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AlmSun - Astronomical compedium

Astronomical compendium is an astronomical-geographical, educational program, which in addition to the calculation of basic astronomical phenomena on the Sun, Moon, Planets, Stars in an accessible way brings us to knowledge in the field of astronomy and partly also of geography. Someone may say - there is so many different, moreover free programs counting the exact same thing, so why should we create another one? The answer is simple. I as a lover of astronomy was not satisfied by none of them. None has all of it in one place and none has everything I need. When I have found one, it turned out that its accuracy is at least questionable and speed is not satisfactory. In my program there is everything I need. I used there algorithms, according to the theory DE404, and if the program will be supplemented with universally accessible ephemerals, published by NASA/JPL DE406, DE422 or DE431 then we can enjoy the perfect accuracy in period years 4713BC - 10999.
An additional advantage of the program is its educational value. Matter from the field of astronomy and geography are recognized in a different, more accessible and understandable manner. What is the present position of the sun? What does it depend on? What is the length of the day and when the sun rises and sets, and what does it depend on? Why is the twilight in the vicinity of the equator shorter? Where and when there are white nights? What are the time zones? How does Saturn look like now and is it visible? Does Easter really depends on the first full moon of spring? Is there possible a situation in which the moon does not sets at all? Is there possible a situation in which the sun rises twice during the same day? These and other questions can be answered by playing this very entertaining program.

The program essentially consists of 7 tabs :

In the main, always active form there are placed components for changing and editing the input data, such as:

  • Date, time
  • Geographical position
  • Time Zone and the parameters of place of observation, i.e. the altitude of the observer, the ambient temperature and atmospheric pressure.

The program has a database of about 2000 major cities in the world, that you can call at any time and watch live how the calculated phenomenon change according to the place of observation.
Importantly, the philosophy of changing the data in this program is not about searching for a specific position in the database, clicking OK and observing changes. All results are calculated online at the time of seeking the specified position. In the program there is also no key to calculate! All data are calculated online while changing any parameter – geographical position, date, time or temperature or pressure of place of observation.

Time can be changed in several ways:

  • button Now - the current time is set.
  • Button 00h – time to 0:00
  • Button 12h – time to 12:00
  • Setting Current time causes that from now on all parameters are calculated online according to the current time. The current time is taken from the time set on the computer.
  • Setting the time start causes that with the time of hooking this setting all parameters are calculated online, but from the previously set time.
  • Button <<->> so-called slider, lets you alternative change of time. The time can then be changed with the use of slider every minute, hour, day, month, year, century and millenium.

Time and data can also be change by direct writing down, or changing with the use of arrows. All data, i.e. year, month, day, hour, minute, second are closely correlated. For example, if we change the second from value of 59 by increasing it by one, then the second takes the value of 00 and minute increases by one. A similar correlation of data takes places while the geographic position.

Time can also be change directly by the mouse, in AstroClock.

In describing tab, there is also panel Time, and in it there is calclated Universal Time UT, Julian Date JD, terrestial dynamic time TDT, and deltaT.

Amendment delta T (terrestian dynamic time TDT - universal time UT) for the years 1620-2017 it is according to the observations. For the remaining years, delta T is approximated. The value of Delta can be always changed. This can be done in two ways.”For the moment” by adding amendment or permanently by entering the proper values measured for the corresponding years.

Permanent correction delta T for the years 2014-2040 can be done by clicking on the "C" button. Here, in addition to the delta T chart for the years 1600-2100 we can enter the correct value in ms.

In the program, there is also possible to permanently set delta T = 0. Then all calculations are done for time TDT. This option can be useful for example in the case, when we want to compare the calculated ephemeris with professional tables, that give the values of the TDT time.

Literature :

  • Stephenson, F. R., and L. V. Morrison, "Long-term changes in the rotation of the Earth: 700 B.C. to A.D. 1980," Philosophical Transactions of the Royal Society of London Series A 313, 47-70 (1984)
  • Borkowski, K. M., "ELP2000-85 and the Dynamical Time - Universal Time relation," Astronomy and Astrophysics 205, L8-L10 (1988)
  • Chapront-Touze, Michelle, and Jean Chapront, Lunar Tables and Programs from 4000 B.C. to A.D. 8000, Willmann-Bell 1991
  • Stephenson, F. R., and M. A. Houlden, Atlas of Historical Eclipse Maps, Cambridge U. Press (1986)

The current time can be changed by direct setting of UT or TDT in the traditional format or in Julain JD date format.

