latest update February 2025 - original post in June 2022
My writings and researches inspired me, to write a "timeless" and over time "expanding" post about this truly mysterious long constellation...
This is the official astronomical constellation map and as such in reference to the celestial equator.
In Astrology we measure or draw in reference to the ecliptic (see picture below).
Eridanus is south of the ecliptic and therefore a non-zodiac constellation. It's one of the 15 equatorial constellations - meaning in reference to the Earth equator.
The constellation starts at the star Kursa (upper corner 5h - -5degrees), close to the star Rigel of Orion.
In ancient times, Eridanus was believed to be directly linked to Orion and sometimes even to the very bright star Canopus of Carina (brightest star of the ancient constellation Argo Navis.
Eridanus ends at the star Achernar (alpha) at roughly 20 degrees sidereal Aquarius - here the river of life flows together with the water out of the Aquarian urn, into the "open mouth" of Pisces Austrinus...
It's a long, winding and curving constellation...
It's a constellation with many named stars but what really is striking, there are 32 stars found with orbiting planets and some of those planets seem to be pretty big as well (near Jupiter's size) and some are compared with Earth and even in the "habitable zone" (in reference of forming life as we know it) at least sometimes during their orbits around their stars....
Not one "Messier object" in Eridanus though - Charles Messier (1730 - 1817) was a very active Astronomer who is credited with many discoveries and his catalogue of 110 objects (mainly clusters and some nebulae) is still in use as the "Messier catalogue"... He was known as a "comet-hunter" and made the catalogue to make it easier to distinguish between "transiting" and "fixed" objects...
So, it's interesting because of what is NOT there - but why??? - Well, I guess after you read the stories below and then what I did find out, you'll be in "wonder" too ;-)
The story that is usually associated with Eridanus is as follows:
Phaeton, Helios' son, asked many times to steer the chariot with the Sun through the sky. After many time receiving a "no" as an answer, one day he was allowed to do and reminded by his father to go the "beaten tracks" and to be careful - with a "yes, yes" off he went....
He couldn't control the horses went straight up into the sky, then very far down and he burnt some places on Earth and other things happened while being out of control...
Zeus watched this from afar and was shocked and didn't know what else to do than to use one of his thunderbolts to get the chariot down. Phaeton fell into the river Eridanus - Helios though was very, very sad and couldn't get up to bring the Sun on it's course for several days....
Some believe that Eridanus does represent the path Phaeton took with his unfortunate "ride" - the constellation Auriga with its bright star Capella north of the ecliptic, over the Taurus-Gemini cusp is representing the Charioteer....
Yet, there's also a Greek deity called Eridanos (latin it's Eridanus and translates to "early-burnt") - he was a river god and described as being of the nature "ready to receive". He's of course associated with the constellation Eridanus and the above story and of course it's "continuation".
Phaeton had sisters (it's said to be 7 - the "seven sisters" is a name for the Pleiades and there's also the Hyades north of Aldebaran who are told to be crying sisters) who were called the Heliades (daughters of the Sun); they shed many tears over their brother's "accident" at the bank of the river Eridanus and then changed their nature to become poplar trees along the riverbank. It's said, their tears manifest as amber.
Phaetons unfortunate loss of control burnt a lot of land and was seen as a fiery torch lightning up the heavens and his fall was a fiery one too - it's said, the river became steamingly hot.... (interesting the placement of the constellation "fornace")...
There's also a Babylonian association with the constellation Eridanus.
According a theory, the name Eridanus comes from the name of a Babylonian constellation known as the Star of Eridu, which was also the name of a city as the "sacred city" of the god Enki-Ea. Eridanus is sometimes also called the "river of forgetfulness"....
Other stories are associated directly to stars - especially to those in the first move/passage through sidereal Aries...
Orbits are a very interesting path to study - Eridanus lies pretty south of the ecliptic, nevertheless, there are some planetary bodies directly transiting through Eridanus or at least some parts of it... in the Taurus and Aries part (first "passages" - more northern parts of the river), there are especially Pallas (main asteroid belt) and Haumea (minor planet in the Kuiper belt) to be noted...
Taurus part of Eridanus
Star Cursa / Kursa (Beta Eridani) - ca. 20 degrees sidereal Taurus
Cursa is bright enough to be easily seen by naked eye and is situated near Rigel (alpha star of Orion). It's classified as a white giant star (evolved to fuse helium at its core instead of hydrogen during main sequence time). Cursa is a variable star, that at times flares up quite intensely (just as the Sun does at times too) - it's about double the mass and 2.4 times the radius of our Sun and shines with 25 times the luminosity of our Sun.
It's name comes from the Arabic "Al Kursiyy al Jauzah, meaning the chair or footstool of the Central One (referring to Orion).
In Chinese Astronomy Kursa is the third star of an asterism called the "Jade Well".
In ancient Arabic and Chinese view, the asterisms containing Cursa were a mix of stars from nowadays Eridanus and Orion...
