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Top 20 Targets in the Northern Sky

A season-by-season tour of the finest deep-sky jewels visible from mid-northern latitudes — with magnitudes, observing tips for every aperture, and finder charts.

30 min read Matthias Wüllenweber
Available in: English Deutsch Español Français Italiano 日本語 한국어 Português

Key Takeaways

  1. 1

    Every class of deep-sky object is on this list — emission and planetary nebulae, open and globular clusters, galaxies, a supernova remnant, and showpiece double stars. Something good is up every night of the year.
  2. 2

    You don't need a big telescope. M42, M31, M45, M44 and the Double Cluster look their best in binoculars. Albireo splits cleanly in a 50 mm refractor.
  3. 3

    Sky darkness matters more than aperture for extended objects. M33, M101 and NGC 7000 vanish under suburban skies no matter how big your scope.
  4. 4

    A cheap UHC or O-III filter transforms emission and planetary nebulae — NGC 7000, M27, M97 in particular.
  5. 5

    Use the lowest power that frames the target. High magnification ruins large clusters (M45, M44, Double Cluster) and low-surface-brightness galaxies (M33, M101). Save the high power for M57, M13 and Epsilon Lyrae.

Contents

Before You Begin 1. M42 — Great Orion Nebula 2. M31 — Andromeda Galaxy 3. M13 — The Great Hercules Cluster 4. M45 — The Pleiades 5. M51 — The Whirlpool Galaxy 6. M57 — The Ring Nebula 7. M27 — The Dumbbell Nebula 8. M81 & M82 — Bode and Cigar Galaxies 9. Double Cluster — NGC 869 & 884 10. Albireo — Beta Cygni 11. M1 — The Crab Nebula 12. M44 — The Beehive Cluster (Praesepe) 13. M33 — The Triangulum Galaxy 14. M101 — The Pinwheel Galaxy 15. NGC 7000 — The North America Nebula 16. M97 — The Owl Nebula 17. M92 — The Other Hercules Globular 18. M35 — An Open Cluster in Gemini 19. NGC 457 — The ET Cluster (Owl Cluster) 20. Epsilon Lyrae — The Double Double Seasonal Quick Reference Test Yourself

Before You Begin

These twenty objects are the crown jewels of the northern sky. They span every major class of deep-sky object — emission nebulae, planetary nebulae, open and globular clusters, galaxies, and showpiece double stars — and cover all four seasons, so there is always something on the list worth chasing.

Every target is visible from mid-northern latitudes (40°–55° N) and most are accessible with a small telescope or even binoculars. For each object you will find the essential data, the best time to observe, what to expect in different apertures, and practical tips for getting the most out of the view.

Aperture tiers used in this guide

  • Binoculars — 7×50 or 10×50
  • Small scope — 80–130 mm / 3–5″
  • Medium scope — 150–250 mm / 6–10″

1. M42 — Great Orion Nebula

4.0Magnitude
85′ × 60′Size
1,344 lyDistance
OrionConstellation
Finder chart for M42 showing its position in Orion
M42 in Orion — 30° field finder chart.

The jewel of the winter sky and the single most impressive deep-sky object visible from Earth. M42 is a stellar nursery where new stars are being born right now — a roiling cloud of glowing hydrogen lit from within by the fierce ultraviolet radiation of the young Trapezium stars at its heart.

Binoculars

Easily visible as a misty patch around the middle star of Orion's Sword. The nebula is obvious even from suburban skies.

Small scope (4″)

Breathtaking. The bright inner region shows wings of nebulosity spreading outward. The four stars of the Trapezium (Theta-1 Orionis) are cleanly split at 50×. Look for the dark bay called the Fish's Mouth cutting into the glow.

Medium scope (8″+)

The nebula fills the eyepiece with complex structure — wisps, arcs, and dark rifts. An O-III or UHC filter reveals faint outer regions extending well beyond the bright core. On a steady night at high power, a fifth and sixth Trapezium star emerge.

Tip

Use your lowest-power eyepiece first to take in the full extent, then switch to higher magnification to explore the Trapezium and the intricate nebular detail around it.