You can also insert the output of the arithmetic sum.

The range of changes of input data :

  • Longtitude : 0 .. 360
  • Latitude : -90 .. 90
  • Date : -4713 .. 8000, but practically there are no restrictions, and the only thing that can appear is the problem with the accuracy of calculations.

Set Location

All formats be accepted
example :



51 30 44
-0 3 54

N51° 30' 44"
W0° 3' 54"

N51 30.7
W0 3.9

N51° 30.7'
W0° 3.9'

0° 3'54.00"Zach.

Select Time Zone

and... occurrence the change of time together with rule Daylight Saving Time

Set locations - Primary base

In main database AlmSun has 8 thousand geographical places in the world which contains information of the number of time zone and editable rule of DST. Geographical places are sorting according to country. You can see illustrative map.

Handy base - Base of cities with geographical positions.

At each stage of the calculations, you can always call database and check online how do the calculated parameters change depending on what point of the world we are. The fact that the geographical position is not set once, and there is a possibility of changing the geographical position during the calculations, it is a very strong point of the program. Database contains 2035 geographical positions and in addition to geographical coordinates, it also contains information on the number of time zone of the place, and the information if in the place there is change for daylight saving time or not. All these information are taken into account when we activate "auto" in the window of time zone.
The following example shows geographical position of two zones, but the time zone, while taking into account the change of time, is 3.

Each city brought from the database will be stored in the program with information about the number of attributed time zone, and whether there is a change of time.
When "auto" function is not selected, during the selection of city, in the main program in the form of preview, there is displayed the hour that is currently in the city. During the selection of the city from database, there is also displayed information on the number of assigned time zone as well as whether there is change of time (1- occurs, 0 – does not occur).
The following example shows a selection of the city of Delhi, in the case, when previously, the operative city was Warsaw in the summer time(zone = 2).

And the titbit of news. New Year's Eve in Europe (first zone) 2009.12.31 at 11:00. In the city of London Kiritimati, on Line Islands they have already greeted the New Year.. This is demonstrated by 0:00+ ("+" – indicates the next day).

If somebody needs a little hint on the fact in which part of our globe the zone is valid, he/she can make a use of illustrative map of zones.

In the window of database you can set only favorites. Then the database will only display the geographical locations, which were previously added to our favorites.

There is also a possibility to create your entire database. It can be called by clicking "My database" button.

Data to base is introduced with the use of "Add" button. If the geographic position does not come from the original database of cities, the program asks for the name.

Geographic position to "My Base" can also be added from the window of base of larger cities in the world.

Positions from "My base" can be edited, deleted as well as sorted.

Base of time-sites

Have you ever been a witness of an astronomical phenomenon and you feel the need to remember it, save all the specific points, i.e. where, when, in what area, and in what circumstances did it occur? In this program the useful thing is database, so-called time-sites, which gathers all the necessary data – input variables needed to calculate the individual data.

One record contains (in the above screenshot the positions marked in green):

  • Geographical position
  • Observer name (city)
  • Date and hour
  • Time zone
  • information if there is a change to daylight saving time
  • observer data, i.e. the altitude, temperature and atmospheric pressure
Record to the database can be added to database at any time, being in any part of the program ("add" button).

The database can also be called at any time. It is very convenient tool, because it allows us to make quick and direct comparison of the two phenomena (e.g. solar eclipse in SunSim) which take place in different times, different places and different weather conditions. Name of the added record is composed of a name or geographic position (if the name does not exist) date and time.
Files with the time-sites base have the extension *.cmf and are stored in cmf directory located in the main program directory.
Cmf database creation tool is used in program also to generate specific reports, which creation, such as: solar eclipses, requires time, and which later view is very convenient.

Illustrative map to the rapid change of geographic position.

Geographic position can also be chosen through illustrative map of Europe.

If somebody wishes, then he/she can select time zones. When this option is enabled, each selection of a geographic location and approval means the transfer of geographical position, together with the information on the number of the zone.

