[Pic]

Abbreviation:

Tuc

English name:

Toucan

Coordinates

see Stellar data

Particulars:

• Double stars delta Tuc, kappa Tuc, lambda Tuc
• Multiple star beta Tuc
• Globular cluster NGC 104, NGC 362
• Irregular galaxy NGC 292 (Small Magellanic Cloud)

General:

A small constellation in the cirumpolar region of the south pole of the sky. it extends from DECL=56 degrees to DECL=75 degrees and RA=22h 10m to RA=1h 20m. There are only few bright stars in this region, but Tucana became known due to the presence of the Small Magellanic Cloud and the second brightest globular cluster in the sky, 47 Tucanae, NGC 104.

Stars and other objects

The double delta Tuc is a nice object for small telescopes. A 4th mag star and its 9th mag companion is revealed.
The components of kappa Tuc are of 5th and 7th mag. The blue-white pair can be viewed with small scopes (30 mm aperture an higher). There are at least two more components, but they a too faint to be observed with small scopes.
The double lambda Tuc consists of a K2 giant of 5.45 mag accompanied by a F7IV-V star of 6.22 mag.
Viewed with binoculars beta Tuc appears as a wide double of two main sesquence stars (a B9 of 4.37 mag and a A0 of 5.09 mag). With a small telescope a third star (4.54 mag) close to the brighter component is revealed. Yet this star is double itself, consisting of an A2 and an A7 main sequence star). In fact it is a sextuple, but the other components are too faint to be observed with small scopes.
One of the finest globular clusters can be found in this constellation, NGC 104, 47 Tucanae. It is the second brightest in the sky (only beaten by omega Cen). To the naked eye this globular appears as a somewhat misty star of 5th mag. Using a binocular the observer will clearly see an increase in brightness towards the center. With a telescope of at least 100 mm one can resolve individual stars. The cluster covers about 0.5 degrees of the sky and contains around 100000 member stars. Its distance has been estimated to be about 20000 light years.
At the northern edge of the Small Magellanic Cloud lies the globular cluster NGC 362. It is not part of the galaxy but a foreground object (about 40000 lightyears distant to us). It is of 6th mag and can be observed with binoculars.
In a distance of about 230000 lightyears lies the smaller one of the two companion galaxies of our galaxy, the Small Magellanic Cloud. It covers 3 degrees of the sky and even binoculars and small scopes are sufficient to reveal some of the stars, clusters and nebulae. To the naked eye the shape of this irregular galaxy reminds somewhat on a tadpole.