Messier 45 - The Pleiades Star Cluster
Updated: Jun 7, 2023
The Pleiades, also known as the beautiful Seven Sisters, is the easiest and most impressive star cluster to photograph the night sky!
M45 is huge, extremely bright, and looks amazing in both close-up shots using a telescope, or through wide-field astrophotography. The stars in the Pleiades are blue, glowing against the faint nebulous gases they are passing through, visible around them.
Object Designation: M45
Also known as: The Pleiades, The Seven Sisters, Subaru
Constellation: Taurus
Object Type: Open Cluster
Distance: 444 light-years away
Magnitude: 1.6
Discovered in: Pre-historic times
We imaged Messier 45 many, many times, and we'll show you each of the main results in this post!
Using our old Canon T3i and our telescope for a total exposure time of 2 hours
Using our old Canon T3i wide-field with our 50mm lens for a total exposure time of 4 hours
Using an ASI071MC and a small refractor telescope
Using our cooled monochrome astrophotography camera for a total exposure time of 3 hours
[NEW!] Using an SVX130 and QHY600C full-frame camera
From our experience, taking a photo with an exposure of about 3 minutes is enough to see the reflection nebulae around the stars. It of course helps if you are under a beautiful dark sky, but the Pleiades are very bright and you should be able to get great results even from the city.
Below you will see our three attempts at this target so that you can really compare the results from each setup. These were all taken from a Bortle 4 zone.
Imaging the Pleiades with a DSLR Camera
February 6th, 2016
The photo below is the result of only 2 hours of total exposure with our unmodified Canon T3i, attached to our 8” f/3.9 Newtonian telescope!
This is a night we will never forget. We made one of the stupidest mistakes in our astrophotography career that day, and it bothered us so much that we never repeated that mistake ever again since. Lesson learned!
What did we do? This was our first attempt at guiding with our new Auto-guiding package from Orion. We set it up and launched PHD2 on our laptop. Because of the 2-second long exposures, we were able to see a couple of white dots on our frames. We were complete beginners and thought these were stars, and decided to guide one of them. We realized two hours later that our pictures were all blurry and full of star trails. This is because these "white dots" were just dust particles from the guide scope's cap we left on... All the frames from the two hours that passed all went to the trash. This is why we only have two hours of stackable data instead of four.
Note that the photo is uncropped and as you can see, Messier 45 fits perfectly in the frame of our 8" telescope.
GEAR USED:
Camera: Canon t3i (600D)
Telescope: 8" Newtonian
Mount: Motorized Equatorial Mount
Guiding: Autoguider - 50mm Guide Scope
Processing: Pixinsight
ACQUISITION DETAILS:
Total Exposure Time: 2 hours
Exposure Time per frame: 3 minutes
40 lights - 15 Darks - 15 Bias
ISO: 400
The Pleiades - Wide-Field with a Camera Lens
December 16th, 2015
The Pleiades is an excellent target for wide-field astrophotography. Our first successful attempt at this target was actually with our camera lens back when we did not own a telescope.
Attaching your DSLR camera to a sky tracker (such as the iOptron Skytracker or Omegon Mini Track LX2) will allow you to take long exposures (3 minutes in our case) and reveal the nebulosity behind the stars pretty easily. You can also directly attach your camera to your motorized mount if you have one!
A good thing to do if using a lens that is 50mm or wider, is to capture the California Nebula in the same frame!
For this, make sure to not center M45 but instead, try to match the position of the cluster from our image below. Notice how you can get a lot of interstellar dust lane as well! Those seem to be dividing the Pleiades from the California Nebula.
GEAR USED:
Camera: Canon T3i (600D)
Lens: Canon 50mm f/1.8
Mount: iOptron Skytracker
Processing: Pixinsight
ACQUISITION DETAILS:
Total Exposure Time: 4 hours
Exposure Time per frame: 3 minutes
ISO: 800
The Pleiades with a Small Refractor Telescope
October 2019
Not expecting to image that night, we decided to head out at the last minute and drive to a Bortle 5 zone (our usual spot is Bortle 3-4). We remember freezing to death that night as we also filmed our review video on the QHY Polemaster.
