This Space Walk is designed around 15x70 binoculars, because that's what I used to make my notes, but you can use any size. The Milky Way star fields will always be good, but some of the objects may be difficult to locate or observe with smaller binoculars. See what you can see!
The Space Walk guides you through the rich star fields of the Summer Milky Way to locate 8 open clusters, a planetary nebula, two emission nebulae, several asterisms, and a few multiple stars. These are visible in 15x70 binoculars from a Bortle 4 or 5 sky (about 21 magnitudes per square arc second, or mpsas). The darker the sky, the better, without the Moon in the sky, as even a crescent Moon will wash out the view a bit.
Cygnus is a summer constellation in the Northern Hemisphere, with its brightest star, Alpha Cygni, Deneb, being one of the stars in the "Summer Triangle." It is at the zenith in late August. You'll need a chair that reclines far enough that you can comfortably look straight up.
As always, I recommend building your own Bino Body Mount, which will make observing, especially with larger binoculars, much more comfortable and enjoyable than trying to handhold or mount your binoculars on a tripod. If you have a parallelogram mount, that will also work, but it is bulkier and expensive, and the selection or commercial offerings has dwindled in the last few years. The Bino Body Mount is inexpensive and easy to make yourself if you have some hand tools and a power drill. If I can do it, you can!
Binocular Space Walk - Cygnus Milky Way
Download the file linked above to the device you will be using to listen to it in the field.
Observing list for Sky Safari Pro, showing all the clusters in the order mentioned in the Space Walk.
This is in the Sky Safari .skylist format. Download to your phone or tablet and import into Sky Safari Pro or Plus. Do this by emailing the .skylist file to yourself, open the email on your device, download it, then select the file, select "open with" and choose Sky Safari. You'll get an acknowledgment that it was imported. The list will show up as "Imported List" followed by the date and time. You can rename it in Sky Safari.
Note that I have added the star SAO 50243 to mark the center star in the "belt" in the "Little Orion" asterism, since it is not included in Sky Safari.
Charts to accompany the Binocular Space Walk. Review these prior to observing with your binoculars.
The objects and their locations. This view is for mid-northern latitudes, looking toward the zenith on a late August evening. You might want to orient your chair so that it matches the chart views.
Click on each chart for a larger version.
Charts adapted from Cartes du Ciel, free sky charting software.
Chart of the Sadr (Gamma Cygni, γ) area.
Chart for the North American and Pelican Nebulas, and showing the "Ant" asterism I reference in the Space Walk to help locate the nebulas.
Transcript of the Space Walk
Astronomerica presents: A Space Walk Among the Stars, Binocular Edition, The Cygnus Milky Way.
We’re going to look at the Milky Way around the constellation Cygnus, the Swan, tonight. This is designed for mid-northern latitudes, where Cygnus will be near the zenith (or directly overhead) on late August or early September evenings (or earlier in the summer but later at night). I’ll be guiding you in a manner known as starhopping, where you use brighter stars and patterns to “hop” to an object. I’ll provide information about the objects we’re observing and points where you can pause the recording and take a break or spend more time looking at an object. I used 15x70 binoculars, but 10x50s should be able to pick out most of these objects from a sky that’s not too light polluted.
Hopefully you have a chair that can recline way back so you can view overhead comfortably with your binoculars, and maybe you built a Bino Body Mount from the instructions on Astronomerica to make your observing even more satisfying. I highly recommend it and use mine whenever I do any binocular observing.
Position your chair such that the view roughly matches the main guide chart provided on Astronomerica for this Space Walk, that is, with Deneb, the brightest star in Cygnus, roughly on your left and Albireo, marking the head of the Swan, on your right.
Let’s get you looking in the right place, first without the binoculars and just using your unaided eyes. Deneb is one of three bright stars marking the Summer Triangle, along with Vega, the brightest of the three, and Altair. Hopefully you checked the accompanying charts first, but if not, pull them up and you’ll be able to recognize the star patterns from the main chart in the sky overhead.
