What Is M42 The Orion Nebula?
M42 The Orion Nebula is located in the Orion constellation, about 1,500 light-years away from Earth. It stands as one of the most noticeable and easily identifiable constellations in the night sky. The Orion Nebula is a diffuse nebula that is also known as Messier 42, M42, or NGC 1976. It’s part of a much larger nebula complex known as the Orion Molecular Cloud Complex.
M42 is the closest large star-forming region to our planet and is one of the brightest nebulae.
The M42 nebula spans an impressive 24 light-years in diameter, which translates to an apparent size of about 1 degree when viewed from Earth. Its mass is extraordinary, estimated to be around 2,000 times greater than that of our Sun. In historical literature, this majestic cosmic feature is often referred to as the Great Nebula in Orion or the Great Orion Nebula.
The Orion Nebula is one of the most intensely studied and photographed objects in the night sky.
M42 is an emission nebula, a type of nebula that glows brightly. This glow is due to the ionization of hydrogen gas (H-alpha) by the high-energy radiation from the young, hot stars formed within it.
Who discovered M42 The Orion Nebula?
- Ptolemy (2nd century): The Greek astronomer Ptolemy may have made one of the earliest known recorded references to the Orion Nebula. He mentioned it as a “nebulous star” following Orion’s Belt in his astronomical treatise, the Almagest.
- Nicolas-Claude Fabri de Peiresc (1610): The French astronomer Nicolas-Claude Fabri de Peiresc is often credited with the first telescopic observation with his refractor telescope of the Orion Nebula on November 26, 1610. His discovery marked the beginning of the telescopic study of nebular objects.
- Christiaan Huygens (1659): The Dutch astronomer Christiaan Huygens made detailed observations of the Orion Nebula and was the first to sketch its nebulous nature accurately. His work greatly contributed to the understanding of the nebula.
These early observations were the foundation for later studies by astronomers such as Charles Messier, who included it as the 42nd entry in his famous catalog of nebulous objects (The Messier Catalog) in 1774, leading to its designation as M42. On March 4, 1769, Charles Messier observed the nebula, during which he also recorded the presence of three stars in the Trapezium cluster.
What makes M42 The Orion Nebula a hotspot for star formation?
M42 The Orion Nebula is not just a spectacle of beauty; it is a cosmic laboratory, a cradle where new stars are born. The processes occurring within it are crucial for understanding star formation. It houses an intense star-making factory, with hundreds of young stars, some only about two million years old. While this age might appear old from a human perspective, it is relatively youthful in the grand scale of the cosmos. The nebula’s mix of gas, dust, and plasma is collapsing under gravity to form new stars and possibly even planetary systems.
Observations by powerful telescopes like the Hubble Space Telescope have revealed protoplanetary disks, known as proplyds, around many young stars in M42. These disks are the early stages of planetary formation, offering a glimpse into the birth of new worlds.
What are protoplanetary disks, known as proplyds?
Protoplanetary disks, commonly referred to as “proplyds“, are dense, flattened discs of gas and dust found around newly formed stars. These disks are significant in the field of astronomy and astrophysics. For example, to study the formation of planetary systems: proplyds are the birthplaces of planets.
With advancements in telescopes and imaging technology, astronomers can observe these disks in various wavelengths of light. Instruments like the Hubble Space Telescope or the Atacama Large Millimeter/submillimeter Array (ALMA) have provided detailed images of proplyds, revealing their structures and the processes occurring within them.
A protoplanetary disk typically lasts for a few million years. Eventually, the material in the disk either gets accreted onto the star, forms into larger bodies, such as planets, moons, asteroids, and comets, or gets dispersed by various processes such as stellar winds, radiation pressure, or interactions with other objects.
What is the significance of the Orion Nebula for astronomy?
- Proximity to Earth: The Orion Nebula is one of the closest star-forming regions to Earth, located roughly 1,500 light-years away. This relative proximity allows astronomers to study in great detail the processes of star and planet formation.
