Star Atlas
[1] This wide-field image obtained with
an Hasselblad 2000 FC camera by Claus
Madsen (ESO) shows a region around
the Southern Cross, seen in the right
of the image (Kodak Ektachrome 200,
70 min exposure time). Alpha Centauri
is the bright yellowish star seen at the
middle left, one of the "Pointers" to the
star at the top of the Southern Cross.
ESO, Claus Madsen[2] This spectacular panoramic view
combines a new image of the field
around the Wolf–Rayet star WR 22 in
the Carina Nebula (right) with an earlier
picture of the region around the unique
star Eta Carinae in the heart of the
nebula (left). The picture was created
from images taken with the Wide Field
Imager on the MPG/ESO 2.2-metre
telescope at ESO’s La Silla Observatory
in Chile.decreased; it's just that most radiation is at infrared wavelengths. It is a highly
unstable star, and in the foreseeable future will flare up as a supernova. This
may happen today, tomorrow, or in a million years or more, but happen it
definitely will.The Southern Cross
The Southern Cross, Crux, contains the lovely double star Alpha Crucis. Here
too is the Jewel Box, a lovely cluster with one prominent red star.
Crux is more or less surrounded by Centaurus the Centaur. Here we
have two first magnitude stars Alpha Centauri or Rigel Kentaurus and Beta
Centauri, otherwise known as Agena or Hadar. They lie side by side in the
sky but are not connected. Agena is a remote giant star hundreds of light
years from us while Alpha Centauri is a member of a triple star sytem,
one member of which, Proxima Centauri, is the nearest star in the sky. Its
distance is 4.2 light years.
In the northern part of the sky Orion is in evidence.In summer in the southern hemisphere Orion is prominent with Sirius
much higher in the sky than it ever appears in Britain. This means it twinkles
and flashes much less. Also high up is the splendid constellation of Carina,
the Keel of the ship Argo, a constellation so large that the International
Astronomical Union broke it up into Carina, the Keel, Puppis the Poop, and
Vela the Sails.
The brightest star in Carina is Canopus, which is the most brilliant star
in the sky apart from Sirius. It has an F-type spectrum meaning the star is
yellow-white in colour, though most see it as white. It is an exceptionally
powerful star, tens of thousands of times more luminous than our Sun.
Eta Carinae
Apart from Canopus, Carina contains many remarkable objects, one of these
is the erratic variable Eta Carinae, which is a remote hypergiant. At one time,
around 1840, it was the brightest star in the sky apart from Sirius, but today it
is only just visible with the naked eye. This does not mean its luminosity has