AnnMarie's Blog

Orion is a large & fascinating constellation, it graces our northern skies through the winter months. This is a brief journey through some of its sights, please click on any of the images in this article, to see a larger more detailed version of that picture. The majority of my imaging time for the last month has gone into this, so I’ll start with the view that you might see with the naked eye & progress through to close-ups of some of the more striking nebulae.

The image above left is what can be seen with the naked eye at a relatively dark site. Orion was “The Hunter” in Greek mythology, there are various tales about him, the most common explanation for his place in the sky is as follows:

Orion, son of Poseidon, loved Merope, one of Atlas’ daughters, as immortalised in M45 Pleiades. Merope did not love Orion and so he wandered the countryside, hunting animals. One day he was fatally injured after stepping on Scorpius, the Scorpion. In his memory, the Gods placed him in the sky, as far from Scorpius as possible. As company, they put his 2 hunting dogs Canis Major & Canis Minor with him. As quarries in the hunt, Lepus the hare & Taurus the bull are also within his region. They all stand by the river, Eridanus. An alternative story has similar details but suggests that the goddess Artemis was tricked into killing him and so created his constellation in her grief. Whichever story one goes by, Orion still chases Merope & the other Pleiades across the night sky – an eternal love story.

If you view the 2nd image, above right, you will see the outline of Orion. He is classically posed, half kneeling to aim his bow, which he holds in front of himself with his left arm. His right arm swings a weapon up above his head. Meanwhile from his belt hangs his sword, dominated by the beautiful nebula M42. The star name Betelgeuse comes from the Arabic for “The armpit”.

 Following on from the above 2 images, we’ll now close in upon Orion’s body bounded by Betelgeuse & Rigel (below left image) and further in to the stunning region around Orion’s Belt (below right image) …

Note how many stars appear as we increase the total exposure time. One of these stars HR1988, located about 1/3 of the way from Alnitak to Betelgeuse, has at least one possibly two planets in orbit around it. HR1988 is a magnitude 5.95 star with a spectral class of G4V. Other stars of note are Saiph & Rigel (knee & toe), Betelgeuse & Bellatrix (shoulders), Meissa (head) and Alnitak, Alnilam, Mintaka (belt). Details as in the table below:

The image ‘Orion’s Belt 105mm’ above right, concentrates on the Belt region. The belt asterism is formed, as mentioned above, by Alnitak, Alnilam & Mintaka. To one side of Alnitak there is the Flame nebula & at right angles to this, the Horsehead Nebula. Orion’s Messier objects are also shown, read on below for more details.

So time to take a look at some of the nebulae within Orion. There are 3 Messier objects within Orion – M42 the Orion Nebula, M43 De Marian’s Nebula and M78. The image below shows M42 & M43 along with their immediate neighbours.

  Click image for larger view …

M42 The Great Orion Nebula is the large pale blue and red nebula just right of centre. The small circular red nebula with a dust column rising in front of it, that is M43. To the left is NGC1977, the Running Man and fully to the left is NGC1981 an open cluster of stars. Deep within the base of M42 lies the Trapezium cluster, click on the image above to view the larger version and pick out some of the Trapezium stars. The M42 nebula is the closest known place of star birth to our solar system. Hubble Space Telescope has not only identified star birth there but also the formation of proto-planetary discs – that from which planets of solar systems are born.

The image below is my first of the other Messier in Orion, M78. I was plagued with high level cloud whilst trying to image it. The result of this is that I currently have less than half my planned exposure time, I will have to revisit when the weather improves.

Click image for larger view …

The M78 image does show the blue star light from the reflection nebula, also appearing are the clouds of interstellar dust that lie across the region. These should become more evident in a longer exposure. This is another area of young hot blue stars. In the top left corner of the image lies NGC2071 a similar & related object.

All the above nebula objects are part of the Orion Molecular Cloud Complex. This huge cloud is about 1600 light years away. The entire complex comprises dark, reflection & emission nebulae and is the birthplace of many stars. Also included in this cloud are Barnard’s Loop and my current favourite region of the night sky – The Horsehead & Flame Nebulas.

Below is my recent image of the Horsehead region …

Click image for larger view …

For more details on this image and the region, please see my previous Horsehead article.

**Update Mar08: For further info, view my post about Barnard’s Loop in Orion**

and/or view the image below:

  Click image for a larger view …

Useful Coordinates:

ID Name RA Dec

NGC2024    Flame Nebula    05:41:42 -01:51:00
M78              NGC2068          05:46:45 +00:04:48
M42     Great Orion Nebula  05:35:16 -05:23:25
M43     De Marian’s Nebula  05:35:31 -05:16:03
B33       Horsehead Nebula   05:40:54 -02:28:00

Further Info:

Betelgeuse is a huge red super giant.

Rigel is a Blue super giant and whilst much smaller than Betelgeuse it is still almost 100 times the size of our Sun.

Orion has been known as a constellation since ancient times though by different names in different cultures. It was Osiris to the ancient Egyptians, Al Jabbar to the ancient Arabs, a Shepherd & Sheep to the Sumerians and part of the White Tiger to the Chinese.

An interesting article about Orion’s potential interest to ancient Britons may be found here.

For more on the Greek Mythology, why not investigate the widget below:�

I hope this article has been useful & interesting to you, it’s certainly been fun in the making

Come back through the autumn/winter for a return to M78 & maybe some deeper region images too.

-

IceRocket tags: Orion, Constellations, AstroPhotography, Guides