| Discovery[1] | |
|---|---|
| Discovered by | J. H. Metcalf |
| Discovery site | Taunton Obs. |
| Discovery date | 4 February 1908 |
| Designations | |
| (1345) Potomac | |
Named after | Potomac River[2] (U.S. Mid-Atlanticriver) |
| 1908 CG · 1932 CF 1932 EA · 1932 FB 1971 DE2 | |
| main-belt · (outer)[3] Hilda[1][4] · background[5] | |
| Orbital characteristics[3] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 111.20yr (40,617 d) |
| Aphelion | 4.7100AU |
| Perihelion | 3.2611 AU |
| 3.9856 AU | |
| Eccentricity | 0.1818 |
| 7.96 yr (2,906 d) | |
| 31.380° | |
| 0° 7m 26.04s / day | |
| Inclination | 11.402° |
| 137.43° | |
| 333.12° | |
| Jupiter MOID | 0.4592 AU |
| TJupiter | 2.9930 |
| Physical characteristics | |
| 71.82±3.0 km[6] 72.975±0.463 km[7] 76.72±2.34 km[8] | |
| 11.41±0.01 h[9] | |
| 0.039±0.003[8] 0.043±0.008[7] 0.0439±0.004[6] | |
| Tholen =X[3] · C[4][10] B–V = 0.719[3] U–B = 0.286[3] | |
| 9.73[3][4][6][8] 9.9[1] | |
1345 Potomac (/pəˈtoʊmək/ ⓘ), provisional designation1908 CG, is a darkHildianasteroid from the outermost regions of theasteroid belt, approximately 73 kilometers (45 mi) in diameter. It was discovered on 4 February 1908, by American astronomerJoel Metcalf at the Taunton Observatory (803) in Massachusetts, United States.[1] TheX-type asteroid has arotation period of 11.4 hours.[4] It was named for thePotomac River on which Washington, D.C. is located.[2]
Potomac is member of the dynamicalHilda group, which stays in 3:2orbital resonance with Jupiter.[1][4] It is, however, not a member of theHilda family but a non-family asteroid of the main belt'sbackground population when applying theHierarchical Clustering Method to itsproper orbital elements.[5]
It orbits the Sun in theoutermost asteroid belt at a distance of 3.3–4.7 AU once every 7 years and 12 months (2,910 days;semi-major axis of 3.99 AU). Its orbit has aneccentricity of 0.18 and aninclination of 11° with respect to theecliptic.[3] The body'sobservation arc begins at theUnited States Naval Observatory, three weeks after its official discovery observation at Taunton.[1]
Thisminor planet was named after the U.S.Potomac River in the Mid-Atlantic region of the United States, on which Washington, D.C. is located. The river flows from West Virginia into theChesapeake Bay and forms the southern boundary ofMaryland. The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 122).[2]
In theTholen classification,Potomac is anX-type asteroid.[3] It has also been characterized as a carbonaceousC-type asteroid byPan-STARRS photometric survey.[10]
Two rotationallightcurves ofPotomac was obtained from photometric observations. Lightcurve analysis gave arotation period of 11.40 and 11.41 hours with a brightness amplitude of 0.22 and 0.24magnitude, respectively (U=2/3).[11][9]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Potomac measures between 71.82 and 76.72 kilometers in diameter and its surface has analbedo between 0.039 and 0.0439.[6][7][8]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0439 and a diameter of 71.82 kilometers based on anabsolute magnitude of 9.73.[4]