View M42 in the catalog · View on star map

2. M31 — Andromeda Galaxy

3.4Magnitude
190′ × 60′Size
2.5 MlyDistance
AndromedaConstellation
Finder chart for M31 showing its position in Andromeda
M31 in Andromeda — 30° field finder chart.

The most distant object visible to the naked eye and our nearest large galactic neighbour. The photons hitting your retina left Andromeda when early humans first walked upright. M31 is a massive spiral galaxy containing roughly a trillion stars, and it is heading toward the Milky Way at 110 km/s — the two will merge in about 4.5 billion years.

Binoculars

A large, elongated glow with a bright core, easily spanning 2–3°. The satellite galaxy M32 appears as a fuzzy star just south of the core. Best view of the full extent you will get.

Small scope (4″)

The bright nuclear bulge dominates. With averted vision and a wide-field eyepiece, trace the disk outward. M32 and M110 (NGC 205) become obvious companion galaxies.

Medium scope (8″+)

Dark dust lanes cross the disk on the near side. Under dark skies, the galaxy stretches beyond 3° — wider than six full moons. Individual star clouds and the dark rift between dust lanes reward patient observation.

Tip

To find M31, star-hop from the Great Square of Pegasus through the stars of Andromeda. Binoculars often give a more satisfying view than a telescope because the galaxy is so large.

View M31 in the catalog · View on star map

3. M13 — The Great Hercules Cluster

5.8Magnitude
20′Size
22,200 lyDistance
HerculesConstellation
Finder chart for M13 showing its position in Hercules
M13 in Hercules — 30° field finder chart.

The finest globular cluster in the northern sky — a ball of roughly 300,000 ancient stars gravitationally bound together for over 11 billion years. M13 sits on the western edge of the Keystone asterism in Hercules and is one of the few globular clusters visible to the naked eye under dark skies.

Binoculars

A round, fuzzy patch that doesn't quite resolve into stars. Easily found between Eta and Zeta Herculis on the Keystone's western side.

Small scope (4″)

At 100× the outer edges begin to sparkle with resolved stars. The core remains a dense, grainy glow. Look for the dark "propeller" — three dark lanes radiating from the centre.

Medium scope (8″+)

Stunning. Hundreds of stars resolved across the face, with chains and arcs of stars streaming outward. At 150–200× the core begins to break up into individual points. One of the most impressive sights in amateur astronomy.

Tip

Once you find the Keystone in Hercules, M13 is one-third of the way from Eta to Zeta on the western side. It is visible in a finderscope and unmistakable at low power.

View M13 in the catalog · View on star map

4. M45 — The Pleiades

1.6Magnitude
110′Size
444 lyDistance
TaurusConstellation
Finder chart for M45 showing its position in Taurus
M45 in Taurus — 25° field finder chart.

The Seven Sisters — the most famous star cluster in the sky and a naked-eye treasure since antiquity. This young cluster (about 100 million years old) contains over a thousand stars, dominated by hot blue giants wrapped in delicate wisps of reflection nebulosity. Counting how many Pleiads you can see with the unaided eye is a classic test of sky quality and visual acuity.

Binoculars

The perfect instrument for the Pleiades. Dozens of stars fill the field with icy blue light. This is one of those rare objects that looks better in binoculars than in most telescopes.

Small scope (4″)

Use the lowest magnification you have. More stars appear between the bright ones. Under dark skies, hints of reflection nebulosity may show around Merope and Maia.

Medium scope (8″+)

The Merope Nebula (NGC 1435) becomes visible as a soft glow south of Merope. Nebulosity around other bright members emerges with averted vision. The cluster is too large for high magnification — keep it wide.

Tip

On an excellent night, try counting Pleiads with the naked eye before reaching for optics. Most people see six; sharp-eyed observers from dark sites report eight or more.

View M45 in the catalog · View on star map

5. M51 — The Whirlpool Galaxy

8.4Magnitude
11′ × 7′Size
23 MlyDistance
Canes VenaticiConstellation
Finder chart for M51 showing its position in Canes Venatici
M51 in Canes Venatici — 30° field finder chart.

