Rd. Robinson et al., ULTRAVIOLET AND RADIO OBSERVATIONS OF THE YOUNG, RAPIDLY ROTATING K0 DWARF STAR HD-197890, Monthly Notices of the Royal Astronomical Society, 267(4), 1994, pp. 918-926
We present the results of UV observations taken with the International
Ultraviolet Explorer (IUE) satellite and microwave observations obtai
ned with the Australia Telescope during an observing campaign of the r
apidly rotating K0 dwarf star HD 197890, nicknamed 'Speedy Mic'. This
star was recently recognized as a powerful, transient EUV source by th
e ROSAT WFC, and subsequent investigation showed it to be a ZAMS or po
ssibly a PMS dwarf which may be a member of the Local Association. Our
observations show it to have strong, variable UV emission lines near
the 'saturation' levels. The radio observations show a level of 'quies
cent' emission consistent with other rapidly rotating stars, but there
is no evidence for the large flux variations that normally characteri
ze the time history of such objects.