At the end of Andromeda’s graceful chain of stars shines Almach (Gamma Andromedae), one of the northern sky’s most beautiful double stars. To the naked eye it appears as a single golden point marking Andromeda’s foot, but through a telescope it transforms into a stunning pair of contrasting colors — amber and blue, glowing together like a cosmic jewel. It’s often described as the finest color-contrast double in the autumn sky, a northern twin to Albireo in Cygnus, though some observers consider Almach even more striking.
The brighter component, Almach A, gleams with a warm golden hue and shines at about magnitude +2.3. Its companion, Almach B, lies 9.8 arcseconds away and glows a cool sapphire blue, around magnitude +5.0 — just enough dimmer to highlight the contrast beautifully. In fact, Almach B is not a single star at all but a multiple system of its own, with inner companions revealed only by large telescopes and spectroscopy. Altogether, Almach is a true multiple star system, but its visual double is what captivates observers most.
Even a small telescope of modest power (40×–80×) will easily split Almach into its two vibrant suns. The color contrast seems to deepen as you increase magnification — the primary’s golden tone growing richer, the secondary’s blue sharpening into an icy hue. Under steady skies, the sight is unforgettable: two tiny gems, side by side in perfect balance, shining across 350 light-years of space.
Almach is a reminder that stargazing isn’t only about faint galaxies or hidden clusters — sometimes the Universe offers simple, elegant beauty. It’s a showpiece for beginners and veterans alike, glowing in the crisp evenings of autumn. Find Andromeda rising in the east, trace its curved line of stars to the end, and reward yourself with one of the night sky’s loveliest pairs — a celestial duet of gold and blue.
Almach
Rating: 🟣 Showpiece Target
Level: 🔵 Easy
How:
When: Oct - Feb
🌟 A Dazzling Color Contrast Almach is celebrated for its vivid hues — a golden primary paired with a cool blue secondary, glowing in sharp relief through almost any telescope. The contrast between the warm amber light and the icy companion is one of the most striking in the heavens, and the colors remain obvious even under moderate light pollution.
🌟 Easily Split by Small Telescopes Unlike many famous doubles that require very steady air, Almach’s components are separated by nearly 10 arcseconds, making them easy to resolve with even small telescopes. The pair opens cleanly at modest magnifications around 40× to 80×, offering a clear, elegant view without the need for high power or advanced equipment.
🌟 A Showcase for Optical Quality Almach’s clean, balanced pair provides an excellent test of optics and focus. The brighter star’s diffraction pattern and the crisp color contrast make it ideal for checking collimation, assessing chromatic correction, or simply appreciating the clarity of your telescope’s optics. It’s both a pleasure to view and a practical benchmark for performance.
🌟 A Hidden Multiple System While most stargazers see Almach as two stars, the fainter blue component is itself a tight multiple system, containing additional stars that orbit closely together. These hidden companions reveal that Almach isn’t just beautiful — it’s scientifically fascinating, showing the complexity and diversity of stellar families in our galaxy.
Double stars: a collection of any two stars that appear close together. If they are gravitationally bound (orbit each other), they are known as binary stars. If they only appear close, they are known as optical doubles.
Almach
The best way to find Almach (Gamma Andromedae) is to begin with the unmistakable Great Square of Pegasus, the large diamond-shaped asterism that dominates the autumn sky.
Find the Great Square of Pegasus.
Start at the northeastern corner of the Square, marked by the star Alpheratz (Alpha Andromedae), which actually belongs to Andromeda rather than Pegasus. From there, trace Andromeda’s gentle chain of stars that curves eastward and slightly north — each step leading you farther from the Square and closer to Almach.
The next bright star along the chain is Delta Andromedae), glowing at about magnitude +3.26 and visible even in mild light pollution. Continue to the next star in line, Mirach (Beta Andromedae), noticeably brighter at +2.07. From Mirach, move one more similar distance along the same curve, and you’ll arrive at Almach, shining warmly at the end of the chain.
Almach’s golden hue often makes it stand out even before you point a telescope. In binoculars it’s a rich amber point marking the “foot” of the Andromeda figure. Once located, center it in your eyepiece and increase magnification — you’ll be rewarded with one of the most colorful double stars in the sky.
