11. It is an irregular variable , its apparent magnitude varying between 2.37 and 2.45. 12. "' PU Aurigae "'is an irregular variable star located in the constellation Auriga. 13. The extrinsic S stars are less luminous and longer-lived, often smaller-amplitude irregular variables . 14. It is also an irregular variable star with a range of less than a tenth of a magnitude. 15. Aldebaran is a slightly variable star, of the slow irregular variable type " LB ". 16. U Antliae is a red irregular variable star that varies between magnitudes 5.27 and 6.04. 17. It is catalogued as an irregular variable star, but a number of possible pulsation periods have been detected. 18. At the time they were simply described as irregular variables , although remarkable for being the brightest stars in those galaxies. 19. It is an irregular variable and has an apparent visual magnitude which varies between 3.36 and 3.44. 20. 13 Bo�tis is a irregular variable star and its brightness varies from magnitude + 5.2 to + 5.3.
