90482 Orcus
From Wikipedia, the free encyclopedia
 |
|
| Discovery | |
|---|---|
| Discoverer | M. Brown, C. Trujillo, D. Rabinowitz |
| Discovery date | February 17, 2004 |
| Alternative names | 2004 DW |
| Minor planet category | Plutino[1] |
| Orbital characteristics Epoch November 30, 2008 (JD 2 454 800) |
|
| Aphelion | 7 188.17 Gm (48.05 AU) |
| Perihelion | 4 535.80 Gm (30.32 AU) |
| Semi-major axis | 5 862.44 Gm (39.188 AU) |
| Eccentricity | 0.226 18 |
| Orbital period | 89 606 d (245.33 yr) |
| Average orbital speed | 4.68 km/s |
| Mean anomaly | 164.68° |
| Inclination | 20.593° |
| Longitude of ascending node | 268.722° |
| Argument of perihelion | 72.474° |
| Satellites | 1 (92-432 km) |
| Physical characteristics | |
| Dimensions | 946.3 +74.1−72.3 km (diameter)[2] |
| Mass | ~7.5×1020 kg |
| Mean density | ~1.5 g/cm³ (assumed) |
| Equatorial surface gravity | ~0.2 m/s² |
| Escape velocity | ~0.44 km/s |
| Rotation period | 13.19h[3] |
| Albedo | 19.75 +3.40−2.76 % |
| Temperature | ~45 K |
| Spectral type | B-V=0.68; V-R=0.37 [4] |
| Apparent magnitude | 19.1 (opposition)[5] |
| Absolute magnitude | 2.3[6] |
90482 Orcus, originally known by the provisional designation 2004 DW) is a Kuiper belt object (KBO) and could be a dwarf planet. It was found by Michael Brown, Chad Trujillo and David Rabinowitz on February 17, 2004. It was also seen in pictures from November 8, 1951.
[change] Moon
A moon of Orcus was found on 22 February 2007.[7] The orbit of this moon has yet to be found out.
The satellite was found at 0.25 arcsec from Orcus with magnitude difference of 2.7.[8] Assuming an albedo similar to that of the primary, the magnitude suggests a diameter of about 220 km. It is thought to be a smaller KBO that was captured.
[change] Other websites
- MPEC 2004-D09 announcing the discovery but attributing it to Raymond J. Bambery, Steven H. Pravdo, Michael D. Hicks, Kenneth J. Lawrence, Daniel MacDonald, Eleanor F. Helin and Robert Thicksten / NEAT
- MPEC 2004-D13 correcting MPEC 2004-D09
- Chad Trujillo's page on 2004 DW
- First BBC article
- First New Scientist article
- Updated orbital elements from Lowell Observatory
- AstDys orbital elements
- Orbital simulation from JPL (Java) / Ephemeris
[change] References
- ↑ Buie, Marc W. (2007-12-22). "Orbit Fit and Astrometric record for 90482". SwRI (Space Science Department). http://www.boulder.swri.edu/~buie/kbo/astrom/90482.html. Retrieved 2008-09-19.
- ↑ Stansberry, J.; Grundy, W.; Brown, M.; et al. (2007). Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope. http://arxiv.org/abs/astro-ph/0702538v1.
- ↑ "Overlooked dwarf planet candidates". BBC. 2008-02-19. http://www.bbc.co.uk/dna/h2g2/A32537720. Retrieved 2008-07-25.
- ↑ Tegler, Stephen C. (2006-01-26). "Kuiper Belt Object Magnitudes and Surface Colors". http://www.physics.nau.edu/~tegler/research/survey.htm. Retrieved 2006-11-05.
- ↑ "HORIZONS Web-Interface". JPL Solar System Dynamics. http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=Orcus. Retrieved 2008-07-02.
- ↑ "JPL Small-Body Database Browser: 90482 Orcus (2004 DW)". 2008-02-10 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Orcus. Retrieved 2008-07-02.
- ↑ [1]
- ↑ Distant EKO The Kuiper Belt Electronic newsletter, March 2007
|
|||||
|
|||||
