DSLR Astrophotograhy Image: The Pleiades Star Cluster
The Pleiades is a gorgeous open star cluster in the constellation Taurus. In the Northern Hemisphere, it is a fall-winter astrophotography target. Messier 45 is a well-known object by fans of the night sky, as the “Seven Sisters” are a stand-out visual delight among a sea of stars. You’ll find this striking cluster of 7 stars within the constellation Taurus.
On top of being an open star cluster, the Pleiades also contains faint reflection nebulosity, that can be seen through long exposure astrophotography.
M45 – The Pleiades
Total Exposure: 2 Hours 13 Minutes
38 x 210″ subs @ ISO 1600
Stacked with 16 darks, 16 flats, 16 bias
Telescope: ES ED80 Triplet Apo
Tracking Mount: ASCG-5 GT
Guide Scope: Orion Mini Guidescope
Guiding Camera: Meade DSI II
Camera: Canon 450d unmodded
The Telescope used for this image
Photographing The Pleiades
The photo you see above was captured on a cool night in September 2012 using my 80mm Explore Scientific Refractor, and a Celestron Advanced Series CG-5 equatorial mount. Stacking multiple exposures will help increase the signal-to-noise ratio in your image, and help bring out the faint reflection nebula that envelope the bright blue stars.
There is a massive amount of dust within the Pleiades star cluster and can be captured in detail with enough exposure time. This 12-hour exposure displays just how much dust there really is surrounding the Pleiades star cluster.
The Pleiades using a Camera Lens
The photo below shows the Pleiades using a Camera Lens with a focal length of 135mm. The Lens in question is a Canon EF 28-135mm F/4L Lens, that was attached to my Canon EOS Rebel T3i camera.
The camera and lens tracked the sky courtesy of the iOptron SkyTracker camera mount. The exposures were 2 minutes each, with 70 frames in total being used. Because this image was captured from my backyard, a light pollution filter was used to help create contrast between the object and the washed-out night sky.
One of the benefits of shooting Pleiades with a DSLR camera is the ability to focus using the bright stars of M45. Unlike many faint nebulae and globular clusters in the night sky, Pleiades is easy to find and shows up well in your camera’s live view screen.
Here’s a look at one of my early versions of M45:
A Wide Field of View
A wide-field instrument such as the 480mm Explore Scientific ED80 that I used is needed to capture the entire star cluster. A larger telescope with a focal length of 800mm or larger will capture more detail in the reflection nebulosity, but crop the full view of the star cluster. M45 covers a large area of the night sky, several times the size of the full moon.
The challenge when processing Messier 45 is the extremely bright and large stars in the image. These stars may have caused some reflections in your image, that will be to be removed using either the clone tool or healing brush. The Content-aware fill feature in Adobe Photoshop will also handle the task quite well.
The image processing steps needed for an image of a star cluster are quite different than they are for a galaxy or nebula. Because the focus is on the stars themselves, less stretching (curves, levels) of the data is needed. For most of my deep-sky images, my goal is to tame the bright stars and pull the light from the DSO (deep-sky object) forward. The Pleiades is a challenge because the stars and reflection nebulae are featured together. This is why you will see so many variations of M45 with fluctuating amounts of nebulosity.
Binoculars are a great tool for observing the Pleiades, as this star cluster is quite large. A wide field of view will ensure that the entire cluster of 7 stars can be seen at the same time.
The first time I noticed the Pleiades was back in 2010 from my backyard. I had just purchased my first telescope (An Orion 4.5″ SkyQuest Dobsonian) and noticed a peculiar glowing region of the sky rising in the East. I pointed my little reflector towards the object – and BAM!
The glowing region was the most intense open star cluster I had ever seen! Surely this must be a popular target for backyard astronomers! Later, I found out that the Pleiades are indeed a well recognized and enjoyed group of stars!
The Pleiades are one of the most beautiful astrophotography subjects in the night sky. Their brightness and forgiving location make imaging M45 a popular choice for beginners. For the latest information and photos, please follow AstroBackyard on Facebook.