comet 2021-A1 Leonard

 JPL c/2020 A1, has the most complete orbital elements data

 vanbuitenen, twitter the person who updates solar system small bodies data to CdC ( Cartes du Ciel) 

for CdC, you can add manually by:

Setup>Solar System>Comet>Load MPC file>Or use a local file>COMx.DAT

which contains following:

    CK21A010  2022 01  3.3079  0.614994  1.000050  225.0905  255.8741  132.6859  20210115   8.5  4.0  C/2021 A1 (Leonard)                                      MPEC 2021-A99

or from JPL Horizons, manually input as follows:

minorplanetcenter  MPEC id: 2021-A99

waa dot at

aerith

This comet will be initially visible from the Northern Hemisphere, and will become visible from the Southern Hemisphere in December 2021 and January 2022.

Will Comet Leonard be visible to the unaided eye? It’s possible. This might be this year’s brightest comet (unless a new brighter one is discovered). It will provide a nice spectacle to observers using long exposure cameras, binoculars and even the smallest telescopes.

minorplanetcenter orbital elements explanation

hyperbolic trajectory

 earthsky

how to enter new comet orbital elements into Carte du Ciel

MPC format