TucanaTucana
Abbreviation:
Particulars:
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.
