| Discovery[1] | |
|---|---|
| Discovered by | F. Kaiser |
| Discovery site | Heidelberg Obs. |
| Discovery date | 20 April 1914 |
| Designations | |
| (786) Bredichina | |
Named after |
|
| A914 HD · 1914 UO | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 105.79yr (38,638 d) |
| Aphelion | 3.6852AU |
| Perihelion | 2.6690 AU |
| 3.1771 AU | |
| Eccentricity | 0.1599 |
| 5.66 yr (2,068 d) | |
| 267.56° | |
| 0° 10m 26.4s / day | |
| Inclination | 14.518° |
| 89.766° | |
| 133.61° | |
| Physical characteristics | |
| Dimensions | 160.5 km × 80.6 km[5] |
| Mass | (9.81 ± 5.40/3.21)×1017 kg[8] |
Meandensity | 1.606 ± 0.884/0.526 g/cm3[8] |
| 29.434±0.001 h[11] | |
786 Bredichina (prov. designation:A914 HDor1914 UO) is a carbonaceous and very largebackground asteroid, approximately 104 kilometers (65 miles) in diameter, located in the outer region of theasteroid belt. It was discovered by German astronomerFranz Kaiser at theHeidelberg-Königstuhl State Observatory on 20 April 1914.[1] The elongatedC-type asteroid has a longer than averagerotation period of 29.4 hours. It was named after Russian astronomerFyodor Bredikhin (1831–1904).[2]
Bredichina is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[4][5][6] It orbits the Sun in theouter main-belt at a distance of 2.7–3.7 AU once every 5 years and 8 months (2,068 days;semi-major axis of 3.18 AU). Its orbit has aneccentricity of 0.16 and aninclination of 15° with respect to theecliptic.[3] The body'sobservation arc begins atHeidelberg Observatory on 21 April 1914, the night after its official discovery observation.[1]
Thisminor planet was named afterFyodor Bredikhin (1831–1904), also known as Theodor or Feodor Alexandrovich Bredichin, a Russian astronomer and director of thePulkovo Observatory. He has made important contributions to the study ofcomets. Thenaming was also mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 78).[2] The lunar craterBredikhin is also named after him.[13]
In theTholen classification,Bredichina is a common, carbonaceousC-type asteroid.[3] It is also a C-type and C0-type in the Tedesco and Barucci classification from the 1908s.[5]
In March 2015, a rotationallightcurve ofBredichina was obtained fromphotometric observations by Spanish astronomers Alfonso Carreño (J08), Amadeo Aznar (Z95), Enrique Arce (J67), Pedro Brines (Z98), and Juan Lozano (I57). Lightcurve analysis gave arotation period of29.434±0.001 hours with a brightness variation of0.51±0.02magnitude (U=3−).[11]
Previously, in August 2008, Argentine astronomerRicardo Gil-Hutton derived period of18.61±0.02 hours with an amplitude of0.60±0.03 magnitude (U=2).[14] Tentative measurements were also made by Italian Nicola Cornero and Federico Manzini at the Sozzago Astronomical Station (A12) in May 2010, which gave a period of27.88 hours with an amplitude of0.049 magnitude (U=2−).[15] The same period was also determined by Eric Barbotin in February 2020, though with a higher brightness variation of0.51±0.24.[15]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE), and the JapaneseAkari satellite,Bredichina measures (91.60±6.2), (108.309±0.868) and (111.47±1.30) kilometers in diameter and its surface has analbedo of (0.0730±0.011), (0.052±0.008) and (0.051±0.001), respectively.[7][9][10] TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0730 and a diameter of 91.60 kilometers based on anabsolute magnitude of 8.65,[12] while Fienga et al. report a diameter of[8] and estimate a mass of (9.81 ± 5.40/3.21)×1017 kg.[8] Alternativemean diameter measurements published by the WISE team include (84.50±26.02 km), (93.62±31.89 km), (98.719±1.004 km), (127.664±58.629 km) and (130.149±43.55 km) with corresponding albedos of (0.04±0.03), (0.05±0.09), (0.0628±0.0021), (0.028±0.014) and (0.0347±0.0308).[5][12]
On 10 January 2015, anasteroid occultation ofBredichina gave a best-fit ellipse dimension of (160.5 km × 80.6 km), indicative of a highly elongated shape, with a good quality rating of 3. These timed observations are taken when the asteroid passes in front of a distant star.[5]