- Star Formation Laboratory: M42 is essentially a live laboratory for observing the birth of stars. It contains a rich array of protostars (stars in the early stages of formation), newly formed stars, and various stages of stellar evolution. This makes it an ideal place to study the lifecycle of stars.
- Insights into Planetary System Formation: The nebula is not just about stars; it also provides insights into the formation of planetary systems. Observations of protoplanetary disks (or proplyds) within M42 give astronomers clues about how planets form around new stars.
- Composition and Dynamics: The Orion Nebula’s diverse composition, including ionized gases, dust, and complex molecules, offers a window into the chemical processes occurring in space. Studying these elements helps in understanding the interstellar medium and the dynamics of nebulae.
- Astrophotography and Public Interest: Its brightness and size make the Orion Nebula a favorite target for both amateur and professional astronomers, especially for astrophotography. It plays a significant role in attracting public interest in astronomy and space science.
- Technological Advancements: The Orion Nebula has been observed by various telescopes and space observatories, including the Hubble Space Telescope. These observations have not only provided stunning images but also have been instrumental in testing and enhancing observational technologies and techniques.
- Historical Importance: M42 has been observed for centuries, and its study has contributed to the historical development of astrophysics. Its observation and analysis have paralleled and contributed to major advancements in the field.
- Educational Value: The Orion Nebula serves as an excellent educational example when teaching various aspects of astronomy, from star formation to the behavior of interstellar gas and dust.
How can you observe the Orion Nebula?
The Orion Nebula is a winter constellation in the Northern Hemisphere and is a treat for both amateur and professional astronomers.
Visually, the Orion Nebula appears as a glowing, hazy patch in Orion’s “sword” (see Orion Star Chart below: 1981, 1973/1975/1977, M43 & M42), just below the three stars ( Alnitak, Alnilam & Mintaka) that form Orion’s belt (see Orion Star Chart below). With an apparent magnitude of 4.0, it’s one of the few nebulae that can be seen with the naked eye in a dark sky, or even in light-polluted areas. Dark, clear skies are essential for the best viewing experience.
Messier 42 is visible from October till February but the best time to observe M42 The Orion Nebula is in December when it’s high in the night sky.
Observing M42 with a pair of binoculars can provide a better view of the Orion Nebula. Even modest binoculars, like 10×50 or 7×35, can reveal the nebulous nature of M42, showing it as a distinct, cloudy spot.
For a more detailed view, a telescope is ideal. Small to medium-sized telescopes can reveal the nebula’s core and its bright central region. Larger telescopes may show color and more intricate structures, including the Trapezium (or The Trapezium Cluster), four very bright young stars that light up the nebula (see picture: M42 The Orion Nebula with annotation „Trapezium“). The youngest stars are probably less than 100,000 years young, possibly even 10,000 years young.
The Trapezium or Trapezium cluster got its name because the four bright stars show the pattern of a trapezium. Robert J. Trumpler, a Swiss-American astronomer was the first to name them The Trapezium Cluster.
For city dwellers, planetariums often feature M42 in their shows, offering a glimpse into this celestial nursery.
During public astronomy gatherings, together with other members of my astronomy club, M42 was often one of the first objects we showed visitors through the telescope. They were always pleasantly surprised then, and you should especially see the glittering eyes of children :-). Those were always fun experiences for all present.
What about NGC 1977 The Running Man Nebula?
NGC 1977, known as the Running Man Nebula (see as example below, Picture 1: NGC1977 Running Man Nebula (top) & M42 Orion Nebula), is a lesser-known yet equally fascinating part of the Orion Nebula complex, adding to the allure and mystery of this region of the night sky. It’s also known as Sh2-279 (alternatively designated S279 or Sharpless 279).
