Skyscript Astrology Forum

Can anyone recommend software that reliably calculates the actual heliacal rising/setting of planets for a given location?

Martin Gansten wrote:Can anyone recommend software that reliably calculates the actual heliacal rising/setting of planets for a given location?

This is pretty dated software but you might want to give it a try. There might be better apps but this one is free.
You want the visibility program, it defaults to the Sun but will do all the planets and stars.
http://www.alcyone-ephemeris.info/download.html

Enjoy.
~AJ

Astro-seek > Planetary Cycles
For Mercury, Venus and Mars
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In-The-Sky.org has a calendar for each month that you can personalize for a specific location
Change your location on top of the page.
https://in-the-sky.org/newscal.php?year=2022&month=10

When you click on an Event in the calendar, for example October 22, Venus at superior solar conjunction, you will see Venus in a blue tab in the middle of the page.
Clicking on it will show you the main phases at the bottom of the page including Occultations in the section Related news.
Clicking again on each item in this section, you find the details under Apparitions of Venus as a morning or evening star.
It is a bit tricky to use at first but you find a lot of astronomical data well explained.
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Also skyandtelescope.org offers 'This Week's Sky at a Glance' featuring transits over the constellations
https://skyandtelescope.org/observing/sky-at-a-glance/
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Besides that, there is the website of the University of Nebraska-Lincoln with lots of Astronomy simulations and animations
https://astro.unl.edu/animationsLinks.html
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For softwares
André Vander Linden - Zodiac software v. 8.4
http://www.astrozodiac.be/
I did a post with the visual on his software
http://skyscript.co.uk/forums/viewtopic.php?t=11372

Bernadette Bardy - Starlight
https://zyntara.com/

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Also curious to see what other astrologers use. I have downloaded Celestia, Occult and Stellarium for astronomy but I am not fully comfortable navigating into these softwares. Alcyone mentioned by AJ is also interesting for a specific planet search.

Thanks, both of you. Alcyone, which I have used before but had forgotten the name of, probably comes closest to what I want. (I'm just interested in the planets, meaning all the potentially visible ones.) I wonder about the visibility parameters, though: you can redefine them yourself, which I'm not sure I understand the point of.

Basically I want something that tells me on what date Mercury or Jupiter or whatever will actually make its first or last appearance in the sky in a given period and for a given location. If I first have to study the matter deeply enough to know what values to enter, that would seem to defeat the purpose of getting the software in the first place.

Martin,

Here is a comprehensive list of astronomy softwares: websites, freewares and sharewares

https://skyandtelescope.org/astronomy-r ... shareware/

You find the link for Alcyone Software
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I wonder about the visibility parameters, though: you can redefine them yourself, which I'm not sure I understand the point of.

Approximations
The calculation of the visibility of the stars is carried out for so-called standard conditions, which neglect the apparent radius of the stars, the altitude of the observer, his horizon as well as the atmospheric conditions.
https://ssp.imcce.fr/forms/visibility/doc

As for the outside conditions that can change the visibility of the planets, the IMCCE explains below these conditions. I guess the softwares use the standard conditions.

Apparent radius of the stars
In order to know the instants of rising and setting of the upper edge of the stars (and not those of their center given in the present form), it is necessary to take into account the apparent radius of the star, that is to say the angle from which it appears to us. For planets, this correction is negligible, since their apparent radius is not perceptible to the naked eye. For the Sun and the Moon, whose apparent radius is of the order of 31.5 ′ , the times of sunrise and sunset can differ by 1 to 2 minutes for medium latitudes (as in metropolitan France), and by several tens of minutes to over an hour for high latitudes.

Observer altitude
This approximation changes the star's true height at sunrise and sunset by an amount approximately equal to –1 ′ 56 ″ × sqrt( A ) where A is the altitude above mean sea level expressed in meters. The times of sunrise and sunset calculated for zero altitude can then differ by several minutes compared to the times observed if the observer is at the top of a rocky peak or on the upper floors of a building. For an observer located on a plateau in altitude and which extends to the horizon, this approximation does not change the instants of rising and setting of the stars.

Observer horizon
If the horizon of the observer is limited by hills or mountains of altitude h above the level of the observer located at a distance d , then the true height of the star at sunrise and at sunset is increased of a quantity atan( h ??? d ). The instants of rising and setting of the stars are then modified from several minutes to several tens of minutes if the ratio h ??? d is large (case of hills or mountains located at a short distance from the observer).

