|Discovered by||Mt. Lemmon Survey (G96)|
|Discovery date||22 January 2013|
|MPC designation||2013 BP73|
|Minor planet category||Apollo NEO,
|Aphelion||2.163 AU (Q)|
|Perihelion||0.4931 AU (q)|
|Semi-major axis||1.328 AU (a)|
|Orbital period||1.53 yr|
|Mean anomaly||139.3° (M)|
|Longitude of ascending node||80.14°|
|Argument of perihelion||251.7°|
|Dimensions||~310 meters (1,020 ft)|
|Mass||4.0×1010 kg (assumed)|
|Absolute magnitude (H)||20.2|
2013 BP73 (also written 2013 BP73) is a near-Earth asteroid and potentially hazardous object. From discovery until August 2013 when Sentry updated to planetary ephemeris (DE431), it had the 4th highest impact threat on the Palermo Technical Impact Hazard Scale. It was discovered on 22 January 2013 by the Mount Lemmon Survey at an apparent magnitude of 21 using a 1.5-meter (59 in) reflecting telescope. It has an estimated diameter of 310 meters (1,020 ft) and is listed on the Sentry Risk Table.
It has an observation arc of 52 days with an uncertainty parameter of 6. Perturbations by Earth, Venus, and Mercury will increase the orbital uncertainty over time. Virtual clones of the asteroid that fit the uncertainty region in the known trajectory show a 1 in 588,000 chance that the asteroid will impact Earth on 11 December 2096. With a 2096 Palermo Technical Scale of −3.42, the odds of impact by 2013 BP73 in 2096 are about 2630 times less than the background hazard level of Earth impacts which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact. Using the nominal orbit, JPL Horizons shows that the asteroid will be 0.9 AU (130,000,000 km; 84,000,000 mi) from Earth on 11 December 2096. 2013 BP73 will make a close approach to Earth around 17 December 2018 that should allow a refinement to the known trajectory.
- "MPEC 2013-B98 : 2011 BP73". IAU Minor Planet Center. 2013-01-31. Retrieved 2013-07-28. (K13B73P)
- "JPL Small-Body Database Browser: (2013 BP73)". Jet Propulsion Laboratory. 2013-03-15 last obs (arc=52 days). Retrieved 2013-07-28.
- "Earth Impact Risk Summary: 2013 BP73". NASA/JPL Near-Earth Object Program Office. Retrieved 2013-07-28.
- "Sentry Risk Table". Wayback Machine: NASA/JPL Near-Earth Object Program Office. 2013-05-29. Retrieved 2013-08-11.
- "JPL Close-Approach Data: (2013 BP73)". 2013-03-15 last obs (arc=52 days). Retrieved 2013-07-28.
- Math: 103.42 = 2630
- "The Palermo Technical Impact Hazard Scale". NASA/JPL Near-Earth Object Program Office. 31 Aug 2005. Retrieved 2013-07-28.
- Horizons output. "Horizon Online Ephemeris System". Retrieved 2013-07-28. (Geocentric Solution)