Almach
✅ Choose a Calm Night The beauty of Almach depends on steady air. Turbulent or hazy skies can blur the colors and cause the stars to dance together. Wait for a night when stars barely twinkle — calm conditions will make the separation sharper and the hues richer.
✅ Use Moderate Magnification Almach’s stars are about 10 arcseconds apart, so medium powers work best. Try magnifications between 60× and 120× to reveal both components cleanly. Too little power may blend them; too much can dim their colors. Adjust slowly until the pair looks crisp and balanced.
✅ View When It’s High in the Sky Wait until Andromeda climbs high above the horizon, where the air is thinner and steadier. The higher Almach rises, the less you’ll be looking through Earth’s atmosphere, giving a steadier, clearer view and minimizing color distortion.
✅ Try Different Eyepieces Experiment with eyepieces to find your telescope’s “sweet spot.” A wide-field view gives context and grace, while higher magnification tightens the split and deepens the color contrast. Switching back and forth can make the experience feel like discovering two different pairs in one.
✅ Share the View Almach is a perfect star to show friends and family — the colors are vivid, the split is obvious, and the story behind it is simple to tell. Watching someone’s reaction as they see gold and blue stars side by side for the first time is as satisfying as the observation itself.
Almach
✅ Naked Eye
To the naked eye, Almach appears as a single, steady point of golden light marking the end of Andromeda’s chain of stars. It stands out clearly even from suburban skies and adds a graceful finishing touch to the constellation, but its true nature remains hidden — there’s no hint of its dual identity without magnification. At this level, Almach is simply a warm, third-magnitude star gleaming quietly in the autumn sky.
✅ Binoculars
Through binoculars, Almach still looks like one star, though its color becomes more apparent. Observers often note a soft amber tone, and with very large or high-quality binoculars under steady skies, a hint of elongation may appear, suggesting something unusual about its light. It remains unresolved, but it draws the eye because of its rich hue and position at the edge of the constellation.
✅ Telescope
A telescope transforms Almach completely. Even a small instrument splits the pair cleanly into two brilliant points: a bright golden primary and a smaller sapphire-blue companion about ten arcseconds apart. The color contrast is striking and unmistakable, one of the most beautiful in the entire sky. Larger telescopes reveal both stars as perfect disks with subtle diffraction rings, the gold and blue gleaming side by side — a visual duet that never fails to delight stargazers.
Almach
Almach’s beauty lies in its vivid color contrast rather than faint details, so it remains an excellent target under nearly any sky. From dark rural locations its colors glow richly against a deep background, while in bright city skies the pair still stands out clearly, though with less surrounding starlight and subtlety.
🟣 Bortle 1–2: Under pristine dark skies, Almach sparkles like a gemstone — the primary glows deep golden-orange while the companion shines a cool sapphire blue. The surrounding starfield of Andromeda enhances the scene, giving the pair a sense of depth and delicacy against a perfectly black sky.
🔵 Bortle 3–4: In rural and good suburban skies, Almach retains nearly all its beauty. The color contrast remains vibrant, and the background still shows a soft scattering of nearby stars. The view loses only a touch of the inky blackness found under truly dark conditions, but the pair remains a standout.
🟢 Bortle 5–6: From typical suburban skies, Almach’s colors are still clear and pleasing, though the golden hue becomes warmer and the blue slightly muted. The surrounding stars of Andromeda fade, leaving the pair to shine almost alone in the field — a bright duet in an otherwise quiet sky.
🟡 Bortle 7–10: Even under heavy light pollution, Almach remains visible and easy to locate. Its components can still be separated, though the color contrast softens and the blue companion may appear whitish. The starfield background all but disappears, but Almach endures — a small splash of celestial color even in the heart of the city.
Almach
DSOs within 48° or 2 outstretched hands at arm's length
Almach - A Golden Jewel with a Sapphire Spark
Find the Great Square of Pegasus.
Start at the northeastern corner of the Square, marked by the star Alpheratz (Alpha Andromedae), which actually belongs to Andromeda rather than Pegasus. From there, trace Andromeda’s gentle chain of stars that curves eastward and slightly north — each step leading you farther from the Square and closer to Almach.
