| Neptune spectroscopy and photometry 2019/09/04 by Christophe.P |
Here are photometry and albedo results reduced from observations carried out on September 4th. These are the first obtained with the addition of a 3,8° prism to the Star Analyzer (the so called "grism" setting). This accessory has noticeably increased the sharpness of the spectrum and introduced a slightly improved spectral resolution especially in the red end of the spectrum, even if it does not turn the SA100 into an ALPY600, of course. Colour coefficients have been recalculated with new star observations. The experimental U coefficients have been adjusted so the U-B color index of HD217877, as found in the AAVSO database, is conserved while re-calculating its UBVRI values starting from Beta Aquarius. Those coefficients produce a coherent value as applied on Neptune so they should be correct. R values are still higher than expected, but I is getting closer.
ALPO-Japan Latest