|Dorado, the gold fish, was added to the
sky by Johann Bayer in 1603. The gold fish it refers to is not the
common aquarium variety but to a tropical fish from Hawaii which changes
colour as it dies. Dorado does not stand out to the naked eye, with
itís brightest star alpha being only magnitude 3.3 but can be easily located
as it contains the northern part of the Large Magellanic Cloud (LMC).
Dorado is diving into the LMC and his eye is marked by the south ecliptic
pole, which was once also known as the Polus Doradinalis. This pole
marks the southern axis of the ecliptic, or in other words, the point
that the ecliptic is shifting around due to the effect of precession.
One alternative name for this constellation
was Xiphias, the Sword Fish. You may spot it on older pictorial atlases
but the name fell from use in more modern times. Xiphias was
also used as a term to describe comets in the form of a sword in late Roman
times, so may have been considered to be confusing.
Large Magellanic Cloud is named after the
seafaring explorer Magellan, who was one of the first Europeans to adventure
into the southern oceans. This "cloud" is the largest satellite galaxy
to our Milky Way and lies only 180 000 light years away from us.
To see the LMC clearly you will need to be away from light pollution and
have no bright moon about. In a bright sky you may need to use averted
vision to gain a good view but in a truly dark sky you will wonder how
you ever missed seeing it before! Binoculars reveal itís irregular
structure and the bright knot of the gigantic Tarantula Nebula (see below).
There are many other nebulae and star clusters in the LMC to explore but
you will need good charts and a large aperture telescope to do so.
An excerpt from Johan van
Keulen's Boeck zee-kaardt, 1709.
It is a small, faint constellation
that lies under
Puppis, the Stern. Despite
this it contains the
South Ecliptic Pole, half
of the Large Magellanic Cloud
and several impressive galaxies
that can be seen in
medium to large telescopes.
There is a magnificent object within the
LMC that has several names: the Tarantula nebula, 30 Doradus, NGC 2070
and once it was also known as the Great Looped Nebula. In binoculars
this massive nebula stands out as a glowing knot to one side of the LMC,
giving you a good look at itís full extent - 1000 light years across, larger
than anything visible in our own galaxy. It is an emission nebula
and telescopes readily show a tight cluster of newborn stars in itís middle
- the eyes of the tarantula. Telescopes will give you good views
of the loops on gas which give the Tarantula Nebula itís modern name.
This article is ©2001
Stargazers Astronomy Shop