A Celestial Artistry: Situated just north of the Great Orion Nebula (M42), NGC 1977 presents a mesmerizing celestial sight. It’s often overshadowed by its more famous neighbor but holds its unique beauty and intrigue. The name “Running Man Nebula” comes from the pattern of dust and gas clouds within it, which, when viewed through telescopes, resembles a figure in motion, akin to a runner.
Nature’s Canvas of Colors and Light: NGC 1977 is a reflection nebula, which means it doesn’t emit its light but reflects the light of nearby stars. The predominant blue hue is a result of the scattering of starlight by the small dust particles within the nebula, similar to the way Earth’s sky scatters sunlight to appear blue.
A Nursery of Star Formation: This nebula is also a site of active star formation, albeit less intense than in the Orion Nebula. The stars that illuminate NGC 1977 are younger and less massive compared to those in the Trapezium Cluster of M42, yet they play a crucial role in shaping the nebula. The winds and radiation from these stars help carve out the intricate structures and shapes seen within the nebula, including the iconic ‘running man’ silhouette.
Astronomical Significance: NGC 1977 serves as an excellent study ground for understanding the processes of reflection nebulae and star formation. Its proximity to the Orion Nebula allows astronomers to compare and contrast different types of nebular environments within the same complex. This comparison provides insights into the lifecycle of stars and the evolution of cosmic dust clouds.
A Cosmic Marvel for Observers: For amateur astronomers and stargazers, the Running Man Nebula offers a captivating target. It can be observed with moderate-sized telescopes and is a popular subject for astrophotography, particularly for its vibrant colors and distinctive shape.
Who discovered NGC1977 The Running Man Nebula?
Sh2-279 is a celestial complex that includes three NGC nebulae – NGC 1973, NGC 1975, and NGC 1977 (see Orion Star Chart above), each separated by dark nebulous areas. This astronomical ensemble also features the open cluster NGC 1981 (see Orion Star Chart above). The most prominent of these nebulae, NGC 1977, was discovered by William Herschel in 1786. The additional two, smaller reflection nebulae, NGC 1973 and NGC 1975, were identified by Heinrich Louis d’Arrest in 1862 and 1864, respectively. These three nebulae were later cataloged together in the New General Catalogue in 1888. The term NGC 1977 is variably used to denote different aspects: it can refer to the reflection region near the star 42 Orionis (located in the southeast part of the reflection nebula), the entire reflection nebula including NGC 1973 and NGC 1975, or the entire nebula complex.
Astrophotography
The M42 Orion Nebula is a beautiful, diffuse nebula that you can find in the south of Orion’s Belt in the constellation Orion (see Orion Star Chart above)
In the core of Orion, you see an open cluster of four stars, called “The Trapezium“ (see picture below) because of their arrangement in a trapezoid pattern. The core of Orion is a clear example of a star-forming region.
You can ask all astrophotographers what the first object they started with, and many of them will answer: The Orion Nebula!
One reason that I mentioned before, is that the Orion Nebula is easy to find in the night sky and another reason because all astrophotographers love this nebula because of its brightness and stunning features.
I’ve photographed the Orion Nebula already several times and each time the final image is getting better and better.
M42 was the first DSO (Deep-sky Object) that I have photographed. Although it’s not the easiest object to create an astrophoto, you‘ll get already a great result with a relatively short exposure time, which is rich in details and colors. And this is even doable in light-polluted skies, which makes this target worthwhile.
The Orion Nebula consists of neutral clouds of gas and dust, associations of stars, ionized hydrogen, and reflection nebulae. Because of the hydrogen (H-alpha), a lot of astrophotographers have already photographed M42 with a narrowband filter, or a duo-narrowband filter (see pictures below) which gives the possibility to split the channels H-alpha (Ha or HII) and OIII (Oxygen III) during processing in astrophotography software like Astro Pixel Processor or PixInsight. H-alpha filters are useful in astrophotography because you can bring out more of the H-alpha region (ionized hydrogen) of a nebula and reduce the effects of light pollution.