We decided to try out our ZWO ASI 071MC camera for the first time. We never tried a One-Shot-Color cooled camera in the past and were excited to see how this one would perform. Because of the cold, we only stayed out to image for one hour and got this image below of the Pleiades star cluster. This is definitely better than we thought and we wish we spent three or four hours instead to get an incredible image. Next time for sure!
GEAR USED:
Camera: ZWO ASI 071MC
Telescope: Meade 70mm APO
Mount: Motorized Equatorial Mount
Guiding: ZWO ASI 290MM Mini
Acquisition: ZWO ASIAIR
Processing: Pixinsight
ACQUISITION DETAILS:
Total Exposure Time: 1 hour
Exposure Time per frame: 1 minute
Gain: 90
The Pleiades with a Cooled Monochrome Camera
November 22nd, 2019
More than three and a half years after photographing M45 with our DSLR camera, we decided to give it a try with our current camera, the ZWO ASI 1600MM. We spent a total of three hours on it this time but faced a challenge we never had to deal with before here in Nevada: humidity.
While imaging, our entire equipment became very cold and wet, including the mirrors of our Newtonian telescope. Because we do not own a dew shield nor a dew heater, this definitely affected our image, and we believe it could have been much better than this. We are still happy anyway, as this version is neater than the one taken with our old DSLR camera.
GEAR USED:
Camera: ZWO ASI 1600mm Pro Mono
Telescope: 8" Newtonian
Mount: Motorized Equatorial Mount
Guiding: ZWO ASI 290MM Mini
Acquisition: ZWO ASIAIR
Processing: Pixinsight
ACQUISITION DETAILS:
Total Exposure Time: 3 hours
Exposure Time per frame: 3 minutes
Filters: L (1h 30m) / R (30m) / G (30m) / B (30m)
Gain: 75
The Pleiades with the QHY600C
October 11th, 2020
Not happy with the result I got from the last attempt due to the humidity, I decided to go out to the desert again, of course making sure it was a dry night.
This time, I used the SVX130 telescope and QHY600C camera which our friend Mark is lending us! This is a fantastic combo and it even included a Nightcrawler rotator and focuser to make our life easier.
The photo below is almost 4 hours of exposure on M45, which turned out fantastic! The un-cropped version can be found at the very top of this post.
GEAR USED:
Camera: QHY600C
Telescope: Stellarvue SVX130
Mount: Paramount MyT
Guiding: ZWO ASI 290MM Mini
Accessories: Moonlite Nightcrawler focuser
Processing: Pixinsight with RC-Astro Plugins
ACQUISITION DETAILS:
Total Exposure Time: 3.8 hours
Exposure Time per frame: 3 minutes
Filters: N/A
Gain: 26
Want to see how I photographed this target? Watch the video below where I spend an entire night in the desert sleeping in the trunk of the car and imaged both M45 and M31!
How to Locate the Pleiades
The Pleiades are by far the easiest Deep Sky Object to spot in the night sky, they can be seen with the unaided eye, binoculars, and of course telescopes.
Light pollution does not affect the visibility of the main stars of the Seven Sisters, as they can be spotted from both a very dark site and the heart of a bright city. With the naked eye, the cluster looks like several bright blue stars, linked to each other by small lines.
Through binoculars, it just looks like several big and luminous stars forming the shape of a cross. The nebulosity around the stars may be seen with a large aperture telescope, although it is very faint and difficult to make out.
M45 is located in the Taurus constellation and is about four times the apparent size of the full moon. The cluster is slowly dispersing and drifting towards the Orion constellation, and will officially be part of the Hunter in about 250 million years. it is not very far from the California Nebula.
Cool Facts about the Pleiades
First observed by Galileo Galilei
Moving toward the Orion constellation
The names of the seven brightest stars making the Seven Sisters are Sterope, Electra, Merope, Maia, Celaeno, Taygeta & Alcyone
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The First Picture of the Pleiades Ever Taken
Did you ever wonder who took the first picture of M45, and when?
