, Petunia.
1994 Shane, provisional designation 1961 TE, is a dark Adeonian asteroid from the central region of the asteroid belt, approximately 25 kilometers in diameter.
2114 Wallenquist, provisional designation 1976 HA, is a Themistian asteroid from the outer region of the asteroid belt, approximately 28 kilometers in diameter. It was discovered by Swedish astronomer Claes-Ingvar Lagerkvist at the Australian Mount Stromlo Observatory near Canberra, on 19 April 1976.
1074 Beljawskya, provisional designation 1925 BE, is a Themistian asteroid from the outer region of the asteroid belt, approximately 48 kilometers in diameter.
1099 Figneria, provisional designation 1928 RQ, is an asteroid from the background population of the outer regions of the asteroid belt, approximately 26 kilometers in diameter. Discovered by Grigory Neujmin at Simeiz Observatory in 1928, the asteroid was later named after Russian revolutionary activist Vera Figner.
1675 Simonida, provisional designation 1938 FB, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 11 kilometers in diameter. Discovered by Milorad Protić in 1938, it was later named after the medieval Byzantine princess Simonida.
1622 Chacornac is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 15 March 1952, by French astronomer Alfred Schmitt at the Royal Observatory of Belgium in Uccle, and named after astronomer Jean Chacornac.
1848 Delvaux is a stony Koronis asteroid from the outer region of the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 18 August 1933, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle, Belgium. It was later named after astronomer Georges Roland's sister-in-law.
3247 Di Martino is a dark Nysa family asteroid from the inner regions of the asteroid belt. It was discovered on 30 December 1981, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station near Flagstaff, Arizona, in the United States. The asteroid has a rotation period of 5.4 hours and measures approximately 13 kilometers in diameter. It was named for Italian astronomer Mario di Martino.
1540 Kevola, provisional designation 1938 WK, is a dark background asteroid from the outer regions of the asteroid belt, approximately 42 kilometers in diameter. It was discovered on 16 November 1938, by astronomer Liisi Oterma at the Iso-Heikkilä Observatory in Turku, Finland. The asteroid was named after the Finnish Kevola Observatory.
1529 Oterma, provisional designation 1938 BC, is a reddish, rare-type Hildian asteroid from the outermost region of the asteroid belt, approximately 56 kilometers in diameter. It was discovered on 26 January 1938, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland. It is named for Liisi Oterma.
4790 Petrpravec is a carbonaceous background asteroid from the central regions of the asteroid belt, approximately 16 kilometers in diameter. It was discovered on 9 August 1988, by American astronomer Eleanor Helin at the Palomar Observatory in California, and later named for Czech astronomer Petr Pravec.