British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

BAA Community

C/2019 Y4 (ATLAS)


Expand image

About this observation
Nick James
Time of observation
25/04/2020 - 22:12
Observing location
Chelmsford, UK
C11 Edge HD + FLI6303

April 25 provided yet another clear, transparent night in Chelmsford. The seeing was very good too. C/2019 Y4 is much more diffuse with the dust from the recent breakup spread down the tail. In the high res inset there is some hint of structure behind the well condensed fragment B.

I've been using FindOrb to play around with combining the astrometry of C/2019 Y4 (ATLAS) before the breakup and fragment B (C/2019 Y4-B) after it emerged on April 9. Without non-gravitational forces (NGFs) the mean residual of the linked data is quite large (0".98) with all the large errors in the frag B astrometry from April 9 onwards. Additon of NGFs gets the frag B residuals back to reasonable levels and the total mean residual down to 0".50 which is similar to the residuals in the pre-breakup data. Assuming fragment B survives, more astrometry will allow us to estimate the forces imparted on this fragment during the breakup.

Copyright of all images and other observations submitted to the BAA remains with the owner of the work. Reproduction of the work by third-parties is expressly forbidden without the consent of the copyright holder. For more information, please contact the webmaster.