Pluto's Lightcurve: Results from Four Oppositions

✍ Scribed by David J. Tholen; Edward F. Tedesco

• Book ID: 102571489
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 475 KB
• Volume: 108
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1006/icar.1994.1054

✦ Synopsis

The rotational lightcurve, phase function, and orbital lightcurve of the Pluto-Charon system were measured in blue light over four consecutive oppositions spanning 1980 to 1983. Compared with observations made in the three previous decades, our lightcurve shows a higher amplitude of (0.29 \mathrm{mag}), as well as a fainter rotationally averaged brightness, which provide constraints on the surface albedo distribution of the two bodies. The synodic rotational period of (6.38726 \pm 0.00007) days is consistent with the orbital period of Charon, which provides evidence for a completely tidally evolved system. The phase coefficient is (0.0372 \pm 0.0016) mag (\mathrm{deg}^{-1}), indicating a very shallow opposition surge compared with asteroids, but consistent with a high albedo surface. The orbital lightcurve shows substantially less fading than the earlier observations, which suggests that there is not a gross difference in average albedo between the southern and northern hemispheres. 01994 Academtc Press, Inc.