When is the best time to observe Shedir?

Shedir is best observed from August through October, with peak visibility during September when it transits around midnight in the Northern Hemisphere.

Where is Shedir located in the sky?

Shedir lies in the constellation Cassiopeia at right ascension 00h 41m and declination +56° 32′.

What telescope do I need to split Shedir?

Splitting Shedir requires an aperture of roughly 60 mm or larger — the components are separated by about 70.9″ at magnitudes near 2.2. The companion is about 6.8 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Shedir — Double Star in Cassiopeia

HIP 3179; Alpha Cassiopeiae; 18 Cassiopeiae

DoubleStar Cassiopeia (Cas) Visible

Star Map + List + Plan

About Shedir

Description

Schedar (also spelled Shedir) is an orange giant of spectral type K0IIIa at magnitude 2.23, the brightest star in Cassiopeia. Located about 228 light-years from Earth, it has a luminosity of roughly 676 times solar. Schedar marks the lower-right of Cassiopeia's W-shape as seen from mid-northern latitudes.

Observing Tips

Schedar is the rightmost bright star of the Cassiopeia W when the constellation is in its normal 'W' orientation high in the sky. Its warm orange color contrasts with the blue-white of the other W stars. Cassiopeia is circumpolar from mid-northern latitudes and visible year-round. Best placed in the evening from September through February.

History

The name Schedar (Shedir) comes from the Arabic 'sadr,' meaning 'breast,' describing its position on the Queen's chest. Cassiopeia represents the vain queen of Ethiopian mythology. The constellation's distinctive W-shape is one of the most recognizable patterns in the northern sky.

Fun Facts

Schedar appears to vary slightly in brightness, but this has been debated for centuries. Some observers report it as variable between 2.2 and 2.8, while others find it constant. The question of Schedar's variability remains one of the minor unsolved puzzles of naked-eye stellar astronomy.

Observe

1Physical Properties

Magnitude 2.23

Spectral Type K0- IIIa

Star Color Red (B-V 1.17)

Distance 228 ly

2Position & Identifiers

RA 00h 40m 30.5s

Dec +56° 32' 14.0"

Constellation Cassiopeia (Cas)

HR 168

HIP 3179

HD 3712

Bayer Alpha

Flamsteed 18 Cas

Variable ID Alp Cas

Double Cat 561

SIMBAD Wikipedia

3How easy to split?

Primary 2.2 mag Companion 9.0 mag Separation 70.9″

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Medium+	Medium+
150 mm Newton 150mm Newt.	Easy	Easy	Easy
Celestron C8 (203 mm SCT) C8 203mm	Easy	Easy	Easy

Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

4Visibility

Set a location in User Settings to see visibility data.

Best season Aug – Oct (peak: Sep)

5Multiple Star System Quadruple D: optical

Components 4 (quadruple)

Component IDs AD

Separation 70.9″

Companion Mag 9.0

Position Angle 283°

Star Colors A: Red

Discoverer H 5 18

Notes

D is 8.5v K2IV-V, vsini <54k/s. All components probably optical.

Separation over time

Measured 1781 → 2023 (242 y)

Separation drift 56.2" → 70.9" (+14.70")

Rate +0.0607" / y

PA drift 275° → 283° (+8°, +0.033°/y)

Apparent motion is significant on a human timescale — worth revisiting in a decade.

Measured from the WDS observational archive. No orbital solution has been derived — most likely the period is too long to fit an orbit to the available measurement arc.