Discovery | |
---|---|
Discovered by | Pan-STARRS |
Discovery date | 26 July 2021 |
Orbital characteristics | |
Epoch | 2021-Aug-21 |
Observation arc | 53 days |
Number of observations | 279 |
Orbit type | Oort cloud [2] |
Perihelion | 0.287 AU [1] |
Eccentricity | 1.00005 (epoch 1950)
[2] 1.002 (epoch 2021) [1] 1.0001 (epoch 2100) [2] |
Inclination | 56.75° |
189.03° | |
Argument of periapsis | 299.97° |
Last perihelion | 21 April 2022 |
TJupiter | 0.446 |
Earth MOID | 0.062 AU [1] |
Jupiter MOID | 2.16 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]
With a short observation arc of 7 days, the Minor Planet Center used an assumed eccentricity of 1.0 for the orbit solution. [10] Due to statistics of small numbers, with a short 10 day arc JPL had an eccentricity of 0.99595±0.00444 which could be as high as 1.00039 or as low as 0.99151. [11] With an observation arc of 53 days, JPL Horizons shows both an inbound and outbound eccentricity greater than 1. [2]
C/2021 O3 probably took millions of years to arrive from the outer Oort cloud and, had it survived, may have been fated to be ejected from the Solar System. [2] This is also the most likely scenario when considering the post-perihelion orbit determination of the surviving object. [9]