ARTICLES
Observation Studies of Constellations in the Earth and Space (continued)
our Suns could line up across it). Rigel is also a multiple star, with
at least two companions believed to be orbiting with it. Down to
the right is another bright blue star, Kappa Orionis (Saiph). Rigel
and Saiph form the legs of the ‘hunter’.
orange hued ‘eye’ at top right is Alpha Tauri which is also known
as Aldebaran. Aldebaran is a red giant believed to be more than
40 times as wide as our Sun and about 65 light years from our
solar system. It would be interesting to see how students would
depict life on a planet with a huge red star as its sun. To the
left of Aldebaran appear two stars close together. This is in fact
a visible double star (Theta Tauri). They appear close together
from our perspective but are light years apart in reality.
The three stars lined up in the middle of this weird rectangle
form the belt of Orion. These are interesting to explore, but the
more fascinating area is to the right: three stars lined up almost
horizontally. Notice the fuzzy object in the middle? You will find
the famous Orion Nebula here and that explains the fuzziness.
Through binoculars or a telescope this cloudy object will appear
quite large indeed. The nebula, as well as other wonders of the
night sky such as the Trapezium Cluster, is easily discerned with a
small telescope, but on a clear night they can be located with the
naked eye. There are many multiple stars and nebula-like objects
to be seen in Orion. They are too numerous to mention here, but
worth researching. There are also two distinct constellations near
Orion, Canis Major and Lepus, which are worthy of exploring.
Alpha Canis Majoris, also known as Sirius, is the brightest star in
the sky and easy to find at this time of the year.
There are other fascinating objects to be seen in this area,
including the Crab Nebula near Zeta Tauri (not in photo), but I
draw your attention to the small cluster of stars near the bottom
left corner of Photo 2. This cluster, resembling in the image a
cooking pan turned upside down, is known as the Pleiades (and
also commonly as the ‘seven sisters’, though there are more than
seven stars in the cluster). This cluster is notable because the
stars are still very young (only about 100 million years old, which,
compared to our Sun at several billion years of age, is young
indeed). The most visible stars are blue and so are very hot.
April – June
Taurus, named after the Latin word for a bull from Greek legends,
is located just below and to the west of Orion. Taurus of course
is one of the constellations of the zodiac. I encourage students to
explore zodiac constellations for the real reason they are called
constellations of the zodiac and because of their familiarity.
Photo 2 shows most of the Taurus asterism, but does suggest the
interesting places to examine. From the southern hemisphere we
mainly see Taurus on its side. You will find the defining feature
of this constellation, the ‘V’ shaped pattern of stars referred to as
the Hyades, at the centre of Photo 2.
As autumn progresses so do the number of interesting
constellations. Crux, otherwise known as the Southern Cross, is
of course visible most of the year in Australia. It is in the best
position for evening observation study, however, from around
April. Crux will be found by looking south and slightly east, about
halfway up the sky from the horizon after sunset. Photo 3 shows
the constellation slightly out of focus so that we can see the
colours of its brightest stars.
Photo 3: Crux in April
Photo 2: Taurus in January
The Southern Cross is on the right side of the photo. The two
‘pointers’ at left are part of the constellation of Centaurus (more
about them later). Alpha Crucis (a blue star also known as Acrux)
The two stars representing the open ends of the ‘V’ represent the
eyes of the ‘bull’ and the ‘V’ as a whole is its face. The brighter,
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SCIENCE EDUCATIONAL NEWS VOL 68 NO 4