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Eridanus(ĭrĭd`ənəs), large southern constellationconstellation,
in common usage, group of stars that appear to form a configuration in the sky; properly speaking, a constellation is a definite region of the sky in which the configuration of stars is contained.
..... Click the link for more information. stretching SW from Orion for about 60°. Because of its long, winding shape it was identified with a river by many ancient civilizations; e.g., the Egyptians called it the Nile and the Babylonians called it the Euphrates. The brightest star in the constellation, AchernarAchernar
, brightest star in the constellation Eridanus; Bayer designation α Eridani; 1992 position R.A. 1h37.4m, Dec. −57°16'. A bluish-white white star with apparent magnitude 0.51, it is one of the 10 brightest stars in the entire sky.
..... Click the link for more information. , marks the southern end of the river. Eridanus reaches its highest point in the evening sky in December.
Eridanus(e-rid -ă-nŭs) (River) A long straggling constellation in the southern hemisphere extending from Orion toward the southern polar region. Except for the zero-magnitude Achernar (α), the brightest stars are of 2nd and 3rd magnitude. Zaurak (γ) is a red giant of apparent magnitude 2.95 and spectral type M1 IIIb, while Rana (δ) is somewhat hotter, an orange subgiant of apparent magnitude 3.54 and spectral type K0 IV. To the northwest of Zaurak lies Epsilon (Ɛ) Eridani, a star close to the Sun that may be a planetary system in the making (see Epsilon Eridani). The 3rd-magnitude Acamar (θ) is a fine double star, possibly once much brighter than it is now. Abbrev.: Eri; genitive form: Eridani; approx. position: RA 1.5 to 5h, dec 0° to –58°; area: 1138 sq deg.
a constellation of the southern hemisphere; its brightest star, Achernar, has a visual stellar magnitude of 0.5. The constellation is most easily viewed in October and November; it is visible in part from all regions of the USSR. (SeeSTELLAR SKY.)
A southern constellation made up of a long, crooked line of stars beginning near Rigel in the foot of Orion, and winding west and south to the first-magnitude star Achernar. Abbreviated Eri; Erid. Also known as River Po.