The map is made using a vector method and is based on the base of about 6000 of geographical locations, which make up the outline of the continent and borders. Accuracy of the map varies, depending on what part of the Europe was measured.

For practical reasons, the map was displayed in Mercator projection and covers a range of lengths from 349° to 45° and width from 34.5° to 72°, i.e. the whole Europe.
On the map we can select cities from the database of cities, only favorites (red) and the points from my database.

The Map of the World

In the program there is also available the illustrative map of the whole world. As in the other tools of this program, each 'trip' by the mouse results in immediate calculation of data in the main program. Thanks to the rapid movement around the map we can quickly learn a number of phenomena, which apparently seem to be obvious and which, thanks to this tool, take another dimension.

If we do not wish the data to be transmitted to the main program and currently calculated, we can turn off ("link" option)

The application includes 3 maps:

  • Outline map of continents
  • Map of zones
  • Political map

Each "trip" by mouse over the map results in:

  • Showing the current geographical position
  • The current time zone, which applies to a particular location
  • Information on whether on the area the change of time to daylight saving time is in force or not
  • Current time zone, including daylight saving time
  • Country or geographical location
In addition, on the map you can show the points from 'my base'

and most of characteristic islands. For example, one of well-described are Line Islands of Kirbati, where time zone +14 is in force (the inhabitants of these islands greet the day as first), Baker and Howland Islands belonging to the U.S., which are the only ones having time zone -12 in force or Chatkam, which have the exotic time zone of 12 3/4. Trip over this map cannot very accurate, because it is difficult, but anyway accurately reproduce the entire world, it is a guarantee of fun and education.
As addendum, there is also available the table of local time, which is valid for input and selected position. All the necessary data, such as zone and whether the change of time is in force or, if the daylight saving time is in force, are taken from the map (after clicking) or from the database (after selecting the position). When "+" appears next to the time, it means the information, that the hour already corresponds to the next day. When there is "-" it refers to the previous day. What is more, there can also appear two pluses - "++". It means that the hour corresponds to the day after tomorrow. Such a difference of time is possible, for example, between the relatively less-distanced islands. Baker Island and Christmas Island of Kirbati. For example, if on Baker Islands there is 23:00 on February 7, then on Christmas Islands there will be 1:00, but it will be already February 9!
There are much more such a titbit news around the line of data change :)


Ortodrome, of course, is the shortest way between two points on the surface of the ball, running on its surface. But all we know that on the publicly available maps – of Mercator, i.e. cylindrical projection, this line, with two exceptions, is the bow.

Ortodrome of flight – Berlin- Los Angeles looks like following

and the shortest flight from London to New Zealand, it turns out, leads through Norway and the Arctic Circle, although intuition suggests something quite different.

Ortodrome of Dehli - New York is also interesting

Orodrome appears after each click on the selected position. In addition, also distance is converted.

Ortodrome is counted on Spheroid. In the result field, as a hint, we can also read the distance on loksodrome and difference in distances between two courses.
Input as well as selected positions can be selected from "Base of geographic locations" or from „my base”. Of course, the course of ortodrome can also be observed during the selection of these sites (it can be turned off - "link" option).

Input and selected geographic position can also be changed manually. After clicking on the symbol 'lamda' there opens the window of change.

Day and night linie, gnomon shadow

Solar Eclipse 29.03.2006 :

Complete files : 2006.03.29 10-40 - 13-40 (10) 2.00.rar

Accuracy of calculations. Ephemerides JPL DE406, DE422 i DE431

Calculations are made according to DE406/DE422/DE431 theory and if we catch on DE406/DE422/DE431 then it will be made in accordance with theory of DE406/DE422/DE431. Data needed to calculate according to this theory are taken from external files of DE406, DE422 or DE424 directory. In this directory we can put files for any 3-centuries that interests us. We can put there all the files enabled by NASA/JPL, i.e. from the year –3000 to the year 3000, selected file (for the current 3-century) or not at all. In such an arrangement, setting of DE406 will not be enabled.
A set of files distributed by JPL and available in : DE406

