I am reading Tetrabiblos (Ashmand edition). In the footnote to Chapter VI, I read,

15:1 “Astronomers call the planets matutine, when, being oriental from the Sun, they are above the earth when he rises; and vespertine, when they set after him.” Moxon’s Mathematical Dictionary.

Matutine and Vespertine

I understand "matutine" to mean that:

1. The star rises before the Sun. (E.g., The star is in Aries, and the Sun is in Taurus.)

2. The star can be seen for a short time prior to dawn. (E.g., The Ascendant is in Aries.)

3. When the Sun rises, the star can no longer be seen. (E.g., the Ascendant is in Taurus.)

I understand "vespertine" to mean that:

1. The star sets after the Sun. (E.g., The Sun is in Aries, and the Star is in Taurus.)

2. After the Sun sets, the star appears in the sky and can be seen for a short time above the Descendant. (E.g., The Descendant is in Aries.)

3. Then, the star also sets in the middle of the night. (E.g., the Descendant is in Taurus.)

East and West

If my understanding is correct, then it is clear that a matutine star must be to the west of the Sun, rather than to the east of the Sun. It is also clear that a vespertine star must be to the east of the Sun, rather than to the west of the Sun, because:

1. The Sun moves from Aries to Taurus in a eastward direction, (as the Sun always moves east along the ecliptic).

2. Therefore, Taurus should be considered the east relative to Aries, and Aries should be considered the west relative to Taurus.

3. It can be seen in the examples shown in the section above that a matutine star must be to the west of the Sun, and a vespertine star must be to the east of the Sun.

Four Phases

Furthermore, the cycle must be as follows:

1. Occultation: The Sun and the star are conjunct. The star cannot be seen.

2. Heliacal rising: The Sun moves east relative to the star. The star is to the west of the Sun. The star can be seen for a short while at dawn. The star can be seen to rise.

(Another way to picture this is: the angle from the Sun to the star is acute moving westward from the Sun and obtuse moving eastward from the Sun.)

The key here is that the star rises, but does not set.

3. Opposition: The Sun is in opposition to the star. The star can be seen to rise, as soon as the Sun sets. The star can be seen to set, as soon as the Sun rises.

4. Heliacal setting: The Sun moves further east, rendering it west relative to the star. The star is to the east of the Sun. At the setting of the Sun, the star appears in the middle of the sky. (The star is not seen to the rise.) Then, the star sets in the middle of the night, before the Sun rises.

The key here is that the star sets, but does not rise.

Daily Motion of the Sky

Yet another way to think about this is:

1. In terms of daily motion, the sky moves westward.

2. Obviously, a star can appear in the sky before the Sun, only if the star is to the west of the Sun, not to the east of the Sun.

Question

In sum, my contention is:

1. "Oriental" does not refer to the star "being oriental from the Sun", as explained by Moxon's Mathematical Dictionary. An "oriental" star must be to the west of the Sun. "Oriental" refers to the fact that the star rises (and can be seen to rise) in the east, rather than its relative position to the Sun.

2. Similarly, "occidental" does not refer to the star being occidental from the Sun. An "occidental" star must be to the east of the Sun. "Occidental" refers to the fact that the star sets (and can be seen to set) in the west, rather than its relative position to the Sun.

Having contradicted so great an authority as Moxon’s Mathematical Dictionary, I am fearful that I might have made, unbeknownst to me, a great error somewhere.

Am I right? If not, where is my error?

Hello Neptune,

Oriental / Occidental
https://www.skyscript.co.uk/gl/oriental.html
It explains the difference between oriental/occidental of the Sun and oriental/occidental in the figure.

As for the visibility of the planets and the phases, my reference remains "Ardua et Astra: On the Calculation of the Dates of the Rising and Setting of Stars' by Matthew Robinson from University College London
https://www.journals.uchicago.edu/doi/10.1086/650145

