4391 Balodis
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| Discovery[1] | |
|---|---|
| Discovered by | N. Chernykh |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 21 August 1977 |
| Designations | |
| (4391) Balodis | |
Named after | Jānis Balodis (Latvian cosmic geodesist)[2] |
| 1977 QW2 · 1977 RR2 1980 GZ | |
| main-belt · Erigone[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 39.70 yr (14,499 days) |
| Aphelion | 2.8989 AU |
| Perihelion | 1.8794 AU |
| 2.3892 AU | |
| Eccentricity | 0.2134 |
| 3.69 yr (1,349 days) | |
| 330.57° | |
| 0° 16m 0.84s / day | |
| Inclination | 5.3519° |
| 190.30° | |
| 108.27° | |
| Physical characteristics | |
| Dimensions | 3.36±0.17 km[4] 8.05 km (calculated)[3] |
| 3.448±0.001 h[5] | |
| 0.057 (assumed)[3] 0.393±0.072[4] | |
| C[3] | |
| 14.2[1][3] · 14.00[4] · 14.37±0.36[6] | |
4391 Balodis, provisional designation 1977 QW2, is a dark and rare Erigone asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered by Soviet–Russian astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula, on 21 August 1977.[7] The asteroid was named for Latvian geodesist Jānis Balodis.[2]
Balodis orbits the Sun in the inner main-belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,349 days). Its orbit has an eccentricity of 0.21 and an inclination of 5° with respect to the ecliptic.[1] Based on its orbital elements, the Collaborative Asteroid Lightcurve Link (CALL) classifies the asteroid as a member of the Erigone family, which is named after its largest member and namesake, 163 Erigone, also a dark body of carbonaceous composition.[3]
Physical characteristics
Diameter and albedo
According to observations by NASA's space-based Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Balodis measures 3.4 kilometers in diameter, and its surface has an exceptionally high albedo of 0.40.[4] However, the CALL assumes a standard albedo for a C-type asteroid of 0.057 and calculates a diameter of 8.4 kilometers with an absolute magnitude of 14.2, as the lower the albedo (reflectivity) the larger the body's diameter.[3]
Rotation period
In July 2010, a rotational lightcurve of Balodis was obtained by Italian astronomer Albino Carbognani from photometric observations taken at the Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) in Italy. It showed rotation period of 3.448±0.001 hours with a brightness amplitude of 0.29 in magnitude (U=2).[5]
