The International Astronomical Union (IAU) Zodiac Is Not So Cut and Dry

 The International Astronomical Union (IAU) Zodiac aka 13 Sign Zodiac is not so cut and dry even though the zodiac takes all the 13 zodiac ecliptic constellations into account.

Some of the IAU zodiac signs have stars of other zodiac constellations including their alpha and beta stars.

In my astrological nativity:

I have Imum Coeli in 11'14 Tropical Sagittarius in Ophiuchus in the IAU Zodiac, but it is conjunct the star, tau Scorpii in 11'03 Sagittarius.

It has a magnitude of 2.8.

Paikauhale is the Hawai'ian name for it. In the Hawai'ian dictionary by Puku'i & Elbert (1986), the word paikauhale means to go gadding about from house to house. In another Hawai'ian dictionary (H.W. Kent, 1993, "Treasury of Hawaiian Words in One Hundred and One Categories", p.367), paikauhale is listed with definition Vagabond owning no home; house-to-house wanderer.

In some astronomical references, the star designated Tau Scorpii had the name "Alniyat" or "Al Niyat", which was duplicative (and now considered obsolete) with the star designated σ Scorpii (now with IAU name "Alniyat")

The indigenous Boorong people of northwestern Victoria saw this star (together with σ Sco) as wives of Djuit (Antares).

In Chinese, 心宿 (Xīn Xiù), meaning Heart, refers to an asterism consisting of τ Scorpii, σ Scorpii and Antares.[21] Consequently, τ Scorpii itself is known as 心宿三 (Xīn Xiù sān), "the Third Star of Heart"

I have North Lunar Node in 10'29 Tropical Aquarius in Capricorn in the IAU Zodiac, but is is conjunct the star, episilon Aquarii Albali in 11'20 Aquarius.

It has a magnitude of 3.8

It is in the left hand of the Water Bearer.

Al Bali was the brightest star of the 21st manzil (Arabic Moon Mansion), Al Sa'd al Bula', the Good Fortune of the Swallower, which included mu (μ) and nu (ν); these last also known as Al Bulaan in the dual. The 13th century Persian astronomical writer Al Kazwini said that this strange title came from the fact that the two outside stars were more open than alpha (α) Giedi Prima and beta (β) Dahib of Capricornus, {p.54} so that they seemed to swallow, or absorb, the light of the otheIn the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, it was designated Nir Saad Bula (نير سعد ألبلع nayyir sa'd al bulaʽ), which was translated into Latin as Lucida Fortunæ Dissipantis, meaning "the brightest of luck of the swallower".

In Chinese, 女宿 (Nǚ Sù), meaning Girl (asterism), refers to an asterism consisting of Epsilon Aquarii, Mu Aquarii, 4 Aquarii, 5 Aquarii and 3 Aquarii.[14] Consequently, Epsilon Aquarii itself is known as 女宿一 (Nǚ Sù yī, English: the First Star of Girl)r.

The Alpha Pisces star, Alrisha is in Aries in the IAU Zodiac.

The Alpha Scorpius star Antares is in Ophiuchus in the IAU Zodiac.

The Beta Aquarius star Sadalsuud is in Capricorn in the IAU Zodiac.

Based off of the 2000 Tropical Zodiacal positions listed in Anne Wright’s site, Constellations of Words

http://www.constellationsofwords.com/

Sun conjunct other zodiac constellation’s stars during Sun in Aries April 18-May 13:

xi Pisces in 27'31 Aries

omicron Pisces in 27'45

tau Pisces in 28'19 Aries

upsilon Pisces in 28'47 Aries

alpha Pisces Alrisha in 29'23 Aries

Sun conjunct other zodiac constellation’s stars during Sun in Libra Oct 30-Nov 23:

lambda Khambalia in 6'57 Scorpio

109 Virgo in 8'31 Scorpio

mu Virgo in 10'08 Scorpio

Sun conjunct other zodiac constellation’s stars during Sun in Scorpio Nov 23-Nov 29:

delta Ophiuchus Yed Prior in 02'18 Sagittarius

epsilon Ophiuchus Yed Posterior in 3'31 Sagittarius

lambda Ophiuchus Marfirk in 5'36 Sagittarius

Sun conjunct other zodiac constellation’s stars during Sun in Ophiuchus Nov 29-Dec 18:

sigma Scorpius in 7'48 Sagittarius

alpha Scorpius Antares in 9'46 Sagittarius

tau Scorpius in 11'28 Sagittarius

epsilon Scorpius in 15'21 Sagittarius

My1 Scorpius in 16'09 Sagittarius

zeta2 Scorpius Grafias in 17'18 Sagittarius

eta Scorpius in 20'45 Sagittarius

upsilon Scorpius Lesath in 24'01 Sagittarius

lambda Scorpius Shaula in 24'35 Sagittarius

theta Scorpius Sargas in 25'36 Sagittarius

Sun conjunct other zodiac constellation’s stars during Sun in Sagittarius Dec 18-Jan 20:

NGC6405 M6 Aculeus in 25'44 Sagittarius

kappa Scorpius in 26'27 Sagittarius

gamma (y) Ophiuchus in 26'38 Sagittarius

iota Scorpius in 27'31 Sagittarius

G Scorpius in 27'55 Sagittarius

NGC6475 M7 Scorpius in 28'45 Sagittarius

nu (v) Ophiuchus in Sinistra in 29'45 Sagittarius

Sun conjunct other zodiac constellation’s stars during Sun in Capricorn

Jan 20-Feb 16:

epsilon Aquarius Albali in 11'43 Aquarius

beta Aquarius Sadalsuud in 23'24 Aquarius

The IAU Constellation boundaries are based on what Eugene Delporte had drawn up in 1930 on behalf of the IAU and published in in Délimitation scientifique des constellations (Cambridge University Press). Before Delporte's work, there was no standard list of the boundaries of each constellation.

Eugene Delporte drew the boundaries along vertical and horizontal lines of right ascension and declination; however, he did so for the epoch B1875.0 which means that due to precession of the equinoxes, the borders on a modern star map (e.g., for epoch J2000) are already somewhat skewed and no longer perfectly vertical or horizontal.

The IAU 13 Sign Zodiac’s boundaries have nothing to do with ecliptic longitude which is the coordinate that contains the zodiac signs (Tropical Zodiac and 12 Sign Sidereal Zodiac). They have to do with Right Ascension and Declination which are the coordinates that Astronomers mainly use to locate celestial objects. The borders of these boundaries are already off. Using an ecliptic longitude 13 sign zodiac based off of Right and Declination doesn’t make any sense. As I already pointed out, the 13 sign zodiac signs have stars from other constellations. Alpha Scorpius star Antares in Ophiuchus in the IAU 13 zodiac is a glaring issue. I am definitely not going to be telling Alpha Scorpions that they are Ophiuchans, and so no 13 Sign Zodiac for me.