Asterism Atlas

Named star-patterns beyond the official constellation boundaries.

Orion / Canis Major / Canis Minor

Winter Triangle

Great Southern Triangle

common observer pattern · high confidence

Betelgeuse, Sirius, and Procyon make a compact winter landmark. From 50°N it clears the southeast in early evening by midwinter and is brilliant even through light haze.

Central RA
06h 46m 31.7s
Central Dec
−01° 21′ 41″
Brightest member
V -1.46
Best months from 50°N
December–March evenings
Suggested instrument
naked-eye
Approx. span
27.1°
Betelgeuse / 58Alp Ori (HR 2061) — V 0.50Procyon / 10Alp CMi (HR 2943) — V 0.38Sirius / 9Alp CMa (HR 2491) — V -1.46SiriusProcyonBetelgeusebrighter → largerV 1 reference1V 3 reference3V 5 reference5
Orion / Canis Major / Canis Minor contextschematic finder — bright-star context, not a constellation boundary mapNE

Finder context

This wider chart is deliberately schematic: it uses nearby bright-star context and boxes the asterism’s member-star footprint, but it does not draw official constellation boundaries or promise horizon/season precision.

Framing: Approximate member-star span: 27.1°; use at least 37.9° field for context.

Observing and imaging

Naked eye

Primary naked-eye pattern; suburban skies should show the main stars unless the description notes a low horizon or dark-sky need.

Binoculars

Binoculars are optional: use them to check colours, nearby doubles, or richer Milky Way background.

Small scope

A telescope is usually too narrow for the whole shape; use it after the pattern has guided you to a target.

Imaging

Frame as a wide-field scene in/near Orion / Canis Major / Canis Minor; a field of view around 38° keeps context without claiming exact constellation boundaries.

Tonight from your latitude

Observability from your latitude: uses this asterism’s centroid RA/Dec with a schematic local clock from longitude, astronomical twilight (Sun below −18°), and the 2026 Moon heuristic. Month stays for the seasonal readout.

Naked-eye visibility by sky class

Approximate limiting magnitudes: Bortle 3 ≈ V 6.6, Bortle 5 ≈ V 5.6, Bortle 7 ≈ V 4.6. The shape is counted recognisable when at least 70% of defining stars clear the limit.

Bortle 3: 3/3 stars — fully visibleBortle 5: 3/3 stars — fully visibleBortle 7: 3/3 stars — fully visible

Moon impact

Reference year 2026, Feb: 16/28 nights (57%) have a sampled ≥2 h window with Winter Triangle above 20° and the Moon below the horizon. At transit the Moon is up on about 50% of nights; the average moonlight penalty is roughly 0.63 mag of naked-eye limiting magnitude. Good nights below are the deterministic 2026 best-month mini-calendar for 50°N; green means a ≥2 h sampled dark window with the Moon down.

01020304050607080910111213141516171819202122232425262728

Member stars

NameBayer / FlamsteedHRRA J2000Dec J2000V mag
Sirius9Alp CMaHR 249106h 45m 08.9s−16° 42′ 58″-1.46
Procyon10Alp CMiHR 294307h 39m 18.1s+05° 13′ 30″0.38
Betelgeuse58Alp OriHR 206105h 55m 10.3s+07° 24′ 25″0.50

Source and confidence

common observer pattern; high confidence. Widely used modern observing guide-pattern; provenance is practical observer usage rather than an official constellation figure.

Citations