Discovery [1] | |
---|---|
Discovered by | P. Wild |
Discovery site | Zimmerwald Obs. |
Discovery date | 30 October 1972 |
Designations | |
(1845) Helewalda | |
Named after | Helen Gachnang (friend of discoverer) [2] |
1972 UC ·1931 VC1 1954 GG ·1971 OR 1971 QX2 | |
main-belt ·(outer) [3] Eos [4] | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 85.50 yr (31,229 days) |
Aphelion | 3.1371 AU |
Perihelion | 2.8001 AU |
2.9686 AU | |
Eccentricity | 0.0568 |
5.11 yr (1,868 days) | |
210.23° | |
0° 11m 33.72s / day | |
Inclination | 10.720° |
142.61° | |
325.05° | |
Physical characteristics | |
Dimensions | 19.930±0.377 [5] 20.426±0.147 km [6] 32.03 km (calculated) [3] |
7.2786±0.0002 h [7] 7.3985±0.0098 h [8] 7.399±0.004 h [9] 7.4±0.1 h [10] | |
0.057 (assumed) [3] 0.1289±0.0185 [6] 0.134±0.014 [5] | |
C (assumed) [3] | |
11.193±0.002 [8] ·11.2 [1] [3] ·11.3 [6] ·11.60±0.98 [11] | |
1845 Helewalda (provisional designation 1972 UC) is a carbonaceous Eoan asteroid in the outer regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland, on 30 October 1972. [12] The asteroid was named after Helen Gachnang, a friend of the discoverer. [2]
Helewalda is a member of the Eos family ( 606 ), the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids. [4] [13] : 23 It orbits the Sun in the outer main-belt at a distance of 2.8–3.1 AU once every 5 years and 1 month (1,868 days). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic. [1] The first precovery was taken at Lowell Observatory in 1931, extending the asteroid's observation arc by 41 years prior to its discovery. [12]
Helewalda is an assumed carbonaceous C-type asteroid. [3]
Based on observations made by French astronomer René Roy in March 2010, Helewalda has a well-determined rotation period of 7.2786±0.0002 hours with a brightness variation of 0.26 in magnitude ( U=3- ). [7]
Between 2009 and 2015, other lightcurves were obtained at the Oakley Southern Sky Observatory in Australia ( E09 ), the Via Capote Observatory at Thousand Oaks, California ( G69 ), and the Palomar Transient Factory at Palomar Observatory. They gave a similar period of 7.399±0.004, 7.4±0.1 and 7.3985±0.0098 hours with a corresponding amplitude of 0.20, 0.28 and 0.15, respectively ( U=2/2+/2 ). [9] [10] [8]
The Collaborative Asteroid Lightcurve Link calculates a diameter of 32.0 kilometers, based on an assumed standard albedo for carbonaceous C-type asteroids of 0.057, [3] while the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer measured a higher albedo of 0.134 and 0.129 and a corresponding diameter of 19.9 and 20.4 kilometers in diameter, respectively. [5] [6]
The discoverer, Paul Wild, named a pair of asteroids after two of his former schoolmates, Susi and Helen, both from the small village of Wald, Zürich in Switzerland. This one was dedicated to Helen Gachnang, while the previously numbered asteroid 1844 Susilva was given to Susi Petit-Pierre. [2] [14] The official naming citation was published by the Minor Planet Center on 18 April 1977 ( M.P.C. 4156). [15]
2747 Český Krumlov, provisional designation 1980 DW, is a carbonaceous asteroid and slow rotator from the outer regions of the asteroid belt, approximately 22 kilometers in diameter. It was discovered by Czech astronomer Antonín Mrkos at Kleť Observatory on 19 February 1980, and named for the Czech town of Český Krumlov.
1024 Hale, provisional designation A923 YO13, is a carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 45 kilometers (28 miles) in diameter. The asteroid was discovered on 2 December 1923, by Belgian–American astronomer George Van Biesbroeck at the Yerkes Observatory in Wisconsin, United States. It was named for American astronomer George Ellery Hale. The dark C-type asteroid may have a rotation period of 16 hours.
1027 Aesculapia, provisional designation A923 YO11, is a Themistian asteroid from the outer region of the asteroid belt, approximately 33 kilometers in diameter.
7167 Laupheim, provisional designation 1985 TD3, is a dark background asteroid from the outer regions of the asteroid belt, approximately 20 kilometers (12 miles) in diameter. It was discovered on 12 October 1985, by American astronomers Carolyn and Eugene Shoemaker at the Palomar Observatory in California. The presumed C-type asteroid has a rotation period of 7.04 hours and was named for Robert Clausen and his team at the public Laupheim Observatory in Germany.
