Mira
Where is Mira?
Look south, about 36° up at 02:18 in Cetus.
- Rises
- 20:33
- Highest
- 02:22
- Sets
- 08:10
- Best after dark
- 02:18 · 36°
Can I see Mira tonight?
From London tonight, Mira is above the horizon after dark. It’s highest after dark at 02:18, in the south at 36°.
At magnitude 6.5 it is too faint for the eye; binoculars will show it.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Mira look like?
Mira looks orange to the eye (color is easier to see in binoculars). Its spectral type is M5-9IIIe+DA: cool red giant (much cooler than the Sun).
Eyes
Visible near maximum as a reddish star in Cetus. For much of its cycle it is invisible to the naked eye.
Binoculars
Follow it through much of its cycle. Its deep red color is obvious near maximum.
Telescope
Track it even at its faintest. Comparing it with nearby stars over weeks is a classic variable-star project.
About Mira
Mira, also called Omicron Ceti, was the first star known to change brightness regularly, apart from novae. Its name means “wonderful” in Latin.
It is a pulsating red giant. Over a cycle of about 332 days it swells and shrinks, brightening to around magnitude 2 or 3 at its best and fading to about magnitude 10 at its faintest, far below naked-eye visibility.
Mira is moving quickly through space, and ultraviolet images show a long tail of material it has shed behind it, more than 10 light-years long.
Mira was first noticed changing brightness by David Fabricius in 1596, and its regular cycle was established in the 1630s.
Not every maximum is equally bright. Some peaks reach about magnitude 2, while others barely make it to magnitude 4 or 5.
Mira has a white-dwarf companion that draws in material from the giant’s wind.
Mira in Cetus
Questions
Why does Mira change brightness?
Can I see Mira tonight?
Sources: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences