Tucana
What is Tucana?
Constellations· Southern spring evenings · not visible from Korea · home of the SMC. The South American toucan of the southern sky. Its stars are faint, but it holds the Small Magellanic Cloud, a satellite of our galaxy, and 47 Tucanae, the second-brightest globular cluster — one of the finest constellations for southern observers. Never visible from Korea; move the Sky view location south.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Tucana is in your sky right now: https://nowsky.org/solar/sky?sel=con:Tucana — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Alpha Tucanae | 2.9 |
| Gamma Tucanae | 4.2 |
The 2 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.
Constellation basics
| Season | southern spring evenings · below the horizon from Korea |
|---|---|
| Brightest star | Alpha Tucanae (2.9) |
| How to find | south of Achernar, around the SMC |
| Area rank | 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Tucana?
- southern spring evenings · below the horizon from Korea.
- How do I find Tucana?
- south of Achernar, around the SMC.
- What is the brightest star in Tucana?
- Alpha Tucanae, magnitude 2.9.
- Where is Tucana in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Thirty millisecond pulsars inside 47 Tucanae
The globular cluster 47 Tucanae in Tucana is so dense, a million stars packed together, that stars brush past one another and exchange partners often. As a result nearly thirty millisecond pulsars, spinning hundreds of times a second, have been found in it: neutron stars spun up to the limit by material taken from companions. Few clusters have yielded so many.
Because each pulsar is accelerated differently within the cluster's gravity, tiny shifts in the arrival times of their pulses are used to measure the distribution of mass in the core. Whether an intermediate-mass black hole sits at the centre has been examined with that data, without a firm answer. Lying in front of the Small Magellanic Cloud, the cluster belongs to our own galaxy at 15,000 light-years, thirteen times nearer than the galaxy behind it.
The constellation in depth
Tucana is one of the twelve constellations Plancius created in 1598 from Keyser and de Houtman's southern observations, celebrating an exotic bird of South America and the East Indies; early charts sometimes called it the Indian Magpie. Lying near the pole, this was sky that Europe had never seen.
Its brightest star is only magnitude 2.9, but its contents are remarkable. The Small Magellanic Cloud, a dwarf galaxy 200,000 light-years away, shows as a hazy cloud to the naked eye, and beside it 47 Tucanae (NGC 104) is the second-brightest globular cluster after Omega Centauri, visible to the eye as a fuzzy star. Beta Tucanae is a six-star multiple system.
Near declination −65°, it never rises anywhere in Korea. From the southern hemisphere it rides high on September–December evenings below Achernar, together with the Small Magellanic Cloud. Set the Sky view location to Sydney or Cape Town and switch on "More objects" to see where the SMC lies.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.