Updated: Jun 5
The Andromeda Galaxy, also known as Messier 31, is the largest and brightest galaxy visible from Earth. It has a magnitude of 3.44 and is one of the easiest deep-sky objects to photograph for beginner astrophotographers. M31 is a spiral galaxy located 2.45 million light-years away in the constellation Andromeda. In this post, you will find pictures, information, and more to help you observe and photograph the Andromeda Galaxy!
Andromeda Galaxy Astrophotography with Amateur Equipment
The Andromeda Galaxy is very simple to photograph, with and without a telescope and no matter your skill level! We have imaged M31 several times over the years, and you can see below one of our favorite pictures of Andromeda we took with our telescope.
This was taken using a QHY600C cooled color camera attached to a Stellarvue SVX130 refractor telescope and the Paramount MyT German equatorial mount. For guiding, we used the small ZWO ASI 290MM Mini and also had a Moonlite Nightcrawler focuser for easy focusing and rotation. No filters were used for this picture.
This image was shot from a Bortle 4 zone and totals 6.5 hours of integration time shooting 3-minute long exposures.
Want to process your images following our own workflow? Download our PixInsight Guide!
Planning on imaging Messier 31 soon? For astrophotography tips, be sure to visit our full blog post about photographing the Andromeda Galaxy! There, we go deeper into how to image M31 with and without a telescope, different types of cameras, and go over the recommended settings to use so you can get the very best image of the Andromeda Galaxy!
How to find the Andromeda Galaxy in the Sky?
The Andromeda Galaxy is located in the small constellation Andromeda. The easiest way to find Messier 31 is to actually use the nearby constellation of Pegasus, most specifically the bright and obvious Pegasus square.
You can see the galaxy annotated on a sky map below. Take a look at the constellations and bright stars around the Andromeda Galaxy.
M31 lies between the Great Pegasus Square and Cassiopeia, two bright and large constellations easily visible even through some light pollution.
The easiest way to find the Andromeda Galaxy is to first locate Pegasus’ square. Once you do, look for the corner closest to Cassiopeia’s “W” shape and jump to the first, then the second star out of that corner. That second star should be the bright Mirach. Finally, do the same double jump, but at a 90-degree angle up this time, and you will find yourself staring at the brightest galaxy in the Messier catalog.
Finding the Andromeda Galaxy by yourself is difficult the first time, but if you try to spot the galaxy every time you are under dark skies, it will quickly become second nature! On my first attempt, it took me a full hour and a half to find M31, but now, I am able to find it easily in just seconds every single time. If you are new to the hobby and are smarter than I was when I was looking up for the first time, use an app to quickly spot Andromeda! Most astronomy apps these days have augmented reality (AR) features, which allow you to aim your smartphone at the sky and be guided to where your desired object is. Some examples of great astronomy apps to find the Andromeda Galaxy are SkySafari, Stellarium, and Skychart to name a few.
The Andromeda Constellation
The constellation Andromeda is rather small and does not stand out in the sky especially because it is overlapping Pegasus, a much larger and brighter constellation.
In Greek mythology, Andromeda was the daughter of Cepheus and Cassiopeia. Cassiopeia was an arrogant mother and wasn't afraid to tell everyone that she and her daughter Andromeda were the most beautiful around. This made Poseidon, god of the sea, furious.
Andromeda ended up being chained to a rock by the water, waiting for the sea monster Cetus to come eat her. Luckily, Perseus was flying overhead on his horse Pegasus, and spotted the princess in distress. Andromeda was saved, but Poseidon decided to chain her mother Cassiopeia to the sky, where she spends 6 months each year upside down as punishment. Andromeda rests in the sky not far from her mother.
[You can learn the full story and learn about all 88 constellations in The Constellations Handbook]
When is the Best Time to See the Andromeda Galaxy?
The best time to observe the Andromeda Galaxy is from late Summer to Early December, more specifically from August to January. Messier 31 peaks in the Fall/Autumn. You can spot M31 before or after this period, as it is visible during most of the year, as long as you don't mind waking up very early in the morning or staying up late!
The Andromeda Galaxy is best observed from the northern hemisphere, but it is not impossible to see in some regions of the southern hemisphere. If you are in latitudes north of -40 degrees, then you can likely get a quick glance at it in November, but expect it to be low on the horizon.
How far away is the Andromeda Galaxy from Earth?
