2021 PH27

2021 PH27
Discovery [1]
Discovered byS. S. Sheppard
Discovery siteCerro Tololo Obs.
Discovery date13 August 2021
Designations
2021 PH27
v13aug1 [2]
Atira · NEO [3][4]
Orbital characteristics [4]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 3
Observation arc4.15 yr (1,515 days)
Earliest precovery date16 July 2017
Aphelion0.7903 AU
Perihelion0.1331 AU
0.4617 AU
Eccentricity0.7116
0.31 yr (114.60 days)
49.496°
3° 8m 28.602s / day
Inclination31.929°
39.411°
7 October 2021
@ 106 km/s[5]
8.575°
Earth MOID0.2251 AU
Mercury MOID0.1123 AU[3]
Venus MOID0.0147 AU[3]
Physical characteristics
>1 km
19.3 (discovery)[1]
14 (unobservable)[6][a]
17.71±0.235[4]

2021 PH27 is a near-Earth asteroid of the Atira group. It was discovered by Scott Sheppard using the Dark Energy Survey's DECam imager at NOIRLab's Cerro Tololo Inter-American Observatory on 13 August 2021. 2021 PH27 has the smallest semi-major axis and shortest orbital period among all known asteroids as of 2021,[7] with a velocity at perihelion of 106 km/s (240,000 mph).[5] It also has the largest relativistic perihelion shift of any object orbiting the Sun, 1.6 times that of Mercury.[8] With an absolute magnitude of 17.7, the asteroid is estimated to be larger than 1 kilometer (0.6 miles) in diameter.[3]

  1. ^ a b Cite error: The named reference MPEC-2021-Q41 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference NEO-Exchange was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Horizons-perihelion was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Horizons-apmag was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference sma-list was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference de la Fuente Marcos-2021 was invoked but never defined (see the help page).


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