| Discovery[1] | |
|---|---|
| Discovered by | C. Shoemaker E. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 8 October 1988 |
| Designations | |
| (11277) Ballard | |
Named after | Robert Ballard[1] (Americanoceanographer) |
| 1988 TW2 · 1995 MG | |
| main-belt[1][2] · (inner) Phocaea[3][4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 28.73yr (10,493 d) |
| Aphelion | 2.9757AU |
| Perihelion | 1.8295 AU |
| 2.4026 AU | |
| Eccentricity | 0.2385 |
| 3.72 yr (1,360 d) | |
| 22.337° | |
| 0° 15m 52.92s / day | |
| Inclination | 22.787° |
| 254.59° | |
| 43.574° | |
| Physical characteristics | |
| 6.298±0.075 km[3][5][6] | |
| >10 h[7] | |
| 0.222[5][6] | |
| S(assumed)[4] | |
| 13.00[5][8][9] 13.10[1][2][4][10] 13.53[11] | |
11277 Ballard (provisional designation1988 TW2) is aPhocaea asteroid from the inner regions of theasteroid belt, approximately 6.3 kilometers (3.9 miles) in diameter. It was discovered on 8 October 1988, by American astronomer coupleCarolyn andEugene Shoemaker at thePalomar Observatory in California.[1] The assumedS-type asteroid has arotation period of at least 10 hours.[4] It was named for American marine scientistRobert Ballard.[1]
Ballard is a member of thePhocaea family (701).[3] It orbits the Sun in theinner asteroid belt at a distance of 1.83–2.98 AU once every 3 years and 9 months (1,360 days;semi-major axis of 2.4 AU). Its orbit has aneccentricity of 0.24 and aninclination of 23° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery taken atPalomar in September 1988, just four weeks prior to its official discovery observation.[1] Ballard is not aMars-crosser, since itsaphelion is larger than 1.67 AU.[2]
Thisminor planet was named after American marine scientistRobert Ballard (born 1942), a professor ofoceanography and director of theDeep Submergence Laboratory, who is known for the discovery of theRMSTitanic and theGerman battleship Bismarck. The official naming citation was published by theMinor Planet Center on 26 May 2002 (M.P.C. 45748).[12]
Ballard is an assumed, stonyS-type asteroid,[4] in line with the Phocaea family's overallspectral type.[13]: 23
In July 2010, a rotationallightcurve of Ballard was obtained from two nights ofphotometric observations in the R-band by Italian astronomerAlbino Carbognani at the OAVdA Observatory (B04) in Italy. Lightcurve analysis gave a tentativerotation period of at least 10 hours with a brightness amplitude of more than 0.25magnitude (U=2-).[7]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, Ballard measures between 5.65 and 6.445 kilometers in diameter and its surface has analbedo between 0.19 and 0.289.[3][4][5][6][8][9][10][11]
TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.23 – derived from the family's largest member,25 Phocaea – and calculates a diameter of 6.65 kilometers based on anabsolute magnitude of 13.1.[4]
