Theta Eridani

Starbox begin
name=Theta Eridani Starbox observe
epoch=J2000
constell=Eridanus
ra=02h 58m 15.70s
dec=−40° 18' 17.0"
appmag_v=3.2 Starbox character
class=A4 III
b-v=0.34
u-b=0.14
variable= Starbox astrometry experimental asymmetric
radial_v=11.9
prop_mo_ra=−44.6
prop_mo_dec=19.0
gal_lat=−60.7362
gal_lon=247.8557
parallax=28.00
p_error=11.00
absmag_v=-0.59 Starbox catalog
names=θ Eri, Acamar, HD 18622, HR 897Starbox reference
Simbad=HD+18622

Theta Eridani (θ Eri / θ Eridani) is a star in the constellation Eridanus. It also has the traditional name Acamar (which means "the last of the river", Arabic "Ākhir an-nahr", with a Roman-alphabet handwriting misread "m" for "rn"). Achernar is also the same Arabic word. It is known as 天园六 (the Sixth Star of the Celestial Orchard) in Chinese.

Acamar is a double star, consisting of a +3.2 magnitude bright main star of the spectral class A4 and a companion of the spectral class A1 of magnitude +4.3. The angular separation of the stars amounts to 8.2". The distance from Earth is 120 light-years.

Interestingly, Ptolemy described it as a first-magnitude star and Al Sufi in the 10th century listed it as one of the thirteen brightest stars in the sky, and Ulugh Beg from Persia in the 15th century also listed it as a first-magnitude star.