1. Rotational Poles and Dimensions of Ceres and Vesta and three STEAs
Jack Drummond
Starfire Optical Range
Air Force Research Lab

2. Rotating 3x2x1 Asteroid

3. Fits are Made in the Fourier Plane
Image = E סּ L
₣ (Image) = K0 2J1(x)/x

4. Juno Fit Diagnostics Shane 3 m at 2.1μm

5. Davida Fit Diagnostics Keck 10 m at 2.1μm

6. Ceres(λ=5550) December 2003 HST

7. Ceres Oblate Spheroid Observations

9. Ceres’ Pole

12. Ceres Dimensions This work Thomas et al a=b=α= 480±1 km 487.3±1.5 km
c=[β2-a2 sin(θ)2]½ / cos(θ)=
448±1 km ±1.5 km

13. Vesta October 1997 HST

14. Vesta Triaxial Results

15. Vesta: AO on Lick 3 m

16. Vesta Resolved

17. HST
Lightcurves SI AO

18. Weighted Mean Vesta This Work (n=4) Thomas et al
a = 562±2 km ±10 km
b = 543±2 km ±10 km
c = 458±4 km ±10 km
RA = 325° °
Dec= +55° °
Error radius = 6.7° °

19. 511 Davida with AO at Keck

20. 511 Davida with AO at Keck

21. 511 Davida with AO at Keck

22. Davida Edge Features

23. 52 Europa with AO at Keck

24. 52 Europa with AO at Keck

25. 52 Europa with AO at Keck

26. 2 Pallas with AO at Keck

27. Pallas Pole on Ecliptic Globe

28. STEAs (Standard Triaxial Ellipsoid Asteroids)
a Al Conrad, Bill Merline, Christophe Dumas, Drummond et al. 2007, Icarus in press:
‘Direct measurement of the size, shape, and pole of 511 Davida with Keck AO in a single night’
b Merline et al. 2007, In prep:
‘Direct measurement of the size, shape, and pole of 52 Europa with Keck AO in a single night’
c Drummond and Julian Christou 2007, Icarus submitted:
‘Triaxial Ellipsoid Dimensions and Rotational Poles of Seven Asteroids from Lick Observatory Adaptive Optics Images, and of Ceres’