unxm3000.406    -3000 .. -2700
unxm2700.406    -2701 .. -2400
unxm2400.406    -2401 .. -2100
unxm2100.406    -2101 .. -1800
unxm1800.406    -1801 .. -1500
unxm1500.406    -1501 .. -1200
unxm1200.406    -1201 ..  -900
unxm0900.406     -901 ..  -600
unxm0600.406     -601 ..  -300
unxm0300.406     -301 ..    -1
unxp0000.406        1 ..   300
unxp0300.406      301 ..   600
unxp0600.406      601 ..   900
unxp0900.406      901 ..  1200
unxp1200.406     1201 ..  1500
unxp1500.406     1501 ..  1800
unxp1800.406     1801 ..  2100
unxp2100.406     2101 ..  2400
unxp2400.406     2401 ..  2700
unxp2700.406     2701 ..  3000

20 files contain ephemerises of the Sun. Moon and Planets. A set of files takes 200 MB. As already mentioned, it is advisable to store only files from the current three-century, i.e. unxp1800.406

We can get information on which file is currently used by the program by selecting DE406.

DE424 or DE422 :
More info :


In the panel of Sun there are counted current parameters of the Sun, given by the astronomical yearbooks, i.e. declination, equation of time, GHA, right ascension, ecliptic latitude, ecliptic longitude, angular diameter, distance of the Sun and inclination of the ecliptic.

Panel perihelion and aphelion

Here we have the values of perihelion and aphelion of the Sun for the current year. Values are calculated by numerical method of DE406 and are given with an accuracy of one second in order to show the consistency of applied algorithms.

Panel Aries

Here we get the current sidereal time as well as GHA of Aries Point.

Panel Current position

In this table there is calculated the current position of the Sun : altitude, azimuth and the altitude of the refraction, which depends on temperature and atmospheric pressure. Value the altitude with refraction (apparent altitude) depends also on the height of eye. Amendment to lower the horizon, taking into account the height of eye, is calculated from a simple formula :
p = 1.76'*sqrt(h)
Apparent altitude is calculated by numerical method and the astronomical refraction value is calculated from the formulas given in Almanac for Computers 1990.

Because apparently, simple question of correcting the altitude is difficult for fans of astronomy, for further understand of the matter the author of the program has implemented some kind of assistance. Clicking "?" icon allows for obtaining a full set of all possible amendments, including the division of the altitude of the upper and lower disc. In this window, there is also a possibility of changing certain parameters (altitude, altitude of the observer, temperature, pressure) in order to better understand what and in which extent depends on something. In the case of an amendment of the altitude of the Sun, the amendment of parallax was abandoned.

Panel Astro Clock

Astro Panel Clock is a graphical visualization of the level of exposure throughout the day. This tool has a lot of educational value, because in quick way you can assess the proportion of the length of day and night as well as the length of dawn/dusk. Thanks to the quick change of days from December to January you can also note the fact that the growth of the day takes place firstly from the west.

Astro Clock 2008.04.15, 16:40:04, Warsaw

Astro Clock 2008.06.20, 16:40:04, Warsaw

Astro Clock 2008.06.20, 16:40:04, Helsinki – here we can 'see' white nights

and here Helsinki but 2008.12.20

Astro Clock 2008.03.20, 16:40:04, Nairobi, Kenya – please note very short twilight

and here Spitsbergen 2008.04.09. Here, the twilight lasts half a day.

and once again Warsaw 2008.06.20

and, for comparison Paris on that day, which is in the same time zone

Because the application is quite processor-consumptive and for slow computers it can slow down the calculation, you can turn it off. You can do this by clicking on the image of the Sun in the panel of the Current Position.

With this panel you can also change the time. In an approximate way, moving the mouse.
In turn, if we make double click on Astro Clock then we will see a graph of the altitude of the Sun as a function of time, so figuratively speaking - the way of the Sun during the day.

Additional click causes also showing the graph of the way of the Moon, which is marked in blue.

Mini Earth's diurnal motion visualizationtion.

In the Current Position panel there is also a mini-visualization of the Earth’s rotation. The Earth is always set to the current geographic position.

Visualization of the Earth's rotation can also be a made in the separate window and accordingly extended. Once called window with virtualization, as an independent will be present (also when calling other programs) and will always show the current status.

