Eridanus, the River (Eri)

(ih-RID-un-us)

The Southern constellation of Eridanus, the River, is best viewed in Winter during the month of December. It's brightest star is Achernar at magnitude 0.46. The boundary of the Eridanus constellation contains 26 stars that host known exoplanets.

1. Pronunciation:
2. ih-RID-un-us

1. Meaning:
2. River

1. Genitive:
2. Eridani

1. Abbreviation:
2. Eri

1. Constellation Family:
2. Heavenly Waters

1. Hemisphere:
2. Southern

1. Quadrant:
2. SQ1

1. Best viewing month*:
2. December

1. Right Ascension (avg):
2. 3h 53m

1. Declination (avg):
2. -17° 59'

1. Brightest star:
2. Achernar (0.46)

1. Stars with planets:
2. 26

1. Messier catalog objects:
2. |

1. Caldwell catalog objects:
2. |

Brightest Stars in Eridanus

The 10 brightest stars in the constellation Eridanus by magnitude.

1. Star
2. Magnitude
3. Spectral class

1. Alpha Eridani (α Eri)
2. 0.45
3. B3Vp

1. Beta Eridani (β Eri)
2. 2.78
3. A3IIIvar

1. Theta Eridani (θ¹ Eri)
2. 2.88
3. A4III+

1. Gamma Eridani (γ Eri)
2. 2.97
3. M1IIIb Ca-1

1. Delta Eridani (δ Eri)
2. 3.52
3. K0IV

1. Upsilon Eridani (υ⁴ Eri)
2. 3.55
3. B9V

1. Phi Eridani (φ Eri)
2. 3.56
3. B8IV-V

1. Chi Eridani (χ Eri)
2. 3.69
3. G5IV

1. Tau Eridani (τ⁴ Eri)
2. 3.7
3. M3/M4III

1. Epsilon Eridani (ε Eri)
2. 3.72
3. K2V

1. 40 Eridani A (40 Eri)
2. 4.43
3. K0.5 V

Double Stars in Eridanus

These are the brightest and easiest-to-find double, triple, and quadruple star systems in the constellation Eridanus . Also see all star clusters.

1. Star system
2. Magnitudes
3. Type

1. 32 Eridani
2. 4.8, 5.9
3. double

1. 55 Eridani
2. 6.7, 6.8
3. double

Nebulae in Eridanus

Notable and easy-to-find nebulae in the constellation Eridanus . Also see all nebulae.

1. Nebula name
2. Catalog #
3. Nebula type

1. Cleopatra's Eye
3. planetary

1. Witch Head Nebula
3. reflection

Milky Way Satellites in Eridanus

Dwarf satellite galaxies that orbit the Milky Way Galaxy located in the constellation Eridanus. Also see all Milky Way satellite galaxies.

1. Galaxy name
2. Alt name
3. Magnitude

1. Eridanus II

1. Eridanus III

* Constellation shown for northen hemisphere skies. For the southern hemisphere, constellations appear rotated 180 degrees (upside-down and left-right reversed) from what is shown. Remember that seasons are reversed too - summer in northern latitudes is winter in southern latitudes.

** Circumpolar constellations are visible year-round in the hemisphere listed (and not at all in the opposite hemisphere).