Caph

HR 21 · HIP 746 · β Cas

👁️ Naked-eye

📋 A written introduction is coming — for now this page shows official values only.

Star

Apparent magnitude: 2.27 mag
Parallax: 59.58 mas → about 54.7 light-years away
Spectral type: F2III-IV
Right ascension: 2.2945°
Declination: 59.1498°
Designation: HR 21
Bayer designation: β Cas
HIP number: 746
IAU name adopted: 2016-06-30
Name language: Arabic
Name origin (IAU): Applied in recent times from an abbreviation of its pre-Islamic Arabian name al-kaff al-khadib "the Stained Hand," alternatively and more correctly used for all the brighter stars of today's Cassiopeia (probably α, β, γ, δ, and ε). The pre-Islamic Arabian figure here represented a hand with its finger-tips stained reddish-brown in the traditional Eastern way using henna leaves. al-kaff al-khatdib, in turn, was part of the larger pre-Islamic Arabian asterism kaff althurayya al-yumna al-mabsuta, "the Outstretched Right Hand of the Pleiades." The latter extended from today's Taurus through Perseus into Cassiopeia. A second hand (the Pleiades were a "head" from which two arms or hands radiated) was al-kaff al-jadhma', "the Amputated Hand," in today's Cetus.

Constellation

Light from this object takes about 55 years to reach Earth — the light you see tonight left around AD 1971 (official distance ÷ speed of light).
At magnitude 2.3 it is bright enough for the naked eye (limit about 6) — look from somewhere dark.
Declination 59.1° — from Seoul (37.6° N) it never sets and circles the northern sky all night.

Worked out from this object's official values.

HR 21 · HIP 746 · β Cas

👁️ Naked-eye

📋 A written introduction is coming — for now this page shows official values only.

Apparent magnitude: 2.27 mag
Parallax: 59.58 mas → about 54.7 light-years away
Spectral type: F2III-IV
Right ascension: 2.2945°
Declination: 59.1498°
Designation: HR 21
Bayer designation: β Cas
HIP number: 746
IAU name adopted: 2016-06-30
Name language: Arabic
Name origin (IAU): Applied in recent times from an abbreviation of its pre-Islamic Arabian name al-kaff al-khadib "the Stained Hand," alternatively and more correctly used for all the brighter stars of today's Cassiopeia (probably α, β, γ, δ, and ε). The pre-Islamic Arabian figure here represented a hand with its finger-tips stained reddish-brown in the traditional Eastern way using henna leaves. al-kaff al-khatdib, in turn, was part of the larger pre-Islamic Arabian asterism kaff althurayya al-yumna al-mabsuta, "the Outstretched Right Hand of the Pleiades." The latter extended from today's Taurus through Perseus into Cassiopeia. A second hand (the Pleiades were a "head" from which two arms or hands radiated) was al-kaff al-jadhma', "the Amputated Hand," in today's Cetus.

Constellation

Light from this object takes about 55 years to reach Earth — the light you see tonight left around AD 1971 (official distance ÷ speed of light).
At magnitude 2.3 it is bright enough for the naked eye (limit about 6) — look from somewhere dark.
Declination 59.1° — from Seoul (37.6° N) it never sets and circles the northern sky all night.

Worked out from this object's official values.