(87) Sylvia, Romulus, and Remus
compiled by Wm. Robert Johnston
last updated 1 September 2005
Orbital elements and other data (Assumed or derived values in parenthesis, my estimates in italics and parenthesis. Source identifications in brackets, see this link for sources):
orbital data, primary (osculating elements) [JPL]:
|
semimajor axis a: |
3.4902552804356 AU
| |
orbital period P: |
6.5207 y (=2381.7 d)
| |
eccentricity e: |
0.0796620231198216
| |
perihelion distance q: |
3.21221448359146 AU
| |
aphelion distance Q: |
3.76829608 AU
| |
inclination i: |
10.8560643032686°
| |
argument of perihelion omega: |
266.047724837443°
| |
ascending node OMEGA: |
73.330182435556°
| |
mean anomaly M: |
53.35606655137°
| |
perihelion passage TP: |
2004-08-30.0074652
| |
Epoch: |
18 AUG 2005
| |
data arc: |
1894-2005 (920 obs.)
|
orbital data, Romulus:
|
semimajor axis a: |
1356 ± 5 km [M05a]
| |
semimajor axis/primary radius a/Rp: |
9.5 [M05a]
| |
orbital period P: |
3.6496 ± 0.0007 d [M05a]
| |
eccentricity e: |
0.001 ± 0.001 [M05a]
| |
inclination i: |
1.7° ± 1.0° [M05a]
|
orbital data, Remus:
|
semimajor axis a: |
706 ± 5 km [M05a]
| |
semimajor axis/primary radius a/Rp: |
4.9 [M05a]
| |
orbital period P: |
1.3788 ± 0.0007 d [M05a]
| |
eccentricity e: |
0.016 ± 0.011 [M05a]
| |
inclination i: |
2.0° ± 1.0° [M05a]
| |
other data, primary:
|
mean diameter: |
286 km [M05a]
| |
triaxial dimensions: |
384 x 264 x 232 km [M05a]
| |
triaxial ratios a/b, b/c: |
1.46, 1.14 [M05a]
| |
absolute magnitude H: |
6.94 [JPL]
| |
rotation period: |
0.2159853 d (=5.18365 h) [SBb]
| |
amplitude delta M: |
0.30-0.62 [MPb]
| |
color index U-B: |
0.251 ± 0.026 [SBa]
| |
color index B-V: |
0.71 [JPL]
| |
color index V-R: |
?
| |
color index R-I: |
?
| |
slope parameter G: |
(0.15) [a]
| |
geometric albedo: |
0.0435 ± 0.005 [IR]
| |
mass: |
(1.478±0.006)x1019 kg [M05a]
| |
density: |
1.2 ± 0.1 g/cm3 [M05a]
| |
type: |
P [SBd]; X [JPL]
|
other data, Romulus:
|
diameter: |
18 ± 4 km [M05a]
| |
diameter ratio Ds/Dp: |
(0.06)
| |
component magnitude difference: |
6.24 ± 0.2 [I7590]
3.8 [M05a]
| |
rotation period: |
?
|
other data, Remus:
|
diameter: |
7 ± 2 km [M05a]
| |
diameter ratio Ds/Dp: |
(0.02)
| |
component magnitude difference: |
4.2 [M05a]
| |
rotation period: |
?
|
|
--(87) Sylvia--discovery and notes:
Primary discovered 16 May 1866 from Madras, India, by N. R. Pogson. Alternate designation A909 GA.
Companion S/2001 (87) 1 discovered 18 February 2001 by M. E. Brown and J. L. Margot from the Keck II telescope at Mauna Kea; announced 23 February 2001. Permanently designated (87) Sylvia I Romulus in 2005.
Companion S/2004 (87) 1 discovered 9 August 2004 by Franck Marchis, Pascal Descamps, Daniel Hestroffer, and Jerome Berthier from the VLT adaptive optics telescope at European Southern Observatory, Cerro Paranel, Chile; announced 10 August 2005. Permanently designated (87) Sylvia II Remus in 2005.
See more information and links at
Asteroid/Comet Connection Catchall Catalog page
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
- Marchis, F., P. Descamps, D. Hestroffer, & J. Berthier, 2005, Nature, 436:822-824, Discovery of the triple asteroidal system 87 Sylvia.