In the Current Position panel, next to the mini-visualization of the Earth's rotation there is also information about the level of light energy that reaches us at the moment, at the background of the sky.

In the Current Position panel there is also available the window with detailed summary of the altitude amendments.

If anyone wants to see more vividly the course of the Sun, Moon and occasionally the selected Planet, then "Graph h=(t)" icon will allow us to view the daily course of the Sun and Moon. Seemingly simple things, but on the chart they enable us to understand some interesting dependences between course of the Sun and Moon that is in New, in the I quarter or Full. On the graph, we can also see how it happens that there are days in which the Moon just does not set.

Thanks to this program, in a relatively fast way (by changing the date) we can also find the most suitable period in which we can observe a given Planet.

As in the main program, we can call a database of major cities of the world and quickly review how everything changes according to the desired location on Earth.

Have you ever wondered what time the Sun reaches a certain azimuth? Of course, every day it happens at a different time. You can find it in the main program by changing the time and if you want to make it faster, helpful will be a small subprogram that sets the time for a particular azimuth.

If someone wishes to have it as a report for the whole year, then just click on the "report" icon. Example report for Paris and azimuth 90 is: HERE
While generating a report we can view it directly in IE in html format. Browser and report will be opened automatically (if we activate this option). Example report generated by AlmSun looks like this: Sun_Azumut_90.00_year_2012.html

What time the Sun reaches a predetermined altitude?
It also can be quickly determined by the small subprogram, and also produces an annual report, also to view in browser : Sun_Alt_45.00_year_2012.html

And when the Sun, Moon or some other Planet reaches a certain position, i.e. a definite altitude and azimuth? For example, on a specific date and time the Sun peeks into the window and we want to know when this opportunity will happen again. We can do this by a subprogram:

Time = f(h,az) - The time calculation for a given altitude and azimuth

The calculations are performed by numerical method, with well-defined step and the angular size of the set point, which from the standpoint of the program is a circle of radius r. The higher the r, the more moments match it. This idea is more like the figure below.

If we want high accuracy of search, it is recommended to set possibly smallest step (e.g. 1 s) and possibly smallest radius r (1’ – one angle minute)

Panel Season

In this panel there are given moments of the seasons, calculated by numerical method based on the DE404 or DE406 (depending on choice).

Zodiac signs

If anyone wants to know the exact moments of transition of the Sun through the Zodiac sign, then you can call this list by clicking the small button next to the ecliptic longitude of the Sun.

en in the range of 1000 years. Example collation generated by AlmSun : Zodiac_1910_count_100.html

Using the same application, one can call a collation of the seasons: Season_1910_count_100.html

Panel Sunrise and Sunset

In this table there are calculated moments of sunrise and sunset. Time and azimuth. Moments of rise and set are calculated taking into account the height of eye, actual radius of the Sun as well as astronomical refraction of the pressure and temperature.

It should be noted that the parameter of observer altitude is not the above sea level altitude, but the observer altitude at the sea(Altitude of eye).

Numerical calculations of sunrises and sunsets.

This method can be used in specific situations. At high latitudes, where there is suspicion that the Sun goes through the horizon just for a moment.

Here's an example. June 2, place: the seat of the Saint Nicholas in Finland, around the Nord Pole. The sun rises at this time about 2 minutes after midnight. It sets at 22:32, but for a short time, because even the same day at 23:55 it rises again. Wow!

Panel Twilights give the moments of dawns and civilian, nautical and astronomical twilights. There is also information about the duration of the dawn.

Map of contour lines of altitude and sunrises as well as sunsets.

Program features :

  • each movement on the map by the mouse results showing the current geographical position as well as the calculation of the current position of the Sun and the moments of sunrises and sunsets.
  • our chosen position can be selected (it is shown by the red cross) the way to have for example the comparison of current results, i.e. those resulting from the "travel by mouse".
  • If there were selected time zones and auto options, then the selected position is calculated in the local time.

This ensures that a few movements by mouse around the whole Europe after few characteristic days of the year (longest day, shortest day, equinox) will even let the average layman to understand the laws governing the motion of the Earth during the day, at any day of the year. If despite of this fact somebody does not know why in such Brest the Sun rises 1.5 later than in Poland then I propose to impose the contour lines of sunrises and sunsets on the map.
This is the contour line of sunset 24.11.2008. Full hours are marked by the bold line.

