Astronomy For Astrologers, 3 Primary Coordinate Systems

[glaucus]

The Three Primary Astrological Coordinate Systems:

Ecliptic Coordinate System

Equatorial Coordinates

Horizon Coordinate System



Ecliptic Coordinates -- In this system, the ecliptic or plane through the Earth's orbit is taken as the plane of reference. The co-ordinates used are Celestial Latitude (the perpendicular distance of the object from the ecliptic in angular measure) and Celestial Longitude (the angular distance along the ecliptic between the plane through the object and the First Point of Aries). The Solstitial Colure is the great circle which passes through the summer and winter solstices (the hour circle of R.A. 90° and 270°).

Celestial Latitude (Ecliptic Latitude) -- The angular distance of any object measured north or south of the plane of the ecliptic to the poles, from 0° to 90°.

Celestial Longitude (Ecliptic Longitude) -- The angular distance of any object as measured from zero Aries to a plane through an object.



Equatorial Coordinates -- In this system, the Earth's Equator is the plane of reference. The poles are at the intersection of the Earth's pole and the pole of the celestial sphere, an imaginary surface at an infinite distance with the Earth as its center. This is true for all points on the Earth, latitude and longitude. The poles are the North Celestial Pole (NCP) and South Celestial Pole (SCP). The circle at the intersection of the plane of the Earth's equator and the celestial sphere is the Celestial Equator.

Right Ascension (R.A.) -- The angle between an hour circle passing through an object and the meridian plane, in the case of equatorial coordinates, zero degrees of Aries. R.A. is measured eastward on the celestial equator from what is called the True Equinox to the body in question. R.A. is expressed in either degrees (0° to 360°) or in Hours-Minutes-Seconds (0h to 24h).

Declination -- The angular distance of any object measured north or south of the plane of the celestial equator, from 0° to 90°.



Horizon Coordinates -- In this system a plane through the observing point parallel to the horizon is the plane of reference. The poles are the Zenith (point overhead) and the Nadir (point underfoot). The vertical circle through a celestial object (such as a star) and the zenith is the Object Circle. The coordinates are given (for the object) by Azimuth (horizontal angle measured from an arbitrary reference direction -- East in our case -- counterclockwise to the object circle) and the Altitude (elevation angle measured upward from the horizon to the object). The great circle through the north and south points and the zenith is the Meridian, and the great circle through the east and west points and the zenith is the Prime Vertical. Circles of parallel altitude to the horizon that are not great circles are called Almucantars.

Altitude -- The angular distance of any body above or below the plane of the local horizon. Altitude is measured from 0° to 90° from the plane of the horizon to either pole.

Azimuth -- The angle measured around the 360° circumference of the horizon, either east or west (there are different practices). The azimuth of an object as measured from the meridian plane of the observer and a vertical plane through any body.

www.astrologysoftware.com/resources/vastrology/vastrology.asp



Coordinate Systems

dept.astro.lsa.umich.edu/resources/ugactivities/Labs/coords/



Celestial Coordinates





Introductory Astronomy: Positions on the Celestial Sphere







Astronomy For Astrologers

Part 1



Part 2



Part 3



Part 4





The Basics – The Ecliptic, The Equator And Coordinate Systems

note:

While we, as astrologers, use Celestial Longitude divided into the Zodiac to define horizontal coordinates, astronomers generally use Right Ascension. As with Celestial Latitude, measurement begins with 0° corresponding to the point of the Vernal Equinox. However, where Celestial Latitude measures counter-clockwise, Right Ascension measures clockwise from this point, with the measurement being expressed either in degrees, minutes, and seconds of arc, or in hours, minutes, and seconds of time. In any event, it is still a system which used the Earth as its center of reference. Why that’s logical and okay for astronomical measurement, but irrational and not okay for astrological measurement is beyond me!

astrologyclub.org/ecliptic-equator-coordinate-systems/

I definitely think Right Ascension is logical and okay for astrological measurement, and I have been using Right Ascension in Astrology since 2009.
It's definitely a coordinate that is highly overlooked and dismissed in Astrology. 

