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David

Darling

Eridanus

Eridanus constellation

Eridanus. © 2003 Torsten Bronger.


Eridanus (abbreviation: Eri), the River, is a very large southern constellation that starts near the southwest corner of Orion and meanders down to the region of the south pole. Although one of Ptolemy's original constellations, its southernmost extension, including its brightest star, was added later.

 

The two Omicrons, Omicron1 (Beid) and Omicron2 (Keid), are not physically connected. Beid is giant F star 125 light-years distant, while Keid is a multiple system, a mere 16 light-years away. Keid contains an easy, wide binary, the secondary of which is itself a binary made up of a red dwarf and the brightest (in terms of apparent magnitude) white dwarf in the sky. See below for details of the constellation's brightest stars.

 


Stars brighter than magnitude 4.0
star vis mag abs mag spec type distance (ly) RA (h m s) Dec (° ' ")
Alpha (Achernar) 0.45 -2.77 B3Vpe 144 01 37 43 -57 14 12
Beta (Cursa) 2.78 0.60 A3III 89 05 07 51 -05 05 11
Theta (Acamar) 2.88 -0.59 A4III+A1V 161 02 58 16 -40 18 17
Gamma (Zaurak) 2.97 -1.19 M0.5IIICa-ICr 221 03 58 02 -13 30 31
Delta (Rana) 3.52 3.74 K0IV 29 03 43 15 -09 45 48
Upsilon4 3.55 -0.15 B9V 178 04 17 54 -33 47 54
Phi 3.56 0.17 B8IV 155 02 16 31 -51 30 44
Tau4 (Angetenar) 3.70 -0.79 M3.5IIIaCa 258 03 19 31 -21 45 28
Chi 3.69 2.47 G8IIIbCN 57 01 55 58 -51 36 32
Epsilon Eridani 3.72 6.18 K2V 10.5 03 32 56 -09 27 30
Upsilon2 (Theemini) 3.81 -0.22 G8III 209 04 35 33 -30 33 45
53 (Sceptrum) 3.86 1.23 K1IIIb 109 04 38 11 -14 18 15
Eta (Azha) 3.89 0.83 K1IIIbBa0.2 133 02 56 26 -08 53 54

 


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