6805 Abstracta, provisional designation 4600 P-L, is a carbonaceous Themistian asteroid and slow rotator from the outer region of the asteroid belt, approximately 10 kilometers in diameter.
10656 Albrecht is a carbonaceous background asteroid from the outer region of the asteroid belt, approximately 10 kilometers in diameter. It was named after German astronomer Carl Theodor Albrecht.
15258 Alfilipenko, provisional designation 1990 RN17, is a carbonaceous background asteroid from the outer region of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 15 September 1990, by Russian–Ukraininan astronomer Lyudmila Zhuravleva at the Crimean Astrophysical Observatory, Nauchnyj, on the Crimean peninsula. The asteroid was named after Russian civil engineer Aleksandr Filipenko.
1319 Disa, provisional designation 1934 FO, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 25 kilometers in diameter. It was discovered on 19 March 1934, by English-born, South African astronomer Cyril Jackson at Johannesburg Observatory in South Africa. It is named for the orchid Disa.
1253 Frisia, provisional designation 1931 TV1, is a carbonaceous Themistian asteroid from the outer regions of the asteroid belt, approximately 20 kilometers in diameter. Discovered by Karl Reinmuth at Heidelberg Observatory in 1931, the asteroid was later named after the region of Frisia and the Frisian Islands.
4000 Hipparchus is a dark background asteroid from the central regions of the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 4 January 1989, by Japanese astronomers Seiji Ueda and Hiroshi Kaneda at the Kushiro Observatory on Hokkaido, Japan. The likely carbonaceous asteroid has a short rotation period of 3.4 hours. It was named for the ancient Greek astronomer Hipparchus.
5385 Kamenka, provisional designation 1975 TS3, is a background asteroid from the outer regions of the asteroid belt, approximately 16 kilometers (10 miles) in diameter. It was discovered on 3 October 1975, by Soviet astronomer Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. The presumed C-type asteroid has a rotation period of 6.68 hours. It was named for the Ukrainian town of Kamianka.
6546 Kaye (prov. designation: 1987 DY4) is a dark and elongated background asteroid from the outer region of the asteroid belt. It was discovered on 24 February 1987, by Czech astronomer Antonín Mrkos at the South Bohemian Kleť Observatory in the Czech Republic. The presumed C-type asteroid has a rotation period of 10.0 hours and measures approximately 22 kilometers (14 miles) in diameter. It was named for American actor Danny Kaye.
1930 Lucifer, provisional designation 1964 UA, is a carbonaceous asteroid from the outer regions of the asteroid belt, approximately 34 kilometers in diameter. It was discovered on 29 October 1964, by American astronomer Elizabeth Roemer at the Flagstaff station (NOFS) of the United States Naval Observatory (USNO). It is named after Lucifer, the "shining one" or "light-bearer" from the Hebrew Bible.
7476 Ogilsbie, provisional designation 1993 GE, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 20 kilometers in diameter. It was discovered by American astronomer Timothy Spahr at the U.S. Catalina Station in Tucson, Arizona, on 14 April 1993.
1297 Quadea, provisional designation 1934 AD, is an Eoan asteroid from the outer regions of the asteroid belt, approximately 23 kilometers in diameter. It was discovered on 7 January 1934, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany. The asteroid was named for the parents-in-law of the discoverer's brother.
4003 Schumann, provisional designation 1964 ED, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 35 kilometers in diameter.
1625 The NORC, provisional designation 1953 RB, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 55 kilometers in diameter. It was discovered on 1 September 1953, by Belgian astronomer Sylvain Arend at the Royal Observatory of Belgium in Uccle, Belgium. It was named after the IBM Naval Ordnance Research Calculator (NORC).
1684 Iguassú, provisional designation 1951 QE, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 30.5 kilometers in diameter. It was discovered on 23 August 1951, by Argentine astronomer Miguel Itzigsohn at the La Plata Astronomical Observatory, located in the city of La Plata, Argentina. It was named after the Iguazu Falls in South America.
1844 Susilva, provisional designation 1972 UB, is a stony Eoan asteroid from the outer region of the asteroid belt, approximately 22 kilometers in diameter. It was discovered on 30 October 1972, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland, and later named after a schoolfriend of the discoverer.
5357 Sekiguchi is an Eos asteroid from the outer region of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 2 March 1992, by Japanese amateur astronomers Tetsuya Fujii and Kazuro Watanabe at the Kitami Observatory in eastern Hokkaidō, Japan. The asteroid was later named after Japanese astronomer Tomohiko Sekiguch.
Helen Gachnang and Susi Petit-Pierre visit the Eschenberg Observatory