[glaucus]

Astrology fundamentals – celestial longitude and latitude
The ecliptic, apparent path of the Sun, is a great circle which can be used as a convenient reference to divide the celestial sphere into two.

The celestial latitude measures how far from the ecliptic a planet or a star is located. It is counted positively when north of the ecliptic, negatively when south of it. The latitudes of stars range within 90 degrees and -90 degrees. The latitudes of the planets range from about 9 to -9 degrees (apart from Pluto which can be further away from the ecliptic due to the irregularity of its orbit).

In Clairvision Virtual Astrologer, you can view the latitudes of the planets by asking for a Detailed Listing.

The celestial longitude is the other axis of this system of coordinates. It starts from 0° Aries (of the tropical zodiac), that is, from the point where the Sun is located at the precise moment of the March equinox (this point is also known as the gamma point.)

A zodiac, as you can see on astrological chart drawings, is nothing but a circle of longitude. Planets are placed along this circle according to their longitude – either close to 0° Aries, or further along the circle.

When you read that a planet's position is 12° Taurus, or 25° Pisces, what these figures indicate is the planet's celestial longitude. Why is it not counted from 0 to 360 degrees? Traditionally, astrologers have found it clearer to divide the longitude circle into 12 parts, called the signs. Each sign is made of 360 ÷ 12 = 30 degrees. The planetary longitudes are indicated within a 0 to 30 degree range, starting from the beginning point of each sign (0° Aries, 0 Taurus, 0 Gemini, and so on.)

Notice that the latitudes of planets do not appear on an astrological chart drawing, which contains only the longitude information. If you want to know about latitudes, you must consult a listing.

Since on an astrological chart, the zodiac is just a circle, without indications of latitudes, in practice what astrological charts show is the ecliptic. In other words, the zodiac circle that you see on all astrological charts is none other than the ecliptic.

Celestial latitude – astrological significance
Aspects tell you how many degrees of longitude are between 2 planets. The tighter an aspect is (that is, the closer the 2 planets are to the exact measure of the aspect), the more influential the aspect is likely to be on the make up of the personality. For instance, if 2 planets are separated by only 1 degree, the conjunction is much more influential than if there were 9 degrees between them.

This is where celestial latitudes can bring additional information – sometimes quite significant. Suppose 2 planets are not only conjunct, but also have the same latitude (or say less than one degree of latitude). This means that the conjunction is likely to be even more powerful. If you were to see the sky at that time, you would see these 2 planets extremely close to each other, possibly even eclipsing one another.

Suppose that 2 planets are not only in an opposition (180 degrees of difference in longitude), but also have opposed latitudes (eg. the latitude of one is 3 degrees, while the latitude of the other is minus 3 degrees). This is an important element which indicates that the opposition is likely to be particularly influential in the person's psyche.

In an astrological chart, it is not rare for one planet or one aspect to be extremely influential, and overpower the influence of various other factors. The latitude is part of these side-elements which can give you clues as to why it is so.

In conclusion, when to check the latitudes?

When you want to study a particular aspect in detail.

Note: planetary latitudes can be viewed by producing a 'Detailed Listing' in Clairvision Virtual Astrologer.

astrology.clairvision.org/static/astrologymanual/Astrology_fundamentals_celestial_longitude_and_latitude.html

[glaucus]

Right ascension and declination
What are right ascension and declination?

To measure the positions of stars and planets on the celestial sphere, there are 2 systems of coordinates. One is based on the ecliptic, the other is based on the celestial equator.

The celestial longitude and latitude use the ecliptic-based system of coordinates.
The right ascension and the declination use the celestial equator-based system of coordinates.
So the right ascension is to the celestial equator what the longitude is to the ecliptic. The declination is to the celestial equator what the latitude is to the ecliptic.

The angle between the ecliptic and the equator is called 'obliquity of the ecliptic' (epsilon) and is worth some 23 degrees (it slowly varies with time), and is due to the inclination of the spinning axis of the Earth.

It follows that the Sun's highest possible North declination is 23 degrees or so (epsilon), and is reached at the June solstice (21 June). The Sun's maximum South declination, 23 degrees, is reached at the December solstice (21 December).

