Asterism Atlas

Named star-patterns beyond the official constellation boundaries.

Cetus

Head of Cetus

Cetus head

skylore / traditional name · medium confidence

Menkar and nearby third- and fourth-magnitude stars form the whale's head below Pisces and Aries. It is best on quiet autumn nights when the eastern sky is relatively dim.

Central RA
02h 38m 20.3s
Central Dec
+06° 56′ 57″
Brightest member
V 2.53
Best months from 50°N
September–December evenings
Suggested instrument
naked-eye
Approx. span
13.1°
65Xi 1Cet (HR 649) — V 4.3773Xi 2Cet (HR 718) — V 4.2887Mu Cet (HR 813) — V 4.2786Gam Cet (HR 804) — V 3.47Menkar / 92Alp Cet (HR 911) — V 2.53Menkar86Gam Cet87Mu Cet73Xi 2Cet65Xi 1Cetbrighter → largerV 1 reference1V 3 reference3V 5 reference5
Cetus 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: 13.1°; use at least 18.4° 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 Cetus; a field of view around 18° keeps context without claiming exact constellation boundaries.

Observability from your latitude

Uses this asterism’s centroid RA/Dec: transit altitude, hours above 20°, and a month-scale evening window. Default is Edmonton-ish 50°N.

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

Member stars

NameBayer / FlamsteedHRRA J2000Dec J2000V mag
Menkar92Alp CetHR 91103h 02m 16.8s+04° 05′ 23″2.53
86Gam Cet86Gam CetHR 80402h 43m 18.0s+03° 14′ 09″3.47
87Mu Cet87Mu CetHR 81302h 44m 56.5s+10° 06′ 51″4.27
73Xi 2Cet73Xi 2CetHR 71802h 28m 09.5s+08° 27′ 36″4.28
65Xi 1Cet65Xi 1CetHR 64902h 13m 00.0s+08° 50′ 48″4.37

Source and confidence

skylore / traditional name; medium confidence. Traditional or folk name carried through older public-domain star-name literature; the plotted stars are still BSC5 positions.

Citations