|Carina is the third and southern most
part of Argo Navis. Stretching across one of the brightest parts
of the southern Milky Way it contains some of the most stunning and interesting
sights in the sky. For more on the story of Argo Navis see
Carinae, is the second brightest star in the sky. Canopus was
actually a person, the navigator for Menelaus, the king who lead the Greeks
into the Trojan War to reclaim his wife Helen from Paris of Troy.
Canopus died on the way home in Egypt and a monument was erected at the
the place and later a city arose. The city, situated on the Nile
delta, slipped suddenly below the water's surface due to some cataclysm
in ancient times. Just recently the city has been re-found beneath
the water and mud and beautiful monuments retrieved. The star itself
has long been used for navigational purposes, roughly marking south.
Even today it is still used by space craft and astronauts to navigate through
space, as it is always visible below the plane of the solar system and
so never goes behind the sun. In the old constellation of Argo Navis
Canopus marked the rudder of the ship, a very appropriate position for
the Navigator's star.
Carinae, is a bit of a mixed name, using both Arabic and Latin, that translates
to meaning "quiet waters." It is the brightest star in the "diamond
cross". This "cross" is seen between Crux and the false cross.
The star h
Carinae has been of particular interest in recent times as it has brightened
once more to naked eye visibility, peaking at a magnitude to 5.0 in 2000,
the brightest it has been since 1843. Then it reached a magnitude
of -1, as bright as Sirius, during a an outburst, before fading to mag.
7 where it remained for a century. In the 1950's it brightened to
mag. 6 but only in the late 1990's it began to brighten rapidly again.
It is known as a Luminous Blue Variable (LBV) and has a mass over 100 times
that of our sun and approaches the theoretical limit for the size of a
star. LBV's are very rare stars. Only 5 are known within our
galaxy and only 30 or so in surrounding Local Group galaxies. They
are thought to be a short term transitional stage as they shed a lot of
mass to become Wolf-Rayet stars and then maybe progress to a supernova
before the star finally dies.
Surrounding this star is the large bright
emission nebula known as the Eta Carinae nebula, but the nebula is not
powered by the star itself. This nebula is as large and bright as the Lagoon
Nebula in Sagittarius and it can be discerned by the naked eye as the brightest
patch of the Milky Way to the west (right side) of Crux, binoculars will
show you it's rough outline. Telescopes will give the viewer only
a portion of this grand sight, but are needed to get a good view of the
star eta Carinae itself. The star glows a bright orange in the upper
'wedge' and if one looks closely with a higher power the star seems a little
elongated. The nebula will also show up clearly on photographs of
only 30-60 seconds.
Carinae and the open cluster IC 2602 that surrounds it is sometimes
known as the southern Pleiades. It covers 10 of sky (2
times the width of the moon) and is at it's best in binoculars. It
can be glimpsed with the naked eye using averted vision and under exceptional
conditions individual stars may be seen directly around theta Carinae.
An excerpt from Johan van
Keulen's Boeck zee-kaardt, 1709.
Carina represents the keel
of the ship Argo Navis,
with Canopus marking the
rudder of the ship.
This article is ©2002