Messier 71 is a fascinating and often overlooked deep-sky object tucked within the small but rich constellation Sagitta, the Arrow. Sitting about 13,000 light-years away, it shines modestly at magnitude 8.2, and spans about 7 arcminutes across. While it was once classified as a dense open cluster, further study revealed it’s actually a loose globular cluster, making it one of the most unusual globulars in the Messier catalog.
To the observer, M71 offers a glittering, finely textured glow that doesn’t resemble the tight, symmetrical form of most globulars. Instead, it appears soft-edged and loosely bound, almost like a star cloud with a dense, star-speckled core and no sharp boundary. In small scopes, it may look like a faint nebula or fuzzy patch; in medium to large telescopes, dozens of tiny stars shimmer into view, giving it a misty, gem-like appearance.
Because of its location along the rich plane of the Milky Way, M71 sits in a densely star-packed field, making it a beautiful object to discover unexpectedly while scanning the area. It’s best observed in late summer and early fall, when Sagitta rides high in the evening sky. For stargazers who enjoy clusters with character, M71 is a rewarding and distinctive object that defies easy classification—and delivers both beauty and intrigue in equal measure.
Messier 71
Rating: 🔵 Stagazer Favorite
Level: 🔵 Easy
How:
When: mid-Jun - Nov
🌟 A Globular Cluster That Breaks the Mold Unlike most globular clusters, which are densely packed and spherical, M71 is loose and lacks a bright, condensed core. This gives it the charm of an open cluster with the richness of a globular. It’s an object that feels familiar but defies expectation—perfect for observers who enjoy subtle surprises.
🌟 Bright Enough for Modest Telescopes At magnitude +8.18, M71 is within reach of small to medium telescopes, and even binoculars under dark skies may hint at its presence. In a 4-inch scope or larger, it reveals a soft glow studded with faint stars. The cluster becomes increasingly rewarding as aperture increases, offering more granularity and star detail.
🌟 Located in a Dense Milky Way Field M71 is surrounded by the rich star fields of Sagitta, a compact constellation situated deep in the summer Milky Way. Scanning the area reveals not only M71 but also nearby asterisms and star chains, making it a great region for slow, immersive observing sessions.
🌟 A Nice Contrast to Classic Globulars Because it lacks the dense core of clusters like M13 or M5, M71 offers an excellent comparison. Observing both on the same night shows how diverse globular clusters can be. M71 feels more airy and textured, with a granular core and a loosely defined edge that invites longer looks.
🌟 Easy to Locate in a Distinctive Constellation Sagitta, though small, is easy to recognize as a tiny arrow pointing westward in the Milky Way between Aquila and Vulpecula. M71 lies along the arrow’s shaft, making it simple to find using low-power star-hopping from nearby bright stars like Gamma Sagittae. It’s a straightforward hop with a big payoff.
🌟 Well-Placed in Late Summer and Fall M71 is ideally positioned for northern observers from August through October, when Sagitta climbs high in the evening sky. During this time, the Milky Way arches overhead, providing both great seeing conditions and an inspiring sky context for finding this subtle gem.
Globular cluster: a dense, spherical collection of tens of thousands to millions of ancient stars bound tightly by gravity, orbiting the outskirts of a galaxy.
Messier 71
Find the Summer Triangle. Be sure to find Altair (+0.93) and Albireo (+3.07) because you'll use them in the next step.
Find the constellation Sagitta. It is halfway between Altair and Albireo and looks like a dart.
Find the five main stars of Sagitta, Alpha, Beta, Delta, Zeta and Gamma Sagittae. Find the point halfway between Gamma and Delta Sagittae. Using binoculars or a telescope finder, point a little below the halfway point. Then, using binoculars or a low-powered eyepiece, look for M71. You’ll see a faint, round glow nestled in a star-rich field. It may appear as a hazy patch with little definition at first glance. Center this glow in your field of view, and switch to a higher magnification in your telescope to resolve its loose core and faint, scattered stars.
Messier 71
✅ Use Moderate Magnification Start with 75x to 120x to frame M71’s soft glow and starry surroundings. Then slowly increase magnification to 150x or more to begin resolving individual stars and teasing out its granular texture.
