THE SPECTRUM OF T CORONAE BOREALIS, FEBRUARY 10-22, 1946

Abstract

On 1946 February 9 U.T., eighty years after its first observed major brightening, T Coronae Borealis was found by Armin Deutsch at the Yerkes Observatory to have again increased in brightness at least to magnitude 3.2. Word of this discovery was received at Mount Wilson in time to make spectroscopic observations on February 10 U.T. Table I gives in condensed form preliminary data derived from spectrograms obtained by W. C. Miller, R. F. Sanford, P. W. Merrill, O. C. Wilson, and A. H. Joy. The next to the last line of the table gives the approximate widths of the emission lines in km/sec. The last line has rough values of the velocities from the absorption components which accompany the emission lines on their shortward sides. Remarks. On February 10, Ha showed a maximum approximately as wide as the other hydrogen lines. The wings on both sides of Ha, however, gave an over-all width of 8600 km/sec, corresponding to an expansion velocity somewhat in excess of 4000 km/sec. Observers at the Yerkes Observatory, who obtained spectrograms on the night of February 9, reported an expansion velocity of about 4000 km/sec. Perhaps Ha alone had sufficient strength on February 10 to show this great velocity. The O in lines which first appeared on February 12 are best shown by multiplet (3) in the ultraviolet. They were the first emission lines to appear sharp.