Cosmic
Spider is Good Mother
Hanging above the Large Magellanic Cloud (LMC) - one of our closest
galaxies - in what some describe as a frightening sight, the
Tarantula nebula is worth looking at in detail. Also designated 30
Doradus or NGC 2070, the nebula owes its name to the arrangement of
its brightest patches of nebulosity that somewhat resemble the legs
of a spider. This name, of the biggest spiders on Earth, is also
very fitting in view of the gigantic proportions of the celestial
nebula - it measures nearly 1,000 light years across!
The Tarantula nebula is the largest emission nebula in the sky and
also one of the largest known star-forming regions in all the Milky
Way's neighbouring galaxies. Located about 170,000 light-years
away, in the southern constellation Dorado (The Swordfish), it can
be seen with the unaided eye.
As shown in this image obtained with the FORS1 multi-mode
instrument on Eso's Very Large Telescope, its structure is
fascinatingly complex, with a large number of bright arcs and
apparently dark areas in between. Inside the giant emission nebula
lies a cluster of young, massive and hot stars, denoted R 136,
whose intense radiation and strong winds make the nebula glow,
shaping it into the form of a giant arachnid. The cluster is about
2 to 3 million years old, that is, almost from 'yesterday' in the
13.7 billion year history of the Universe.
Several of the brighter members in the immediate surroundings of
the dense cluster are among the most massive stars known, with
masses well above 50 times the mass of our Sun. The cluster itself
contains more than 200 massive stars.
In the upper right of the image, another cluster of bright, massive
stars is seen. Known to astronomers as Hodge 301, it is about 20
million years old, or about 10 times older than R136. The more
massive stars of Hodge 301 have therefore already exploded as
supernovae, blasting material away at tremendous speed and creating
a web of entangled filaments. More explosions will come soon - in
astronomical terms - as three red supergiants are indeed present in
Hodge 301 that will end their life in the gigantic firework of a
supernova within the next million years.
While some stars are dying in this spidery cosmic inferno, others
are yet to be born. Some structures, seen in the lower part of the
image, have the appearance of elephant trunks, not unlike the
famous and fertile "Pillars of Creation" at the top of which stars
are forming. In fact, it seems that stars form all over the place
in this gigantic stellar nursery and in all possible masses, at
least down to the mass of our Sun. In some places, in a marvellous
recycling process, it is the extreme radiation from the hot and
massive stars and the shocks created by the supernova explosions
that has compressed the gas to such extent to allow stars to
form.
To the right and slightly below the central cluster, a red bubble
is visible. The star that blows the material making this bubble is
thought to be 20 times more massive, 130 000 times more luminous,
10 times larger and 6 times hotter than our Sun. A possible fainter
example of such a bubble is also visible just above the large red
bubble in the image.
Earlier colour composite images of the Tarantula nebula have been
made with other instruments and/or filters at Eso's telescopes,
e.g. PR Photo 05a/00 in visual light with FORS2 at the VLT at
Paranal, and PR Photos 14a-g/02 and 34a-h/04 with the Wide-Field
Imager at the ESO/MPG 2.2-m telescope at La Silla.
High
resolution images here