The textbook spiral galaxy — a face-on grand design spiral interacting with its smaller companion NGC 5195. M51 was the first galaxy in which spiral structure was discovered (Lord Rosse, 1845, using his 72-inch "Leviathan of Parsonstown"). It remains one of the best galaxies for visual observers hoping to glimpse spiral arms.

Binoculars

A faint smudge near the end of the Big Dipper's handle. The companion appears as a slightly offset brightening. Requires dark skies.

Small scope (4″)

Two distinct cores connected by a bridge of faint nebulosity. The main galaxy has a noticeably brighter core surrounded by a diffuse halo.

Medium scope (8″+)

Under dark, transparent skies the spiral arms emerge with averted vision — one of amateur astronomy's great thrills. The bridge connecting M51 to NGC 5195 is obvious. Look for the dark lane separating the arm from the core on the companion side.

Tip

Star-hop from Alkaid (the end star of the Dipper's handle) about 3.5° southwest. Patience and fully dark-adapted eyes are essential for the spiral arms.

View M51 in the catalog · View on star map

6. M57 — The Ring Nebula

8.8Magnitude
1.4′ × 1.0′Size
2,300 lyDistance
LyraConstellation
Finder chart for M57 showing its position in Lyra
M57 in Lyra — 20° field finder chart.

A ghostly smoke ring hovering between the two southern stars of Lyra's parallelogram. M57 is the shell of gas expelled by a dying sun-like star, now illuminated by the remaining white dwarf at its centre. It is the most observed planetary nebula in the sky and an easy target for any telescope.

Binoculars

Invisible or just barely detectable as a point slightly fuzzier than a star. Not a binocular object.

Small scope (4″)

At 100× it appears as a tiny, slightly elongated grey doughnut — distinctly non-stellar. The ring shape is clear. The dark centre is obvious once you know to look for it.

Medium scope (8″+)

At 200×+ the ring is beautifully defined, with the interior appearing slightly brighter than the surrounding sky. A faint greenish tint may be noticed. The 15th-magnitude central star is a challenging but achievable target in 12″+ apertures on excellent nights.

Tip

M57 sits almost exactly between Beta and Gamma Lyrae. Point halfway between them and it is in the field. Use at least 80× to distinguish it from a star.

View M57 in the catalog · View on star map

7. M27 — The Dumbbell Nebula

7.5Magnitude
8.0′ × 5.7′Size
1,360 lyDistance
VulpeculaConstellation
Finder chart for M27 showing its position in Vulpecula
M27 in Vulpecula — 25° field finder chart.

The first planetary nebula ever discovered (Charles Messier, 1764) and the brightest and largest of its kind. M27 is what the Ring Nebula would look like if you could see it from a different angle — a barrel-shaped shell of glowing gas. Its distinctive apple-core or bow-tie shape is unmistakable.

Binoculars

Visible as a small, distinctly fuzzy spot. Easy to find, but the shape won't be apparent. Worth a look to confirm your aim before switching to a telescope.

Small scope (4″)

The dumbbell shape is immediately obvious at 50–80×. Two bright lobes with fainter extensions give the distinctive bow-tie outline. One of the most satisfying views in a small telescope.

Medium scope (8″+)

Rich structure appears — the fainter outer envelope fills in the "ears" of the dumbbell into a more rounded shape. An O-III filter dramatically enhances contrast. The 13.5-mag central star is visible with careful observation.

Tip

Find the star Sagitta (the Arrow constellation) just south of Cygnus. M27 is about 3° north of Gamma Sagittae. An O-III or UHC filter is one of the best upgrades for this object.

View M27 in the catalog · View on star map

8. M81 & M82 — Bode and Cigar Galaxies

6.9 / 8.4Magnitude
27′ / 11′Size
11.8 MlyDistance
Ursa MajorConstellation
Finder chart for M81 and M82 showing their position in Ursa Major
M81 and M82 in Ursa Major — 30° field finder chart.

A spectacular contrasting pair separated by just 38 arcminutes — easily fitting in the same low-power eyepiece. M81 is a stately grand design spiral, smooth and symmetrical. M82, just half a degree away, is a starburst galaxy torn apart by their gravitational interaction — irregular, filamentary, and bristling with dark lanes. Together they are one of the finest galaxy pairs in the sky.

