(450894) 2008 BT18
Synodic rotation period | 2.726±0.007 h[5] | |
| 0.20 (assumed)[4] | ||
| V[5][6] · S (assumed)[4] | ||
| 18.3[1][4] | ||
(450894) 2008 BT18 is a sub-kilometer
In 2008, its minor-planet moon, designated S/2008 (450894) 1, was discovered by radar astronomers. It measures approximately 200 meters in diameter, or one third of its primary.[3][b]
Orbit and classification
2008 BT18 orbits the Sun at a distance of 0.9–3.5 AU once every 3 years and 4 months (1,209 days). Its orbit has an eccentricity of 0.59 and an inclination of 8° with respect to the ecliptic.[1] Published by the Digitized Sky Survey, a first precovery was taken at Palomar Observatory in 1955, extending the asteroid's observation arc by 53 years prior to its discovery.[2]
The asteroid has a low Earth
Physical characteristics
2008 BT18 has been characterized as a V-type asteroid by astronomers using the SpeX spectrograph at NASA Infrared Telescope Facility, IRTF.[5][6]
Rotation period
A rotational
Binary system
On 6 and 7 July 2008, research conducted using the Arecibo Observatory produced evidence that 2008 BT18 is a synchronous binary asteroid with a minor-planet moon in its orbit. The secondary component, provisionally designated S/2008 (450894) 1, has a diameter of at least 200 meters, about 33% the size of and up to 1.5 kilometers apart from its primary.[3][a][b] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 650 meters, based on an absolute magnitude of 18.3.[4]
There are more than 60 binary near-Earth objects known to exist (2016).
Mineralogy
On 26 July 2008, observations at the IRTF using the SpeX-spectrograph showed that 2008 BT18 is a
Naming
As of 2017, this minor planet remains unnamed.[2]
Notes
- ^ a b c Benner (2008) web: diameter 0.6 kilometers. Central Bureau Electronic Telegrams, No. 1450, #1 (2008). Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (450894)
- ^ a b c Central Bureau for Astronomical Telegrams, No. 1450, from 29 July 2008:
Arecibo (2380-MHz, 12.6-cm) and Goldstone (8560-MHz, 3.5-cm) radar observations during July 6, 7, and 11 reveal that minor planet 2008 BT_18 (cf. MPECs 2008-C03, 2008-H06; MPO 140193) is a binary system. Preliminary estimates for the component diameters are about 0.6 km and > 200 m. The maximum distance between the components on July 11 is at least 1.5 km.
Reported by: L. A. M. Benner, Jet Propulsion Laboratory (JPL), California Institute of Technology (CIT); M. C. Nolan and E. S. Howell, Arecibo Observatory, National Astronomy and Ionosphere Center; C. Magri, University of Maine at Farmington; J. D. Giorgini, S. J. Ostro, and M. Brozovic, JPL/CIT; M. W. Busch, CIT; J. L. Margot and P. A. Taylor, Cornell University; M. K. Shepard, Bloomsburg University; L. M. Carter, Smithsonian Institution; and T. M. Becker, Lehigh University CBET No. 1450
References
- ^ a b c d e f "JPL Small-Body Database Browser: 450894 (2008 BT18)" (2015-10-17 last obs.). Jet Propulsion Laboratory. Retrieved 2 June 2017.
- ^ a b c d "450894 (2008 BT18)". Minor Planet Center. Retrieved 21 May 2016.
- ^ a b c d Johnston, Wm. Robert (18 February 2017). "Asteroids with Satellites Database – (450894) 2008 BT18". Johnston's Archive. Retrieved 15 November 2017.
- ^ a b c d e "LCDB Data for (450894)". Asteroid Lightcurve Database (LCDB). Retrieved 21 May 2016.
- ^ ISSN 1052-8091. Retrieved 16 November 2017.
- ^ Bibcode:2008DPS....40.2507R. Retrieved 16 November 2017.
External links
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- Binary and Ternary Near-Earth Asteroids Detected by Radar, Lance Benner at echo.jpl.nasa.gov
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- (450894) 2008 BT18 at NeoDyS-2, Near Earth Objects—Dynamic Site
- (450894) 2008 BT18 at ESA–space situational awareness
- (450894) 2008 BT18 at the JPL Small-Body Database
