How to Find the Orion Nebula, Messier 42

How to Find the Orion Nebula, Messier 42

Orion Nebula - Hubble


Shaped like a rose in the night sky. This incredible nebula sits around 1000 light years away but still is visible to the naked eye. The nebula is a nursery where new stars are being formed.

Messier 42, the Orion nebula has to be one of the most breathtaking deep space objects to see in the night sky. It resides 1,345 light years away and was first discovered in 1610 by Fabri de Peiresc. This diffuse nebula spans an area some 20,000 times the size of our solar system and is the nearest source of intense star formation to us. It is visible to the naked eye with a magnitude of 4, but M42 is so large it has a surface brightness of 11. The distribution of its light isn't uniform across the object and is mainly in the centre making this a deceiving surface brightness, as the object is much closer to magnitude 4 than 11. When looking at the Orion nebula try to observe the four stars at its centre that make up the Trapezium. You'll probably need to increase your magnification to resolve all four of them. Enjoy this rose shaped beautiful and bright nebula.

Image credit: NASA/ESA


Other Names:

Orion nebula

Messier 42

M42

NGC 1976


Telescope Image to Scale:

M42 from a telescope


The nebula is so large that the image above is scaled at 120 x 120 arc minutes. The full moon is equivalent to 30 x 30 arc minutes.


Brightness:

Magnitude = 4

Surface Brightness = 11

The surface brightness is confusing here. It suggests the nebula is quite faint. This is because a large part of the nebula is very faint but the centre is very bright. The surface brightness is a measure of how bright the object would be if all the light from it was spread evenly over the whole object. As a large part of the nebula is very faint this brings the surface brightness number to 11. 

Telescope Aperture City Suburbs Rural Dark Sky
4 inches 9 10 11 12.5
5 inches 9.5 10.5 11.5 13
6 inches 10 11 12 13.5
8 inches 10.5 11.5 12.5 14
10 inches 11 12 13 14.5


Use this chart to estimate if you can see the object from your location with your telescope. For more help on using this chart click here.


How to See It:

This is one of the easiest nebula to see. It is visible to the naked eye on a dark night. It can be found below Orion's belt, hanging like a sword.  It's co-ordinates are: RA 05h 36m 05.15 DEC -05° 26′ 37.1″ if you are using guiding software.

How to find Messier 42


The nebula is easily visible in binoculars and small telescopes. The trick is to see if you can resolve the stars in the shape of a trapezium in the middle of the nebula. There are actually five stars in the trapezium, but you would struggle to see this with small telescope. Below is the shape of stars you are looking for.

trapezium in Orion nebula


Credit: NASA, C.R. O'Dell and S.K. Wong (Rice University)

To find more space objects have a look at the constellation guide by clicking the link or go back to the list of deep space objects.


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