IJAA  Vol.4 No.1 , March 2014
A 3-D Shape Model of (704) Interamnia from Its Occultations and Lightcurves
ABSTRACT

A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 December 17 observed from 13 sites in the USA. An elliptical cross section of (344.6 ± 9.6 km) × (306.2 ± 9.1 km), for position angle P = 73.4 ± 12.5° was fitted. The lightcurve around the occultation shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just before the minimum. The second stellar occultation was the occultation of HIP 036189 on 2003 March 23 observed from 39 sites in Japan and Hawaii. An elliptical cross section of (349.8 ± 0.9 km) × (303.7 ± 1.7 km), for position angle P = 86.0 ± 1.1° was fitted. A companion of 8.5 mag. of the occulted star was discovered whose separation is 12 ± 2 mas (milli-arcseconds), P = 148 ± 11°. A combined analysis of rotational lightcurves and occultation chords can return more information than can be obtained with either technique alone. From follow-up photometric observations of the asteroid between 2003 and 2011, its rotation period is determined to be 8.728967167 ± 0.00000007 hours, which is accurate enough to fix the rotation phases at other occultation events. The derived north pole is λ2000 = 259 ± 8°, β2000 = -50 ± 5° (retrograde rotation); the lengths of the three principal axes are 2a = 361.8 ± 2.8 km, 2b = 324.4 ± 5.0 km, 2c = 297.3 ± 3.5 km, and the mean diameter is D = 326.8 ± 3.0 km. Supposing the mass of Interamnia as (3.5 ± 0.9) × 10-11 solar masses, the density is then ρ = 3.8 ± 1.0 g·cm-3.


Cite this paper
Satō, I. , Buie, M. , Maley, P. , Hamanowa, H. , Tsuchikawa, A. and Dunham, D. (2014) A 3-D Shape Model of (704) Interamnia from Its Occultations and Lightcurves. International Journal of Astronomy and Astrophysics, 4, 91-118. doi: 10.4236/ijaa.2014.41010.
References
[1]   Taylor, G.E. (1952) Occultations of Stars by Asteroids. Handbook of the British Astronomical Association for 1953, The University of Chicago, Chicago.

[2]   Taylor, G.E. (1962) Diameters of Minor Planets. Notes from Observatories, 926, 17.

[3]   Sinvhal, S.D., Sanwal, N.B. and Pande, M.C. (1962) Observation of the Occultation of BD-5°5886 by Pallas. Notes from Observatories, 926, 16-17.

[4]   Millis, R.L., Wasserman, L.H., Bowell, E., Franz, O.G., Klemola, A. and Dunham, D.W. (1984) The Diameter of 375 Ursula from Its Occultation of AG +39°303. Astronomical Journal, 89, 592-596. http://dx.doi.org/10.1086/113553

[5]   Satō, I., Sarounova, L. and Fukushima, H. (2000) Size and Shape of Trojan Asteroid Diomedes from Its Occultation and Photometry. Icarus, 145, 25-32. http://dx.doi.org/10.1006/icar.1999.6316

[6]   Tedesco, E.F., Noah, P.V., Noah, M. and Price, S.D. (2002) The Supplemental IRAS Minor Planet Survey. Astronomical Journal, 123, 1056-1085. http://dx.doi.org/10.1086/338320

[7]   Tholen, D.J. (1984) Asteroid Taxonomy from Cluster Analysis of Photometry. Ph.D. Thesis, University of Arizona, Tucson.

[8]   Hiroi, T., Peters, C.M. and Zolensky, M.E. (1983) Comprison of Reflectance Spectra of C Asteroids and Unique C Chondrites Y86720, Y82162, and B7904. Proceedings of 24th Lunar and Planetary Science Conference, Part 2 G-M, 659-660.

[9]   De Angelis, G. (1995) Asteroid Spin, Pole and Shape Determinations. Planetary and Space Science, 43, 649-682. http://dx.doi.org/10.1016/0032-0633(94)00151-G

[10]   Michalowski, T., Velichko, F.P., Di Martino, M., Krugly, Y.N., Kalashnikov, V.G., Shevchenko, V.G., Birch, P.V., Sears, W.D., Denchev, P. and Kwiatkowski, T. (1995) Models of Four Asteroids: 17 Thetis, 52 Europa, 532 Herculina, 704 Interamnia. Icarus, 118, 292-301.

[11]   Buie, M.W., Wasserman, L.H., Millis, R.L., White, N.M., Nye, R., Dunham, E.W., Bosh, A.S., Stone, R., Hubbard, W.B., Hill, R., Dunham, D.W., Fried, R., Kilinglesmith, D., Sanford, J., Schwaar, P., Maley, P., Owen, W., Benner, L., Rivken, A.S., Spitale, J., Marcialis, R.L. and Lebofsky, L.A. (1997) Occultation of GSC 23450183 by (704) Interamnia on 1996 December 17. Bulletin of the American Astronomical Society Abstract, No. 29, 973.

[12]   Wasserman, L.H. (1997) Occultations and Asteroids: The Rest of the Story. Lowell Observers, 35, 2-4.

[13]   Yang, X.Y., Zhang, Y.Y. and Li, X.Q. (1965) Photometric Observations of Variable Asteroids III. Acta Astronomica Sinica, 13, 66-74.

[14]   Tempesti, P. (1975) Photoelectric Observation of the Minor Planet 704 Interamnia during Its 1969 Oppositions. Memorie della Societa Astronomica Italiana, 46, 397-405.

[15]   Lustig, G. and Hahn, G. (1976) Photoelektrische Lichtkuven der Planetoiden 2 Pallas und 704 Interamnia. Acta Physica Austriaca, 44, 199-205.

[16]   Shevchenko, V.G., Chiornija, V.G., Kruglya, Y.N., Lupishkoa, D.F., Mohameda, R.A. and Velichkoa, F.P. (1992) Photometry of Seventeen Asteroids. Icarus, 100, 295-306. http://dx.doi.org/10.1016/0019-1035(92)90102-D

[17]   Satō, I., Soma, M. and Hirose, T. (1993) The Occultation of Gamma Geminorum by the Asteroid 381 Myrrha. Astronomical Journal, 105, 1553-1561. http://dx.doi.org/10.1086/116535

[18]   Michalak, G. (2001) Determination of Asteroid Masses: II. (6) Hebe, (10) Hygiea, (15) Eunomia, (52) Europa, (88) Thisbe, (444) Gyptis, (511) Davida, and (704) Interamnia. Astronomy & Astrophysics, 374, 703-711. http://dx.doi.org/10.1051/0004-6361:20010731

[19]   Hilton, J.L. (2002) Asteroid Masses and Densities, Asteroids III. University of Arizona Press, Tucson, 103-112.

[20]   Michalowski, V. (1993) Poles, Shapes, Senses of Rotation, and Siderial Period of Asteroids. Icarus, 106, 563-572.

[21]   Harris, A.W. (1998) A Thermal Model for Near-Earth Asteroids. Icarus, 131, 291-301.
http://dx.doi.org/10.1006/icar.1997.5865

[22]   Stamm, J. (1984) Occultation Newsletter, 3, 185.

[23]   Stamm, J. (1991) Occultation Newsletter, 5, 93.

[24]   Satō, I. (1996) Asteroid Occultation Observations from Japan. Doctoral Thesis at the Graduated University for Advanced Studies, 163.

[25]   Dunham, D.W., et al. (2013) http://sbn.psi.edu/pds/asteroid/EAR_A_3_RDR_OCCULTATIONS_V11_0/

 
 
Top