Once you’ve located the Summer Triangle, you can look for the Northern Cross, which looks like a crucifix with Deneb at the top (corresponding to the tail of the Swan), and Albireo at the foot of the cross, or the head of the Swan. The wings extend out beyond the crossbar stars in the cross, giving a very lifelike impression of a giant swan flying overhead.
The Milky Way cuts right through the length of Cygnus, so that should help you. Also look for a huge dark lane extending through the Northern Cross down to the south towards Sagitarrius. This is a huge cloud of obscuring interstellar dust in the arm of the galaxy known as the Great Rift.
The best way to get a star or object in view is to look directly at it and then bring the binoculars up to your eyes without shifting your vision or your head. Try this on Deneb, otherwise known as Alpha Cygni. For the Bayer designation of stars, created by German astronomer Johann Bayer in the early 1600s, we use the Greek lowercase letter (alpha, beta, gamma, delta, etc.) and Latin genitive case for the constellation name. So for Deneb, its letter is Alpha and Cygnus becomes Cygni (or Cyg C-Y-G for short): Alpha Cygni. Deneb is a blue supergiant. It’s an incredibly luminous star: somewhere between about 50,000 and 200,000 times as bright as the Sun, depending on what it’s actual distance is from us, which is not acurately known—perhaps between 1400 and 2600 light years. It shines at magnitude 1.3 in our sky. Remember that the smaller the number, the brighter the magnitude.
From Deneb, let’s move down the Northern Cross, toward the head of the Swan marked by the famous double star Albireo, about 6 degrees, to the star marking the center of the cross, Sadr (S-A-D-R), or Gamma Cygni. Well how much is 6 degrees? Lower your binoculars and hold up your pinky with your arm outstretched: that’s about 1 degree. Hold up your three middle fingers pressed together: that’s about 5 degrees. Hold up your fist: that’s about 10 degrees. The typical field of view in 10x50 binoculars is about 6.5 degrees, so Deneb and Sadr will just fit in that field of view. For 15x70s, you’ll typcally have about 4.5 degrees, mine are about 4.4, so you’ll have to move the binoculars about a field and a half to get to Sadr.
How do you know you have Sadr and not some other star? First, it’s the brightest star in that part of the constellation. Second, it’s in a very rich star field. Third, it’s at the end of a unique hook-shaped asterism visible in binoculars. Look for a hook of eight stars that are brighter than the surrounding stars that form a hook with Sadr at the tip of the hook. Closest to Sadr is what looks like a little double star. The hook shape can be bit hard to discern because of all the stars in the field, but unmistakable once you recognize it. I’ve got it labeled in the chart showing the area around Sadr. But pause the recording now and just look at the star field around here!
If you follow the hook from Sadr down toward the south, toward the head of the Swan or the foot of the Northern Cross, in about 2 degrees, or just less than half the field of view in 15x70s, you’ll come upon a very faint cluster, Berkeley 86. It's really hard to pick it out as a cluster, but it does look like a little bit of a fuzzy spot. If you look to the east of there about 2/3 of a degree, you'll see the brighter cluster M29. Neither of them really stands out as a cluster at first, until you examine the area a bit, the clusters being a little bit more coagulated than the surrounding stars, but they're kind of lost in this huge star field. Berkeley 86 in my 15x70s shows about four stars resolving, with some unresolved stars forming a slight background glow. M29 is about twice the size and much brighter and I can make out about half a dozen stars resolving. If you can't find these two, don't worry about it and just move your binoculars around Sadr. You'll see all sorts of really beautiful views.
Berkeley 86 is a relatively young star cluster somewhat over 5,000 light years away. We’re seeing it through a lot of interstellar dust, so it’s dimmed down quite a bit from our perspective. M29 is roughly the same distance away and also dimmed by interstellar matter. M29 is approximately 11 light years across. Light, traveling at 670.6 million miles per hour, takes 11 years to get from one side of the cluster to the other.
