A report is presented of the occultation of 28 Sagittarii by Titan on 1989 July 3. Visual, video and photoelectric observations, some depicting a central flash event, are reported. The optical characteristics of Titan's upper atmosphere (300-700km altitude) are derived. It is postulated that the distribution of light in the central flash pattern exhibits dispersion as a function of wavelength, and that one unfiltered CCD video recording contains features indicative of absorption by methane. An upper limit for the diameter of 28 Sgr is determined.
Journal of the British Astronomical Association
- Pub Date:
- April 1994