Observation by Dawson: Mercury's sodium tail

Uploaded by

Dawson

Observer

Dawson

Observed

2025 Dec 02 - 06:55

Uploaded

2025 Dec 03 - 07:38

Objects

Mercury

Equipment

William Optics Meg 72
0.8x reducer
ASI 2600MM
589nm Alluxa filter

Exposure

10 x 30 second exposures

Location

Nottingham

Target name

Mercury sodium tail

Title

Mercury's sodium tail

About this image

Another apparition of Mercury's elusive sodium tail. The apparent length of the tail I've detected is 0.38 degrees (22.5 arcminutes), which if doing all the trigonometry equates to 985,849km in true length. Mercury's radial velocity was 8.59km/s and True Anomaly Angle (TAA) 58.7. Mercury was 0.875 AU from Earth and 0.330 AU from the Sun, and the Sun 0.986 AU from Earth. This is a cropped image. Chris Hooker and I have submitted a paper to the BAA Journal on the sodium tail.

Files associated with this observation

Sodium Tail.jpg (81.8 kB)

Like this image

Jeremy Shears, Bill Leatherbarrow

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