Binoculars

Both visible as faint elongated smudges in the same field. M81 is the brighter of the two. Requires reasonably dark skies.

Small scope (4″)

Both galaxies are obvious in one wide-field view. M81 shows a bright oval with a stellar nucleus. M82 is a narrow slash of light — distinctly different in character. A beautiful contrast.

Medium scope (8″+)

M81's spiral arms become detectable as subtle brightenings. M82 reveals dramatic dark lanes slicing across its body and hints of the red hydrogen filaments visible in photographs. Try examining each galaxy at higher magnification after taking in the pair together.

Tip

Draw a diagonal line from Phecda (Gamma UMa) through Dubhe (Alpha UMa) and continue the same distance beyond. The pair is roughly 10° northwest of Dubhe.

View M81 in the catalog · View M82 in the catalog · View on star map

9. Double Cluster — NGC 869 & 884

3.7 / 3.8Magnitude
30′ eachSize
7,500 lyDistance
PerseusConstellation
Finder chart for the Double Cluster showing its position between Perseus and Cassiopeia
The Double Cluster in Perseus — 30° field finder chart.

Two rich open clusters sitting side by side in the Milky Way between Perseus and Cassiopeia. Known since antiquity as a hazy patch visible to the naked eye, the Double Cluster is one of the finest low-power telescope targets in the entire sky. Both clusters are physically related — young (about 13 million years old), at nearly the same distance, and moving through space together.

Binoculars

Glorious. Two dense knots of stars separated by a star-poor gap, both resolved into dozens of individual suns. One of the best binocular objects in the sky.

Small scope (4″)

At 25–50× both clusters fit in the field, alive with over a hundred stars. Note the scattering of ruby-red giant stars — these elderly suns contrast beautifully with the blue-white cluster members.

Medium scope (8″+)

So rich that the field seems to overflow with stars. Chains and arcs of stars weave through both clusters. Best at lower magnifications — higher power loses the grand overview that makes this object so spectacular.

Tip

Find the "W" of Cassiopeia and look toward Perseus. The Double Cluster is roughly halfway between the two constellations, visible as a hazy bright patch to the naked eye.

View NGC 869 in the catalog · View NGC 884 in the catalog · View on star map

10. Albireo — Beta Cygni

3.1 / 5.1Magnitudes
34.3″Separation
430 lyDistance
CygnusConstellation
Finder chart for Albireo showing its position in Cygnus
Albireo in Cygnus — 35° field finder chart.

The most beautiful double star in the sky. Albireo marks the head of Cygnus the Swan (the foot of the Northern Cross) and splits into a gorgeous colour-contrast pair: a warm golden-amber primary and a vivid sapphire-blue companion. The 34-arcsecond separation makes it easy to resolve in any telescope — even a 50-mm refractor at 25× will show it cleanly. No other double star offers such striking colour contrast at such wide separation.

Binoculars

Steady 10×50 binoculars may just split it. Most people will see a single amber star. Worth trying on a tripod.

Any telescope

Spectacular at virtually any magnification. Even 25× shows the pair cleanly split with vivid colour. Try 50–100× for the most satisfying view. Show this to guests — it never fails to impress.

Tip

Albireo is the star at the base of the Northern Cross asterism (or the head of the Swan). No star-hopping needed — just point at the bright star and enjoy. The colours are real: the primary is a K3 giant, the companion a B8 main-sequence star.

View Albireo in the catalog · View on star map

11. M1 — The Crab Nebula

8.4Magnitude
6′ × 4′Size
6,500 lyDistance
TaurusConstellation
Finder chart for M1 showing its position in Taurus
M1 in Taurus — 30° field finder chart.

The expanding wreckage of a star that exploded on July 4, 1054 — recorded by Chinese and Japanese astronomers as a "guest star" bright enough to be seen in daylight. M1 was the first object Messier catalogued (hence M1) and the first supernova remnant to be identified. At its heart lies a pulsar spinning 30 times per second, powering the nebula's eerie glow.

