41 Daphne

41 Daphne
VLT-SPHERE image of Daphne
Discovery
Discovered byH. Goldschmidt
Discovery date22 May 1856
Designations
Pronunciation/ˈdæfni/
Named after
Daphne
1949 TG
Main belt
AdjectivesDaphnean /ˈdæfniən/
Orbital characteristics
Epoch 31 December 2006 (JD 2454100.5)
Aphelion3.517 AU (526.144 million km)
Perihelion2.014 AU (301.220 million km)
2.765 AU (413.682 million km)
Eccentricity0.272
4.60 a (1,679.618 d)
247.500°
Inclination15.765°
178.159°
46.239°
Known satellitesPeneius /pɛˈniːəs/
(S/2008 (41) 1)
Physical characteristics
Dimensions213×160 km
239x183x153 km
187±13 km
205.495±1.881
189 km
Flattening0.35
Mass(6.1±0.9)×1018 kg
≈ 6.8×1018 kg
Mean density
1.78±0.45 g/cm3
≈ 1.95 g/cm3
5.988 hr
0.052 (calculated)
0.059±0.007
C
7.61

41 Daphne is a large asteroid from the asteroid belt. It is a dark-surfaced body 174 km in diameter and is probably composed of primitive carbonaceous chondrites. The spectra of the asteroid displays evidence of aqueous alteration. It was discovered by H. Goldschmidt on 22 May 1856, and named after Daphne, the nymph in Greek mythology who was turned into a laurel tree. Incorrect orbital calculations initially resulted in 56 Melete being mistaken for a second sighting of Daphne. Daphne was not sighted again until 31 August 1862.

The orbit of 41 Daphne places it in a 9:22 mean motion resonance with the planet Mars. The computed Lyapunov time for this asteroid is 14,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.

In 1999, Daphne occulted three stars, and on 2 July 1999, produced eleven chords indicating an ellipsoid of 213×160 km. Daphnean lightcurves also suggest that the asteroid is irregular in shape. Daphne was observed by Arecibo radar in April 2008. Based upon radar data, the near surface solid density of the asteroid is 2.4+0.7
−0.5 g cm−3.

Satellite

Peneius
Daphne and Peneius as seen by the W.M. Keck II telescope in 2008
Designations
Pronunciation/pɛˈniːəs/
S/2008 (41) 1
AdjectivesPeneian /pɛˈniːən/
Orbital characteristics
Inclination°

41 Daphne has at least one satellite, named Peneius (provisionally S/2008 (41) 1). It was identified on 28 March 2008, and has a projected separation of 443 km, an orbital period of approximately 1.1 days, 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. In Greek myth, Pēneios is the god of the river of that name, and father of Daphne.

Notes

  1. ↑ Flattening derived from the maximum aspect ratio (c/a): , where (c/a) = 0.65±0.08.
  2. ↑ Using the formula for volume of an ellipsoid (m = v × d), 239 × 183 × 153 km times a density of 1.95 g/cm3 yields a mass of 6.8×1018 kg.

References

  1. 1 2 3 4 5 6 7 8 Yeomans, Donald K., "41 Daphne", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 7 April 2013.
  2. ↑ "Daphne". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 31 October 2020.
  3. ↑ "Daphne". Oxford English Dictionary (online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  4. 1 2 "1999 European Asteroidal Occultation Results". euraster.net (a website for Asteroidal Occultation Observers in Europe). 9 February 2009. Retrieved 1 December 2008. (1999-Jul-02 Chords)
  5. 1 2 3 Conrad, Al; Carry, B.; Drummond, J. D.; Merline, W. J.; Dumas, C.; Owen, W. M.; et al. (2008). "Shape and Size of Asteroid (41) Daphne from AO Imaging" (PDF). American Astronomical Society. 40 (28.12): 438. Bibcode:2008DPS....40.2812C. Archived from the original (PDF) on 18 September 2009.
  6. 1 2 3 4 5 P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
  7. ↑ 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. Bibcode:2011Icar..215...47M. doi:10.1016/j.icarus.2011.07.012.
  8. ↑ Fornasier, S.; et al. (February 1999), "Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites", Astronomy and Astrophysics Supplement, 135: 65−73, Bibcode:1999A&AS..135...65F, doi:10.1051/aas:1999161.
  9. ↑ Appletons' annual cyclopaedia and register of important events of the year: 1862. New York: D. Appleton & Company. 1863. p. 173.
  10. ↑ Šidlichovský, M. (1999), Svoren, J.; Pittich, E. M.; Rickman, H. (eds.), "Resonances and chaos in the asteroid belt", Evolution and source regions of asteroids and comets : proceedings of the 173rd colloquium of the International Astronomical Union, held in Tatranska Lomnica, Slovak Republic, August 24–28, 1998, pp. 297–308, Bibcode:1999esra.conf..297S.
  11. ↑ Mike Nolan (18 January 2012). "Scheduled Arecibo Radar Asteroid Observations". Planetary Radar at Arecibo Observatory. Retrieved 23 January 2012.
  12. ↑ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 23 January 2012.
  13. ↑ Magri, C.; et al. (December 2001), "Radar constraints on asteroid regolith compositions using 433 Eros as ground truth", Meteoritics & Planetary Science, 36 (12): 1697–1709, Bibcode:2001M&PS...36.1697M, doi:10.1111/j.1945-5100.2001.tb01857.x.
  14. ↑ "MPEC 2019-E58 : SATELLITE OF (41) Daphne". IAU Minor Planet Center. 6 March 2019. Retrieved 7 March 2019.
  15. ↑ "IAUC 8930: COMET P/2006 B7 (ODAS); S/2008 (41) 1; 196P; STEREO SPACECRAFT". IAU Central Bureau for Astronomical Telegrams. 31 March 2008. Retrieved 31 March 2008.
  16. ↑ "Discovery of an Extreme Mass-Ratio Satellite of (41) Daphne in a Close Orbit" (PDF). Lunar and Planetary Institute. 2008. Retrieved 13 October 2011.