Now let's move further south down the neck of the Swan toward Albireo. Put Sadr on one edge of our field of view, and toward the the southwest about 4-1/2 degrees we'll find the magnitude 4.9 star b3 Cygni (which is also designated 29 Cygni) and b2 Cygni (or 28 Cygni), also magnitude 4.9. b3 forms a smile or a frown, depending on your orientation, of four stars, and b2, which is more to the west, is the the third star in a chain of a dozen or so stars that continues on toward the the south. At the other end of that chain near magnitude 5.4 star b1 Cygni (or 27 Cygni) is NGC 6871, a magnitude 5.2 open cluster about the same distance as Berkeley 86 and M29 that we just looked at. In the binoculars, NGC 6871 again doesn't look like much of an open cluster, but I like this field with b1, b2 and b3 all together because of its richness and that nice chain of stars that ends in the cluster.
Pause the recording here to look at this star field and take a break.
You're about a third of the way from Sadr to Albireo. Because it's so difficult to navigate in these crowded star fields, we're just going to go straight to Albireo by setting down the binoculars, looking up at the Northern Cross, or the Swan, and picking out the star at the foot of the cross, or the head of the Swan, which is on the southwestern end, or the end opposite Deneb, the brightest star in the cross.
Albireo (A-L-B-I-R-E-O), or Beta Cygni, is a beautiful double for binoculars but they have to be held steady, which is why I use the Bino Body Mount. With that, I can easily split it in 15x70s or 10x50s and also see the nice blue color of the secondary, which is on the side toward Deneb, and the yellow primary. A beautiful sight.
The components are magnitude 3.1 and 4.7. The angular separation between the two components of Albireo is about 35 arc seconds, or roughly half an arc minute. 10 power binoculars can see the split on a night of good seeing with a steady hold. The primary is a yellow-orange and the secondary is blue–one of the finest color contrasts in the sky.
We still aren’t sure whether Albireo is an actual double, with the stars revolving around a common center of gravity, or merely an optical alignment. Just goes to show that we still have a lot to learn, considering Albireo has been admired for many hundreds or even thousands of years, and it’s relatively close at 420 light years, possibly closer. The primary component has been identified spectroscopically as a triple system.
Next we’ll move from Cygnus over to the constellation Vulpecula (V-U-L-P-E-C-U-L-A), the Fox. How they got a fox out of one line segment I really don’t know, but we're going find M27, the Dumbbell Nebula there. This is not an easy one to find without knowing exactly where to look, but we'll get there. Consider the line back from Albireo to Deneb as being 6:00 on a clock face. Take a line at about 3:00, or toward the southeast. You'll be going right between what look like two huge open clusters that together fill up a good part of the field of view, with Albireo still in the field.
In this field you'll see the next bright star directly opposite Albireo going straight between those two groupings of stars. That’s 10 Vulpeculae, at magnitude 5.5, and we're now in the constellation Vulpecula, the Fox. Continue in the same direction we moved from Albireo, from 10 Vulpeculae one degree and you'll see two stars of about 6th magnitude that form the base of a thin triangle that points back toward Albireo, with 10 Vulpeculae as the the apex of the thin triangle. On the other side of that base, fairly close, are two 7th magnitude stars close together that point away from the triangle, continuing in that same direction we've been moving. To recap, move 3:00 from Albireo, between the two big pseudo-clusters, to a thin triangle pointing back toward Albireo and to the little pair of stars just on the other side of the base of the triangle.
Continue in the same direction we’ve been moving for another field of view and put that close pair of 7th magnitude stars on the edge of your field. You should see on the opposite side of the field, about 3-1/2 degrees away, an unmistakably fuzzy bright spot. There are several brighter stars before you get to that fuzzball. That fuzzball is M27, the Dumbbell Nebula. You won't mistake something else for this one, as it's the only really bright large fuzzball in the area.
