astro.wikisort.org - Asteroid

1998 DK₃₆ is a 30-meter sized asteroid and near-Earth object that is possibly the first Apohele asteroid (Atira) – an asteroid that is always closer to the Sun than Earth – detected. It was first observed on 23 February 1998, by David J. Tholen at Mauna Kea Observatory, Hawaii, but is now considered a lost minor planet.[1][4]

1998 DK₃₆

Discovery[1]
Discovered by	D. Tholen
Discovery site	Mauna Kea Obs.
Discovery date	23 February 1998
Designations
MPC designation	1998 DK36
Minor planet category	NEO · Atira[1][2]
Orbital characteristics[2]
Epoch 24 February 1998 (JD 2450868.5)
Uncertainty parameter 9
Observation arc	(1 day)
Aphelion	0.9802 AU
Perihelion	0.4043 AU
Semi-major axis	0.6923 AU
Eccentricity	0.4160
Orbital period (sidereal)	0.58 yr (210 days)
Mean anomaly	183.25°
Mean motion	1° 42m 40.32s / day
Inclination	2.0175°
Longitude of ascending node	151.46°
Argument of perihelion	180.04°
Earth MOID	0.0084 AU · 3.3 LD
Physical characteristics
Mean diameter	30 m (est. at 0.20)[3]
Absolute magnitude (H)	25.0[2]

Although its orbital elements have not been well established, its aphelion (farthest distance from Sun) was determined to be less than the Earth's distance to the Sun (0.980 ± 0.05 AU).[2] Therefore, it has a claim to title "first Apohele detected", if not "first Apohele confirmed", which goes to 163693 Atira. This asteroid is estimated to measure 30 meters in diameter based on its absolute magnitude 25.0 and an assumed albedo of 0.20, typical for stony S-type asteroid and common among near-Earth objects.[3]

References

External links

• Astronomers Find New Class of Asteroid, University of Hawaii Institute for Astronomy, 1 July 1998
• 1998 DK36 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 1998 DK36 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 1998 DK36 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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