Eridanus (constellation)
Constellation|name = Eridanus |abbreviation = Eri |genitive = Eridani |symbology = the
river|RA = 3.25 |dec= −29 |areatotal = 1138 |arearank = 6th |numberstars = 4 |starname =
Achernar (α Eri) |starmagnitude = 0.46 |meteorshowers = None |bordering =
*
Cetus*
Fornax*
Phoenix*
Hydrus*
Tucana (corner)
*
Horologium*
Caelum*
Lepus*
Orion*
Taurus |latmax = 32 |latmin = 90 |month = December |notes=}}
Eridanus is the sixth largest of the 88 modern
constellations. It was also one of
Ptolemy's 48 constellations.
At its southern end is the
first magnitude star Achernar (α Eri). Achernar is a very peculiar star because it is one of the flattest stars known. Observations indicate that its radius is about 50% larger at the equator than at the poles. Responsible for this is the fact that Achernar is spinning extremely fast.
Another well-known star in Eridanus is
Epsilon Eridani, which has been popular in
science fiction because it is relatively close and relatively
sun-like. It is now known to have at least one planet (see
extrasolar planet), which is thought to be a gas giant, like
Jupiter.
Eridanus is associated with two Greek myths, both likely to be derived from the shape of the constellation - that of very twisty path. Eridanus was sometimes considered to be a river which flowed from the waters of
Aquarius, and in such situations, Aquarius was considered to face Eridanus (requiring a change of angle, and this required the redesigning of how the stars of Aquarius connect, so that the water poured onto the same side as Eridanus).
Eridanus was more usually connected to the myth of
Phaëton, who took over the reigns of
Helios' (i.e. the Sun's) sky chariot, but didn't have the strength to control it, and so veered wildly in different directions. The result was that sometimes the chariot got too close to earth, creating desert and burning people's skin (a myth they considered to explain the skin of the
Ethiopians). Zeus intervened by striking Phaëton dead with a thunderbolt. The constellation was considered, originally, to be the path Phaëton drove along, in later times, it was considered to be the river of the underworld that he fell into.
:Stars with proper names::* (α Eri) 0.45
Achernar < آخر النهر
Ākhir al-Nahr = "Last of the river":* (
67/β Eri) 2.78
Cursa [
Kursa] or
Dhalim:* (
34/γ Eri) 2.97
Zaurak [Zaurac, Zaurack] < زورق
zawraq = "boat":* (
23/δ Eri) 3.52
Rana:* (
18/ε Eri) 3.72
Epsilon Eridani– nearby; has at least one planet, dust disk:* (
13/ζ Eri) 4.80
Zibal < ? The ostrich:* (
3/η Eri) 3.89
Azha (?) corruption of Persian آشيانه
āšiyāne The (ostrich) nest:* (
θ Eri)
Acamar – double 3.89, 4.35 < آخر النهر
ākhir an-nahr = "Last of the river" [named before Achernar was added], with a
handwriting misread
rn ->
m.:* (
ο Eri):** (38/ο¹ Eri) 4.04
Beid < بيض
baiđ̧ eggs (of the ostrich):** (
40/ο² Eri)
Keid [
Kied] – triple 4.43, 9.5; nearby < ?
al-qayd The (egg) shells:* (
2/τ² Eri) 4.76
Angetenar [
Al Anchat, Anchenet, Hinayat (al Nahr)] < عوجة النهر
cawjat[u] an-nahr Bend of the river:* (
υ Eri):** (52/υ¹ Eri) 4.49
Theemin [
Beemin]:** (52/υ² Eri) 3.82
Beemin [
Theemin]:* (
53/l Eri) 3.86
Sceptrum:Stars with Bayer designations:::
ι Eri 4.11;
κ Eri 4.24;
69/λ Eri 4.25;
57/μ Eri 4.01;
48/ν Eri 3.93;
42/ξ Eri 5.17;
26/π Eri 4.43;
8/ρ1 Eri 5.75;
9/ρ2 Eri 5.32;
10/ρ3 Eri 5.26;
1/τ1 Eri 4.47;
11/τ3 Eri 4.08;
16/τ4 Eri 3.70;
19/τ5 Eri 4.26;
27/τ6 Eri 4.22;
28/τ7 Eri 5.24;
33/τ8 Eri 4.64;
36/τ9 Eri 4.62;
41/υ4 Eri 3.55;
χ Eri 3.69;
φ Eri 3.56;
65/ψ Eri 4.80;
61/ω Eri 4.36;
62/b Eri 5.50;
51/c Eri 5.22;
43/d Eri – double 3.97, 5.85;
82/e Eri 4.26 – nearby;
f Eri – double 4.30, 4.73;
g Eri 4.17;
h Eri 4.59;
i Eri 5.11;
p Eri – double 5.76, 5.76;
q1 Eri 5.52 – has a planet;
q2 Eri 5.04;
s Eri 4.74;
17/v Eri 4.74;
w Eri – double 4.79, 6.14;
y Eri 4.57;
39/A Eri 4.87:Stars with Flamsteed designations:::
4 Eri 5.44;
5 Eri 5.56;
6 Eri 5.82;
7 Eri 6.11;
14 Eri 6.14;
15 Eri 4.86;
20 Eri 5.24;
21 Eri 5.97;
22 Eri 5.53;
24 Eri 5.24;
25 Eri 5.56;
30 Eri 5.48;
35 Eri 5.28;
37 Eri 5.44;
44 Eri 5.53;
45 Eri 4.91;
46 Eri 5.71;
47 Eri 5.20;
49 Eri 5.32;
54 Eri 4.32;
55 Eri 5.98;
55 Eri 6.70;
56 Eri 5.78;
58 Eri 5.49;
59 Eri 5.76;
60 Eri 5.03;
63 Eri 5.39;
66 Eri 5.12;
68 Eri 5.11:Other notable stars::*
EF Eri 14.5 - <17.5 – cataclysmic variable
*
The Deep Photographic Guide to the Constellations: Eridanus*
Epsilon Eridani*
New 'Vulcan' Planet Tantalizes Astronomers
