Orion - The Mighty Hunter
Pronounced "Oh - Rye - Un"
Where to find the constellation
Constellation Chart
The great hunter Orion - visible from late Autumn to early Spring, as the constellation sweeps across from South-East to South-West - is home to some of the finest deep-sky targets for astrophotographers, and visual observers alike.
M42, the Great Orion nebula, is many people's favourite DSO of all. A huge cloud of dust and gas, about 100 light-years across, and 1500 light-years away from us, is collapsing under it's own gravity, to form new stars.
The core of this stellar nursery is known as the Trapezium, because of the 4 bright (and many other not-so-bright) stars, which are the main light source of the rest of the nebula. Several million years from now, the majority of the gas will have either been used up (collapsed into new star-systems) or blown away by the stellar winds created by these new stars.
Several other nebulae reside in Orion, as well as open clusters, the red Supergiant star Betelgeuse, the famous (but difficult to spot) 'Horsehead nebula', and the nearby 'Flame', as well as the multi-coloured, multiple star Sigma Orionis.
M42 area of Orion
The huge star forming region sits amid several other treats for the visual observer
Collectively, this line of objects, extending down from Orion's belt, represent his sword.
Immediately above M42, is M43, a small 'breakaway' part of M42, situated around the 7th magnitude star 'Nu Orionis'
Above that is ngc1977, the Running Man nebula - so called because of the dark patch n the middle, which gives the appearance of a running figure - and above that is a 4.2 magnitude open cluster, ngc1981
To me - ngc1981 looks a little bit like a dot-to-dot drawing of a small crown- maybe Orion has a 'crown' logo on the handle of his sword?
Below M42 is another open cluster, enveloped in a very faint nebulosity - ngc1980, centred around the bright star Nair Al Saif.
Of these objects - the stars, and clusters are easy to see in an amateur scope - but the nebulosity of NGCs 1977, and 1980, is very difficult to spot visually
M42 and surrounds - Image by James
As you can see, the running man nebula (at the top) is MUCH dimmer than M42
The Trapezium
A group of new-born stars at the heart of the Orion nebula
4 are visible in most amateur scopes at high power - with a good quality refractor, I've also been able to detect a couple more.
M78
Small emission nebula, located up the side of the Orion constellation
Difficult in scopes under 6", if you have any ligh-pollution - but becomes much easier to spot under a dark sky.
Near the top of this pic, you can also see the smaller, and slightly dimmer, ngc2071
Horsehead and Flame area
This image (in Hydrogen-alpha) by Andy (labelled by me) shows the
immediate area around the two nebulae, and their relative positions
compared to each other, and the surrounding bright stars.
Horsehead nebula
Image by Andy - The Horsehead (also known as Barnard 33 - B33) is a patch of dark dust, as seen against the background of the brighter diffuse nebula IC434
IC434 is VERY faint, so detecting the Horsehead visually is a REAL challenge - pretty much the 'Holy-Grail' of visual observing -
combination of large aperture, great sky, filter, and good 'averted vision' technique, is needed to even stand a chance of marginal detection.
Also best to keep the glare from Alnitak outside of your field of view.
Flame nebula
Image by James - Located right beside Alnitak - another very faint nebula - although no as difficult visually as the Horsehead.
Another one that benefits from keeping Alnitak outside of the field of view
Betelgeuse
Red supergiant star - about 425 light-years away - this star has used up all of it's hydrogen fuel, and is now fusing heavier elements - the outer shell has grown so bloated that if it were in the centrte of our solar-system, all the planets out as far as Jupiter, would be within it's distended outer layers.
It is already in the carbon-burning stage of it's life cycle, so it is expected to explode in a type 2 supernova, in a thousand years or so - when this happens, it is expected to be about as bright as the Moon, and visible in daylight, for a few months.
Collinder 70 (Cr70)
Huge, very distended open cluster - situated around the stars of Orion's belt - most of the stars in this area - a circle roughly the same
diameter as the width of the 'belt', and centred on the belt's middle star Alnilam - are members of the cluster.
Collinder 69 (Cr69)
Another large open cluster - although not as large as Cr70 - centred around the star 'Miessa' which marks the hunter's head.
Sigma Orionis
A multiple star, just below the left-hand belt star (Alnitak) and quite close to the Horsehead.
4th Magnitude white primary - with 7th mag red star, 13 arcsec to it's East - and a 7th mag blue star, 42 arcsec east - there's also a 10th mag white star, 11 arsec over to the West of the primary
Orion NGCs (with magnitudes) - from my own "1200 Northern NGCs" list
For those with 'GoTo' or a good chart
1662 - OC - 6.4
1684 - Gal - 12
1691 - Gal - 12
1973 - Neb - 7
1975 - Neb - 7
1976 - Neb - 4 (M42 - Orion nebula)
1977 - Neb - 7 (Running Man nebula)
1980 - OC with Neb - 2.5
1981 - OC - 4.2
1982 - Neb - 9 (M43)
2022 - PN - 12.8
2024 - Neb (Flame nebula)
2068 - Neb - 8 (M78)
2071 - Neb - 9
2169 - OC - 5.9
2175 - OC - 6.8
2194 - OC - 8.5
Portal 
