Mira

Brightest long-period pulsating variable star, located in the constellation Cetus. Mira was the first star discovered to vary periodically in brightness.

In 1596 Dutch astronomer David Fabricius noticed Mira as a third-magnitude object. Because it did not appear on any of the star charts available at the time, he mistook it for a nova. The German astronomer Johann Bayer included it on his star atlas in 1603 and designated it Omicron Ceti. The star vanished from view again, only to reappear within a year. It was named ‘Stella Mira’, ‘the wonderful star’, by Hevelius, who observed it 1659–82.

It has a periodic variation between third or fourth magnitude and ninth magnitude over an average period of 331 days. It can sometimes reach second magnitude and once almost attained first magnitude in 1779. At times it is easily visible to the naked eye, being the brightest star in that part of the sky, while at others it cannot be seen without a telescope.