Over the last couple of weeks I’ve been observing Uranus both from my home observatory and remotely. I took a low resolution spectrum from home and recorded the methane bands in the atmosphere of the planet using an objective prism on loan from the BAA instrument collection. I’ve also imaged the satellites on two occasions using remote telescopes.All the results are on the forum of the Orwell Astronomical Society at: http://forum.oasi.org.uk/viewforum.php?f=6.I’m hoping to follow up on these initial ‘quick look’ results later this year with more detailed spectra and a better sequence of satellite images.Mike.
Posted by Robin Leadbeater at 19:04 on 2014 Jan 10
Hi Mike,While Uranus does show more intense Methane absorption bands than Jupiter, I am wondering if in this case the difference is being exaggerated by some effect which has reduced the contrast in the Jupiter spectrum. (The H beta absorption band, from the reflected sunlight, is also significantly weaker in the Jupiter spectrum whereas it would be expected to be of similar intensity.) Perhaps the larger angular size of Jupiter (which determines the resolution in a slitless spectrum) is playing a part here?Robin
Hi Robin,Yes that’s exactly right…Jupiter is an extended object at 550mm focal length so the objective prism set-up blurs the spectrum. One of the methane bands in the spectrum of Jupiter is faintly visible.This was just an experiment to see what is possible with such a system and is reported here to hopefully stimulate interest in spectroscopy in general…Mike.