Star Theemin (Upsilon 2 Eridani) - ca. 5 degrees sidereal Taurus
Theemin is located very south of the ecliptic - rounded up ca. 52 degrees south - and marks the "second bending" of the river. From Kursa all the way through sidereal Aries, then curving back into earlier Taurus or Theemin to then flow back through very southern areas of sidereal Aries, Pisces and ultimately Aquarius. Theemin can also be seen as the "pointer of the heart" when drawing a mental line between Theemin and Kursa...
Theemin is much further away than Kursa and therefore, even though with a much brighter absolute magnitude than Kursa, it appears fainter but is still visible to the naked eye in very dark skies and from the southern hemisphere...
At the moment, there are no planets used in Astrology, that would come this south of the ecliptic (Eris close in latitude but in another area of the heavens). Therefore, we have Theemin not as a directly involved star, which does mean its influence is more subtle or hidden...
Theemin is a yellowish giant star (again helium fusing) with a radius around 16 times solar and a luminosity 138 times the Sun. Theemin is about 214 light years from the Sun.
Ptolemy's Almagest mentions this star named "he kampe", meaning the bend of the river. In Arabic it became Beemin and its etymology from Hebrew "te'o;mim" (meaning twins) produced the name. There's now another star actually called "Beemin" - do these stars actually have anything in common??
In Chinese Theemin is the 12th star of Celestial Orchard.
Aries part of Eridanus
Star Beemin (Upsilon 3 Eridani) - 29 degrees 29 minutes sidereal Aries
Beemin is, as Theemin, very far south of the ecliptic - out of the reach of the so far astrologically known planetary bodies. Furthermore, are the two stars not far apart in longitude either and so we do have a "relationship" here.
Beemin is a orange giant star about 296 light years distant from the Sun. It got about 54 times the sun's radius and 426 times its luminosity.
Beemin in Chinese Astronomy is the 11th star of Celestial Orchard.
Star Zaurak (Gamma Eridani) - 29 degrees sidereal Aries
The word Zaurak or Zaurac is one of the Persian words for a "boat".
In Chinese, gamma eridani is called "the first star of Celestial Meadows".
Zaurak is an evolved red giant with the classification M0III-IIIb of which it became the "standard star". Zaurak is also a variable star, without further details known yet.
Zaurak got a mass about 1.55 times solar, with a radius about 58.5 times our Sun and a luminosity 630 times solar.
The evolutionary state is one called "asymptotic giant branch" - stars in this state are fusing hydrogen in a shell outside the core - "outsourcing" comes to mind... it's something many stars are doing but by far not all of them!! So, just one way of many...
Zaurak marks the ditch of the imagined "heart"...
Star Rana (Epsilon Eridani) - ca. 25 degrees sidereal Aries
holds a planetary system similar to ours (well 2 planets so far known). Ran is the name-giving Nordic goddess of the Sea together with her husband Aegir. She's said to capture sea-men in a big net and in the story sea-monsters are also mentioned (think of Cetus). Ran is from a "god family" of war and government... She and Aegir got 9 daughters which are representing waves....
Interestingly the "star" Tau Eridani actually consists of 9 stars but it's said that they're not "related" (astronomically/according to current physics)...
Rana is the latin word for "the frog" - the fairytale "frog prince" comes to mind - it's though said, frog is a walker between worlds as well as one that asks to take care of emotional stuff. The responsibility we have for self-care and self-love, which is interestingly reflected in the Venus mythology, which tells us that the frog was one of her sacred animals...
Rana is a orange subgiant, which means it has evolved away from the hydrogen fusing main sequence state to become a giant, this transformation may end soon (in star timing). Well, this star is already very old with it's estimated ca. 6.2 billion years of age...
Star Zibal (zeta Eridani) - ca. 19 degrees sidereal Aries
according to Wikipedia this name resulted from an old misreading of the Arabic word - it would be "Ri 'al" which means "ostrich chicks"...
Zibal is a binary star system with a fast orbital period which means, there's not much distinction possible. Zibal is a "younger" white main sequence star with almost double the mass and radius of the Sun and about 10 times solar luminosity.
Star Azha (eta Eridani) - ca. 14 degrees sidereal Aries
got its name from an Arabic asterism udḥiyy al-naʽām "the ostrich nest" (or "hatching place") - in Chinese it's the "6th star of the celestial meadows"....
It's classified as a K3 star with roughly 60 times the luminosity of the Sun. It seems kind of "special" as a "mild Barium star" (chemical element) being "alone" - as usually Barium-stars are found in binary systems...
Azha also marks a turning point of the river, now flowing back into the direction of Taurus...
Star 82 Eridani - early sidereal Aries (not far from Acamar in sid. Pisces)
In early 2025, this stars or better said one of its orbiting planets made some News in scientific publications. A so called "super-Earth" was discovered and characterized and now "introduced" to the public - it's a planet crossing through the "habitable zone" with a very eccentric (oval) orbit around 82 Eridani.
This star hosts several planets and even so, it's visible to the naked eye (faintly though) it doesn't have a proper name (yet!?).
This star is similar to our Sun, yet, a little smaller. The star is pretty close to our system and therefore offers the possibility for more intense observations and analysis especially as technology is advancing...