M27 is a planetary nebula, the first of its kind discovered, back in 1764 by Charles Messier, and became entry 27 in his catalog of bright comet-like objects. It’s about 1300 light years away. Planetary nebulae like M27 are the result of an older star that has used up all its nuclear fuel and whose stellar winds have puffed out its outer layers into a large cloud, leaving the star as a white dwarf, in this case, one of the largest white dwarfs known. At magnitude 13.8, the white dwarf can be glimpsed sometimes in smaller telescopes on a good night with some dedication. The double-lobed shape visible in telescopes gave rise to its nickname, the Dumbbell Nebula.
In binoculars we can’t make out the shape, but it’s quite bright and large for a deep sky object. If you have a telescope, M27 will soon become a much visited old friend. Several billion years from now, the Sun is expected to produce a planetary nebula by the same process, which will likely exceed the size of Earth’s orbit. By the way, M27 is only one of four planetary nebulae included in the Messier Catalog. Can you name the other three? Pause here to think about your answer, then I’ll give it to you.
The other three planetaries in the Messier catalog are: M57, the Ring Nebula, M76, the Little Dumbbell, and M97, the Owl Nebula. Good on you if you got them all.
Have you ever heard anyone mention the Coathanger? It’s a grouping of unrelated stars called an asterism, that form a pattern that looks like a coathanger.
Set down the binoculars again and with the unaided eye, find Albireo, the head of the Swan, and the bright star Altair. Again, if Deneb is at 6:00 from Albireo, Altair would be at about 2:00 and almost the same distance, only a little bit closer to Albireo than Deneb is. At magnitude 0.76, it's just a little brighter than Deneb, at magnitude 1.25. Altair, Deneb, and Vega form the Summer Triangle, with Vega, at magnitude 0, being the brightest toward the west side.
If you look halfway between Albireo and Altair, there's a little group of stars there in a line perpendicular to the line between Albireo and Altair. These are the main stars in the tiny constellation Sagitta, the Arrow. Point your binoculars there and slightly northwest and you'll see what's called the Coathanger, also known as Brocchi's Cluster, or Collinder 399, which is really an asterism, or pattern of unrelated stars, not a cluster. It consists of a straight line of six stars with a hook of four stars toward the south. You can't miss it. Sweep around until you can find it. Once you locate it in binoculars, see if you can spot it with the unaided eye. It's just faintly visible in my Bortle 4.5 sky as something of a small glow.
Another way of finding the Coathanger is just starting at Altair and following that prominent magnitude 2.7 star near Altair, named Tarazed, that points off to the northwest and go just slightly north of that line until you hit the Coathanger, about 13 degrees from Altair, or about a third of the way from Altair to Vega.
Pause the recording here and take a break if you need one.
Let’s go back to Deneb, the brightest star in Cygnus, marking the top of the Northern Cross. We need to orient ourselves to the compass now. Deneb lies on the northeast end of the Northern Cross, with Albireo on the southwest end. If we look with the unaided eye to the east of Deneb about 5 degrees, or the width of your three middle fingers with your arm outstretched, you’ll see magnitude 3.7 Xi Cygni, spelled X-I. In between Xi and Deneb, and closer to Xi, is a very dense, cloudy area that holds the North American Nebula , NGC 7000, and the Pelican Nebula, IC 5070.
Now that we have an idea of where we’re headed, let’s put Deneb in the binoculars and move them in the direction of Xi, or to the east. In 15x70s, Xi will pop into view just as Deneb departs on the other side. With 10x50s, they’ll both fit in the field. Hopefully you checked out the chart showing the “Ant” asterism and the two nebulae. With Deneb oriented toward the top of your binocular view, the Ant’s head is an oval circlet of five stars, with two antennae making a V shape toward Deneb. On either side of the Ant’s head is a long bent leg made up of four main stars each. This completes the Ant shape. The Ant is facing us, as if daring us to try to see the nebulosity in which it’s enveloped.
