2005 LW₃

2005 LW₃
	Radar image of 2005 LW3 and its satellite (below) by the Goldstone Solar System Radar on 23 November 2022
Discovery
Discovered by	Siding Spring Survey
Discovery site	Siding Spring Obs.
Discovery date	5 June 2005
Designations
MPC designation	2005 LW3
Minor planet category	NEO · Apollo · PHA
Orbital characteristics
	Epoch 25 February 2023 (JD 2460000.5)
	Uncertainty parameter 0
Observation arc	17.49 yr (6,389 days)
Aphelion	2.106 AU
Perihelion	0.771 AU
Semi-major axis	1.439 AU
Eccentricity	0.4638
Orbital period (sidereal)	1.73 yr (630.3 days)
Mean anomaly	81.385°
Mean motion	0° 34m 16.171s / day
Inclination	6.021°
Longitude of ascending node	59.587°
Time of perihelion	5 October 2022
Argument of perihelion	288.663°
Earth MOID	0.001397 AU (209,000 km; 0.544 LD)
Jupiter MOID	3.335 AU
Physical characteristics
Mean diameter	400 m (primary)
Synodic rotation period	3.6 h
Geometric albedo	0.02
Absolute magnitude (H)	21.89 · 21.68

2005 LW₃ is a binary near-Earth asteroid classified as a potentially hazardous object of the Apollo group. It was discovered on 5 June 2005 by the Siding Spring Survey at Siding Spring Observatory in Australia.^[2] It made a close approach of 2.97 lunar distances (1.14×10^⁶ km; 0.71×10^⁶ mi) from Earth on 23 November 2022, reaching a peak brightness of apparent magnitude 13 as it passed over the northern celestial hemisphere sky.^[1] It was extensively observed by astronomers worldwide during the close approach, and radar observations by NASA's Goldstone Solar System Radar in California discovered a 100 m (330 ft)-wide natural satellite orbiting the asteroid at a wide separation of 4 km (2.5 mi).^[6]^[7]

Physical characteristics

Goldstone Solar System Radar observations in November 2022 resolved the shape of 2005 LW₃, revealing a body 400 m (1,300 ft) in diameter—larger than its previously expected diameter of 150 m (490 ft).^[4]^[7] For an absolute magnitude of 21.9, this radar-measured diameter indicates that 2005 LW₃ has a very low geometric albedo of 0.02.^[5] These radar observations also determined a rotation period of 3.6 hours for 2005 LW₃.^[4]

Satellite

The satellite of 2005 LW₃ was discovered by a team of astronomers^[a] using Goldstone Solar System Radar observations from 23–27 November 2022. The satellite appears elongated, with equatorial dimensions of 100 m × 50 m (330 ft × 160 ft).^[4] The satellite is widely separated from 2005 LW₃ (the primary body of the system) at a semi-major axis of about 4 km (2.5 mi),^[4] which is around 17% of the primary's Hill radius (24 km or 15 mi for an assumed primary density of 1.6 g/cm³).^[5] The satellite's discovery was announced in a Central Bureau Electronic Telegram on 10 December 2022.^[4]

Notes

^ Observers credited for the discovery of the satellite include: S. P. Naidu, L. A. M. Benner, M. Brozovic, J. D. Giorgini, S. Horiuchi, I. Savill-Brown, J. Stevens, C. Phillips, P. Edwards, and E. Kruzins.^[4]

References

^ ^a ^b ^c ^d "2005 LW3". Minor Planet Center. Retrieved 10 December 2022.
^ ^a ^b "MPEC 2005-L19 : 2005 LW3". Minor Planet Electronic Circular. Minor Planet Center. 6 June 2005. Retrieved 10 December 2022.
^ ^a ^b "JPL Small-Body Database Browser: (2005 LW3)" (2022-12-02 last obs.). Jet Propulsion Laboratory. Retrieved 10 December 2022.
^ ^a ^b ^c ^d ^e ^f ^g ^h Green, Daniel W. E. (10 December 2022). "CBET 5198: 2005 LW_3". Central Bureau Electronic Telegram. Central Bureau for astronomical Telegrams. Retrieved 10 December 2022.
^ ^a ^b ^c Johnston, Wm. Robert (1 December 2022). "2005 LW3". Johnston's Archive. Retrieved 10 December 2022.
^ "MPEC 2022-U222 : International Asteroid Warning Network (IAWN) Timing Campaign". Minor Planet Electronic Circular. Minor Planet Center. 24 October 2022. Retrieved 10 December 2022.
^ ^a ^b Benner, Lance A. M. (10 December 2022). "Goldstone Radar Observations Planning: 2005 LW3, 1998 SS49, and 2017 QL33". echo.jpl.nasa.gov. NASA. Retrieved 10 December 2022.

External links

2005 LW3: Timing Assessment, International Asteroid Warning Network, last updated 29 November 2022
Asteroid 2005 LW3 Campaign: Timing is Everything!, Leonard David, 5 November 2022
2005 LW3 at NeoDyS-2, Near Earth Objects—Dynamic Site
- Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
2005 LW3 at ESA–space situational awareness
- Ephemerides · Observations · Orbit · Physical properties · Summary
2005 LW3 at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

[8] Observers credited for the discovery of the satellite include: S. P. Naidu, L. A. M. Benner, M. Brozovic, J. D. Giorgini, S. Horiuchi, I. Savill-Brown, J. Stevens, C. Phillips, P. Edwards, and E. Kruzins.^[4]

[MPC-object-1] "2005 LW3". Minor Planet Center. Retrieved 10 December 2022.

[MPEC-2005-L19-2] "MPEC 2005-L19 : 2005 LW3". Minor Planet Electronic Circular. Minor Planet Center. 6 June 2005. Retrieved 10 December 2022.

[jpldata-3] "JPL Small-Body Database Browser: (2005 LW3)" (2022-12-02 last obs.). Jet Propulsion Laboratory. Retrieved 10 December 2022.

[CBET5198-4] ^ ^a ^b ^c ^d ^e ^f ^g ^h Green, Daniel W. E. (10 December 2022). "CBET 5198: 2005 LW_3". Central Bureau Electronic Telegram. Central Bureau for astronomical Telegrams. Retrieved 10 December 2022.

[johnston-5] Johnston, Wm. Robert (1 December 2022). "2005 LW3". Johnston's Archive. Retrieved 10 December 2022.

[MPEC-2022-U222-6] "MPEC 2022-U222 : International Asteroid Warning Network (IAWN) Timing Campaign". Minor Planet Electronic Circular. Minor Planet Center. 24 October 2022. Retrieved 10 December 2022.

[Goldstone-7] Benner, Lance A. M. (10 December 2022). "Goldstone Radar Observations Planning: 2005 LW3, 1998 SS49, and 2017 QL33". echo.jpl.nasa.gov. NASA. Retrieved 10 December 2022.

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