Messier 31 is a galaxy, which means that unlike a huge majority of nebulae and star clusters visible from Earth, it is located outside of our Milky Way. The Andromeda Galaxy lies approximately 2.537 million light-years away from Earth. M31 is the closest non-dwarf galaxy from the Milky Way.
If you think this is far, think again, because, in the vast expanse of the universe, 2.5 million light-years is actually not an incredible distance for another galaxy. M31 is much closer than most other known galaxies because it is located within our Local Group of galaxies.
The Local Group includes more than 80 galaxies that are linked by gravity. Most of the galaxies in the Local Group are dwarf satellites of the three main players: the Andromeda galaxy, our Milky Way galaxy, and the Triangulum galaxy.
How long would it take to reach the Andromeda Galaxy?
Despite how close the Andromeda Galaxy is compared to other galaxies in the sky, it would still be completely impossible to reach it with our current technologies.
Remember that Messier 31 is located about 2.5 million light-years away... which means that even if NASA had a ship capable of reaching the speed of light, which is not the case, it would still take at least 2.5 million years to reach Andromeda. 🚀
What if we took a spaceship that is already going very fast in space and re-route it to M31?
Using Voyager 1 as an example, which was launched on September 5, 1977 and is currently traveling at a speed of 38,210 miles per hour, it would take 3.3 billion years before it finally reached the Andromeda Galaxy... And that's assuming it has infinite power and fuel.
Andromeda vs Milky Way Size - How Big is the Andromeda Galaxy?
The Andromeda Galaxy is the largest object in our Local Group of galaxies. It has a diameter of approximately 200,000 light-years which is slightly larger than our Milky Way.
It was long thought that the Andromeda Galaxy was two to three times more massive than our galaxy. Then for a short time, scientists believed that our Milky Way was in fact larger than the Andromeda Galaxy. In 2018, new measurement tools became available and NASA confirmed that both spiral galaxies were about the same size.
Although it is difficult to fathom, the Andromeda Galaxy spans the size of six full moons in the night sky! You can get a better sense of scale by looking at the composite picture above. For those of you who like doing astrophotography time-lapses, you likely will "accidentally" capture M31 going through your frame depending on where you are pointing your camera in the sky. The Andromeda Galaxy is so large and bright that it easily appears in short exposure shots even at wide focal lengths, like in time-lapses and even landscape astrophotography images.
How many stars are in the Andromeda Galaxy?
The Andromeda Galaxy is believed to contain about a thousand billion stars. This is much more than the number of stars in the Milky Way galaxy, estimated anywhere between 100 and 400 billion. If these numbers are correct, and both galaxies are indeed about the same size, it would be that the Andromeda Galaxy is much more densely populated than the Milky Way, with double to triple the number of stars in the night sky.
The Andromeda Galaxy also contains plenty of star clusters and nebulae (star-forming regions). The picture above was taken by the Hubble Space Telescope, and shows a tiny fraction of the galaxy, annotated with objects of interest.
Now, how old is the Andromeda Galaxy? It is 10 billion years old, which makes it younger than our Milky Way galaxy (13.61 billion years old)!
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How to Observe the Andromeda Galaxy
The Andromeda Galaxy is one of the best deep-sky objects you can observe visually. There are several ways you can spot the galaxy, either with or without instruments, but the most important thing to do is to get as far away from light pollution as you can. The less light pollution you have at your observing location, the brighter and more defined the Andromeda Galaxy will appear.
Can you see the Andromeda Galaxy with your naked eye?
The Andromeda Galaxy is one of the few galaxies visible to the naked eye from Earth in the Northern hemisphere. The fact that it is the largest and brightest galaxy in the entire sky definitely helps!
Spotting M31 with your naked eye can be a little tricky at first and will require you to drive to a dark site. We recommend choosing an observing location that is Bortle 4 or better to be able to see the Andromeda Galaxy. You can learn about the Bortle scale in our full guide to escape light pollution. It is simply impossible to spot the Andromeda Galaxy under city lights.
Here are some tips we can give you if you are trying to find M31 in the sky:
Be prepared to know exactly where to look in order to find the galaxy
You can use an app on your phone or look at a map and learn to star-hop
Let your eyes get used to the darkness for at least 30 minutes.
Do not turn any light on or look at your cell phone for a minimum of 30 minutes.
Use averted vision
Do not look at the galaxy directly but instead, look slightly off to the side of it. Very faint light, like the one that comes from galaxies, will better reach your retina and optic nerve if it doesn't go through the exact center of your eye. Using peripheral vision makes your eyes more sensitive to faint objects and is often used in visual astronomy.
