Redshift challenge in Seyferts Sextet Seyferts Sextet image NOAO The National Optical Astronomy Observatory (NOAO) site tells about the image: "This picture was taken at the Kitt Peak National Observatory s 2.1-meter telescope in July of 1998, as part of the KPNO Research Experiences for Undergraduates program, sponsored by the National Science Foundation . North is up, east is to the left." The accompanying image shows labeling and redshifts expressed in speeds km/s. While most redshifts in the sextet are in the range 4017 km/s - 4482 km/s there is one odd galaxy in the center with the speed of 19813 km/s. This is another story, altogether. Image NOAO Always ready for new adventures in Science, arent we! "Five of the members show very similar redshifts, from 4000 to 4500 km/s, while the fifth is measured at nearly 20000 km/s. Conventional wisdom argues that this is a chance projection of a distant background galaxy: some would have otherwise and require a complete reth...