You have 8 phases

Resume of Matthew Robinson article and the terminology.
Page 3
"The ‘true’ risings and settings take place when the star crosses the horizon at the same time as the sun: as the sky is still bright at this time, these phenomena cannot be observed and the dates can only be reached by calculation. The ‘apparent’ risings and settings take place just before sunrise or just after sunset, when the sky is just dark enough for the star to be visible. Since the ‘apparent’ phenomena are the only ones which can actually be seen, it seems clear that they are the phenomena referred to in the majority of literary texts and parapegmata; references to the ‘true’ phenomena, which cannot be seen and whose dates cannot be ascertained without mathematical or mechanical assistance, are obviously of less practical use and tend to be confined to ancient handbooks on astronomy."
-------------------
1) True Morning Rising (TMR) (true) cosmical rising
The star crosses the eastern horizon with the sun: for the previous few days it had crossed the eastern horizon after sunrise (and was thus invisible); on the day of the true morning rising, it was below the horizon shortly before sunrise (and thus was invisible), and will remain invisible as it crosses the horizon (as the day has now dawned and the sun’s light obscures that of the star).

2) Apparent Morning Rising (AMR) heliacal rising ‘first visibility’
The star crosses the eastern horizon shortly before the sun, and is thus briefly visible (for the first time). With every morning that follows, the interval between the star’s rising and sunrise increases: the star is visible earlier, and for longer. This is the first of many visible risings.

3) True Morning Setting (TMS) (true) cosmical setting
The star crosses the western horizon as the sun crosses the eastern horizon: for the previous few days, the sun had risen before the star had set, and so as day dawned the star could be seen some distance above the western horizon.. On the day of the true morning setting, the star was visible before sunrise, but its setting is obscured by the light of the rising sun.

4) Apparent Morning Setting (AMS) (visible) cosmical setting
The star crosses the western horizon just before the sunrise, and so can be seen to set (for the first time) in the morning twilight. With every morning that follows, the interval between the star’s setting and the sunrise increases: this is the first of many visible settings.

5) Apparent Evening Rising (AER) (visible) acronychal rising
The star crosses the eastern horizon just after sunset. On previous days the star had crossed the horizon some time after sunset, and so its rising was easily visible. On subsequent days the interval between sunset and the star’s rising diminishes, and the sky is too bright for the star’s rising to be seen, and by the time the sky is dark the star is already some distance above the eastern horizon. Thus the apparent evening rising is the last visible rising of the star after sunset.

6) True Evening Rising (TER) (true) acronychal rising
The star crosses the eastern horizon as the sun crosses the western horizon, and is thus is invisible. By the time the sky is dark enough for the star to be seen, it will have already risen and be some distance above the eastern horizon.

7) Apparent Evening Setting (AES) heliacal setting ‘last visibility’
The star crosses the western horizon shortly after sunset. On previous days the star crosses the western horizon some time after sunset, and so it could be seen for some time in the night sky and it setting was easily visible. This is the last visible setting of the star, as on subsequent days the star will have disappeared under the horizon by the time the sky is dark, and so will be invisible.

8 ) True Evening Setting (TES) (true) acronychal setting
The star crosses the western horizon with the sun: by the time the sky is dark enough for stars to be seen, the star is beneath the horizon and so is invisible.

Best to you,
Ouranos

neptune789..

not to take anything away from ouranos answer to you, but the idea of east and west is in reference to our planet - specifically the horizon line - sun rises in the east and sets in the west for everyone i know... it would be different in some other galaxy perhaps! as for some star being east or west of the sun - where is the point you are referencing it?? you have to be somewhere! these terms east and west are using the planet and ones position on it as a reference point... now, maybe i am really thick and miss what you are saying, or what is being asked here... but without a reference point, east and west are meaningless terms... cheers..

Hi, Ouranos.

Thank you for referring me to the article. I will digest it before responding to you.

Hi, james_m.

My understanding is that in common parlance the Sun moves east along the ecliptic, while the sky rotates to the west. For instance, in terms of the Sun's movement, Taurus is to east of Aries, and Gemini is to the east of Taurus.

My point here is that, for a star to be matutine, e.g., to rise before the Sun, the star must be to the west of the Sun. In other words, if the Sun is in Aries, then, in order for the star to be matutine, the star must be in Pisces.

Therefore, the footnote to Tetrabiblos (Ashmand edition), citing Moxon’s Mathematical Dictionary, is misleading, (unless I have misunderstood it). It says

15:1 “Astronomers call the planets matutine, when, being oriental from the Sun, they are above the earth when he rises; and vespertine, when they set after him.” Moxon’s Mathematical Dictionary.

