TESTING FOR INTERACTION BETWEEN THE GALAXIES NGC-450 AND UGC-807

The Sc spiral, NGC 450 (v0 = 1863 km s-1) has conspicuously brighter H II regions at just the point o projected contact with the spiral UGC 807 (v0 = 11,600 km s-1). New spectra and photometry are reported whic h show the following: 1. The rotation curve of the low-redshift spiral has asymmetries and large discontinuities. 2. The brightest H ii regi ons show differences between them of the order of 100 km s-1, and one knot shows a discrepancy of 400 km s-1, well in excess of escape veloc ity. 3. The distribution of neutral hydrogen in NGC 450 is heavily ove rbalanced to the side of the bright knots and the position of UGC 807. 4. The rotation curve of the high-redshift spiral shows a shallow inc rease to maximum rotational velocity (v(max) = 171 km s-1) which is ch aracteristic of lower luminosity spirals. The rotation curve is also a symmetric and shows irregularities. 5. The relative Halpha surface bri ghtness, a distance-independent quantity, signifies currently enhanced star formation in UGC 807. The Halpha luminosity of the higher redshi ft spiral is unprecedentedly large if placed at its redshift distance. 6. The morphology of the higher redshift spiral is more extended on t he side toward NGC 450 than on the side away and the color index isoco ntour lines indicate a discontinuity where the UGC 807 image merges we ll that of NGC 450. The conclusion from the extensive analysis is that one would have to invoke an enormous conspiracy of accidents in order to avoid the conclusion that UGC 807 is a moderately low luminosity g alaxy interacting with NGC 450.