Astrophotography: M16 - The Eagle Nebula

Messier 16, also known as the Eagle Nebula, is one of the most well-known objects in the night sky. It contains, at its heart, an active star forming region, famously known as the 'Pillars of Creation' after the Hubble Photograph that depicted its towering dust clouds. Located in the constellation of Serpens, light emitted from the nebula takes about 7,000 years to arrive. It is thought that the pillars have already been destroyed by a supernova which exploded some 8,000 years ago. However, since light takes 7,000 years to travel across the void, we would be looking at the nebula as it was just 1,000 years after the explosion. Since the shockwaves coming from the supernova will take several thousand years to propagate, we can still see the beautiful Pillars in all its glory. 

Photographic Information:

Imaging location: Mersing, Johor, Malaysia (Light pollution region: Suburban Sky)

Date of data acquisition: 23 August 2014

Exposure Details: ~60min, 800mm FL at f/4

Camera: Canon EOS 400D Modified

Stacked and processed with Pleiades Astrophoto PixInsight. 

Astrophotography: The Swan Nebula

Having visited dark skies and saw the summer milky way for the first time in my life some two months ago, I went on and lugged my imaging setup across the border into dark skies northwards into peninsular Malaysia. Far from the blazing city lights of Singapore, I found myself lucky to have a perfectly clear night, a rare occurrence under tropical skies. Testing out my new imaging rig - an iOptron ZEQ25GT mount with my trusty 800mm f/4 Astrograph, I turned my telescope towards Sagittarius, where deep sky jewels abound. Having taken some time to drift align and get my autoguider up and functioning, I managed only one object from the region, and that is the emission nebula M17, also known as the Swan or Omega Nebula.

With a total exposure of 40 minutes using an unmodified DSLR, I was able to pull out a reasonable amount of detail.

Being primarily a hydrogen alpha emitting nebula, the unmodified DSLR used only allowed approximately a quarter of the HA Data through its IR filters. As a result, I have lost a significant amount of red nebulosity in the periphery. Still, imaging from dark skies, a hint of the surrounding ionised hydrogen gas can still be seen.

Photographic Information:

Imaging location: Mersing, Johor, Peninsular Malaysia (Light pollution: Suburban region)

Date of data acquisition: 27 July 2014

Exposure Details: 13x3min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

Astrophotography: The Andromeda Galaxy

Galaxies tend to be much more sensitive to light pollution as compared to other deep sky objects. Living in a city-state with heavy light pollution, imaging galaxies is very challenging indeed. Their low surface brightness, coupled with the fact that they emit light in all wavelengths (therefore rendering astronomical filters useless) makes them difficult targets to acquire. Aside from the Milky Way, I had my first try imaging a galaxy, or rather, three of them, two nights ago. My target is naturally the Great Andromeda Galaxy, M31, as it is the brightest galaxy in the sky. The difficulty in shooting M31 is in bringing out its dark lanes of cold molecular gas. Although the core shines bright, the dim spiral arms make it challenging to process. Also, M31 is huge, not just in physical size, but also in angular size as seen from Earth. It covers the area of six full moons in the sky, but we do not see it in all its glory because of, once again, low surface brightness. 

Photographic Information:

Imaging location: Changi, Singapore (Light pollution: Red zone/Outer City)

Date of data acquisition: 29 June 2014

Exposure Details: ~50min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

Shining the light of a trillion suns, the Andromeda galaxy and its two neighbours, M32 and M110 as pictured here, lie 2 million light years away. Although the Andromeda Galaxy is the closest spiral galaxy to the Milky Way, light, the fastest thing in the universe, takes a whopping two million years to arrive into the mirror of my telescope. Looking at the andromeda galaxy, we are looking at the light that originated from the stars long before modern humans have even evolved. 

Astrophotography: The Dumbbell Nebula

Nebulae often signify the important events of a star's life. Where large diffuse nebulae typically form the materials needed for starbirth, planetary nebulae and supernova remnants signify the death of stars. Whether a dying star becomes a supernova or a planetary nebula depends on its mass: high mass stars, with large amounts of matter, can collapse gravitationally at the end of their lives, overcoming degenerate pressures and creating a sudden runaway nuclear reaction. Low and medium mass stars, with insufficient mass to collapse under its own weight, will slowly expel its outer layers in a slow and gradual death, forming a planetary nebula. One such example of a star that is undergoing this process is the dumbbell nebula. As the star puffs out its outer layers, the atmosphere of the star begins to disperse, creating a gas cloud that surrounds what used to be the core of the star - a white dwarf. Although nearing the end of their lives, white dwarf stars still emit high amounts of high energy radiation, primarily in the ultraviolet range. This ultraviolet radiation is capable of ionising the surrounding gas cloud, resulting in the emission of light as the ions recombine with electrons to form electrically neutral atoms. The recombination process produces a very exact wavelength of light, dependent on the nature of the ion, and the orbitals in which the electron transit involves. Since planetary nebulae are formed at the end of a star's life, large amounts of the higher elements tend to be present in the expanding nebular cloud. One such example is oxygen, which can produce greenish-blue light during ion-electron recombination. This is why the dumbbell nebula glows so strongly in the blue-green part of the spectrum.  