Right ascension charts
There are 2 main systems of coordinates on the celestial sphere. One is based on the ecliptic, the other one is based on the celestial equator. One can therefore conceive 2 ways of drawing charts:

The usual way is based on the ecliptic – not right ascension. As we saw when discussing celestial longitude and latitude, a 'normal' astrological chart is a graphic representation of planetary longitudes. The zodiac band which has the ecliptic as its middle) is drawn, and the planets are placed on it according to their longitude.
In a right ascension chart, instead of using the zodiac/ecliptic, one uses the celestial equator. This is why on a right ascension chart, you will not see any zodiacal signs, just 12 sections which represent 12 divisions of the celestial equator. Along this circle, the planets are placed according to their right ascension.
To get a listing of right ascensions and declinations in Clairvision Virtual Astrologer, click on 'View', 'Listing', then 'Detailed'. You will notice that right ascensions are not expressed in degrees, but in hour angles.

Right ascension charts – what they mean
How does the meaning of a right ascension chart differ from a normal chart?

To answer this question, some say that the celestial equator is a more 'earthy' reference than the ecliptic. This makes sense, for the celestial equator is the projection of the earth's equator on the celestial sphere, while the ecliptic is the path of the Sun.

Consequently, they regard the right ascension chart as an indication of how a person manifests the potentialities of their 'normal' (longitude-based) chart into their life. From this perspective, the 'normal' chart shows potentialities; the right ascension chart shows how these potentialities are likely to manifest in real life. Hence the motto: right ascension chart – manifestation chart.

For instance, if an aspect or a cluster of planets is really critical in a person's chart, you may want to look at their right ascension chart to see if the aspect is also present, and if it is any different.

In astrological readings, it is not rare to see people who are not like their chart! For instance, one sees charts with beautiful potentialities which are not translated into the reality of the person's life. The right ascension chart may give clues as to why and how, and also clues as to how to manifest what is in the chart.

From these indications, you may also deduct that the right ascension charts of solar returns may be quite interesting, since when doing predictions you are precisely trying to determine how influences will manifest in real life.

To draw a right ascension chart in Clairvision Virtual Astrologer, click on 'View', 'Drawing', choose either 'PNG' or 'AVG', then 'Configure', and 'Right Ascension Chart'.

Parallels and contraparallels of declination
When two planets have the same declination (distance north or south of the celestial equator) they are said to be in parallel of declination. Contraparallels of declination take place when they are opposed in relation to the celestial equator, for example one is 3 degrees above the celestial equator, and the other is 3 degrees below it.

In Clairvision Virtual Astrologer you will find parallels and contraparallels of declination under 'View', 'Listing', 'Aspects'. In the grids of PDF charts, parallels and contraparallels are found in the upper part – above the diagonal line (while the aspects are found below the diagonal line). Click on 'View', 'Drawing', 'PDF', 'Configure'.

As with all aspects, there are orbs for parallels and contraparallels of declination. Most astrologers who use parallels and contraparallels of declination use an orb of only one degree. In Clairvision Virtual Astrologer you can view and customize the orbs by clicking on 'Aspect Orbs' under 'Preferences'.

What they mean, in short
According to certain astrologers, a parallel of declination is like a 'mini conjunction', and a contraparallel is like a 'mini opposition'. Parallels and contraparallels of declination add to the intensity of the relationship between the two planets but are secondary to other aspects.

astrology.clairvision.org/static/astrologymanual/Right_ascension_and_declination.html

[glaucus]

An Introduction to
LOCATIONAL ASTROLOGY

by C. Michael Smith

Most astrologers have by now heard of "local space", a term introduced to astrology by Michael Erlewine in the early 70's. Many have seen or are familiar with Astro*Carto*Graphy maps introduced in the mid 80's by Jim Lewis. Probably a lot of us ordered standard relocation charts from ACS prior to the personal computer and astrological software.

While locational techniques have been around for awhile, the question I hear most often is - But how do I use them?

Generally speaking, most people who consult an astrologer are concerned about themselves, their relationships and their jobs. All of these issues may be influenced by where they live, directions of daily travel and the planets that are energized in a given location. I have found that locational techniques can be applied in virtually every counseling situation, in many cases giving information not apparent using the more common astrological approaches.