If you combine your broadband data with your narrowband data, you’ll get an amazing result that is even more enriched with details and colors than just a broadband image. I haven’t done this myself but I’ve seen already awesome images of other astrophotographers who have combined broadband data with narrowband data of M42 The Orion Nebula. I will try this for sure in the future.
Here you can see my progress in my astrophotography of M42 The Orion Nebula from example 1 to example 4:
This was my first real deep-sky image (Example 1: NGC1977 Running Man Nebula (top) & M42 Orion Nebula (below))
I captured the data begin 2018. Back then, I wasn’t able to process it due to a lack of processing skills. So, another member of the astronomy club which I was a member of, helped me out with processing the image above.
At that time, I was so happy with how the result came out. You’ll never forget your first astrophoto and the memories bound to it :-D.
Unfortunately, I had forgotten to put my Astronomik CLS Clip filter (anti-light pollution filter) in my Canon EOS 750D DSLR (see pictures below). That’s why the background came out brownish instead of dark and I was very disappointed by that. But hey, that’s why we learn from failures. After that incident, I’ve never forgotten to use my anti-light pollution filter anymore when doing astrophotography :-).
However, it is possible to get rid of the light pollution while editing your astrophoto using certain tools in astrophotography software, but as I mentioned above, my knowledge in editing was very limited at that time.
Image details (Example 1)
- Telescope: William Optics Zenithstar 61 (first generation)
- Field flattener: William Optics F-Flat61 (first generation)
- Mount: Sky-Watcher Star Adventurer gen.1 on a Cullmann 525M camera tripod (the tripod on the picture below is from Sky-Watcher, not from Cullmann 525M)
- Camera: Canon EOS 750D DSLR
- Intervalometer: Photospecialist
- Software: DeepSkyStacker 3.3.0 (stacking); Photoshop CS6 (processing)
Data was captured on 05/02/2018 in Bortle Class 6 skies -> RAW files at ISO800, 30-second exposures.
No guiding, no filter (not on purpose but because I had forgotten :-))
The image below, example 2, was my third attempt. It’s an image from 12/10/2019 and was fully processed by me this time, I learned a lot about stacking & processing. You can see that the core of M42 Orion Nebula is unfortunately blown out – a challenge you can overcome by using frames with different exposure times – and the bright stars have trails because there were frames in between that suffered from bad tracking. I’ve overseen it in my images before stacking.
Another big newbie failure I did, was clipping the blacks (shadows).
“Clipping the blacks” in astrophotography refers to a process in image editing where the darkest parts of an image are made even darker, to the point where they become completely black with no visible detail. This is often done to enhance the contrast and make the brighter objects, like stars or nebulae, stand out more against the background of space.
In technical terms, this involves adjusting the levels or curves in the image processing software. The histogram, which shows the distribution of brightness levels in the image, is manipulated so that the leftmost part (representing the darkest areas) is pushed towards or beyond the baseline. This effectively removes all variations in those darkest areas, turning them into a uniform black.
While this can improve the visual impact of the image by increasing contrast, it’s important to use this technique judiciously. Overdoing it can lead to loss of detail in the darker regions of the image, which might contain subtle but important features. It’s a common practice in astrophotography, but like all post-processing techniques, it requires a careful balance to maintain the integrity and natural appearance of the celestial objects being photographed.
Image details (Example 2)
- Telescope: William Optics Zenithstar 61 (gen.1)
- Field flattener: William Optics F-Flat61
- Mount: Sky-Watcher NEQ5 Synscan GoTo
- Camera: Canon EOS 750D DSLR
- Filter: Astronomik CLS Canon EOS clip-filter APS-C
- Intervalometer: Photospecialist
- Software: Astro Pixel Processor (stacking); Photoshop CS6 (processing) and DPP4 (Canon software: Digital Photo Professional 4, final touch)
Data captured on 12/10/2019 in Bortle Class 6 skies -> unguided RAW files at ISO800, 60-second exposure.
