| Uranus Spectra 2018/12/9 by Christophe.P |
Here is a new experience on Uranus spectroscopy. For this time, I took a second spectrum for both Uranus and the reference star with an infrared filter (Baader IR685) and then assembled the two cuts (visible+IR) under Vspec to get a full spectrum up to the infrared end. This is necessary since with the SA100, the blue end of the second order is overlapping with the IR end of the 1st order, as a result the data after 750 nm is mixed and not exploitable. Using a filter of order allows to get a pure IR spectrum, and because exposure time is higher, allows a correct recording of the very faint Uranus features. As a result the greatt 890 nm CH4 band and the last continuum at 940 nm are clearly showing. Processing is done by diving raw Uranus spectra by raw G2V spectra. Overlapping zone between the two cuts is 700-710 nm. Offset, dark, flat corrected and skybackground removed during IRIS processing. More experiences when clouds go away!Here is again my full spectrum of Uranus, with a different processing. The results are now obtained with ISIS and Gnuplot, which gives a synthetic colorisation that I prefer. The first serie is the same at the one previously sent, and represents the pure capacity of the planet to reflect the sunlight (the reflectance). For the second serie I divided the raw Uranus spectrum by the instrument response, calculated on an adjacent star (the same, actually, but this is not important there). This serie now reveals the real color response of the planet. As the reflectance shows Uranus almost perfectly reflects light in the deep blue, the blue end is now similar to the Sun spectrum. Best regards and may you all have nice end of year celebrations.
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