Locational astrology is basically quite simple and straightforward; however, following standard astrological tradition, it has been kept mysterious, complex and confusing. What follows is a basic introduction, a brief synopsis of what I have found to be the most important aspects of using locational astrology, hopefully making it a usable technique rather than a theoretical concept.

Most of us are familiar with standard relocation charts; converting the birth date and time to a new place with new geographical coordinates, producing new chart angles and planet house positions. An Astro*Carto*Graphy map simply takes any given date, time and location and graphically plots a map showing where planets rise and set along with locations that place planets at the MC or IC based on the local horizon. Local Space and Astro*Carto*Graphy use the same calculation, further reducing the geocentric concept and changing the perspective, bringing the planets and stars "down to earth".

At any given time and place, an azimuth chart (one type of local space chart) will show where a planet or star is in relation to us geographically using azimuth and altitude. Or, in plain English, the direction on a compass and distance above or below the horizon a celestial body is.

When you first start exploring astrology you learn that each planet has certain basic qualities and energies associated with it. In locational astrology the principles remain the same; it is these basic energies that you want to keep in mind when evaluating the chart.

I generally use a 10 degree orb for the horizon and chart angles (North/South & East/West). First look at the local horizon, noting any body that falls within a 10 degree orb. Any body that falls within this orb will be highly energized and its qualities will play a very significant role. Next, look at the chart angles and note any body within orb of angular placement. These placements are the next most important as far as strength. Angular planet energies will supplement the planets on the horizon adding their own "flavor". If there are no planets on the horizon, angular placements become most potent. I am still evaluating the role of inter-planet aspects, but think that the planets conjunct the angles are more significant.

The difference between a natal azimuth chart and a standard natal chart is that when a standard chart is relocated the angles change, but the planets always remain in the same relationship to one another. However, in an azimuth chart, the same relocation does not change the chart angles; North is still North, East is still East. The planetary relationships to the angles and each other do change. So, the bottom line is that by geographical movement it is possible to enhance or reduce a body's energy or intensity.

Locational techniques add a valuable dimension to synastric work, providing a fascinating new view and perspective in inter-chart analysis. Any locational counseling should be highly interactive, as each client's requirements are unique and reasons for moving or travelling need consideration when recommending a relocation or direction of travel. A locational chart will help delineate the underlying theme of a given location and identify which planet or planets are being followed or shifted away from by any movement.

Locational astrology can be brought right into your home, expanded to your local community, taken to a county or state level, or further yet to the country, continent and world. It is another tool that helps show how and where we are connected, to which places we've travelled, the people we've met and situations only dreamt of.

Many computer programs now calculate some type of azimuth chart. Depending on the developer, it may be called something different and the presentation may change, but the information is available. Check it out!

I try to keep the current eclipse charts and maps on our home page, so go look for them there.

users.netonecom.net/~sos/Localsp1.htm

[Ava]

Thanks very much, glaucus.

Reading this bit by bit.

[Ava]

Feb 28, 2019 3:35:15 GMT glaucus said:

Celestial Latitude (Ecliptic Latitude) -- The angular distance of any object measured north or south of the plane of the ecliptic to the poles, from 0° to 90°.

From this link above: astrologyclub.org/ecliptic-equator-coordinate-systems/

Putting it there for visual reference.

Checking dates @ www.true-node.com/eph1

Just trying to get a feel for the latitude range of the planets.

The maximum possible Latitude of each planet, and the location of its Node, are as follows:


...Planet.......Node as of 1946.....Maximum Latitude

...Moon...................................5°17'

...Mercury.........47°32'.................7°

...Venus...........76°05'.................0°24'

...Mars............49°02'.................1°51'

...Jupiter.........99°46'.................1°18'

...Saturn.........113°04'.................2°29'

...Uranus..........73°39'.................0°46'

...Neptune........131°02'.................1°47'

...Pluto..........109°25'................17°09'

www.astrologyweekly.com/dictionary/latitude.php

 

----

Also from that link:

"The Equator, the Ecliptic, and the Seasons

The tilt of the Earth’s Axis of Rotation is also responsible for our seasons. This is reflected in the yearly cycle of the Sun’s Declination. The Sun is always at 0° of Celestial Latitude, since it is always right on the Ecliptic. However, throughout the yearly cycle as the Earth travels around the Sun, the Earth’s Axis of Rotation will be tilted either towards the Sun, away from the Sun, or somewhere in between. In the illustration below, note that the Celestial Equator intersects the Ecliptic at two points. These points define a line which precisely pass through 0° Aries and 0° Libra. It is precisely this intersection which defines the Vernal Equinox and the Autumnal Equinox, and the first degree of both Aries and Libra (speaking of the Tropical Zodiac)."

