THE ULTRAVIOLET BRIGHTNESS OF URANUS AND NEPTUNE
We carried out brightness measurements of the planets Uranus and Neptune in the Johnson U filter (wavelength ~0.36 micrometers) during the fall of 2018. The SSP-5 photometer manufactured by Optec Inc was used in making the measurements. The mean normalized magnitudes are ‒6.299 (0.023) and ‒6.435 (0.032) for Uranus and Neptune, respectively. Standard deviations are in parentheses. A two-tailed t-Test at the 95 % confidence level was carried out and there were no differences between the mean normalized magnitudes for the 2014-2018 apparitions even though the sub-Earth latitude had increased from ~26° N in late 2014 to ~44° N in late 2018. The ultraviolet brightness values of Neptune also show little statistical difference for the five apparitions between 2014 and 2018. The U(1, 0) values selected by Harris (probably made in the early 1950s) are -6.35 and -6.25 for Uranus and Neptune, respectively. The value for Neptune is almost 0.2 magnitudes brighter in 2018 than that reported by Harris. One possible reason for this discrepancy is the sub-earth latitude in the early 1950s was near 12° N whereas in 2018 it was near 25° S.
The writers would like to thank Truman Boyle for his assistance
Schmude, Richard W. Jr. and Harden, Brian
"THE ULTRAVIOLET BRIGHTNESS OF URANUS AND NEPTUNE,"
Georgia Journal of Science, Vol. 77, No. 1, Article 129.
Available at: https://digitalcommons.gaacademy.org/gjs/vol77/iss1/129