- Marchis, F., Descamps, P., Hestroffer, D., Berthier, J., Brown, M. E., &
Margot, J.-L. 2005, International Astronomical Union Circular Satellites
of (87) Sylvia
- Bus, S. & Binzel, R. P. 2004, NASA Planetary Data System,
EAR-A-I0028-4-SBN0001/SMASSII-V1.0:87SYLVIA01 87 Sylvia CCD Spectrum
- Hestroffer, D. J. G. J. 2004, AAS/Division of Dynamical Astronomy Meeting On Equilibrium Shapes among Binary Asteroids
- Storrs, A., Makhoul, K., Wells, E., Gaffey, M., Vilas, F., Landis, R., Wood, C., & Zellner, B. 2002, AAS/Division for Planetary Sciences Meeting Imaging Asteroidal Companions with the Hubble Space Telescope (HST)
- Margot, J. L. & Brown, M. E. 2001, American Astronomical Society, DPS meeting #33, #52.02 Discovery and characterization of binary asteroids 22 Kalliope and 87 Sylvia
- Consolmagno, G. J. & Britt, D. T. 2001, American Astronomical Society, DPS meeting #33, #41.03 Classifying Asteroids by Macroporosity
- Storrs, A., Vilas, F., Landis, R., Wells, E., Woods, C., Zellner, B., &
Gaffey, M. 2001, International Astronomical Union Circular S/2001 (87) 1
- Brown, M. E., Margot, J. L., Keck, W. M., II, de Pater, I., & Roe, H. 2001,
International Astronomical Union Circular S/2001 (87) 1
- Prokof'eva, V. V., Demchik, M. I., Karachkina, L. G., & Gaftonyukm, N. M. 1999, Astronomicheskii Vestnik, vol. 33, p. 200 (1999) Photometric Observations of the Asteroid 87 Sylvia in 1989 and 1992-1993 at the Crimean Astrophysical Observatory and Their Fourier Analysis
- Karachkina, L. G., Prokof'eva, V. V., & Gaftonyuk, N. M. 1999, Astronomicheskii Vestnik, vol. 33, p. 49 (1999) On the Forced Precession of Asteroid 87 Sylvia
- Prokof'eva, V. V. & Demchik, M. I. 1994, Astronomy Letters, Volume 20, Issue 2, March 1994, pp.245-252 Fourier analysis of simultaneous BVR observations of the asteroid 87 Sylvia and its duplicity
- Prokofeva, V. V. & Demchik, M. I. 1994, Pis ma Astronomicheskii Zhurnal Fourier Analysis of Simultaneous BVR Observations of the Asteroid 87 Sylvia and its Duplicity
- Prokof'eva, V. V., Demchik, M. I., Karachkina, L. G., & Pavlenko, E. P. 1992, Astronomicheskii Vestnik: Issledovaniia Solnechnoi Sistemy (ISSN 0320-930X), vol. 26, no. 5, p. 3-13. Asteroid photometry and colorimetry using a digital TV system
- Blanco, C., di Martino, M., Gonano, M., Jaumann, R., & Mottola, S. 1989, (Societa Astronomica Italiana, Annual Meeting, 32nd, Catania, Italy, May 4-7, 1988) Societa Astronomica Italiana, Memorie (ISSN 0037-8720), vol. 60, no. 1-2, 1989, p. 195-198. Research supported by CNR, MPI, and DFG. CCD observations of minor planets
- Brown, R. H. & Morrison, D. 1984, Icarus (ISSN 0019-1035), vol. 59, July 1984, p. 20-24. Diameters and albedos of thirty-six asteroids
- Milani, A. & Nobili, A. M. 1984, IN: Asteroids, comets, meteors; Proceedings of the Meeting, Uppsala, Sweden, June 20-22, 1983 (A85-26851 11-89). Uppsala, Sweden, Astronomiska Observatoriet, 1984, p. 127-135. Dynamical instabilities in the outer asteroidal belt
- Degewij, J., Tedesco, E. F., & Zellner, B. 1979, Icarus, vol. 40, Dec. 1979, p. 364-374. NASA-supported research. Albedo and color contrasts on asteroid surfaces
- Schober, H. J. & Surdej, J. 1979, Astronomy and Astrophysics Supplement Series, vol. 38, Nov. 1979, p. 269-274. Research supported by the Oesterreichischer Fonds zur Foerderung der wissenschaftlichen Forschung UBV photometry of the asteroids 9 Metis, 87 Sylvia and 247 Eukrate during their oppositions in 1978 with respect to lightcurves
- Pogson, M. 1966, Astronomische Nachrichten Entdeckung eines Planeten (87) Sylvia durch M. Pogson
- McDonald, Sophia L. & Steel, Thomas B., Jr. 1952, Astronomical Journal, Vol. 57, p. 17 Representations of observations of thirty-four minor planets belonging to a group which includes the group one-half.
- Ventosa, V. 1882, Astronomische Nachrichten Observations de la petite planète (87) Sylvia
- Tietjen, F. 1874, Astronomische Nachrichten Elemente und Ephemeride der Sylvia
- Pogson, N. R. 1874, Astronomische Nachrichten Observations of Sylvia at Madras
- Pogson, Norman R. 1869, Astronomische Nachrichten Entdeckung eines neuen Planeten und Wiederauffindung der Sylvia durch Herrn Norman R. Pogson, Director der Sternwarte zu Madras
- Peters, C. F. W. 1869, Astronomische Nachrichten Über die Wiederauffindung der Sylvia, von Dr. C. F. W. Peters
- Peters, Karl Friedrich Wilhelm 1868, Gottingen, Druck der Deiterichschen univ.-buchdruckerei W. F. Kaestner, 1868. Bahnbestimmung der (87) Sylvia ...
- Peters, C. F. W. 1868, Astronomische Nachrichten Bahnbestimmung des Planeten (87) Sylvia. Von Dr. C. F. W. Peters
- Pogson, Norman Robert 1867, Astronomische Nachrichten Observations of the 87th New Planet Sylvia. By Mr. Norman Robert Pogson
- Peters, C. F. W. 1867, Astronomische Nachrichten Elemente der Sylvia (87), von C. F. W. Peters
- de Gasparis, Annibal 1867, Astronomische Nachrichten Elemente der Sylvia, von Herrn A. de Gasparis
- Pogson, Norman 1866, Monthly Notices of the Royal Astronomical Society, Vol. 26, p.311 Minor Planet 87 Sylvia
© 2001-2004, 2005 by Wm. Robert Johnston.
Last modified 1 September 2005.
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