Observation by Chris Hooker: Mercury's sodium tail, 24th Februar...

Uploaded by

Chris Hooker

Observer

Chris Hooker

Observed

2026 Feb 24 - 18:48

Uploaded

2026 Feb 26 - 17:36

Objects

Mercury

Equipment

William Optics ZS66 refractor
0.45x re-imaging focal reducer
Alluxa 2.1 nm bandpass 589.2 nm filter
ZWO ASI178MM camera

Exposure

10 x 60 seconds

Location

Didcot, Oxfordshire

Target name

Mercury

Title

Mercury's sodium tail, 24th February 2026

About this image

Mercury's sodium tail imaged on the first clear evening for several weeks! Five days after perihelion on the 19th, Mercury's True Anomaly Angle was 33 degrees, slightly more than the 27 degrees where the tail typically first becomes detectable. The image is a contrast-stretched stack of 10 60-second exposures, taken over a period when Mercury's mean altitude was 3.5 degrees. The brighter star on the left of the image is 12 Psc, magnitude 6.85, which was 41 arc minutes from Mercury. The visible extent of the tail is approximately 30 arc minutes. A faint ghost image of the occulting strip which blocks most of the light from the planet can be seen extending down from the upper left.

This is a wider-field view than the one Martin Lewis posted recently: see his page for that image.

Files associated with this observation

Tail 24 Feb 26 1848 UT.jpg (1.3 MB)

Like this image

Honor Wheeler, David Basey, Dominic Ford, Alan Dowdell, Geof Lewis, Dawson

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