Example 3 above, is a more dramatic version of example 2.
Data was captured on 12/10/2019 (like example 2). But for this picture, I’ve used 3 different exposure times at ISO800: 25 sec, 70 sec & 120 seconds. However, even with the use of these different exposures, called HDR composition, I wasn’t able to tame the core. It’s still overexposed, so you can’t see the Trapezium also known as the Orion Trapezium Cluster.
Here again, like in my example 2, I did clip the blacks (see explanation below example 2), which often is seen as a popular rookie mistake. It is to say, I still do this sometimes :-).
Image details (Example 3)
- Telescope: William Optics Zenithstar 61 (gen.1)
- Field flattener: William Optics F-Flat61
- Mount: Sky-Watcher NEQ5 Synscan GoTo
- Camera: Canon EOS 750D DSLR
- Filter: Astronomik CLS Canon EOS clip-filter APS-C
- Intervalometer: Photospecialist
- Software: Astro Pixel Processor (stacking) Affinity Photo (processing) and DPP4 (Canon software: Digital Photo Professional 4, final touch)
Data was captured on the night of 12/10/2019 in Bortle Class 6 skies.
Unguided RAW files at ISO800 with 3 different exposures: 25 sec, 70 sec, and 120 seconds.
The image above, example 4, was my 5th attempt at photographing The Orion Nebula.
I imaged it during several cold nights but the seeing was most of the time not so great. There were a few low clouds and high clouds in between. Also during 2 nights, the Moon was out (one night 63% and another night 44%).
Despite the not-so-good weather conditions, I’m the proudest of this image of the M42 Orion Nebula compared to my other, older examples. The reason: Finally, I managed to get the core not overexposed like my previous astrophotos of the Orion Nebula. Now, you can see the four bright stars of the Trapezium Cluster. I used again the same method, as in my example 3 above, which is called: HDR composition. I used 4 different exposure times to be able to create an HDR composition: 3 sec, 10 sec, 30 sec, and 60 seconds.
This time, I didn’t clip the blacks (shadows) and that’s why all the dust around the Orion Nebula is much more visible compared to the previous examples. ‚Embrace the dust in your astro images!‘, as pro astrophotographers say :-).
There is of course room for improvement, like always in astrophotography. Astrophotography is the hunt for perfection!
Image 4 was taken with my 8″ Newtonian telescope (Picture below) and my cooled dedicated astro camera, the ZWO ASI 294MC Pro (one-shot-color camera). I did use the Optolong L-Pro as a broadband light pollution filter because the Orion Nebula is coming up in the south where I have to deal with a lot of light pollution coming from an industrial area.
Image details (Example 4)
- Telescope: Sky-Watcher Explorer Black Diamond N200/1000
- Mount: iOptron CEM60 on iOptron tri-pier
- Camera: ZWO ASI294MC Pro
- Filter: Optolong L-Pro 2″
- Telescope control: ZWO ASIair gen.1
- Software: PixInsight (stacking & processing)
Data captured on the nights: of 27/10-28/10/2021 & 28/10-29/10/2021
SQM-L: 18.41 (average) => Bortle Class 6
No guiding, no coma corrector
Conclusion
As you can see, M42 The Orion Nebula, is more than just a beautiful object in our night sky.
The next time you gaze up at the stars, remember the Orion Nebula. This glowing cloud, a cradle of star birth, is a testament to the beauty and mystery of the universe. It invites us to keep exploring, keep wondering, and keep looking up.
My progress in my astrophotography of M42 The Orion Nebula also shows that you should never give up!
Processing astro images is still the hardest part of astrophotography for me. But with a lot of training and expanding my knowledge about astrophotography software, I’ll get better and better over time with a lot of trial and error.
Patience and perseverance are key in astrophotography!
