Observation by Chris Hooker: Mercury's tail, 19th December 2024

Uploaded by

Chris Hooker

Observer

Chris Hooker

Observed

2024 Dec 19 - 07:00

Uploaded

2024 Dec 20 - 18:08

Objects

Mercury

Equipment
  • StellaMira 110 mm F/6 APO refractor
  • 0.45x re-imaging focal reducer
  • Alluxa 589.2 nm filter (2.1 nm bandwidth)
  • ZWO ASI178MM camera
Exposure

15 seconds

Location

Didcot, Oxfordshire

Target name

Mercury

Title

Mercury's tail, 19th December 2024

About this image

At 13 days after perihelion, Mercury's radial velocity was 9.6 km/sec, close to the maximum of 10.1 km/sec, so the sodium tail was fully developed. Conditions were difficult, with cloud and occasional showers delaying the setup. A few minutes' break in the cloud allowed me to locate Mercury and focus the image, but there was no time to position it behind the occulting strip. I captured only 5 frames of 15 seconds' exposure before the clouds (visible at the upper right) returned. Four of the frames were stacked to obtain this image: a mild contrast stretch has been applied, but no sharpening. The bright spot below and left of Mercury is an internal reflection in the optics. The star in line with the tail at the edge of the clouds is 29 arc minutes from Mercury. 

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