Binoculars

Difficult. Appears as an extremely faint, slightly elongated smudge near Zeta Tauri (the southern horn of Taurus). Requires dark skies and careful star-hopping.

Small scope (4″)

A soft, oval glow with no sharp edges. It resembles a dim, unresolved comet — which is exactly what confused Messier into creating his catalog. Slightly brighter toward the centre.

Medium scope (8″+)

The elongated shape becomes more pronounced, with hints of mottled texture. Under excellent seeing, the edges appear ragged rather than smooth. An O-III filter helps separate the nebula from the sky background.

Tip

Find Zeta Tauri (the tip of the Bull's southern horn) and look about 1° northwest. M1 is historically significant but visually subtle — appreciate it for what it is rather than how it looks.

View M1 in the catalog · View on star map

12. M44 — The Beehive Cluster (Praesepe)

3.7Magnitude
95′Size
577 lyDistance
CancerConstellation
Finder chart for M44 showing its position in Cancer
M44 in Cancer — 30° field finder chart.

One of the nearest open clusters to Earth and known since antiquity as a misty patch at the heart of Cancer. Praesepe ("the Manger") contains about a thousand stars spread over 1.5° of sky. Galileo was the first to resolve it into individual stars with his telescope in 1609.

Binoculars

Superb. Dozens of stars fill a field nearly two degrees across. Like the Pleiades, this is a cluster that shines in binoculars. The swarm of relatively faint, evenly-spaced stars gives the impression of bees around a hive.

Small scope (4″)

Use lowest power. The cluster spills over the field of most eyepieces. Look for chains and groupings of stars, and the contrast between the white main-sequence members and the occasional orange-red giant.

Medium scope (8″+)

Too large for high magnification. A wide-field eyepiece at 30–50× is ideal. The cluster reveals subtle colour differences among its members — a lesson in stellar evolution playing out before your eyes.

View M44 in the catalog · View on star map

13. M33 — The Triangulum Galaxy

5.7Magnitude
73′ × 45′Size
2.7 MlyDistance
TriangulumConstellation
Finder chart for M33 showing its position in Triangulum
M33 in Triangulum — 25° field finder chart.

The third-largest member of our Local Group and one of the most challenging Messier objects. M33 is bright on paper (mag 5.7) but its light is spread over an area larger than the full moon, making its surface brightness very low. It is a true test of sky darkness and observing technique. Under pristine skies, some observers can spot it with the naked eye — making it arguably the most distant object visible without optics.

Binoculars

A very large, very faint, round glow with almost no central brightening. Requires truly dark skies (Bortle 4 or better). Use averted vision and sweep slowly.

Small scope (4″)

Use the lowest power available. A subtle, ghost-like glow with a slightly brighter core. If you're not seeing it, try a larger field eyepiece and look for a large smudge, not a small one.

Medium scope (8″+)

Under dark skies, spiral arm structure can be glimpsed. The giant H-II region NGC 604 appears as a knot in one spiral arm — one of the largest stellar nurseries in the Local Group. An H-beta or UHC filter helps reveal NGC 604.

Tip

If you can't find M33, the problem is almost certainly light pollution, not technique. This galaxy requires dark skies. Don't use high magnification — it will make the already-low surface brightness even harder to see.

View M33 in the catalog · View on star map

14. M101 — The Pinwheel Galaxy

7.9Magnitude
29′ × 27′Size
21 MlyDistance
Ursa MajorConstellation
Finder chart for M101 showing its position in Ursa Major
M101 in Ursa Major — 30° field finder chart.

A large, nearly face-on spiral galaxy that rewards dark skies and patience. M101 is physically enormous — about 70% larger than the Milky Way — and its asymmetric spiral arms are thought to be the result of a past interaction with a companion galaxy.

Binoculars

A very faint, round glow. Like M33, the low surface brightness makes this difficult from anything but dark sites.

Small scope (4″)

A soft, round glow with a slightly brighter core. The galaxy is much larger than it first appears — give your eyes time to pick up the outer regions.

Medium scope (8″+)

Under dark skies, two or three spiral arms emerge with averted vision. Several bright H-II regions (NGC 5461, NGC 5462, NGC 5471) are visible as knots along the arms. A wonderful galaxy for sketching.

