𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A Photometric Study of Enceladus

✍ Scribed by Anne J. Verbiscer; Joseph Veverka


Publisher
Elsevier Science
Year
1994
Tongue
English
Weight
721 KB
Volume
110
Category
Article
ISSN
0019-1035

No coin nor oath required. For personal study only.

✦ Synopsis


We have supplemented Voyager imaging data from Enceladus (limited to phase angles of (13^{\circ}-43^{\circ}) ) with recent Earth-based CCD observations to obtain an improved determination of the Bond albedo, to construct an albedo map of the satellite, and to constrain parameters in Hapke's (1986, Icarus 67, 264-280) photometric equation. A major result is evidence of regional variations in the physical properties of Enceladus' surface. The average global photometric properties are described by single scattering albedo (\tilde{\omega}{0}=) (0.998 \pm 0.001), macroscopic roughness parameter (\bar{\theta}=6 \pm 1^{\circ}), and Henyey-Greenstein asymmetry parameter (g=-0.399 \pm 0.005). The value of (\bar{\theta}) is smaller than the (14^{\circ}) found by fitting whole-disk data, which include all terrains on Enceladus. The opposition surge amplitude (B{0}=0.21 \pm 0.07) and regolith compaction parameter (\boldsymbol{h}=0.014 \pm 0.02) are loosely constrained by the scarcity of and uncertainty in near-opposition observations. From the solar phase curve we determine the geometric albedo of Enceladus (p_{\mathrm{v}}=0.99 \pm) 0.06 and phase integral (q=0.92 \pm 0.05), which correspond to a spherical albedo (A=p_{\mathrm{v}} q=0.91 \pm 0.1). Since the spectrum of Enceladus is fairly flat (D. P. Cruikshank, 1980, Icarus 41, 246-258; B. J. Buratti, 1984, Icarus 59, 392-405), we can approximate the Bond albedo (A_{\mathrm{B}}) with the spherical albedo. Our photometric analysis is summarized in terms of an albedo map which generally reproduces the satellite's observed lightcurve and indicates that normal refiectances range from 0.9 on the leading hemisphere to 1.4 on the trailing one. The albedo map also reveals an albedo variation of (15 %) from longitudes (170^{\circ}) to (200^{\circ}), corresponding to the boundary between the leading and trailing hemispheres. 1994 Academic Press, Inc.


πŸ“œ SIMILAR VOLUMES


A Photometric Study of Uranus
✍ Paul Slavenas πŸ“‚ Article πŸ“… 1928 πŸ› John Wiley and Sons 🌐 English βš– 128 KB
A photometric study of Eros 433
✍ Chen Dao-Han; Yang Xiu-yi; Wu Zhi-xian πŸ“‚ Article πŸ“… 1977 πŸ› Elsevier Science βš– 460 KB
A photometric study of BO Canum Venatico
✍ B. Albayrak; Z. MΓΌyesseroğlu; S. Γ–zdemir πŸ“‚ Article πŸ“… 2001 πŸ› John Wiley and Sons 🌐 English βš– 332 KB
A photometric study of eclipsing binary
✍ B. Albayrak; G. DjuraΕ‘eviΔ‡; S.O. Selam; O. AtanackoviΔ‡-VukmanoviΔ‡; M. YΔ±lmaz πŸ“‚ Article πŸ“… 2005 πŸ› Elsevier Science 🌐 English βš– 436 KB

Photoelectric BVR light curves of the recently discovered eclipsing binary V351 Peg were studied for the first time to derive the physical parameters of the system. The light curves were obtained at the TU Β¨B\_ ITAK National Observatory (TUG) during three nights in August 2003. The solutions made by