The Ant’s head, or the circlet of five stars, is a handy asterism to locate the North American Nebula, NGC 7000. If you have a decent sky, you should see some faint nebulosity there. In this orientation, the outline of North America is on its side, standing on California, with Florida and Mexico pointing to the right. The Ant’s head covers the western half of the United States. That area and Canada are the biggest and brightest sections of the nebula, but a good sky and some patience should also net you Mexico and possibly Florida, Mexico being expecially prominent due to its shape.
Pause the recording here to make sure you’re in the right place and to get your bearings.
If you can make out the outline of the North American Nebula, you can try for the more difficult Pelican Nebula, IC 5070. In this same orientation, the Pelican is above North America, or toward Deneb, facing back toward the North American Nebula. The tip star in the Ant’s antenna on the right, 57 Cygni, at magnitude 4.8, is just off the Pelican’s big bill. Continue to the next brightest star, 56 Cygni, magnitude 5.1, which could be considered an extension of that antenna. 56 marks the back of the Pelican. The brightest nebulosity tends to be roughly between those two stars, 57 and 56. Refer to the chart if you’re having trouble orienting things. Also, if your sky barely shows the Milky Way, you may need a darker sky. Regardless, a darker sky will show these objects more easily.
If you have a narrow band UHC filter, I use an NPB filter, you can hold it in front of one of the eyepieces and see the nebulosity better, while still seeing the stars with the other eyepiece. My binoculars have threaded eyepieces so I can just thread a filter onto one side. Or if you have a 2-inch filter, you can hold it in front of either the eyepiece, or even the objective lens, to enhance your view.
These two emission nebulae, or HII regions, consist of ionized atomic hydrogen glowing from the radiation of hot blue stars that recently formed in a cloud of molecular hydrogen. This is similar to the process in the Orion Nebula and other star forming regions. The North American and Pelican Nebulae are really one nebula with a cloud of obscuring dust creating a lane between them and helping to give them their unique shapes. Most of the star formation is taking place in the Mexico part of the nebula. The nebula is a little over 2500 light years away, and the North American Nebula alone stretches about 90 light years from “north” to “south.”
Before we leave this area, I’ll point out a little asterism known as “Little Orion,” because the stars form a shape similar to the constellation Orion. What would be the star Betelgeuse, at the upper left of the Orion form is located just at the tip of Florida in the North American Nebula, and the three stars in a line that form the belt are just off Florida, roughly where Cuba would be. Can you make out the Orion shape? It’s shown in the chart I provided for the area.
Pause the recording here if you’d like to.
From here, we’ll go back to Deneb to star hop to a nice multiple star for binoculars, Omicron 1 Cygni, at magnitude 3.8, also known as 31 Cygni. It’s on the other side of Deneb from the North American Nebula, where we just were, but about twice as far—about 5 degrees. Omicron 1 forms a naked eye pair with the slightly dimmer 30 Cygni, roughly halfway from Deneb to the star marking the northwest wing of the swan, or arm of the Northern Cross, magnitude 2.8 Delta Cygni, or Al Fawaris (A-L F-A-W-A-R-I-S). Once you’ve located the pair, bring your binoculars up to your eyes to take a look.
In the binoculars, you’ll see a nice trio of color contrasting stars, component A, the brightest, at magnitude 3.8, with an orange tint, component D, listed in Sky Safari as 30 Cygni, at magnitude 4.8, plain white and 5.5 arc minutes from A, and component C, or HD 192579, the dimmest, at magnitude 7.0, blue-white and a little under 2 arc minutes from A on the other side from component D. Component A is a spectroscopic eclipsing binary like the star Algol in Perseus. The group is about 750 light years away.
