Secular and Rotational Light Curve of Double Comet C/2021 A1 Leonard
ATel #15361; Ferrin, I., University of Antioquia, Medellin, Colombia; Gomez, A., International University of Valencia, Valencia, Spain
on 3 May 2022; 22:05 UT
Credential Certification: Ignacio Ferrin (ignacio.ferrin@udea.edu.co)
Subjects: Optical, Comet, Solar System Object
Using the Secular Light Curve (SLC) formalism (Ferrin, 2010), we have obtained the SLC of comet C/2021 A1 Leonard. We have found the following results:
A) The absolute magnitude of the comet is mv(1,1,0)=11.8+-0.2. If we assume a geometric albedo pv=0.04, we find an effective diameter D= 29.3+-0.5 km.
B) The comet exhibits periodic oscillation in its magnitude near perihelion. We believe that those oscillations are due to the rotation of the nucleus. We find a rotational light curve with a period of 6.56+-0.10 days with an amplitude of Arot= 0.42+-0.3 magnitudes. This same rotational value is confirmed in the nuclear data.
C) The comet appears to be a contact binary with equal components, each of diameter 10.4+-0.6 km. It exhibits an eclipse of duration 55+-4 days.
D) According to images of the comet, it disintegrated around February 22, 2022, so no additional observations will be possible.
Evidence and additional information is being sent for publication.
REFERENCES
Ferrin, I. (2010). Atlas of Secular Light Curves of Comets. PSS, Vol. 58, p. 365.
