Achernar

HR 472 · HIP 7588 · α Eri

👁️ Naked-eye

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

Star

Apparent magnitude: 0.46 mag
Parallax: 23.39 mas → about 139.4 light-years away
Spectral type: B3Vp
Right ascension: 24.4285°
Declination: -57.2368°
Designation: HR 472
Bayer designation: α Eri
HIP number: 7588
IAU name adopted: 2016-06-30
Name language: Arabic
Name origin (IAU): Arabic name آخر النهر (āḫiru ʾn-nahr) meaning, the End of the River; originally used for θ Eri that was considered the end of the river in the ancient star catalog (Almagest).The name was transferred to α Eri in the Early Modern Era when the constellation was extended south to this new terminus.

Constellation

Light from this object takes about 139 years to reach Earth — the light you see tonight left around AD 1887 (official distance ÷ speed of light).
At magnitude 0.5 it is bright enough for the naked eye (limit about 6) — look from somewhere dark.
Declination -57.2° — it never rises in Seoul (37.6° N); you need to be farther south to see it.