C/2021 O3 (PanSTARRS)

C/2021 O3 (PanSTARRS)
Discovery
Discovered byPan-STARRS
Discovery date26 July 2021
Orbital characteristics
Epoch2021-Aug-21
Observation arc53 days
Number of
observations		279
Orbit typeOort cloud[2]
Perihelion0.287 AU[1]
Eccentricity1.00005 (epoch 1950)[2]
1.002 (epoch 2021)[1]
1.0001 (epoch 2100)[2]
Inclination56.75°
189.03°
Argument of
periapsis		299.97°
Last perihelion21 April 2022
TJupiter0.446
Earth MOID0.062 AU[1]
Jupiter MOID2.16 AU
Comet total
magnitude (M1)		10.6

C/2021 O3 (PanSTARRS) is perhaps an Oort cloud comet, discovered on 26 July 2021 by the Pan-STARRS sky survey. It came to perihelion on 21 April 2022 at 0.287 AU (42.9 million km). from the Sun.

The comet was expected to reach apparent magnitude 5 by late April 2022, while being only 15 degrees from the Sun.[3][4] While near perihelion the comet was dimmer than expectations. It was faintly visible in STEREO/SECCHI COR2-A on 27 April 2022.[5] Observations by Lowell Discovery Telescope on April 29 in the twilight detected a diffuse glow with a magnitude of 9 where the comet was expected to be, indicating that the comet nucleus disintegrated during perihelion.[6] C/2021 O3 made its closest approach to Earth on 8 May 2022 at a distance of 0.60 AU (90 million km).[7] As a dynamically new comet from the Oort cloud there was a high risk of disintegration.[8]

The comet was recovered by multiple observatories after perihelion at magnitudes not too different from those observed pre-perihelion.[9] Calculations carried out using the pre- and post-perihelion orbits indicate that although the comet is probably dynamically old, it may also be a fragment of a dynamically new comet that was released during the first perihelion passage of its parent comet.[9]

  1. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference horizons was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference CBET5009 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Yoshida was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Worachate was invoked but never defined (see the help page).
  6. ^ Zhang, Qicheng; Ye, Quanzhi; Farnham, Tony L.; Holt, Carrie E. (2 May 2022). "ATel #15358: Disintegration of Near-Sun Comet C/2021 O3 (PANSTARRS)". The Astronomer's Telegram. Retrieved 8 May 2022.
  7. ^ Cite error: The named reference Earth was invoked but never defined (see the help page).
  8. ^ Machholz, Donald (5 May 2022). "EarthSky | Darn! Comet C/2021 O3 PanSTARRS has disintegrated". earthsky.org.
  9. ^ a b Cite error: The named reference Evangelista-Santanaetal2023 was invoked but never defined (see the help page).