Images taken with the 80 cm f/4 telescope of the Celado Observatory (Italy) -  Giancarlo Favero and Mauro Facchini

Comet C/2019 Y4 ATLAS, 2020/04/07 UT21:30

A preliminary analysis of the last year apparition of comet 38P/Stephan - Oterma shows that the peak of activity was about 25 days before perihelion

The latest Winafrho User Manual has been published
By Cavezzo Observatory

http://cara.uai.it/manuale-winafrho-v05-202034144341

On January 2 and 3 a small outburst was observed By Erik Bryssinck on comet 64P/Swift-Gehrels.  Despite the small amplitude  of the event it's trace is evident in the changing of the coma morphology. The Af[rho] quantity increased from about 160 cm to 290 cm in R band for measuring windows between 5,000 and 10,000 km. Below the images and plots made by Erik Bryssinck.

In this period comets 46P/Wirtanen and 64P/Swift-Gehrels are among the more interresting objects. The enclosed plots have been updated by Erik Bryssinck and show the behavior of the two comets reporting the Af[rho] quantity vs. days from perihelion.

The observers that are contributing to the observing campaigns are listed below in alphabetical order.  The data for 46P have been normalised for a zero phase angle while for 64P have been used the observed values.

The recent apparitions of periodic comets 21P/Giacobini-Zinner and 46P/Wirtanen have been intensively monitored.  The analysis and the enclosed plots made by Erik Bryssinck well show the preliminary results on the two objects. Comet 21P displayed a regular curve peaking about 18 days before perihelion in agreement with the 1998 apparition (Lara et al, A&A 399- 2003).