Hubble Astrometry and the 3D Structure of eta Carinae

Previous abstract Next abstract

Session 34 -- Massive Hot Stars with the Hubble Space Telescope Part I
Oral presentation, Tuesday, 31, 1994, 8:30-12:30

[34.04] Hubble Astrometry and the 3D Structure of eta Carinae

D.G. Currie, D.J. Dowling, P.V. Avizonis (U of MD), J.J. Hester, P.A. Scowen (ASU), E.J. Groth (Princeton U), WF/PC IDT, WFPC-2 IDT

The structure, physics and history of the massive eruptive variable star, eta Carinae, have been addressed by measuring the proper motion of the numerous dust fragments and condensations. The motions of elements within the Homunculus and of the other debris have been measured using our three WF/PC images obtained over a three-year interval.

WF/PC and WF/PC-2 measurements are compared internally and then to older ground-based data on outer condensations using a longer (25-year) temporal baseline [Walborn and Blanco, 1988] to determine the precision of the measurements. The accuracies of the WF/PC velocities for the Homunculus over the three year interval are found to be comparable to the accuracy of the earlier data on the outer condensations.

Combining our measurements of the astrometric motion with published spectrometry data on the radial velocities [Allen and Hillier, 1993] and the general morphology displayed in our WF/PC-2 image, we define the three-dimensional structure of this unique object.

The measurements of astrometric motion are performed by cross- correlating small patches (5x5 pixels) extracted from the temporally separated images. In order to evaluate the inner structure, we have modified the Lucy-Richardson algorithm to reduce the algorithmic features. The procedures used to implement and evaluate the deconvolution algorithms, the role of the optical distortion of the WF/PC camera optics, and the spatial relationships among the CCD's will be described.

\parindent 0in Walborn, N. R. and Blanco, B. M., PASP, 100, 797-800, 1988. \\ Allen, D. A. and Hillier, D. J. Proc. ASA, 10(4), 338-341, 1993.

Tuesday program listing