| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 8 March 1938 |
| Designations | |
| (1453) Fennia | |
| Pronunciation | /ˈfɛniə/ |
Named after | Finland(Scandinavian country)[2] |
| 1938 ED1 | |
| main-belt · (inner) Hungaria[3] · background[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 79.50 yr (29,037 days) |
| Aphelion | 1.9502AU |
| Perihelion | 1.8438 AU |
| 1.8970 AU | |
| Eccentricity | 0.0281 |
| 2.61yr (954 days) | |
| 72.856° | |
| 0° 22m 37.92s / day | |
| Inclination | 23.675° |
| 7.0898° | |
| 254.79° | |
| Knownsatellites | 1(D: 1.95km;P: 23.55h)[5][6][7] |
| Physical characteristics | |
| Dimensions | 6.36±0.68 km[8] 6.573±0.245 km[9] 6.96±0.39 km(derived)[6] 7.23±0.4 km[10] 7.32 km[3][11] 8.98±0.28 km[12] |
| 4.412±0.002h[7][a] 4.4121±0.0001 h[11][13][b] 4.41224±0.0004 h[14] 4.4124±0.0004 h[15] 4.413±0.002 h[16] 6±1 h[17] 12.23±0.04 h(wrong)[18] | |
| 0.140±0.029[19] 0.186±0.013[12] 0.244±0.031[11] 0.2494±0.032[10] 0.409±0.040[9] 0.50±0.16[8] | |
| Tholen =S[1][3] · K[20] B–V = 0.928[1] B–V =0.890±0.030[11] U–B = 0.532[1] V–R =0.500±0.020[11] V–I =0.980±0.020[11] | |
| 12.38±0.05(R)[14] · 12.50[1][8][9] · 12.69[12] · 12.81±0.06[17] · 12.82±0.24[21] · 12.83[10] · 12.83±0.07[11] · 12.835[3] · 12.835±0.06[22] | |
1453 Fennia, provisional designation1938 ED1, is a stony Hungariaasteroid and synchronousbinary system from the innermost regions of theasteroid belt, approximately 7 kilometers in diameter. Discovered byYrjö Väisälä at theTurku Observatory in 1938,[23] the asteroid was later named after theNordic country ofFinland.[2] The system'sminor-planet moon was discovered in 2007. It has a derived diameter of 1.95 kilometers and is orbiting its primary every 23.55 hours.[6][7]
Fennia was discovered on 8 March 1938, by Finnish astronomerYrjö Väisälä at theIso-Heikkilä Observatory in Turku, southwest Finland.[23] Fifteen days later, it was independently discovered by Soviet astronomerGrigory Neujmin at theSimeiz Observatory on the Crimean peninsula, which also served as a confirmation of the first observation.[1][2] TheMinor Planet Center only recognizes the first discoverer.[23]
Fennia is a bright member of theHungaria asteroids,[23] adynamical group that forms the innermost dense concentration of asteroids in theSolar System. The group includes all members of largeasteroid family of the same name (003). When applying theHierarchical Clustering Method to itsproper orbital elements,Fennia is a non-family asteroid of the main belt'sbackground population.[4]
It orbits the Sun in theinner main-belt at a distance of 1.8–2.0 AU once every 2 years and 7 months (954 days). Its orbit has aneccentricity of 0.03 and aninclination of 24° with respect to theecliptic.[1] The body'sobservation arc begins at the discovering observatory (or at Simeiz Observatory), 15 days after its official discovery observation at Turku.[23]
In theTholen classification,Fennia is a common, stonyS-type asteroid. It has also been characterized as a rareK-type asteroid.[20]
Since 1991, a large number of rotationallightcurves ofFennia have been obtained from photometric observations. Lightcurve analysis gave a consolidatedrotation period of 4.4121 hours with a brightness amplitude between 0.10 and 0.20magnitude (U=0/3/3/3/3/3-).[7][13][11][14][15][16][17][18][b][a] Due to its relatively low brightness amplitude,Fennia is likelyspheroidal in shape.
In 2007, thesephotometric lightcurve observations revealed thatFennia is a synchronousbinary asteroid, orbited by aminor-planet moon.[5][6] The moon has an orbital period of 22.99 hours,[11][13][b] later revised to 23.55 hours.[7][a] It is at least a quarter the size ofFennia itself – a secondary-to-primary mean-diameter ratio of0.28±0.02) – which translates into a diameter of1.95±0.18 kilometers based on current estimates.[6]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Fennia measures between 6.36 and 8.98 kilometers in diameter and its surface has analbedo between 0.140 and 0.50.[8][9][10][11][12][19]
The Johnston's archive derives a diameter of 6.96 kilometers,[6] whileCollaborative Asteroid Lightcurve Link adopts an albedo of 0.244 and a diameter of 7.32 kilometers using anabsolute magnitude of 12.835, taken from the revised WISE-results.[3][11]
Thisminor planet was named in honor of theNordic country ofFinland. "Fennia" is theLatin word for Finland. The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 130).[2]