Photographic Information:

Imaging location: Changi, Singapore (Light pollution: Red zone/Outer City)

Date of data acquisition: 29 June 2014

Exposure Details: ~20min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

Astrophotography: The Lagoon Nebula Revisited, and the Trifid Nebula

With cloud cover obscuring much of the view of Messier 8, the Lagoon Nebula during my previous shoot, I was pleasantly greeted by clear skies with superb transparency last night. It was by far my most productive astrophotography session, clocking a total of four objects. I managed to try out one of the darkest spots in my heavily light polluted country, and it really made the difference. Without further ado, I present the Lagoon and Trifid Nebulae of Sagittarius:

A.) The Lagoon Nebula

The Lagoon Nebula, also known as Messier 8, is a region of active star formation. Located in the constellation of Sagittarius, the nebula glows bright in the Hydrogen Alpha spectrum.

Photographic Information:

Imaging location: Changi, Singapore (Light pollution: Red zone/Outer City)

Date of data acquisition: 29 June 2014

Exposure Details: ~45min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

B.) The Trifid Nebula

The Trifid Nebula, also known as Messier 20, is a nebula located in the constellation of Sagittarius, with a very close proximity to the Lagoon Nebula. The striking feature about this nebula is its trifurcated shape, formed by dark lanes of molecular clouds cutting through the pink hydrogen alpha region into three parts, hence its name. The trifid nebula is an intriguing object because it contains all the three types of nebula: Emission in the pink region, absorption in the dark lanes, and reflection in the blue region. 

Photographic Information:

Imaging location: Changi, Singapore (Light pollution: Red zone/Outer City)

Date of data acquisition: 29 June 2014

Exposure Details: ~30min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6.

Astrophotography: The Lagoon Nebula

Astrophotography is one of those things that can leave many people feeling frustrated, particularly when it comes to uncontrollable variables like the weather. Because of the sensitivity of optical transparency to volatile sky conditions, imaging conditions can often be far from perfect. However, this does not mean that it is completely impossible to shoot under cloud cover. From locations where relatively clearer skies are rare, one has to make do with moving layers of clouds obscuring the faint starlight coming from the distance. 

Indeed, such was the case when I attempted to image the Lagoon Nebula. Classified in Messier's catalogue as the 8th object, the Lagoon Nebula is a strong Hydrogen Alpha emitting region, with active star formation occurring as dense hydrogen clouds coalesce into a nuclear furnace. Despite the cloud cover, the stretched image unveils detail that could not be seen before post processing. Intricate tendrils of dark molecular clouds can be seen, silhouetting the glow of ionised gas. 

Photographic Information:

Imaging location: East Coast Park, Singapore (Light pollution: Red zone/Outer City)

Date of data acquisition: 21 June 2014

Exposure Details: ~40min, 800mm FL at f/4

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

Astrophotography: A shot at widefield imaging

Being primarily a deep sky astrophotographer, I rarely attempted shooting the stars using just a camera and a lens, set on a non-tracking tripod. I guess the main reason for this is that I live in such a light polluted city, which offers little by way of widefield shots. Although some pioneers have now demonstrated that shooting the milky way is possible even from the most light polluted spots imaginable, the images that are to follow are taken from a suburb in a neighbouring country. 

Although I have been into astronomy for several years, it's rather surprising that I never saw the summer milky way before, that is, until my recent trip overseas a couple of weeks ago. Of the times when I ventured out of my country, I have never seen the vast expanse of the galactic bulge, mainly because I typically leave the country only during the end of the year when the winter milky way is up. 

Anyhow, when I finally got to see the milky way with my own eyes, it was a breathtaking moment. Everywhere I looked, the sky was filled with countless stars. The Milky Way was a strange glowing cloud hanging in the sky, stretching from one end to the other. Through binoculars, for every star you can see with the naked eye, you could see a hundred more. With a telescope, the grey mist of the milky way is resolved into the individual stars that make it up. Looking at the milky way with different instruments makes it seem almost fractal-like. No matter how much you zoom, all you see are countless stars fading into infinity. 

Of course, my instinct was to grab my camera and start shooting. With a micro four thirds and wide angle 12mm lens, I caught the milky way in all its glory and splendor. 

Photographic Information:

Imaging location: Bekok, Malaysia (Light pollution: Suburban Sky/Yellow Zone)

Date of data acquisition: 1 June 2014

Exposure Details: ~5min, 12mm FL at f/2 (on a M4/3 Crop)

Camera: Olympus OM-D EM10 Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6. 

With skies staying clear before midnight till dawn, I obviously had to grab the opportunity and image more objects. Because of my short focal lengths used, limited by gear and lack of tracking, most deep sky objects remained out of reach. The largest object in terms of angular size that can at least show a hint of detail with my setup is probably the rho ophiuchus cloud complex. The rho ophiuchus cloud complex is a reflection/absorption nebula that surrounds the star Antares. With dark lanes extending from the Antares region towards the central bulge, this is a prime target for widefield astrophotography. 

The image above frames Antares nicely close to the centre, with the dark lanes extending towards the bottom of the frame. Reflection nebulosity is visible as well. 

Repositioning the direction of the camera, I attempted to shoot the nebula whilst keeping the dark lanes of the milky way partly in view. 

This image shows the intricate colour details, although part of it is contributed by chromatic aberrations. The focus of the image is also not as good as the previous image, which is undoubtedly difficult to get while shooting at a very fast focal ratio. 

Photographic Information (for both images of the Rho Ophiuchus complex):

Imaging location: Bekok, Malaysia (Light pollution: Suburban Sky/Yellow Zone)

Date of data acquisition: 1 June 2014

Exposure Details: ~10min, 50mm FL at f/1.8 (on an APSC crop)

Camera: Canon EOS 600D Unmodified

Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6.