Mira at maximum
WHEN: Last week of November
The constellation of Cetus represents a Whale or Sea Monster in mythology. It’s a large, sprawling collection of stars defined by mag. +2.0 Deneb Kaitos (Beta (`) Ceti) to the west and the irregular pentagonal pattern forming the creature’s head to the east. Mag. +2.5 orange Menkar (Alpha (_) Ceti) is one of the stars in the pentagon.
The bottom of the head is marked by mag. +3.5 Kaffaljidhma (Gamma (a) Ceti) which together with mag. +4.1 Delta (b) Ceti form the neck. A line from Delta to mag. +3.7 Baten Kaitos (Zeta
(c) Ceti) defines the creature’s back. The variable star Mira (Omicron (k) Ceti) sometimes appears along the back. Also known as ‘Wonderful’, Mira holds the record for having the largest brightness range of any variable star visible to the naked eye at peak.
From late November into December, Mira should be visible to the naked eye as a tangible addition to Cetus. A typical maximum has it as bright as mag. +3.5. Records exist of it as bright as mag. +2.0, rivalling the brightest star in Cetus. Over a period of 332 days it drops from its easy naked-eye maximum to
around 9th magnitude at minimum. At such times,
you’ll need a telescope to see the star clearly.
For naked-eye observers, Mira is only part of Cetus some of the time