52 Europa
52 Europa is the sixth largest asteroid in the asteroid belt, having a diameter of over 300 km, though it is not correspondingly massive. It is not round but is shaped like an ellipsoid of approximately 380×330×250 km.[4] It was discovered on 4 February 1858, by Hermann Goldschmidt from his balcony in Paris. It is named after Europa, one of Zeus's conquests in Greek mythology, a name it shares with Jupiter's moon Europa.
Physical characteristics
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/52_Europa_Lightcurve_Inversion.png/220px-52_Europa_Lightcurve_Inversion.png)
Europa is approximately the sixth largest asteroid by volume. Most likely it has a density of around 1.5 g/cm3, typical of C-type asteroids.[4] In 2007, James Baer and Steven R. Chesley estimated Europa to have a mass of (1.9±0.4)×1019 kg.[7] A more recent estimate by Baer suggests it has a mass of 3.27×1019 kg.[8]
Europa is a very dark carbonaceous C-type, and is the second largest of this group. Spectroscopic studies have found evidence of olivines and pyroxenes on the surface,[9] and there is some indication that there may be compositional differences between different regions.[10] It orbits close to the Hygiea asteroid family, but is not a member.
Lightcurve data for Europa have been particularly tricky to interpret, so much so that for a long time its period of rotation was in dispute (ranging from 5+1⁄2 hours to 11 hours), despite numerous observations.[11] It has now been determined that Europa is a prograde rotator, but the exact direction in which its pole points remains ambiguous. The most detailed analysis indicates that it points either towards about ecliptic coordinates (β, λ) = (70°, 55°) or (40°, 255°) with a 10° uncertainty.[12] This gives an axial tilt of about 14° or 54°, respectively.
In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.[13]
Observations
It has been found that the reputed cataclysmic variable star CV Aquarii, discovered in 1934, was actually a misidentification of 52 Europa.[14]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/20/Animation_of_52_Europa_orbit_2000-2020.gif/220px-Animation_of_52_Europa_orbit_2000-2020.gif)
Sun Earth · Mars · Jupiter · 52 Europa
Notes
- ^ (11.39 ± 0.79) × 10−12 M☉
References
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ a b c d e JPL data Retrieved 2021-09-29
- ^ a b c d P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
- ^ a b c d e Merline, W.J. (2013). "The Resolved Asteroid Program – Size, shape, and pole of (52) Europa". Icarus. 225 (1): 794–805. arXiv:1301.5101. Bibcode:2013Icar..225..794M. doi:10.1016/j.icarus.2013.01.010. S2CID 119286695.
- ^ James Baer, Steven Chesley & Robert Matson (2011) "Astrometric masses of 26 asteroids and observations on asteroid porosity." The Astronomical Journal, Volume 141, Number 5
- ^ Dotto, E.; Müller, T. G.; Barucci, M. A.; Encrenaz, Th.; Knacke, R. F.; Lellouch, E.; Doressoundiram, A.; Crovisier, J.; Brucato, J. R.; Colangeli, L.; Mennella, V. (2000). "ISO results on bright Main Belt asteroids: PHT-S observations". Astronomy and Astrophysics. 358: 1134. Bibcode:2000A&A...358.1133D. Retrieved 23 February 2024.
- ^ Baer, James; Steven R. Chesley (2007). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris". Celestial Mechanics and Dynamical Astronomy. 100 (2008). Springer Science+Business Media B.V. 2007: 27–42. Bibcode:2008CeMDA.100...27B. doi:10.1007/s10569-007-9103-8.
- ^ Baer, James (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 2 July 2013. Retrieved 29 November 2008.
- ^ Dotto, E. (2000). "ISO results on bright Main Belt asteroids: PHT–S observations" (PDF). Astronomy & Astrophysics. 358: 1133. Bibcode:2000A&A...358.1133D. Archived from the original (PDF) on 14 May 2005. Retrieved 29 April 2006.
- ^ Sawyer, Scott Raleigh (1 January 1991). "A High-Resolution CCD Spectroscopic Survey of Low-Albedo Main Belt Asteroids". PhD Thesis. Bibcode:1991PhDT.......105S – via NASA ADS.
- ^ Zappalà, V.; di Martino, M.; Cacciatori, S (1983). "On the ambiguity of rotational periods of asteroids: The peculiar case of 52 Europa". Icarus. 56 (2): 319–324. Bibcode:1983Icar...56..319Z. doi:10.1016/0019-1035(83)90041-6.
- ^ Michałowski, T (2004). "Photometry and models of selected main belt asteroids I. 52 Europa, 115 Thyra, and 382 Dodona" (PDF). Astronomy & Astrophysics. 416: 353–366. Bibcode:2004A&A...416..353M. doi:10.1051/0004-6361:20031706.
- ^ Gradie, J.; Flynn, L. (March 1988), "A Search for Satellites and Dust Belts Around Asteroids: Negative Results", Abstracts of the Lunar and Planetary Science Conference, vol. 19, pp. 405–406, Bibcode:1988LPI....19..405G.
- ^ "CV Aquarii identified with (52) Europa" (PDF). Archived from the original (PDF) on 14 February 2006. Retrieved 29 April 2006.
Bibliography
- PDS lightcurve data
- Sawyer, S. R. (1991). A High-Resolution CCD Spectroscopic Survey of Low-Albedo Main Belt Asteroids PhD thesis (Thesis). The University of Texas. Bibcode:1991PhDT.......105S.
- Schmeer, P., and M. L. Hazen, CV Aquarii identified with (52) Europa, Journal of the American Association of Variable Star Observers, Vol. 28, p. 103 (2000).
External links
- "Elements and Ephemeris for (52) Europa". Archived from the original on 4 March 2016. Retrieved 26 May 2011.
- shape model deduced from lightcurve
- 52 Europa at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
- 52 Europa at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
- v
- t
- e
- 51 Nemausa
- 52 Europa
- 53 Kalypso