Can you see the Andromeda Galaxy with binoculars?
The Andromeda Galaxy is one of several galaxies visible with binoculars, and it is actually the easiest and most impressive way to observe the galaxy! Because of its very large size, using a pair of astronomy binoculars instead of a telescope will allow you to have a full view on the galaxy.
We recommend buying a pair of 15x70 binoculars if you would like to observe not only the Andromeda galaxy but also other bright deep sky objects like the Orion Nebula or the Pleiades.
Our very first time seeing the galaxy through binoculars was with a pair of 20x80. It was difficult because of how heavy these are and do require a small tripod for long sessions. 15x70 binoculars are lighter and in our opinion, perfect for astronomy.
Note that viewing this target with binoculars will also reveal its satellite galaxy: M110! You may also observe M32, but it will most likely not be visible as it might appear washed out in M31’s gases.
Can you see the Andromeda Galaxy with a telescope?
You can spot the Andromeda Galaxy with your naked eye and with binoculars, so of course, you can also see it with a telescope!
We recommend using a small/medium telescope to observe Andromeda. Due to its gigantic size, the galaxy will likely not fully fit in the field of view of your instrument unless you use something small with the right eyepiece. Through a large telescope, the Andromeda Galaxy does not look that impressive because the bright core tends to overwhelm the view.
We do not recommend buying a cheap telescope like you often find during Christmas because they often have terrible optics and will ruin astronomy for you.
For more information about purchasing your first telescope, be sure to read our beginner telescope buying guide!
This might come as a shocker but we would pick a pair of astronomy binoculars over a telescope if we had to choose one to view the Andromeda Galaxy!
The Andromeda Galaxy without a Telescope
As we said earlier, Messier 31 is large and bright, making it an easy target for beginner astrophotographers. In case you did not know, you can photograph the Andromeda Galaxy without a telescope, using any DSLR camera and lens you already have.
To prove it to you, we have imaged M31 in two ways, which you can see below.
Left: The Andromeda Galaxy widefield with just a tripod, a DSLR camera, and a lens.
Right: The Andromeda Galaxy widefield with a tripod, a star tracker, a DSLR camera, and a lens.
For both of these images, the camera used was an old Canon T3i (600D) bought used from eBay, and the lens is the affordable Canon 50mm f/1.8 which is great for widefield astrophotography.
If you are planning on imaging M31 with your DSLR/mirrorless camera and a lens, be sure to frame it to your liking! If you use a wide enough lens (50mm for example in our case), you can easily include M33, the Triangulum Galaxy in the same frame! Messier 33 can be seen on the second image near the bottom center, in blue.
Recommended Equipment for Photographing the Andromeda Galaxy
What gear should you use to take pictures of the Andromeda Galaxy? M31 can be imaged with any telescope/camera combo and with pretty much any camera lens.
Equipment to capture Messier 31 without a telescope
A camera - If you already have a DSLR camera at home, use it instead of buying a new one! If not, aim for an affordable camera that does well for astrophotography, like any camera in the Canon TXi series.
An intervalometer. If your camera does not have a built-in intervalometer, be sure to purchase one before going out on the field! With it, you'll be able to take long exposure shots and more.
A lens - You can image M31 with any lens, but we suggest going with either a 50mm lens, an 85mm lens, or a 135mm lens. Wider than 50mm will make the galaxy appear tiny, and longer than 135mm will force you to only take 1 or 2 second exposures max before seeing star trails. The Canon EF 50mm f/1.8 and the Samyang 135mm f/2 are our two favorite lenses for widefield astrophotography of deep sky objects.
A star tracker - This is optional but if you are looking to get the best possible results, you need to track the sky! This will let you take much longer exposures and get a much better signal-to-noise ratio. The tracker we use is the popular Sky-Watcher Star Adventurer Pro.
Equipment to capture Messier 31 with a telescope
A telescope - A small to medium size telescope is recommended to photograph the Andromeda Galaxy. This is because M31 is so large and using a telescope with a long focal length will clip the edges of the galaxy. The picture below shows what field of view to expect when targeting M31 with both a small refractor telescope and a reflector telescope using a cropped sensor camera. As you can see, the galaxy does not entirely fit at 800mm of focal length. If you are looking for a small refractor telescope, we recommend something like the William Optics RedCat 51 or the Zenithstar 61. If you don't mind something bulkier, we suggest going with an 8" reflector or with the RASA8!