Omicron 1 is a good jumping off point for open cluster NGC 6819. You can either move about 5 degrees west from Omicron 1 to get to Delta Cygni, Al Fawaris, or just put down the binoculars and look with your unaided eye at the Northern Cross. Remember Delta is the northwestern wing star in the cross. Put your binoculars on that. Move about one field of view or about 4 and a half degrees toward Albireo, the head of the Swan, and you'll see a tiny straight line of three stars that stands out. Put that in the center of your field, and down toward the neck of the swan you'll see a grouping of bright stars with a fuzzy spot in the middle. That's NGC 6819. In my 15x70s, it looks like an unresolved ball with diffuse edges and a slightly brighter center. Just a hint of graininess to it but no real resolution. To me it looks kind of like a globular cluster in the binoculars.
NGC 6819 is about 7200 light years away and was another discovery by Caroline Herschel. Its brightest stars are only 10th magnitude, so that’s why we can’t resolve it. NGC 6819 is a very nice cluster for small telescopes, and some see a Fox head in the pattern of its stars, with the fox ears pointing off toward the northeast. I can also see it as a printed number 4, with the top of the 4 to the west southwest. Check it out if you have a scope.
Pause the recording if you need a break.
Now let's take the star that marks the opposite side of the northern cross, or the southeastern wing of the swan. This is Epsilon Cygni, or Gienah (G-I-E-N-A-H). You'll know you have Epsilon because you'll see fifth magnitude T Cygni about half a degree toward the north, and just beyond that, two fainter pairs of stars close in. Once you have Epsilon, look back in the same field, toward Sadr, and you'll see a nice, roughly circular, grouping of stars forming a very loose but bright open cluster. This is Ruprecht 173. The main part consists of a ring of about a dozen stars with some other stars hovering outside that ring. I can only make out two faint stars within that ring in my 15x70s. Otherwise it's a bit of a void in the middle. Ruprecht 173 bears the name of Czech astronomer Jan Ruprecht, who studied star clusters. The cluster doesn’t show in Sky Safari unless you do a search on it. As with many of these, it’s not an easy cluster to pull out from the surrounding star field.
We can’t look at Cygnus in binoculars without trying to spot the Veil Nebula, NGC 6960, NGC 6974, and NGC 6995. The Veil is a supernova remnant, the remains of a star that exploded about 10 to 20,000 years ago.
Go back to Epsilon, or Gienah, and put it on the northern edge of your field of view, and the next brightest star should be on the opposite or southern edge, the side away from Deneb. That's 52 Cygni, magnitude 4.2, and that marks roughly the center of a long thin strip of nebulosity making up the Western Veil Nebula, NGC 6960. It's difficult to see the nebulosity in the binoculars, but you might see a slight fuzziness cutting through the star.
Move your binoculars toward the east northeast about 2/3 of a field of view, and you'll see a faint and larger arc of nebulosity with the tips pointing toward the north and south. This is the Eastern Veil, NGC 6995.
You can try the UHC narrowband filter trick again on the Veil. But from a good sky you can see at least the Eastern Veil without a filter. You should be able to see the details of the shape of the Eastern Veil, which you may recognize from images that you've seen. In a really good sky you can see both eastern and western portions. You might even be able to pick up Pickering's Triangle, NGC 6974, the third portion of the Veil, in between them and closer to the Western Veil and 52 Cygni.
Pause the recording for a break.
Once you're done admiring the Veil, move from 52 Cygni, marking the Western Veil, toward the opposite side from the Eastern Veil about the same distance between the two and slightly south and you'll come to a nice almond-shaped large open cluster, which is NGC 6940, back across the border in Vulpecula. This is an excellent cluster for binoculars consisting of many, many unresolved stars with a few of them resolving, in a very rich cluster that gives it a cloudy look, surrounded by an almond-shaped grouping of brighter stars. A real nice sight for binoculars. NGC 6940 is about 2500 light years away and almost a billion years old. It was discovered by William Herschel. It’s a rich cluster in the telescope, with a couple hundred stars visible in a 10-inch, and the almond shape of its outlining stars looking a bit like a goldfish.
