Cassiopeia

Cassiopeia W

Cassiopeia chair

common observer pattern · high confidence

The zig-zag W is circumpolar from Alberta and flips to an M when it passes over the pole. It is the northern autumn counterweight to the Big Dipper.

Finder context

Use the nearby bright stars to locate the gold box, then move to the larger chart for the pattern itself.

Framing: Approximate member-star span: 13.3°; use at least 18.6° field for context.

Start with the unaided eye. Suburban skies usually show the main stars.

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

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

Frame a 19° field around Cassiopeia to include the pattern and its nearby stars.

Set your location and date to see a useful window, peak altitude, sky visibility, and Moon conditions. Use Month to compare the season ahead.

Latitude 50°NLongitude -114°Date Month Sky darkness Bortle 4 · limit V 6.1

Bortle class rates night-sky brightness. The atlas counts a pattern as recognisable when at least 70% of its defining stars are visible.

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

For 50°N in the best month, green dates mark at least two hours with the pattern above 20° and the Moon below the horizon.

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Name	Bayer / Flamsteed	HR	RA J2000	Dec J2000	V mag
Schedar	18Alp Cas	HR 168	00^h 40^m 30.5^s	+56° 32′ 14″	2.23
Caph	11Bet Cas	HR 21	00^h 09^m 10.7^s	+59° 08′ 59″	2.27
Gamma Cassiopeiae	27Gam Cas	HR 264	00^h 56^m 42.5^s	+60° 43′ 00″	2.47
Ruchbah	37Del Cas	HR 403	01^h 25^m 49.0^s	+60° 14′ 07″	2.68
Segin	45Eps Cas	HR 542	01^h 54^m 23.7^s	+63° 40′ 12″	3.38

common observer pattern; high confidence. A commonly used constellation-part or seasonal guide pattern.

Bright Star Catalogue, 5th Revised Ed.: Hoffleit, D. & Warren, W.H. Jr. (1991). Positions, V magnitudes, Bayer/Flamsteed identifiers. source
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.