_Tanina.png) Modelled shape ofTanina from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | G. Neujmin |
| Discovery site | Simeiz Obs. |
| Discovery date | 27 March 1916 |
| Designations | |
| (825) Tanina | |
Named after | unknown[2] |
| A916 FH · A904 UB 1916 ZL · 1904 UB | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 114.92yr (41,974 d) |
| Aphelion | 2.3937AU |
| Perihelion | 2.0578 AU |
| 2.2257 AU | |
| Eccentricity | 0.0755 |
| 3.32 yr (1,213 d) | |
| 112.91° | |
| 0° 17m 48.48s / day | |
| Inclination | 3.3998° |
| 101.41° | |
| 111.50° | |
| Physical characteristics | |
| 6.940±0.001 h[10] | |
| 11.4[1][3] | |
825 Tanina (prov. designation:A916 FHor1916 ZL) is a stonybackground asteroid from the region of theFlora family, located in the inner part of theasteroid belt. It was discovered on 27 March 1916, by Russian astronomerGrigory Neujmin at theSimeiz Observatory on Crimea.[1] The elongatedS-type asteroid (SR) has arotation period of 6.9 hours and measures approximately 13 kilometers (8.1 miles) in diameter. Any reference of the asteroid's name to a person is unknown.[2]
Tanina is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method (HCM) byNesvorný to itsproper orbital elements.[5] In the 1995 HCM-analysis byZappalà,[6] however,Tanina is a member of theFlora family (402), a giantasteroid family and the largest family of stony asteroids in the main-belt.[11]: 23 In the HCM-analysis byMilani andKnežević (AstDys), it is also a background asteroid as this analysis does not recognize the Floraasteroid clan.[4] The asteroid orbits the Sun in theinner main-belt at a distance of 2.1–2.4 AU once every 3 years and 4 months (1,213 days;semi-major axis of 2.23 AU). Its orbit has aneccentricity of 0.08 and aninclination of 3° with respect to theecliptic.[3]
Tanina was discovered by Russian astronomerGrigory Neujmin at theSimeiz Observatory on Crimean peninsula on 27 March 1916. One week later, on 3 April 1916, it was independently discovered byMax Wolf at theHeidelberg Observatory in Germany. TheMinor Planet Center only recognizes the first discoverer. The asteroid was first observed asA904 UB at Heidelberg on 17 October 1904, while the body'sobservation arc begins with Wolf's independent discovery observation.[1]
Thisminor planet was named "Tanina". Any reference of its name to a person or occurrence is unknown.[2]
Among the many thousands ofnamed minor planets,Tanina is one of 120 asteroids for whichno official naming citation has been published. All of these asteroids have low numbers, the first one being164 Eva. The last asteroid with a name of unknown meaning is1514 Ricouxa. They were discovered between 1876 and the 1930s, predominantly by astronomersAuguste Charlois,Johann Palisa,Max Wolf andKarl Reinmuth.[12]
In theTholen classification,Tanina is closest to a stonyS-type asteroid, and somewhat similar to an uncommonR-type asteroid,[3] while in theSMASS classification by Bus–Binzel,Tanina is a common S-type asteroid.[13]
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In February 2002, a rotationallightcurve ofTanina was obtained fromphotometric observations by Italian astronomer Andrea Ferrero at the Bigmuskie Observatory (B88). Lightcurve analysis gave a well-definedrotation period of6.940±0.001 hours with a high brightness variation of0.54±0.03magnitude, indicative of an elongated, non-spherical shape (U=3). The result supersedes previous period determinations of6.746±0.001 hours with an amplitude of0.48±0.02 magnitude (U=2) byWiesław Z. Wiśniewski from February 1992,[14] and6.9398±0.0005 hours with an amplitude of0.47±0.05 magnitude (U=2) byAgnieszka Kryszczyńska in May 1999.[15] In 2011, a modeled lightcurve using data from the Uppsala Asteroid Photometric Catalogue (UAPC) and other sources gave a sidereal period6.93981±0.00005 hours, as well as twospin axes at (46.0°, 48.0°) and (231.0°, 60.0°) inecliptic coordinates (λ, β).[16]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, and the JapaneseAkari satellite, and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE),Tanina measures (11.02±0.7), (13.06±0.38) and (13.423±0.150) kilometers in diameter and its surface has analbedo of (0.2624±0.038), (0.278±0.018) and (0.181±0.042), respectively.[7][8][9] TheCollaborative Asteroid Lightcurve Link adopts an albedo of 0.1508 fromPetr Pravec's revised WISE data, and takes a diameter of 14.67 kilometers based on anabsolute magnitude of 11.84.[13] Alternative mean-diameter measurements published by the WISE team include (12.690±0.350 km) and (14.611±0.068 km) with corresponding albedos of (0.275±0.042) and (0.1537±0.0333).[5][13]