A camera - You can use any camera of your choice, including the one you would have used in the widefield section above. Our first picture of the Andromeda Galaxy through a telescope was taken with a used Canon T3i. Read our full guide about the best cameras for astrophotography.
Auto-guiding - Lastly, this is optional but definitely recommended, you will need an auto-guiding solution. We use the ZWO ASI290mm Mini as our guide camera because of how small and lightweight it is. As for the guide scope, we recommend a 50mm or 60mm aperture guide scope.
Picture of the Andromeda Galaxy by the Hubble Space Telescope
On January 5, 2015, NASA released a mind-blowing high-resolution image of the Andromeda Galaxy taken by the Hubble Space Telescope. Because of its size, we only get about a third of the galaxy here despite the HST stitching hundreds of frames into a mosaic. The size of the image is 69536 x 22230 pixels and it would have taken NASA many more months if they wanted to include the entire galaxy.
This Hubble image of the Andromeda Galaxy is (was?) the biggest image NASA ever released from the HST. More than 100 million stars can be seen over this 40,000 light-years-long panorama.
Talking about imaging M31 with professional telescopes, take a look at this interesting compilation of images of the Andromeda Galaxy taken through different filters. Here you can see the object as it looks in the following wavelengths:
Infrared (Where the JWST would excel)
Optical (What you see with your camera and no filters from Earth)
The structures in the Andromeda Galaxy are fascinating to look at and study, and it so great to have such a huge galaxy this close to ours!
Is Andromeda a Galaxy or a Nebula?
Well, just "Andromeda" is a constellation. But what about the main object in it? M31 has been called "The Great Nebula in Andromeda" until his galactic nature was recognized in the 1920s. People who read older astronomy texts might get confused as to why M31 was classified as a nebula for so long.
The Andromeda Galaxy was known to exist for hundreds of years but was added to the Messier Catalog in 1764.
Charles Messier scribbled the following note:
"I have employed different instruments, especially an excellent Gregorian telescope of 30 feet, the large mirror 6 inches in diameter, magnification 104x. The center of this nebula appears fairly clear in this instrument without any stars appearing. The light gradually diminishes until it becomes extinguished. The former measurements were made with a Newtonian telescope of 4.5 feet, provided with a silk thread micrometer. Diameter 40".
As you can see in Messier's notes, he referred to the galaxy as a "nebula". This was actually the norm back then, as astronomers believed that every galaxy in the sky was in fact a nebula within our Milky Way.
The main reason for that is that despite their true dark skies, they were not able to distinguish much detail through their optics. For example, it wasn't possible for Charles Messier to see the spiral arms of Andromeda, and the object looked like a fuzzy blob... just like any nebula.
It wasn't until the year 1923 that galaxies were proven to exist, thanks to Edwin Hubble.
The Very First Image of the Andromeda Galaxy Ever Taken
The first picture of the Andromeda Galaxy was taken on December 29, 1888, by Isaac Roberts. Isaac Roberts was a Welsh engineer and businessman, but was very interested in astronomy and made it his main hobby.
Back then, M31 was believed to be a nebula within our own galaxy, so Isaac Roberts named his picture "The Great Nebula in Andromeda" when he took it, four days after Christmas. This picture had a great impact on astronomy, as it finally made astronomers realize that Messier 31 had a spiral structure.
For this shot, Isaac Roberts used a 20” reflector made by Howard Grubb, an optical designer from Dublin.
In his notes about M31, Isaac Roberts noted:
"The photograph was taken with the 20-inch reflector on December 29th, 1888, between sidereal time 1h 38m and 5h 45m, with an exposure of the plate during four hours.
Three nebulae are shown on the photograph. 1st, the Great Nebula, Messier 31; 2nd, the one on the south side is h 51 (M32), and was discovered by Le Gentil in 1749; 3rd, that on the north preceding side is h 44, and was discovered by Caroline Herschel in 1783.
A monograph of this nebula was prepared by George P. Bond, and published in the
Memoirs of the American Academy of Arts and Sciences, New Series, Vol. III., pp. 75 to 86, 1848. The monograph is accompanied by a carefully prepared and well-executed drawing of the nebula, and, taken together, they contained the fullest information extant concerning the object, until the photographs, of which the annexed is one of a series, were taken.
Bond, with the 15-inch refractor of the Harvard Observatory, saw in the nebula two
dark bands or canals, perfectly straight, suddenly terminated, and slightly diverging at an angle of about three degrees. He also states that he estimated above 1500 stars to be involved within the limits of the nebula.
