Doppler shifts of sunspot NOAA 10008

The CN line at 1564.6 nm showing a Doppler shift as a function of azimuth angle around the sunspot NOAA 10008 during a period of three days. The spot positions were 0.65 (east), 0.27 and 0.66 (west) solar radii from disk center on June 21, 24, and 27, 2002, respectively. The line absorption can be seen at a variety of wavelengths ranging from zero outflow speed up to about 9 km/sec. The dashed lines show the typical horizontal speed of 6 km/sec corrected for projection effects. See the science highlights section of the June 2003 NOAO Newsletter (currently only available in PDF format), and the companion image from the article.