Atmospheric conditions
The instants of rising and setting of a star may differ from the instants observed due to the variation in atmospheric refraction with respect to the value used in the calculations. The calculation of atmospheric refraction requires knowing the atmospheric conditions at the time and place of observation. However, these cannot be satisfactorily predicted. We therefore use by default the Radau constant (36.6 ′ ), which empirically represents the refraction at the horizon under normal conditions of pressure (101,325 Pa), temperature (15°C), pressure of dry steam (0 Pa) and wavelength (0.590 µm). In extreme cases, this approximation can vary the value of the refraction by several minutes of degrees.

Ouranos wrote:Here is a comprehensive list of astronomy softwares: websites, freewares and sharewares

Thank you. Have you tried using any of these specifically to find heliacal risings and settings?

The calculation of the visibility of the stars is carried out for so-called standard conditions, which neglect the apparent radius of the stars, the altitude of the observer, his horizon as well as the atmospheric conditions.

Yes, of course. That's all right: astrologers do the same. But Alcyone allows you to define the arcus visionis yourself, that is, as the software says, the least distance of the sun below the horizon at which the planet can be seen at heliacal rising and setting, first and last visibility, and at acronychal rising and cosmical setting, on the horizon opposite the sun. I'm not sure why or on what grounds one would want to do that -- it seems to imply that the standard values of the software are up for debate. Though I'm sure they are more accurate than the ancient practice of just treating everything as rising/setting at a longitudinal distance of 15 degrees from the sun!

I use Alcyone.
In Alcyone after you set up your city, you click on
Settings on the menu bar
Show dates of visibility phenomena.
That's it!

The 2 sites I use for rising and setting stars
https://in-the-sky.org/newscal.php?year=2022&month=10
Example:
You click on Venus at superior solar conjunction in the calendar for Oct 22, 2022
In the section Night Sky > Inner Planets > Related news at the bottom
Click on 03 May 2023 - Venus at highest altitude in evening sky
Below in the page you will find a section - Apparitions of Venus
Example: 04 Jun 2023 Evening apparition with many related details

Another example, for Oct 8th - Mercury at dichotomy
Morning apparition here in Canada at 04:53 EDT, shining brightly at mag -0.5 with its altitude from Sept 28th to Oct 28th, highest at 16 degrees between Oct 7th to Oct 13th.

https://skyandtelescope.org/observing/sky-at-a-glance/
This Week's Sky at a Glance for a day to day motion of the planets and fixed stars in the sky.
At the bottom the section This Week's planet roundup section gives you the brightness of the planets (magnitude) and visibility.
Nothing for Pluto as it has been declassified by the astronomers as you know.

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As for the minor corrections, the astronomers would certainly use it in their calculations. At higher altitudes and in mountains this can make a difference for the observer but for most people, this will not be huge.

Ouranos wrote:I use Alcyone.
In Alcyone after you set up your city, you click on
Settings on the menu bar
Show dates of visibility phenomena.
That's it!

Yes, I know -- but you can change the definition of the arcus visionis if you like, and as I said, that made me wonder a bit.

As for the minor corrections, the astronomers would certainly use it in their calculations. At higher altitudes and in mountains this can make a difference for the observer but for most people, this will not be huge.

Astrologers who bother with this sort of thing at all will typically be traditionalists who just want to find out the day (or even the approximate day) on which heliacal rising or setting takes place. (I don't think I've ever done a chart for someone born on a mountain!)

(I don't think I've ever done a chart for someone born on a mountain!)

Wait till you meet a Capricorn!

Ouranos wrote:Wait till you meet a Capricorn!

Ah, but if we're sufficiently traditional they turn out actually to be sea-monsters!

The fish part of the goat-fish is so woefully underestimated isn't it?
Martin this might seem a very lame suggestion, and I haven't used the software myself for many years so I don't know if it does this, but I found Stellarium to be incredibly useful in seeing the visible reality of astronomical cyles, so you might want to think about that.

In any case, a reminder about how useful Stellarium is for astrologers as well as astronomers is always worthwhile -

https://stellarium.org

Thanks for the suggestion, Deb. I know of Stellarium but have never used it much. I tried searching the website for the word 'heliacal' but didn't get a hit, so I suspect this may not be among its features.