Observation by Chris Hooker: Io's sodium cloud, 19th December

Uploaded by

Chris Hooker

Observer

Chris Hooker

Observed

2023 Dec 19 - 22:27

Uploaded

2023 Dec 21 - 11:11

Objects

Jupiter

Equipment

110 mm F/6 ED refractor
0.45x re-imaging focal reducer
Alluxa sodium D-line filter
Thorlabs 570 nm filter

Exposure

40 seconds (sodium), 7 seconds (off-band)

Location

Didcot, Oxfordshire

Target name

Jupiter

Title

Io's sodium cloud, 19th December

About this image

Images of Io's sodium cloud are strongly affected by glare around Jupiter due to scattering in our atmosphere. This can be eliminated by subtracting an image taken at a nearby wavelength, in which the scattering is essentially the same but the sodium light is not present. The result in this image shows a faint fan of sodium emission extending around 20 Jovian radii to the right of Io.

Io and Jupiter were masked in the off-band image before subtracting it, so they appear bright. Europa to the left of the planet and Callisto to the right moved slightly between the captures. The black circle around Jupiter is where the sodium and off-band images were both saturated and hence the same brightness. The two rings in the lower part of the image are due to internal reflections in the optics.

Files associated with this observation

Io cloud 19 Dec 2023 OB sub.png (536.6 kB)

Like this image

Jeremy Shears, Michael O'Connell, Nick Hewitt, Callum Potter, Paul G. Abel, James Weightman, Bill Leatherbarrow, Steve Knight, Dr Richard John McKim

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