Comet C/2011 L4 (PanSTARRS) with sodium tail - 15 March 2013

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This image clearly show a yellow straight tail that is supposed to be a neutral sodium tail. The large and brighter one is made of dust. The images here below show a size comparison with the Moon (shot a few minutes after, using HDR technique). And the other image below show an RGB decomposition, where the sodium tail is clearly emitting not blue light, and so it is clear the absence of a ion tail.

Technical Data
Optics TEC 140
Focal Length
1011 mm
Focal Ratio f/7.2
Exposure Time Average of 100 shots of 4 s each, ISO auto (from 800 to 3200 ISO)
CCD Canon EOS 60D
Location Capanne di Cosola (AL, Italian Apennines), at 1500 m height
15 March 2013, 18.30 UT
Mount Gemini G-41
Tracking none
Temperature and humidity T= -11°C, RH=49%
Sky brightness at zenith (with SQM-L) Bright sky after sunset
Notes -

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