Leda, or Jupiter XIII


Leda was discovered in 1971. Probes sent to Jupiter have since revealed Leda to be 21 km in diameter and when these images were created it was at magnitude 18.7.

To form the images above, 29 exposures were taken with a total duration of 940 seconds. The satellite was moving with respect to the background stars during this time so the sub-images were in two different ways. In the left-hand image the subs were stacked on the stars, so that Leda is trailed. In the right-hand image the subs were stacked on the predicted motion of the satellite, not on the stars themselves. In consequence, Leda shows up as a fairly sharp circular object whereas all the stars are now trailed slightly.

Image information
Date and time of observation  2021-08-28 22:25 UT
Telescope 0.4m f/6.5 Dilworth-Relay
Camera Starlight Xpress Trius-PRO SX814 CCD
Filter None
Exposure 1×10s,25×30s and 3×60s median-stacked
Centre of image RA 21h52m57.0s  Dec -13°40'15"
Image dimensions 7.0 arcmin × 6.8 arcmin