Discover the Wonders of the Sword Of Orion (There is more to see than just the Orion Nebula)
In this article I am going to look at one of the most amazing asterisms in the night sky of northern hemisphere's, Orion's Sword which, is found unsurprisingly in the constellation Orion. Orion’s Sword contains some of the best sights in the night sky including the Orion Nebula the most famous nebula in the northern hemisphere.
Click to enlarge the Orion star chart |
The constellation itself does resemble a person with a distinctive
belt consisting of three equidistance stars once you have found Orion's belt
head south from the central star of the belt. Dangling from it you will see another three fainter stars in a row
this is Orion's Sword.
So, let us head down the top of sword located near Orion’s
Belt and inspect each celestial phenomenon in turn. One useful feature of the
asterism is that so many of the features are so close together you can easily move
between the stars in the sword. Most of the stars in the Sword or Orion have
nebulosity weather or not it will show up depends on what astronomy equipment
you use.
Click to enlarge the Sword of Orion star chart |
The next target in Orion's Sword is the Running Man Nebula
this consists of NGC 1973, NGC 1975 and NGC 1977. From now on I will just refer
to it as the Running Man Nebula rather than using the individual definitions listing
it is possible to see the Running Man Nebula in medium and large aperture
telescopes in a dark sky site. However, is best suited as a target for astrophotography
as it is not a bright object as you may suspect the Running Man Nebula consists
of three separate nebulae, separated by dark lanes.
Next let us look at the Orion Nebula (M42) and M43 Nebulas together,
M43 is located towards the top of the sword and is separated from M42 by a dark
lane. The Orion Nebula without as you can see in this amazing image the cloud
visible in this image is approximately 20 light-years across, however when radio telescopes were turned to the Orion Nebula it was found that the nebula clouds are at least 100 light years
across. This region of space is also an intense area of active star formation so much so that the gas
in the nebula is illuminated by the newly formed stars.
When observing nebulae many use a O-III filter as it is usually great at bringing
out nebula cloud structure. However, this filter seems to hide the M43
Nebula so I would not use it in this case.
M43 has an apparent magnitude of nine and it is visible in the
dark sky with binoculars, however some of the elongated wisps of structure require
a larger instrument or astrophotography. The Orion Nebula has an apparent
magnitude of four and is visible to the naked eye in a dark sky location so it
should be easily visible in all telescopes and binoculars.
One feature to look out for is the Trapezium, this is a small open cluster of stars at the centre of the Orion Nebula, which contains approximately 300 newly formed stars, however you are only likely to see four to six stars depending on your astronomy equipment.
Another often overlooked nebula in the Orion constellation is M78, if you have had enough of being dazzled by the Orion Nebula then that may well be worth a look.
The final object in Orion's Sword is the open cluster NGC
1980. This open cluster is located around the bright star Iota Orionis while
the cluster looks like this is part of the Orion Nebula it is in fact a
separate cluster located closer to Earth than the nebula itself. If you would like to view more clusters there is also a nice open cluster in the Cassiopeia, M103.
To see what each of these astronomy targets look like through
the eyepiece as well as their exact locations. Along with some great long
exposure astrophotography shots of targets like M42 and the Running Man Nebula watch
this episode below.
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