42 Isis

42 Isis
A three-dimensional model of 42 Isis based on its light curve on the top and an image of 42 Isis on the bottom.
Discovery
Discovered byNorman Robert Pogson
Discovery date23 May 1856
Designations
Pronunciation/ˈaɪsɪs/
Named after
Isis Pogson
Main belt
AdjectivesIsidian /aɪˈsɪdiən/
Orbital characteristics
Epoch 31 December 2006 (JD 2454100.5)
Aphelion446.706 million km (2.986 AU)
Perihelion283.890 million km (1.898 AU)
365.298 million km (2.442 AU)
Eccentricity0.223
1393.737 d (3.82 a)
121.874°
Inclination8.530°
84.398°
2024-Oct-17
236.626°
Physical characteristics
102±4 km
Mass(1.58±0.52)×1018 kg (composite estimate)
(1.47±0.16)×1018 kg
Mean density
2.8±1.0 g/cm3
2.64±0.43 g/cm3
13.58364 h
108° ± 1°
47° ± 3°
0.171 (geometric)
S
9.18 to 13.50
7.53

42 Isis is a large main-belt asteroid, measuring 100.2 km in diameter with a stony (S-type) composition. It was discovered by English astronomer N.R. Pogson on 23 May 1856 at Oxford, and was his first asteroid discovery. The asteroid's name was chosen by Manuel John Johnson, director of the Radcliffe Observatory in Oxford. Although Isis is the name of an Egyptian goddess, the name was chosen in homage to Pogson's astronomer daughter, (Elizabeth) Isis Pogson. In addition, the Isis is the stretch of the River Thames that runs through Oxford.

This asteroid is orbiting the Sun with a period of 3.82 years. The light curve inversion technique, when applied to photometric observations of this asteroid, show multiple local irregularities. The overall shape displays little elongation, with a ratio between the major and minor axes equal to 1.1. The measured rotation period for this model is 13.6 hours. The spectrum of 42 Isis reveals the strong presence of the mineral olivine, a relative rarity in the asteroid belt.

Notes

  1. ↑ Calculated from its standard gravitational parameter GM = 0.098±0.011 km3/s2.

References

  1. ↑ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ↑ E.g. Adriano La Regina ed. (2004) Archaeological Guide to Rome, p. 66. Cf. the pronunciation of "isidium". Oxford English Dictionary (online ed.). Oxford University Press. (Subscription or participating institution membership required.).
  3. 1 2 3 4 5 Viikinkoski, M.; Hanuš, J.; Kaasalainen, M.; Marchis, F.; Ďurech, J. (November 2017). "Adaptive optics and lightcurve data of asteroids: twenty shape models and information content analysis". Astronomy & Astrophysics. 607: A117. arXiv:1708.05191. Bibcode:2017A&A...607A.117V. doi:10.1051/0004-6361/201731456. ISSN 0004-6361. S2CID 67813915.
  4. ↑ Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73 (1): 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009, S2CID 119226456. See Table 1.
  5. 1 2 Fuentes-Muñoz, Oscar; Farnocchia, Davide; Giorgini, Jon D.; Park, Ryan S. (1 December 2025). "Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release". The Astronomical Journal. 170 (6): 353. Bibcode:2025AJ....170..353F. doi:10.3847/1538-3881/ae0cc9. ISSN 0004-6256. S2CID 283347135.
  6. ↑ Asteroid Data Sets Archived 17 December 2009 at the Wayback Machine
  7. ↑ "AstDys (42) Isis Ephemerides". Department of Mathematics, University of Pisa, Italy. Archived from the original on 27 March 2012. Retrieved 27 June 2010.
  8. ↑ Bruck, Mary (2009), Women in Early British and Irish Astronomy, Springer, p. 157, ISBN 978-90-481-2472-5.
  9. ↑ Lutz D. Schmadel (2011). Dictionary of Minor Planet Names (Addendum to Fifth Edition: 2006–2008 ed.). Springer. ISBN 978-3-642-01966-1.
  10. ↑ Torppa, Johanna; et al. (August 2003), "Shapes and rotational properties of thirty asteroids from photometric data", Icarus, 164 (2): 346–383, Bibcode:2003Icar..164..346T, doi:10.1016/S0019-1035(03)00146-5, S2CID 119609765.
  11. ↑ Burbine, T. H.; et al. (July 2000), "The Nature of Olivine Asteroids", Meteoritics & Planetary Science, vol. 35, pp. A35, Bibcode:2000M&PSA..35R..35B, doi:10.1111/j.1945-5100.2000.tb01796.x.