Isaac Roberts, an engineer and businessman from Wales decided to attempt imaging the Pleiades with his self-built 20" reflector telescope from Maghull, Lancashire.
It was a clear night on December 8, 1888, and the total exposure time was 4 hours.
The result he obtained is visible on the left. What do you think?
You could say that Roberts should have turned the plate at a 90-degree angle to have a much better framing 😅, but besides that, this picture is very impressive!
You can clearly see some of the nebulous gas behind the bright star Merope (bottom star) and even some hints of gas near the other stars too! This is very impressive considering the equipment Roberts had back in 1888, that's more than 130 years ago!
For fun, here is a comparison image between the very first picture of M45 by Isaac Roberts in 1888, and our picture of M45 taken in 2020, 132 years later.
Single Shot & Processing of M45
Processing M45 is fairly easy, but can be tricky at times no matter what camera you use.
The one thing we struggled the most with was the very first step: The extraction of the Background. Using Dynamic Background Extraction on PixInsight, make sure to have another image of M45 ready next to you, and be certain to not have any of the crosses from the process where the nebulosity is supposed to be. The rest was pretty straightforward, just once again make sure that your background preview is not on some of the gases when doing the background neutralization process.
If you are interested in learning how I process all our images, you can get our PixInsight guide "follow along" which contains 18 lessons and tutorial videos, our custom pre-sets for your dashboard, and even raw data HERE.
As for the wide-field version, the only challenge is to reveal the black interstellar dust lanes within the image, but both M45 and the California Nebula pop out nicely without much trouble.
Below is what a single shot of M45 looks like using our ASI 1600MM. The single shot with the DSLR camera was actually pretty similar. See how just 3 minutes of exposure easily reveals some of the nebulosity.
Because our ASI 1600MM is a monochrome camera, we had to use filters which we later combined to make a color image. For this particular target, we used 4 filters: L, R, G and B.
You might wonder what the master files look like after combining each filter, so we decided to keep them and show them to you!
Below you can see the stacked image for each filter, in order: Luminance, Red, Green, and Blue. You can see that they all look very similar.
Practice Makes Perfect
Our very first picture of the night sky, using a point-and-shoot camera, The Pleiades were visible in the very wide image - 09/11/2015
Our first DSLR picture of the Pleiades, 3 months later - 12/02/2015
Our first tracked picture of the Pleiades, using our DSLR, tripod, and iOptron Skytracker - 12/04/2015
Our first picture of the Pleiades with a telescope, having huge trouble with the guiding - 02/06/2016
Our first picture of the Pleiades with a cooled monochrome camera, struggling with humidity and dew - 11/22/2019
Our image of the Pleiades with a cooled color camera, f/5 refractor, and a clear dry night - 10/11/2020
Between number 1 and number 4 (in the very first collage image only), we drove an hour back and forth to the desert 77 times in order to get this much progress that fast. That's 154 hours of driving without counting the hours of mounting the equipment every time. Don't expect to learn fast if you are not giving it 100%!
If you live away from light pollution and can photograph the night sky from your backyard, you are super lucky! Update: We now have a backyard 🥳!
Years of Progress on M45
Below are many of our early attempts at capturing M45, taken over time. Our very first shot was taken on September 12, 2015. Our first "happy result" can be seen last using our 8" Astrograph and our DSLR camera.
Final Thoughts
The Pleiades Star Cluster is by far the most impressive and best cluster to photograph in the night sky. If photographed wide field with a DSLR/Mirrorless camera and lens, you will also be able to get the California Nebula, as well as dark dust lanes in the image.
You will likely never feel tired of capturing M45 over and over again as you get better at the hobby of astrophotography.
We've been photographing the cluster almost every single year since we started, and each time we are able to reveal more details and colors within the object.
If you'd like to download our raw data for this object, you can visit our Raw Data page to get a high-quality dataset for several DSOs! The files have been prepared carefully so that you can open them in any processing software and start practicing!
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