What Moxon should have said was,

Astronomers call the planets matutine, when they are above the earth when the Sun rises, and vespertine, when they set after him. Matutine planets are also called oriental of the Sun, and vespertine planets are also called occidental of the Sun. Note well, however, that planets that are oriental of the Sun are (from our perspective) of necessity situated to the west of the Sun, and planets that are occidental of the Sun are (from our perspective) of necessity situated to the east of the Sun.

hi neptune789

thanks. you might be right about that, but it makes my head hurt thinking about it! maybe some of the local pundits - martin gansten and etc - will chime in, the next day or 2.. cheers..

This thread might be better suited to the Traditional forum. Yes, oriental and occidental are confusing terms. Traditionally they refer to visibility: if a planet is visible in the eastern sky (oriental), that means it has risen before the Sun. In the case of Mercury and Venus, which are never far from the Sun, that means rising early in the morning, so the term matutine is applied to them. Conversely, if a planet is visible in the western sky (occidental), that means it will set after the Sun. For Mercury and Venus, that means setting late in the evening, hence vespertine.

Heliacal rising, which was mentioned, refers to first visibility after a period of being too close to the Sun to be seen (and conversely, heliacal setting refers to last visibility). This is nothing to do with rising/setting at the horizon, and may occur either in the eastern sky (for the superior planets) or in the western sky (for the Moon). For Mercury and Venus it can be either, depending on their more complex phases with the Sun. There is an in-depth article on some of these terms in an old paper by Susanne Denningmann here:
https://www.cultureandcosmos.org/issues/vol11.php

Martin,

In the article of Susanne Denningmann, there seems to be a consensus on ancient literature about a 15 degrees distance from the Sun for the visibility.
Was it an approximation or does it have to do with a moiety with the Sun?
And what about Cazimi for the Ancients? How did they know that a planet was Cazimi if they couldn't see it?
Neil Michelsen is telling me that my questions do not make sense?

Thank you,
Ouranos

Ouranos wrote: Wed Jan 03, 2024 10:41 am In the article of Susanne Denningmann, there seems to be a consensus on ancient literature about a 15 degrees distance from the Sun for the visibility.
Was it an approximation or does it have to do with a moiety with the Sun?

I think we can safely regard it as an approximation. Presumably the notion of a 15-degree orb (or rather, as you say, moiety) of the Sun was derived from it.

And what about Cazimi for the Ancients? How did they know that a planet was Cazimi if they couldn't see it?

The same way they knew that a planet was in any of the houses below the horizon: they calculated it. Modern astrologers often underestimate how much of astrology has always been based on calculation as opposed to direct observation. Of course, the ancients didn't use the term cazimi (which is bastardized Arabic) but talked of a planet being synodic ('in the same path') with the Sun, or, eventually, 'in the heart' of the Sun (enkardios).

Ouranos wrote: In the article of Susanne Denningmann, there seems to be a consensus on ancient literature about a 15 degrees distance from the Sun for the visibility.
Was it an approximation or does it have to do with a moiety with the Sun?

Hi Ouranos,

Just happened to be reading up on the Synodic Cycle this morning; the 15º does seem to be a consensus of later authors; there's a footnote by Rob Hand in Meira Epstein's trans. of Ibn Ezra's The Beginning of Wisdom where he gives 15º to Saturn, 18º to Mars, that says "Later authors usually give the same arc of combustion for all planets. This reference may be a survival of the tradition of giving each planet its own arc of combustion. See Julius Firmicus Maternus, Matheseos, Book II, chapter ix. There the following are given: Saturn 15º, Jupiter 12º, Mars 8º, Venus 8º, Mercury 18º". Paulus uses 15º, and Abu Ma'shar and Al-Qabisi appear to as well.

Schmidt, in his Definitions and Foundation says "I think it is more than likely that the Hellenistic astrologers regarded the 15-portion interval as an ideal interval that has a distinct significance of its own....in the images that have long ascensional times, a planet will normally helically rise at a shorter elongation from Helios than 15 portions; such a planet is forthright and eager to come out of concealment. In the images of shorter ascension, a planet will not normally helically rise until it becomes more than 15 portions distant; such a planet has something to hide and is reluctant to put in an appearance. So there is astrological meaning as to whether a planet helically rises or sets before or after the standard value." (p234-5)

Thank you Martin
And Jane for the references and I like the idea of short and long ascensional times adding up a layer of understanding.

Cheers!
Ouranos