A photograph which I took with the 20-inch reflector on October 10th, 1887, revealed for the first time the true character of the Great Nebula, and one of the features exhibited was that the dark bands, referred to by Bond, formed parts of divisions between symmetrical rings of nebulous matter surrounding the large diffuse centre of the nebula, Other photographs were taken in 1887, November 15th; 1888, October Ist; 1888, October 2nd; 1888, December 29th; besides several others taken since, upon all of which the rings of nebulosity are identically shown, and thus the photographs confirm the accuracy of each other, and the objective reality of the details shown of the structure of the nebula.
The Photograph annexed is an enlargement from the negative taken in 1888, December 29th, and will remain a permanent record, unquestionable in accuracy, of the state or the appearance of the three nebula shown on the night when the photograph was taken, so that any changes that may take place in the form or density of the nebulosity, or in the positions or magnitude of the stars, will in future be capable of demonstration. These photographs throw a strong light on the probable truth of the Nebular Hypothesis, for they show what appears to be the progressive evolution of a gigantic stellar system."
As you can see, Isaac Roberts mentions that George Phillips Bond did take a picture of the galaxy years prior, but after some extended research, the only images I could find taken by Bond were of Vega and other stars.
The comparison image below shows Isaac Roberts' picture of the Andromeda Galaxy (1888) and our first picture using a telescope of this same object, taken in 2016... 128 years later.
In both images, The two main satellite galaxies of M31 are visible, M32 (top left) and M110 (bottom right).
The Andromeda-Milky Way Collision
The Andromeda Galaxy is the nearest main galaxy from the Milky Way, and it's only going to get closer! Scary yet fun fact about the Andromeda Galaxy, it's headed straight towards our Milky Way galaxy and is doomed to crash into us! Yaay! 🥳
The collision is expected to occur in about 3.75 billion years, so don't expect to see it in your lifetime. Ultimately, both galaxies will merge and be renamed "Milkomeda", until colliding with a third galaxy many years later, the Triangulum Galaxy.
NASA and several artists did their best to recreate what a night sky on Earth would look like as the Andromeda Galaxy gets closer and closer to the Milky Way. Take a look at the illustrated timeline below!
Square 1 - Present day. You can see the Andromeda Galaxy as a small white fudge to the left of the Milky Way band.
Square 2 - 2 billion years from now. The Andromeda Galaxy is noticeably larger as it approaches.
Square 3 - 3.75 billion years from now. The Andromeda Galaxy fills the field of view.
Square 4 - 3.85 billion years from now. The night sky is filled with new star formation activity as the spiral arms of both galaxies start to merge.
Square 5 - 3.9 billion years from now. The galaxies continue to interact in a fiery spin. Star formation is at its peak and the entire sky is filled with dust, gases, and new stars.
Square 6 - 4 billion years from now. The Andromeda Galaxy is tidally stretched and the Milky Way becomes warped.
Square 7 - 5.1 billion years from now. The cores of the Milky Way and Andromeda appear as a pair of bright lobes.
Square 8 - 7 billion years from now. The merged galaxies form a huge elliptical galaxy, its bright core dominating the nighttime sky
Fun Facts about the Andromeda Galaxy
The Andromeda Galaxy is the brightest and largest galaxy visible from Earth
The very first picture taken of the Andromeda Galaxy was in 1888 by Isaac Roberts
The Andromeda Galaxy was believed to be a nebula until 1923
The Andromeda Galaxy and the Milky Way will merge into the Milkomeda Galaxy
Distance from Earth to the Andromeda Galaxy in light-years: 2.537 million light-years
Distance from Earth to the Andromeda Galaxy in miles: 1.4914073e+19 miles
Distance from Earth to the Andromeda Galaxy in kilometers: 24001873898112000000 km
Do you have any additional interesting Andromeda Galaxy facts we missed? Let us know in the comments and we will add them to the list!
The Andromeda Galaxy is by far the most beloved galaxy in the night sky, thanks to its size, brightness, and availability throughout most of the year. M31 is the perfect target to practice on if you are a beginner astrophotographer, no matter the equipment you have!
Getting ready to capture Messier 31? Be sure to first go through our full guide about how to photograph the Andromeda Galaxy for tips and more.
If you think our image of M31 is beautiful, consider getting a print to hang in your home! This is a nice way to help us or thank us for these tutorials, and we have no doubt that you will love the quality of the print!
Antoine & Dalia Grelin
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