(741081) 2005 LW3

(741081) 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. 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. 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).

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). For an absolute magnitude of 21.9, this radar-measured diameter indicates that 2005 LW₃ has a very low geometric albedo of 0.02. These radar observations also determined a rotation period of 3.6 hours for 2005 LW₃.

Satellite

The satellite of 2005 LW₃ was discovered by a team of astronomers 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). 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), 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). The satellite's discovery was announced in a Central Bureau Electronic Telegram on 10 December 2022.

Notes

References

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
• (741081) 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
• (741081) 2005 LW3 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• (741081) 2005 LW3 at the JPL Small-Body Database