Ursa Major

Big Dipper

Plough, Charles's Wain

common observer pattern · high confidence

The famous ladle is the brightest northern guide-pattern: use Merak-to-Dubhe to hop to Polaris, then follow the bent handle to Arcturus. At 50°N it is circumpolar but rides highest on spring evenings.

Central RA: 12^h 20^m 02.0^s
Central Dec: +55° 34′ 47″
Brightest member: V 1.77
Best months from 50°N: March–June evenings
Suggested instrument: naked-eye
Approx. span: 25.7°

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: 25.7°; use at least 36.0° 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 Ursa Major; a field of view around 36° 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.

Latitude 50°NMonth Sky darkness Bortle 4 · limit V 6.1

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

Member stars

Name	Bayer / Flamsteed	HR	RA J2000	Dec J2000	V mag
Alioth	77Eps UMa	HR 4905	12^h 54^m 01.7^s	+55° 57′ 35″	1.77
Dubhe	50Alp UMa	HR 4301	11^h 03^m 43.7^s	+61° 45′ 03″	1.79
Alkaid	85Eta UMa	HR 5191	13^h 47^m 32.4^s	+49° 18′ 48″	1.86
Mizar	79Zet UMa	HR 5054	13^h 23^m 55.5^s	+54° 55′ 31″	2.27
Merak	48Bet UMa	HR 4295	11^h 01^m 50.5^s	+56° 22′ 57″	2.37
Phecda	64Gam UMa	HR 4554	11^h 53^m 49.8^s	+53° 41′ 41″	2.44
Megrez	69Del UMa	HR 4660	12^h 15^m 25.6^s	+57° 01′ 57″	3.31

Source and confidence

common observer pattern; high confidence. Commonly used constellation-part or seasonal guide-pattern name, with member-star positions plotted from BSC5.

Citations

Bright Star Catalogue, 5th Revised Ed.: Hoffleit, D. & Warren, W.H. Jr. (1991). Positions, V magnitudes, Bayer/Flamsteed identifiers. source
Star Names and Their Meanings: Allen, R.H. (1899). Public-domain skylore and traditional names.
Star Tales: Ridpath, I. Constellation and asterism notes used to cross-check common sky-pattern names. source
The Hipparcos and Tycho Catalogues: ESA SP-1200 (1997). Used as the modern astrometric reference named by the atlas; the MVP pages expose BSC5 J2000 fields for the plotted bright-star members.