Characteristics
Although the largest asteroid apart from the "big four", Interamnia is a very little-studied body. It is easily the largest of the F-type asteroids, but there exist very few details of its internal composition or shape and no lightcurve analysis has yet been done to determing the ecliptic coordinates of Interamnia's poles (and hence its axial tilt). Its apparently high bulk density (though subject to much error) suggests an extremely solid body entirely without internal porosity or traces of water. This also strongly suggests that Interamnia is large enough to have fully withstood all the collisions that have occurred in the asteroid belt since the Solar System was formed.Its very dark surface and relatively large distance form the Sun means Interamnia can never be seen with 10x50 binoculars. At most oppositions its magnitude is around +11.0, which is less than the minimum brightness of Vesta, Ceres or Pallas. Even at a perihelic opposition its magnitude is only +9.9, which is over four magnitudes lower than Vesta.
Its orbit is slightly more eccentric that that of Hygiea (15% versus 12%) but differs from Hygiea's in its much greater inclination and slighly shorter period. Another difference is that Interamnia's perihelion is located on the opposite side from the perihelia of the "big four", so that at Interamnia at perihelion is actually closer to the Sun than Ceres and Pallas are at the same longitude. It is unlikely to collide with Pallas because their nodes are located too far apart, whilst although its nodes are located on the opposite side from those of Ceres, it is generally clear of Ceres when both cross the same orbital plane and a collision is again unlikely.
References
External links
- Orbital simulation from JPL (Java) / Ephemeris
- G. Michalak Determination of asteroid masses Astronomy & Astrophysics, Vol. 374, 703 (2001)
- Animation of Asteroid Interamnia taken on April 1st & 2nd, 2003
- Occultation of GSC 23450183 by (704) Interamnia on 1996 December 17 (dia: 329km; rotation period of 8.70 +/- 0.06 hours)
- Interamnia Occultations Observed before 2003
- Occultation of HIP36189 by (704) Interamnia on 2003 March 23 (dia: 350.4×303.7 km) recorded by Isao Ootsuki (graze) and Hideo Takashima and Fujio Ohbain Japan, analysis by Tsutomu Hayamizu
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Last updated on Saturday July 19, 2008 at 14:56:09 PDT (GMT -0700)
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