Pisces part of Eridanus
Acamar (theta Eridani) - ca. 28 degrees sidereal Pisces
This star was the "first end" of the river - Acamar shares the Arabic name root as being the river's end with the alpha star of Eridanus.
In Chinese, Acamar did mean the "6th star of the celestial orchard".
Acamar is a binary star system - both white class A stars. According to Jim Kaler, Theta 1 an A4 giant with a luminosity of 96 times that of the Sun and Theta 2 an A1 dwarf with a luminosity 36 times that of the Sun.
The color white is associated with purity, spirituality etc. - an orchard is associated with rewards, plentitude, fullness and flow.... yet, the journey continues...
Chi Eridani - ca. 1 degree 16 minutes sidereal Pisces
According to Jim Kaler, this star is used as a "pointer" to 2 stars in Horologium - yet, it's most interesting feature is, that it seems to go through evolutionary processes much faster than "normal" (if we even know what that is when it comes to stars) - the star is currently classified as G8/G9 which, I think puts it as being yellowish to light orange with weaker hydrogen. It also seems to hold at least one planet....
I really find this correlation "funny" - this star evolves fast and is used as a pointer to Horologium, the clock - don't you agree ;-)
Aquarius part of Eridanus
Achernar (alpha Eridani - at ca. 20 degrees sid. Aquarius)
is a binary system and got its name from Arabic and translates "end of the river".
Yet - another confusion - it seems that this Arabic origin also applies to the star Acamar (theta Eridani)... well, if they saw the end of Eridanus with Acamar and not Achernar - what was Achernar been assigned to and representing or was Achernar just "missed out" because of it's southern location (probably why it's also the only 1st Magnitude-Star not listed in Ptolemy's catalogue) - it would be interesting to know what people in the southern hemisphere did tell about this bright star....
The Chinese aren't of help here, as they couldn't observe it either and therefore did kind of "copy" the Western catalogue - yet, there Achernar marks the beginning....
This star is also in it's form special - it's very "oblate", called the "least spherical star" so far studied... it's said that this might be caused by it's very high rotation speed....
"Specialty" of Eridanus?
Now the really strange thing I discovered, without being able to really "locate" it on any constellation map exactly but....
we got hints.... what am I talking about? Well, there is something called the "CMB cold spot" - this area could only be discovered by using microwave data...
It's a big area that seems to lack warmth and also galaxies....
Now the cold spot was discovered a while ago but now they also detected a massive "Super void" that is connected to this cold spot or may explain it.... This Super void was at first (discovery published December 2021) estimated to be 1 billion lightyears across but now even estimated to be 1,8 billion ly in a "cigar like form/shape"...
In the article by resonancescience. org, (newly called International Space Federation ISF) you'll find a lot of scientific explanation and maps included that gave me the hint, the CMB to be located roughly south of the star Rana and Azha...
Now remember Ran being the sea-goddess that did capture seamen and according to myth, pulled them down into the "abyss".... coincidence!!??
Well, we Astrologers (never mind of which "school") may need to examine charts about this specific region too, lol.... Please, let me know what you come up with!!!!
Eridanus holds even more mysteries
You thought it's enough mystery now with Eridanus.... sorry, giggles....
A 2022 article by sci-news. com - an excerpt from that article:
"Dr. McCully and colleagues think that the half-exploded star got brighter because it puffed up to a much bigger state. SN 2012Z wasn’t strong enough to blow away all the material, so some of it fell back into what is called a bound remnant.Over time, they expect the star to slowly return to its initial state, only less massive and larger. Paradoxically, for white dwarfs, the less mass they have, the larger they are in diameter."
Yeah, if you thought stars either explode or not - well, it seems not to be as simple....
(we might have observed something similar a few years ago with the star Betelgeuse of Orion - just a personal note)
A supernova is a very "violent" occurrence" and its remnants do give enormous energies off and of course, the initial "explosion" itself does send "shock-waves" throughout big regions... The "location" of this incident was in the galaxy NGC 1309 we see it's (on flat paper) not far from Ran neither - ecliptical I think still in Aries...
Another thought that I had, is the fact, that mass as a direct link to gravity, may indicate a "holding back" whereas a larger size does reduce the density (like same amount of stuff within a bigger container, therefore less dense or packed together) ...
Interesting to note the correlation to "wisdom teachings"...
Linking this "story" with the "mythical Ran story" - I think there's a link to "manifestations" as well - whatever there might arise in the "void", an idea of some sort, does go through some kind of "development" in order to become "dense" (in other words physical)....
At times though, it's this "physicality" that might kind of "keeps us" where we are...
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Credits/references:
Credit/References: all charts are created using the free software by Astrodienst.com - choose "extended chart selections".... sidereal Zodiac (Galactic Equator Fiorenza)
Nick Anthony Fiorenza - lunar planer (website no longer available directly but in internet archives)
Dane Rudhyar - many publications and books.... available through "Rudhyar Archival Project"... by Astrology University..... by Michael Meyer on Khaldea.com
Greek mythology: https://www.theoi.com/Titan/Phaethon.html
Animal symbolism: https://whatismyspiritanimal.com/about-me/
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