✅ Wait for a Dark, Moonless Night M71’s loose structure and faint stars are easily overwhelmed by moonlight or light pollution. Choose a moonless night in a dark location for the best chance to see its full extent and subtle detail.
✅ Let Your Eyes Adapt Fully Spend 20 minutes away from bright lights before observing. Full dark adaptation will help bring out the cluster’s faint stars and enhance the contrast between its misty core and the surrounding field.
✅ Use Averted Vision to Spot Stars M71’s individual stars are faint and scattered. Looking slightly off-center from the cluster brings more of these to view, revealing its shimmering, uneven structure more clearly.
✅ Scan the Milky Way Nearby Take time to pan around Sagitta and its rich surroundings. The nearby star fields are dense and beautiful, and the contrast between M71 and neighboring stars makes the cluster stand out more distinctly.
✅ Compare with Other Globulars Observe a classic globular like M13 or M15 on the same night. Comparing their dense, symmetrical cores to M71’s loose and irregular appearance deepens your appreciation for this unusual cluster.
Messier 71
❌ Naked Eye
To the naked eye, Messier 71 is invisible. Though it lies in a star-rich region of the Milky Way, its magnitude of 8.18 and compact size prevent it from standing out without optical aid, even under pristine skies.
⚠️ Binoculars
Through binoculars, M71 may appear as a faint, slightly fuzzy patch in a dense star field, particularly under dark skies. It lacks the distinct shape or structure to immediately signal itself as a cluster, but its glow hints at a condensed gathering of stars when carefully observed.
✅ Small Telescope
With a small telescope, around 3 to 4 inches in aperture, M71 begins to take shape as a soft, round haze with a slightly mottled texture. A few of the brighter peripheral stars may become visible, but the core remains unresolved. It resembles a faint, unresolved globular or a bright open cluster caught in between.
✅ Medium Telescope
In a medium telescope of 6 to 8 inches, the cluster becomes more granular. The central region remains somewhat diffuse, but many faint stars begin to resolve around the edges and into the core. Its loose, irregular form and lack of a dense core make it look more like a rich star cloud than a classic globular cluster.
✅ Large Telescope
With a large telescope, 10 inches or more, M71 transforms into a fine network of delicate stars. Dozens of individual points sparkle across its face, and the cluster’s grainy texture stands out clearly. Although it still lacks the tight, spherical concentration of brighter globulars, it becomes a striking and richly detailed object, especially under dark skies.
Messier 71
Messier 71 is best viewed under dark skies where its delicate texture and scattered stars can fully emerge. In light-polluted conditions, it quickly fades into obscurity, losing much of what makes it special.
🟣 In Bortle 1–2 skies, Messier 71 appears as a softly glowing, loosely concentrated cluster filled with faint, resolved stars. Its grainy texture stands out, and the surrounding Milky Way background enhances the experience with rich contrast and dense star fields.
🔵 In Bortle 3–4 skies, the cluster still shows well. Many stars remain visible, and its hazy, irregular shape is distinct. The surrounding star field is less intense but still provides a pleasing context for the cluster’s appearance.
🟡 In Bortle 5–6 skies, M71 loses much of its subtle granularity. The brighter stars may still resolve, but the overall glow becomes more muted, and the faint stars begin to fade into the background. The cluster appears softer and less detailed.
🟠 In Bortle 7+ skies, Messier 71 is challenging. It may appear as a faint, formless smudge with little or no detail. The background glow overpowers its fainter members, and its loosely packed nature makes it easy to miss or mistake for a faint star cloud.
Messier 71
DSOs within 48° or 2 outstretched hands at arm's length
Messier 71 - A Cluster with a Split Personality
Find the Summer Triangle. Be sure to find Altair (+0.93) and Albireo (+3.07) because you'll use them in the next step.
Find the constellation Sagitta. It is halfway between Altair and Albireo and looks like a dart.
Find the five main stars of Sagitta, Alpha, Beta, Delta, Zeta and Gamma Sagittae. Find the point halfway between Gamma and Delta Sagittae. Using binoculars or a telescope finder, point a little below the halfway point. Then, using binoculars or a low-powered eyepiece, look for M71. You’ll see a faint, round glow nestled in a star-rich field. It may appear as a hazy patch with little definition at first glance. Center this glow in your field of view, and switch to a higher magnification in your telescope to resolve its loose core and faint, scattered stars.
