41 Daphne
Daphne and satellite as seen by the W.M. Keck II telescope in 2008
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Discovery[1]
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| Discovered by | H. Goldschmidt |
| Discovery date | May 22, 1856 |
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Designations
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| Named after | Daphne |
| Alternate name(s) | 1949 TG |
| Minor planet category |
Main belt |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 526.144 Gm (3.517 AU) |
| Perihelion | 301.220 Gm (2.014 AU) |
| Semi-major axis | 413.682 Gm (2.765 AU) |
| Eccentricity | 0.272 |
| Orbital period | 1679.618 d (4.60 a) |
| Average orbital speed | 17.58 km/s |
| Mean anomaly | 247.500° |
| Inclination | 15.765° |
| Longitude of ascending node | 178.159° |
| Argument of perihelion | 46.239° |
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Physical characteristics
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| Dimensions | 174.0 km (IRAS)[1] 189 km[2] 213×160 km[3] 239x183x153 km[4] |
| Mass | ~6.8×1018 kg[5] |
| Mean density | ~1.95 g/cm³[4] |
| Rotation period | 5.9 hr[1] |
| Albedo | 0.083[1] |
| Temperature | ~167 K |
| Spectral type | C[1] |
| Absolute magnitude (H) | 7.12[1] |
41 Daphne (
/ˈdæfniː/) is a large 174km main-belt asteroid.[1] This dark-surfaced body is probably composed of primitive carbonaceous chondrites. It was discovered by H. Goldschmidt on May 22, 1856, and named after Daphne, the nymph in Greek mythology who was turned into a laurel tree.
In 1999, Daphne occulted three stars, and on July 2, 1999 produced eleven chords indicating an ellipsoid of 213×160 km.[3] Daphnean lightcurves also suggest that the asteroid is irregular in shape. Daphne was observed by Arecibo radar in April 2008.[6][7]
[edit] Satellite
41 Daphne has at least one satellite, named S/2008 (41) 1.[8] It was identified on March 28, 2008, and has a projected separation of 443 km, an orbital period of approximately 1.1 days,[4] and an estimated diameter of less than 2 km. If these preliminary observations hold up, this binary system has the most extreme size ratio known.[9]
[edit] References
- ^ a b c d e f g "JPL Small-Body Database Browser: 41 Daphne". Jet Propulsion Laboratory. 2011-12-15 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=41. Retrieved 2012-01-23.
- ^ Matter, Alexis; Marco Delbo, Sebastiano Ligori, Nicolas Crouzet, Paolo Tanga (2011). "Determination of physical properties of the asteroid (41) Daphne from interferometric observations in the thermal infrared". Icarus 215 (1): 47–56. arXiv:1108.2616. doi:10.1016/j.icarus.2011.07.012.
- ^ a b "1999 European Asteroidal Occultation Results". euraster.net (a website for Asteroidal Occultation Observers in Europe). 2009/02/09. http://www.euraster.net/results/1999/index.html. Retrieved 2008-12-01. (1999-Jul-02 Chords)
- ^ a b c Conrad, Al; Carry, B.; Drummond, J. D.; Merline, W. J.; Dumas, C.; Owen, W. M.; Chapman, C. R.; Tamblyn, P. M.; Goodrich, R. W.; Campbell, R. D. (2008). "Shape and Size of Asteroid (41) Daphne from AO Imaging". American Astronomical Society 40 (28.12): 438. Bibcode 2008DPS....40.2812C. http://www2.keck.hawaii.edu/inst/people/conrad/research/pub/dps08oct2008v4b.pdf.
- ^ Using the volume of an ellipsoid of 239x183x153km * a density of 1.95 g/cm³ yields a mass (m=d*v) of 6.8E+18 kg
- ^ Mike Nolan (2012 January 18). "Scheduled Arecibo Radar Asteroid Observations". Planetary Radar at Arecibo Observatory. http://www.naic.edu/~pradar/sched.shtml. Retrieved 2012-01-23.
- ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. http://echo.jpl.nasa.gov/asteroids/. Retrieved 2012-01-23.
- ^ "IAUC 8930: COMET P/2006 B7 (ODAS); S/2008 (41) 1; 196P; STEREO SPACECRAFT". IAU Central Bureau for Astronomical Telegrams. 2008 March 31. http://www.cbat.eps.harvard.edu/iauc/08900/08930.html#Item2. Retrieved 2008-03-31.
- ^ "Discovery of an Extreme Mass-Ratio Satellite of (41) Daphne in a Close Orbit". Lunar and Planetary Institute. 2008. http://www.lpi.usra.edu/meetings/acm2008/pdf/8370.pdf. Retrieved 2011-10-13.
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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