View M101 in the catalog · View on star map

15. NGC 7000 — The North America Nebula

4.0Magnitude
120′ × 100′Size
2,590 lyDistance
CygnusConstellation
Finder chart for NGC 7000 showing its position in Cygnus near Deneb
NGC 7000 in Cygnus — 30° field finder chart.

A vast emission nebula whose shape resembles the North American continent, complete with a "Gulf of Mexico" dark bay and a "Florida peninsula." At 2° across, it is far too large for most telescope eyepieces and is best appreciated with the naked eye, binoculars, or a camera. It lies just 3° east of Deneb in Cygnus.

Naked eye / binoculars

Under dark skies, the nebula is visible as a brighter patch in the Milky Way near Deneb. Binoculars with an H-alpha or UHC filter held in front of one eyepiece make the shape pop dramatically.

Small scope (4″)

Too large for most fields of view. With a UHC or O-III filter at lowest power, you can trace the brightest regions — particularly the "Mexico Wall" (the dark rift forming the Gulf of Mexico).

Medium scope (8″+)

Explore sections of the nebula at medium power. The Cygnus Wall (the Mexico/Central America border) is a stunning region of bright and dark nebulosity. An O-III filter transforms this area.

Tip

This is a nebular filter showcase. Even a cheap UHC filter will dramatically improve the view. Without a filter, you may see nothing; with one, the nebula appears as if switched on.

View NGC 7000 in the catalog · View on star map

16. M97 — The Owl Nebula

9.9Magnitude
3.4′ × 3.3′Size
2,030 lyDistance
Ursa MajorConstellation
Finder chart for M97 showing its position in the bowl of the Big Dipper
M97 in Ursa Major — 30° field finder chart.

A large, round planetary nebula named for the two dark hollows in its disk that give it the look of an owl's face. M97 is one of the more challenging Messier objects due to its low surface brightness, but it rewards careful observation with a haunting, eerie beauty. It lies in the bowl of the Big Dipper, just 2.3° southeast of Merak (Beta Ursae Majoris).

Binoculars

Very difficult — at best a faint, round smudge under excellent conditions. Not a practical binocular target.

Small scope (4″)

A faint, round disc that is distinctly non-stellar. Appears as a grey circle of uniform brightness. The "eyes" are very difficult in small apertures.

Medium scope (8″+)

The two dark "eye" hollows emerge with an O-III filter and patience. At 150–200× the owl face is unmistakable. The nearby galaxy M108 lies just 48 arcminutes away and both fit in a wide-field eyepiece — a popular pairing.

View M97 in the catalog · View on star map

17. M92 — The Other Hercules Globular

6.3Magnitude
14′Size
26,700 lyDistance
HerculesConstellation
Finder chart for M92 showing its position in Hercules
M92 in Hercules — 30° field finder chart.

Living permanently in the shadow of its famous neighbour M13, M92 is an outstanding globular cluster in its own right and would be the showpiece of any other constellation. It is actually one of the oldest known globular clusters at roughly 14.2 billion years — nearly as old as the universe itself. Brighter and more concentrated than most globulars, M92 deserves far more attention than it typically receives.

Binoculars

Visible as a small, bright, unresolved fuzzy star. Easy to find about 6° north of the Keystone.

Small scope (4″)

A bright, compact cluster with a blazing core. Outer stars begin to resolve at 100×. Noticeably more concentrated than M13.

Medium scope (8″+)

Dozens of stars resolved across the face, with a dense, brilliant core that resists resolution. Fine star chains radiate outward. Compare it directly with M13 in the same session — the structural differences are striking.

View M92 in the catalog · View on star map

18. M35 — An Open Cluster in Gemini

5.3Magnitude
28′Size
2,800 lyDistance
GeminiConstellation
Finder chart for M35 showing its position at the foot of Castor in Gemini
M35 in Gemini — 25° field finder chart.

A big, bright open cluster at the foot of Castor in Gemini, easily visible to the naked eye as a hazy spot. M35 contains about 500 stars and is one of the richest open clusters in the winter sky. As a bonus, the much older, smaller, and fainter cluster NGC 2158 sits just 15 arcminutes to the southwest — a beautiful contrast in cluster ages.

