PI: P. Frank Winkler, Middlebury College, email@example.com
Address: Department of Physics, Bicentennial Hall, Middlebury, VT 05753, USA
CoI: Knox S. Long, STScI
CoI: William P. Blair, The Johns Hopkins University
CoI: Matthew Vaughan, Middlebury College
Title: Tycho's Supernova Remnant: Deep Imaging, Proper Motions, and Distance Measurement
Abstract: We propose deep \ha imagery of the SN 1572 (Tycho) remnant. By comparing the new images with those from epochs back to 1988, we will obtain the first CCD measurement for proper motions of Tycho's optical filaments-improving precision by a factor of 3 or more over classic photographic studies. Balmer-dominated filaments like those in Tycho have broad profiles whose width is well correlated with shock velocity, as we can measure using our recent spectra from the MMT. Through the combination of transverse velocity and proper motions, we expect to measure the distance to SN 1572 to \lesssim 10%, compared with the present uncertainty of a factor of 2. Measurement of the proper motion around a significant fraction of the shell (~ 120\deg in azimuth) should help resolve the mysterious conflict between recent radio and X- ray measurements of the shell expansion rate for Tycho and other young SNRs. Beyond simply obtaining a ``good-enough" current-epoch image for measuring Tycho's expansion, we propose to use \it either the WIYN with Mini-mosaic (run 1, our preference) \it OR the 2.1m (run 2) to obtain a deep, high-resolution image of Tycho. Deep imaging with continuum subtraction may reveal faint emission around much of the shell, or place stringent limits on its surface brightness. Either will tell us about Tycho's surroundings. With broadband B and V images to combine with \ha, we will produce a color image that should be valuable for use in textbooks and for general public outreach.