British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

BAA Community

Mercury IR 10th June 2017


Expand image

About this observation
Chris Hooker
Time of observation
10/06/2017 - 08:45
Observing location
Didcot, Oxfordshire
25 cm Newtonian & x3 Barlow @ F/19
ZWO ASI120MM-S camera
Baader IR filter (685nm cut-on)
0.346 msec (1/2890 sec)

Poor seeing (Ant III - IV) and a strong gusty breeze made for tricky conditions. Out of a total capture of around 80,000 frames of video, the final image is a stack of only 350 selected frames. This and the verification frames are noisy thanks to the small stack size, but the comparison with the reference image shows that the markings recorded do match those on the planet fairly well. Registration and stacking were done in Registax, with frame selection in VirtualDub. Thanks to Steve Knight for providing the reference image from Sky Safari.

The apparent difference in phase between the telescopic image and the reference is due to the strong brightness gradient in the image. Trying to brighten the terminator region to show the markings there leads to saturation on the bright limb, and reducing the gamma lowers the contrast on the disc. If anyone can suggest a way to improve the processing to bring out more detail I would be happy to hear from you.

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.