Binoculars

A beautiful splash of stars, easily resolved. One of the finest binocular open clusters in the winter sky.

Small scope (4″)

Spectacular at 30–60×. Over a hundred stars fill the field with chains, loops, and a loose central concentration. NGC 2158 appears as a small, dense, unresolved glow to the southwest — a "cluster of clusters" moment.

Medium scope (8″+)

M35 fills the field with stars while NGC 2158 begins to partially resolve. The age contrast is beautiful: M35's bright blue-white stars against NGC 2158's dim, ancient population. Look for the curving star chains that give M35 its character.

View M35 in the catalog · View on star map

19. NGC 457 — The ET Cluster (Owl Cluster)

6.4Magnitude
13′Size
7,900 lyDistance
CassiopeiaConstellation
Finder chart for NGC 457 showing its position in Cassiopeia
NGC 457 in Cassiopeia — 25° field finder chart.

A delightful open cluster whose star pattern looks like a stick figure with outstretched arms — variously called the ET Cluster, the Owl Cluster, or the Dragonfly Cluster. Two bright stars form the "eyes," with the brilliant mag-5 Phi Cassiopeiae as one eye, and fainter stars trace out a body and sweeping wings. It is one of the most recognisable and charming clusters in the sky.

Binoculars

Visible as a small bright patch near Delta Cassiopeiae. The pattern won't be clear at this low magnification, but the cluster is easy to locate.

Small scope (4″)

The stick-figure pattern is immediately apparent at 40–80×. The two bright "eyes" anchor a body and wings of fainter stars. A favourite of star party crowds, especially children.

Medium scope (8″+)

More cluster members appear in the wings and body, enriching the pattern. The colour contrast between the blue-white eye stars and the fainter reddish background members adds depth. Try different magnifications — the figure appears best at moderate power.

View NGC 457 in the catalog · View on star map

20. Epsilon Lyrae — The Double Double

4.7 / 4.6Magnitudes
208″Wide Sep.
2.3″ / 2.4″Tight Sep.
LyraConstellation
Finder chart for Epsilon Lyrae showing its position near Vega
Epsilon Lyrae in Lyra — 20° field finder chart.

The ultimate double star challenge and a favourite test of telescope optics and atmospheric seeing. To the naked eye, Epsilon Lyrae appears as a single star near Vega. Binoculars split it into a wide pair (Epsilon-1 and Epsilon-2, separated by 208″). A telescope then reveals that each component is itself a close double — a quadruple star system, hence "the Double Double."

Naked eye / binoculars

Sharp-eyed observers can split the wide pair without optics under good conditions. Binoculars show two distinct stars easily. Note the nearly equal brightness.

Small scope (4″)

At 100× the wide pair is obvious. Splitting each component into its own tight pair requires 150–200× and steady air. On a good night, all four stars spring into view — a deeply satisfying moment. On a poor night, they stubbornly refuse to split.

Medium scope (8″+)

All four components are cleanly split. Notice that the two tight pairs are oriented nearly perpendicular to each other. At high power, the Airy disks with their diffraction rings are a beautiful test of optical quality and collimation.

Tip

Epsilon Lyrae is the ultimate "seeing tester" — if you can split both tight pairs, the atmosphere is excellent and your optics are well collimated. Find it just northeast of Vega, the brightest star in the summer sky.

View Epsilon Lyrae in the catalog · View on star map

Seasonal Quick Reference

Plan your observing by season. Each target is best placed during the months shown — though many are visible for much longer from northern latitudes.

Season Targets
Winter (Dec–Feb) M42 · M45 · M1 · M35
Spring (Mar–May) M51 · M81 & M82 · M44 · M101 · M97
Summer (Jun–Aug) M13 · M57 · M27 · NGC 7000 · M92 · Albireo · Epsilon Lyrae
Autumn (Sep–Nov) M31 · M33 · Double Cluster · NGC 457

Find all of these objects on the interactive Star Map, or create a Plan to track your progress.

Test Yourself

Q1 You're at a Bortle 6 suburban site with a 4-inch refractor, and you want to impress a visiting friend. From this list, which three objects would you aim for, and why?