If you like double stars, try for 61 Cygni. Just look for a rectangle formed by Deneb, Sadr, Gienah, and magnitude 3.7 Tau Cygni (T-A-U) forming the fourth corner. 61 Cygni is a little over 1-1/2 degrees inside the rectange from Tau, towards Sadr. It makes a nice binocular double, two apparently white stars, one a little brighter than the other with a nice clean separation, 32 arc seconds, in binoculars.
61 Cygni is a true binary system with an orbital period of about 659 years. The two components are magnitude 5.4 and 6.1. 61 Cygni has the sixth highest proper motion in the sky of all cataloged stars, and the highest of any naked eye star. In fact, Giuseppe Piazzi first documented its high proper motion in 1804, hence the moniker “Piazzi’s Flying Star.” It’s only 11.4 light years away from us.
Nearing the end of our Space Walk now, we’ll turn to the big open cluster M39. This sits back behind the tail of the Swan. It’s a great object for binoculars, big and bright, about the size of the full Moon. Another one that’s probably better in binoculars than in a telescope.
You can find it by following the Milky Way toward the north from Deneb about 9 degrees and you'll sweep it up. Or just go from the North American Nebula about 1-2/3 fields of view, or about 7 degrees, and you'll see it there, just to the west of it. There's a long thin asterism of stars that makes kind of a spear blade shape nearby. It'll fit in the same field of view with that spear. The brightest star in the field, at 5th magnitude, sits between the spear and M39. In my 15x70s, M39 shows about 25 stars in a roughly triangular shape. Put down your binoculars. Can you still spot it with the unaided eye?
Just as a little bonus, we’re going to make a brief foray in the constellation Cepheus, The King, to spot a favorite telescopic and photographic target, the cluster and galaxy pair consisting of the brighter open cluster NGC 6939 and the dimmer spiral galaxy NGC 6946, which straddles the line between Cepheus and Cygnus, with the core of the galaxy being in Cygnus.
To find them, find the W pattern of the main stars of the constellation Cassiopeia and trace a line from the two southernmost stars, or end stars, in the W, the ones closest to Cygnus, and trace that line toward the west about 20 degrees, and you'll come to Alpha Cephei, or Alderamin (A-L-D-E-R-A-M-I-N), the brightest star in Cepheus. This star is also a little more than halfway from Polaris to Deneb and shading slightly off to the east.
Continue that line from the two end stars in the Cassiopeia W through Alpha and you'll see a couple of fainter 3rd magnitude stars just beyond that about 4 or 5 degrees. You can see these with the unaided eye. Get these two stars in your binocular field of view. They form the base of an almost equilateral triangle with the cluster, on the Cygnus side, or away from Cassiopeia. The cluster and galaxy are further along the line that we’ve been following and toward Cygnus. You may be able to pick up two faint spots in the same field of view a little over half a degree apart, with the galaxy in the direction of Cygnus. The cluster is not resolvable in my 15x70s, and the galaxy may take a little searching before you can spot it, as it's dimmer than the cluster. Just look in the direction towards Cygnus from the cluster.
Calling these a “pair,” though is very misleading. Their alignment in our sky puts them very close to each other in our view, but in fact the cluster is within our own galaxy and only about 4,000 light years away. NGC 4946, however, is a galaxy unto itself, and our current best estimates place it somewhere around 25 million light years away. Because of the vast distances, we’re also seeing the cluster in its much more recent appearance, but we’re seeing the “Fireworks” galaxy, as it is often called, as it was 25 million years ago. Think about that when you’re looking at them with your binocular “time machine.”
Well, that wraps it up for us tonight. I hope you had a nice journey through the Cygnus Milky Way. You’re likely to return many times over and hopefully you can find your way around a bit better now. Thanks for listening.
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