(5587) 1990 SB
| Discovery[1] | |
|---|---|
| Discovered by | H. E. Holt and J. A. Brown |
| Discovery site | Palomar Observatory (675) |
| Discovery date | 16 September 1990 |
| Designations | |
| (5587) 1990 SB | |
| 1990 UV12 | |
| NEO · Amor | |
| Orbital characteristics[2] | |
| Epoch 21 November 2025 (JD 2461000.5) | |
| Uncertainty parameter 0 | |
| Aphelion | 3.70727 AU |
| Perihelion | 1.09391 AU |
| 2.40059 AU | |
| Eccentricity | 0.544317 |
| 3.71951 y (1358.55 d) | |
| 209.583° | |
| 0.264987° / d | |
| Inclination | 18.0410° |
| 189.278° | |
| 87.6129° | |
| Earth MOID | 0.31005 AU |
| TJupiter | 3.251 |
| Physical characteristics | |
| 3.57 km[3]: 125 | |
| 5.05219 h[4]: 187 | |
Pole ecliptic longitude | 253°[4]: 187 |
Pole ecliptic latitude | –60°[4]: 187 |
| 0.32[3]: 125 | |
| Sq-type[2] Color indices:[5]: 368 B–V = 0.831±0.004 V–R = 0.471±0.002 V–I = 0.795±0.004 V–Z = 0.772±0.007 | |
| 13.89[2] | |
(5587) 1990 SB is an unnamed near-Earth asteroid (NEA) orbiting in the inner Solar System. It was discovered on 16 September 1990 by astronomers Henry E. Holt and J. A. Brown. An Amor asteroid, it is 3.57 kilometres (2.22 mi) in size and has a highly elongated shape. It has a rotation period of 5.05 hours, spinning in a retrograde direction.
History
1990 SB was discovered on 16 September 1990 by astronomers Henry E. Holt and J. A. Brown, who noted its fast motion at that time. It was observed using the 48-in Schmidt telescope at Palomar Observatory. It was given the provisional designation 1990 SB, and its discovery was announced in an International Astronomical Union Circular on 22 September.[6] The asteroid was observed by the Crimean Astrophysical Observatory on 23 October, but it was reported as a new asteroid and given the provisional designation 1990 UV12.[7]: 44 The 23 October observation was later linked to 1990 SB by the Minor Planet Center on 4 June 1993, and the asteroid received the number (5587) that same day.[8]: 123 As of 2025, it remains unnamed.[2]
Orbit
1990 SB is classified as a near-Earth object (NEO) of the Amor class.[2] The Amor asteroids are a group of NEOs that have semi-major axes greater than one astronomical unit (AU) and do not cross Earth's orbit.[9] 1990 SB has a semi-major axis of 2.40 AU, taking 3.72 years to complete one orbit around the Sun. Along its orbit, its distance from the Sun varies from 1.09 AU at perihelion to 3.71 AU at aphelion, due to its orbital eccentricity of 0.54. Its orbit is inclined by 18° with respect to the ecliptic plane.[2]
Physical characteristics
1990 SB is about 3.57 kilometres (2.22 mi) in size, based on thermal models using thermal-infrared observations from the Keck telescope.[3]: 125 Photometric observations suggest that its shape is quite elongated, with axes ratios of a/b = 2.0 and b/c = 1.2. Its shape is also regular and symmetrical. Any concavities are not very deep; if it is a contact binary object, it is not very strongly bifurcated.[4]: 192–193 The asteroid is classified as an Sq-type asteroid under the Bus classification scheme.[2] In 2003, a team of astronomers led by C. L. Dandy suggested that it is instead intermediate between the Q-type and R-type.[5]: 365 However, a 2007 study reaffirmed that 1990 SB's spectrum is consistent with an Sq-type classification.[10]: 117
Observations of 1990 SB's lightcurve, or variations in its observed brightness, indicate that it has a rotation period of 5.05 hours.[4]: 187 Its spin pole points toward the ecliptic south, meaning that the asteroid rotates in a retrograde direction.[4]: 187
References
- ^ "(5587) = 1990 SB = 1990 UV12". Minor Planet Center. Retrieved 3 December 2025.
{{cite web}}: CS1 maint: url-status (link) (4610 obs) - ^ a b c d e f g "JPL Small-Body Database Lookup: 5587 (1990 SB)" (2025-12-01 last obs.). Jet Propulsion Laboratory. Retrieved 3 December 2025.
- ^ a b c Delbó, Marco; Harris, Alan W.; Binzel, Richard P.; Pravec, Petr; Davies, John K. (November 2003). "Keck observations of near-Earth asteroids in the thermal infrared". Icarus. 166 (1): 116–130. Bibcode:2003Icar..166..116D. doi:10.1016/j.icarus.2003.07.002.
- ^ a b c d e f Kaasalainen, Mikko; et al. (January 2004). "Photometry and models of eight near-Earth asteroids". Icarus. 167 (1): 178–196. Bibcode:2004Icar..167..178K. doi:10.1016/j.icarus.2003.09.012.
- ^ a b Dandy, C. L.; Fitzsimmons, A.; Collander-Brown, S. J. (June 2003). "Optical colors of 56 near-Earth objects: trends with size and orbit". Icarus. 163 (2): 363–373. Bibcode:2003Icar..163..363D. doi:10.1016/S0019-1035(03)00087-3.
- ^ Holt, H. E.; Brown, J. A.; Holt, H. R.; Olmstead, C. M.; Bowell, E. (22 September 1990). "IAUC 5098: 1990 SB; 1990c". International Astronomical Union Circulars. International Astronomical Union. Retrieved 3 December 2025.
- ^ Minor Planet Center Staff (21 November 1990). "MPC 19055-19346" (PDF). Minor Planet Electronic Circular. Minor Planet Center. Retrieved 3 December 2025.
{{cite journal}}: CS1 maint: url-status (link) - ^ Minor Planet Center Staff (4 June 1993). "MPC 22089-22274" (PDF). Minor Planet Electronic Circular. Minor Planet Center. Retrieved 3 December 2025.
{{cite journal}}: CS1 maint: url-status (link) - ^ "NEO Groups". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 February 2002. Retrieved 4 June 2012.
- ^ Davies, John K.; et al. (January 2007). "Near-infrared spectra of 12 Near-Earth Objects". Icarus. 186 (1): 111–125. Bibcode:2007Icar..186..111D. doi:10.1016/j.icarus.2006.08.008.
External links
- (5587) 1990 SB at AstDyS-2, Asteroids—Dynamic Site
- 5587 at the JPL Small-Body Database