M42 (the Orion Nebula, in winter), M45 (Pleiades), and Albireo are the crowd-pleasers under light-polluted skies. M42 punches through suburban sky because it is a bright emission nebula with a wide dynamic range — the Trapezium is a showpiece at any aperture. The Pleiades dazzle in any instrument because the cluster stars themselves are naked-eye bright; light pollution barely touches them. Albireo's colour-contrast split is unaffected by sky darkness — a 4-inch at 50× will show it identically from a city centre or a dark mountain. Avoid M33, M101, and NGC 7000 from a Bortle 6 site; their low surface brightness gets swallowed by skyglow.

Q2 Why does M33 have a magnitude of 5.7 (brighter than M57 at 8.8) and yet M33 is often invisible where M57 is easy?

Integrated magnitude is deceptive for extended objects. M33's light (mag 5.7) is spread over roughly 73′ × 45′ — about 3,300 square arcminutes — giving a very low surface brightness. The galaxy competes directly with sky glow. M57 is tiny (1.4′ × 1.0′), so its mag-8.8 total light is packed into a much smaller patch. That concentrated glow stands out clearly against any sky brighter than itself. The lesson: for extended objects, surface brightness beats integrated magnitude every time.

Q3 A friend hands you three filters — a UHC, an O-III, and a light-pollution reduction (LPR) filter. Which target on this list benefits most from each, and which should you observe without a filter?
  • O-III on M57 and M27 — these planetary nebulae emit strongly in the doubly-ionised oxygen line. The O-III filter dramatically increases contrast.
  • UHC on NGC 7000 — the North America Nebula is a broad-band emission nebula; UHC passes H-beta, H-alpha and O-III and makes the shape pop even in small telescopes.
  • LPR is a mild broadband filter and helps marginally on bright emission nebulae like M42, but is a compromise on planetaries (where O-III is better) and useless on galaxies and star clusters.
  • No filter on Albireo, the Pleiades, M45's stars, the Double Cluster, M13, M92, NGC 457, or Epsilon Lyrae — filters only dim stars. Reflection nebulosity and galaxies also get no help from narrowband filters.
Q4 You want to split Epsilon Lyrae into all four components with an 80 mm refractor. What magnification do you need, what atmospheric condition matters most, and why might you fail on a clear night?

Each tight pair is about 2.3″–2.4″. The Dawes limit for an 80 mm scope is roughly 1.4″, so the pair is theoretically within reach. In practice you need 150–200× (well above the commonly-quoted "50× per inch" rule) to pull the Airy disks far enough apart to see them as two. The critical factor is seeing — atmospheric turbulence. On a clear but turbulent night the Airy disks boil into a shimmering blob and merge. Good seeing (steady, unblurred star images) usually occurs when the jet stream is not overhead and temperature is stable. Cold, clear nights after a front often have terrible seeing. A slightly hazy but still night can split Epsilon Lyrae while a glass-clear but windy night cannot.

Q5 Your goal is to glimpse spiral arms in a galaxy with an 8-inch Newtonian. Rank M51, M31, M33, M101 and M81 in order of likelihood of success — and explain the ranking.

From easiest to hardest for spiral-arm detection in an 8-inch under dark skies:

  1. M51 — compact, relatively high surface brightness, and the spiral pattern is face-on, grand-design, and right at the threshold of 8-inch reach under dark skies. Your most likely "wow" moment.
  2. M101 — face-on and large, arms are visible with averted vision if the sky is dark (Bortle ≤ 4). In a suburban sky the arms disappear entirely.
  3. M33 — face-on and close, so resolution is good, but surface brightness is very low. Arms are a whisper rather than a structure. Requires exceptional sky darkness.
  4. M81 — well-defined arms but they are tightly wound and low contrast. Subtle brightenings rather than obvious arms.
  5. M31 — too tilted (oriented only about 13° from edge-on) for face-on arm detection. You'll see dust lanes rather than spiral arms — still impressive, just a different visual experience.

The unifying lesson: spiral arms need dark skies (Bortle ≤ 4) far more than they need big aperture.

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