2000 BD₁₉

Discovery
Discoverer	LINEAR
Discovery Date	January 26, 2000
Alternate Designations
Category	Aten asteroid, Mercury-crosser asteroid, Venus-crosser asteroid, Earth-crosser asteroid, Mars-crosser asteroid
Orbital Elements Epoch February 26, 2000 (JD 2451600.5)
Eccentricity (e)	0.895
Semi-Major Axis (a)	131.109 Gm (0.876 AU)
Perihelion (q)	13.749 Gm (0.092 AU)
Aphelion (Q)	248.470 Gm (1.661 AU)
Orbital Period (P)	299.681 d (0.82 a)
Mean Orbital Speed	23.85 km/s
Inclination (i)	25.639°
Longitude of the Ascending Node (Ω)	333.878°
Argument of Perihelion (ω)	324.184°
Mean Anomaly (M)	202.259°
Physical Characteristics
Dimensions	~1.6 km
Mass	?×10? kg
Density	2 ? g/cm³
Surface Gravity	? m/s²
Escape Velocity	? km/s
Rotation Period	? d
Spectral Class	?
Absolute Magnitude	16.74
Albedo	0.1 ?
Mean Surface Temperature	~409 K

An asteroid discovered by LINEAR in January of 2000, 2000 BD₁₉ (also written 2000 BD19) was soon after located by DANEOPS on Palomar plates from February 10, 1997. This allowed a reasonably precise orbit determination, and as a result it was spotted again on February 27, 2001 and January 21, 2002. 2000 BD₁₉ has the closest perihelion of any known asteroid (as of July 2004), at 0.092 AU —38% of Mercury's orbital radius. That and its high eccentricity (0.895) and inclination (25.7°), seem to indicate an inactive or extinct comet. It hasn't been caught displaying cometary activity so far.

One can estimate that 2000 BD₁₉'s surface temperature reaches ~1260 K at perihelion, enough to melt silver and nearly enough to melt gold and copper. 2000 BD₁₉ is considered a good candidate for measuring the effects of Albert Einstein's General theory of relativity because of how close it comes to the Sun.

When it was discovered, it beat 1995 CR's record for both asteroid with the smallest perihelion and for Aten asteroid with the highest eccentricity. With a high eccentricity, not only does 2000 BD₁₉ get close to the Sun, but it also travels relatively far away from it. It has the third largest aphelion of any Aten asteroid and is one of the few Aten asteroids that is also a Mars crosser.

Reference

• MPEC 2000-C49 (http://cfa-www.harvard.edu/mpec/K00/K00C49.html)

The Minor Planets

Vulcanoids | Main belt | Groups and Families | Near-Earth objects | Jupiter Trojans

Centaurs | Trans-Neptunians | Damocloids | Comets | Kuiper Belt | Oort Cloud

(For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system)

(For a complete listing, see: List of asteroids)