|T Centauri | 6.5 | 8.0 | 90¼ | Period unusually | | | | | |short for this | | | | | |class of variables. | | | | | | | |R Centauri | 5.3 | 13.0 | 568 | An Antarian | | | | | |star. Double max. | | | | | |and min. The | | | | | |secondary min. | | | | | |about mag. 8½. | | | | | | | |R Scuti | 4.8 | 7.8 | ? | Bright and faint | | | | | |minima, usually | | | | | |alternative. Period | | | | | |perhaps irregular. | | | | | | | |S Sculptoris| 5.8 | 11.8? | 366 | | |R Horologii | 5.9 | 12.0 | 405 | | |L² Puppis | 3.4 | 6.2 | 140 | | | | | |or longer| | |R Carinae | 4.5 | 10.0 | 309 |{ Antarian stars. | | | | | |{ Spectra very similar| |S Carinae | 5.8 | 9.0 | 148 |{ to that of Mira. | |R Hydrae | 4.0 | 9.8 | 425 | | |S Virginis | 5.6 | 12.3 | 379½ | | |R Aquarii | 6.2 | 11.0 | 387 | | +------------+----------+----------+---------+----------------------+ Against this suggestion we must set the fact that no stars have been found to link together the slow and slight change represented by the sunspot period with the rapid and violent change suffered by Mira variables. Their periods, though never less than three months, are never more than two years, and the light radiated by Mira at maximum sometimes amounts to five thousand times as much as at a faint minimum. Nevertheless, the fact that these perplexing stars are a link in an unbroken chain of which our sun also forms part suggests that research on the sun, our nearest star, will some day help us to understand more about Mira and stars like Mira. IX ECLIPSING STARS There is another type of variables quite distinct from the Mira stars. These run through smaller light-changes in much shorter periods, also they change abruptly with clockwork regularity, and the spectrum shows no bright lines at maximum, indicative of physical change.