[glaucus]

Yeah
Pluto and the other minor planets have high orbital inclination and tend to orbit well off the ecliptic.
true 3D conjunctions,oppositions with these objects are rare


Clyde Tombaugh was lucky to discover Pluto because it was on the ecliptic at the time

[Ava]

My image link above is broken and I was unsuccessful in trying to locate a replacement.

---

"Right Ascension (R.A.) -- The angle between an hour circle passing through an object and the meridian plane, in the case of equatorial coordinates, zero degrees of Aries. R.A. is measured eastward on the celestial equator from what is called the True Equinox to the body in question. R.A. is expressed in either degrees (0° to 360°) or in Hours-Minutes-Seconds (0h to 24h)."

Nice graphic on the wikipedia page:



en.wikipedia.org/wiki/Right_ascension

Noting that the numbers increase moving right to left. 

Maybe that image link will break, too, though.

Edit:

Images like this are common:




No wonder I get confused ~ here the arrow points to the right, but above, it starts at the right and moves left. Wikipedia says RA increases eastward. 

[Ava]

I don't have software, I just use whatever's free on the internet.

www.true-node.com/eph1 generates right ascension. Click "Show RA (as zodiacal)."

Tables of right ascension here:
www.skyscript.co.uk/ra.htm

360° divided into 24 hours, each hour = 15°.

Skyscript also shows RA increasing eastward.

[glaucus]

I am going to be posting lists of stars in Right Ascension and Declination order based on the 2000 epoch
I have been looking at lists, and I am noticing how some of these stars are Equinoctial and Solstitial Stars.
Some stars that I noticed figure into the start of the seasons are Alpheratz,Caph,Sinistra,Menkalinan,Betelgeuse,Etamin,Spiculum,Alnasl

Right Ascension and Declination do figure into the Equinoxes and Solstices

Vernal Equinox:
Sun in 0h00m00s in Right Ascension
Sun in 0'00 N in Declination

Summer Solstice:
Sun in 6h00m00s in Right Ascension
Sun in 23'26 N in Declination

Autumnal Equinox:
Sun in 12h00m00s in Right Ascension
Sun in 0'00 S in Declination

Winter Solstice:
Sun in 18h00m0s in Right Ascension
Sun in 23'26 S in Declination






"www.true-node.com/eph1 generates right ascension. Click "Show RA (as zodiacal)."


Yep...I use it
I wish that they had an option to show it in Sidereal Time and not just zodiac longitude equivalent which can be misleading and cause confusion for some people about the zodiac is ecliptic longitude and that Right Ascension has nothing to do with the zodiac.

I wish the site was able to show rising,setting,culminating,anti-culminating times for objects which would help figure out parans

[Ava]

Sorry, I'm a slow learner. VERY slow with certain things.

I can't figure out if RA increases moving to the left or right and can't move on without being sure of it.

In one of these videos, the man said graphs like this always show hours decreasing from left to right:





So, does this graph represent and follow the way RA is calculated? So we start at the vernal equinox (on the right) and move to the left?

The "right" in right ascension, does that indicate the starting point (as we see above, 0h is on the right) or the direction in which the hours increase, moving to the right on the celestial sphere?

I have the impression that this is correct:




In that case, graphics like this are incorrect (I think?):

[Ava]

Everywhere I'm looking it says right ascension increases eastward. So now I understand this here is showing me....




That on the FAR SIDE of the sphere, looking through it to the other side, the numbers appear to increase, moving westward. Spin all that around to the front of the sphere, and it's increasing eastward. 

I'm just going to assume it increases eastward and ignore graphics that confuse me.