The Absolute Proper Motion of the Sculptor Dwarf Spheroidal Galaxy
Session 51 -- Dwarf Galaxies
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [51.07] The Absolute Proper Motion of the Sculptor Dwarf Spheroidal Galaxy

A. E. Schweitzer (U. Wisconsin- Madison), K. M. Cudworth (Yerkes Obs., U. Chicago)

We have measured an absolute proper motion with uncertainties $\le$0.025 arcsec/century in each coordinate for the Sculptor dwarf spheroidal galaxy. Sculptor is a companion to the Milky Way at a distance of 79 kpc from us. This result is based on 26 plates taken over the course of more than half a century from four different telescopes, with the zero point of the absolute proper motion set by several background galaxies. Our proper motion uncertainty is similar to or smaller than those obtained by different groups for other distant satellites of the Galaxy. The motion of Sculptor, after correction for the solar peculiar velocity and the orbital motion of the LSR, is less than twice the uncertainty. Nevertheless, the direction of the motion is significant because it rules out motion along the Magellanic Stream, but allows motion (within 3 $\sigma$) toward the Fornax dwarf spheroidal galaxy. This research has been partially supported by the National Science Foundation.