And this is the contour line of the sunrise in one of the longest days of the year. Please note that at latitudes above 65 parallel the contour line lines do not exist. Of course, because above the polar circle the sun does not rise. It lights all the time.

Not less fun give us the contour lines of the current altitude of the Sun.

RAPORT - Year 2012

This is the contour line of the altitude of the Sun and midnight in one o the longest days of the year. Please note the contour line –6° being the border of the place, where there are so-called white nights.

Graphic Astro-calendar

Astro-calendar is a graphical visualization of the length of day, together with selection of the dawns and twilights throughout the year.

Although everyone knows that at the large widths in the summer there occur white nights and long twilight and equator of the twilight is short, and during the whole year the length of the day is comparable to the night, however, graphical representation of this fact brightens the matter to some extent.
Above there is shown the visualization of Reykjavik and Cairo.

Interesting thing is the visualization at the pole or with the change of time.

Astro-calendar contains many valuable features. They concern Planets, therefore more information can be found in the description of the tab called "Planet".
Astro-calendars "liste" to a window of visualization of the Earth and Moon, which are always on the top. While "traveling" with the mouse on the chart we can quickly change the date and time and immediately observe the effect in mentioned window, thereby providing the user with fun and even brightening a bit the matter of the Earth's rotation.


Everyone probably saw analemme and closely the representation of the declination as well as the equation of time throughout the year.

However, hardly anyone knows how analemma evolved over the centuries, i.e. how did it look like 3000 years ago and how it will look after 4000 years. Here you go:

But even more interesting looks analemma after 7000 years. Oh my ...

Analemma in larger resolution : analema1900.png

Declination charts, equations of time, the apparent diameter of the disc size and other parameters of the Sun

If someone, within the scope of education, would like to look at the course of the declination of the Sun or the equation of time, then these charts are available by clicking on the small buttons next to the values of declination and the equation of time.

For comparison, you can also "call" the course of the declination of the Moon.

and here is the course of time equation

It is also worth to see how the course of time equation changes after 5000 years.

Interesting thing is also the graph of the diameter size of the Sun and Moon.


Insolation, in other words, sunlight – the energy provided by the Sun during the day. The energy is expressed in inch per cm 2. 2.
The graph gives us the course of insolation during the whole year and also gives us the annual insolation.

Insolation depends on geographic latitude, so by changing this parameter we can carefully observe it.

There is also available the chart of sunshine of all the globe as the function of geographical latitude.

Observations of sunspots

Subprogram Observations of sunspots was written specially for fans of astronomy who like observations of the sunspots. The program has algorithms and complete theory used to calculate the parameters and current position of the solar disc. The program allows you to load pre-made pictures of the measurements and then with the use of the mouse, gathering observed spots and putting them on the program. Speaking more vividly, program calculates the points of spots on the image of X,Y coordinates of the loaded image into heliographical coordinates of the Sun L,B with the current parameters of the Sun P, Bo i Lo.

Image of the measurements should have 641x641 pixels, while the solar disc should have 601 pix. Disc should be located centrally.
Example BMP file is: HERE

After loading of the file :

After applying the spots:

And here after unhooking the image with spots in a completely different day :

Visualization of the Earth's rotation, i.e. the view of the Earth in the space :)

The program is in 3D and is written in OpenGL. All textures are taken from the website of NASA.
There is a possibility of loading your own texture.

Texture of higher resolution.

And here the Earth at night...

Additional features of the program :

  • Observer positions can be selected arbitrarily i.e. observing the Earth around and up - down.
  • For two selected geographical locations (selecting manually or selecting from the base) there is calculated the current position of the Sun (altitude, azimuth). Position 1 is marked in green, while position 2 in red.
  • Position 1 and 2 can be linked together by ortodroma, i.e. the shortest connection between two points on a sphere.
Example of ortodroma between Paris and Hawaii.

And here is the connection between Poland and Hawaii. The shortest connection goes of course throughout the pole.

And here are textures selected from the set for each month. Selection of texture is automatic, depending on the selected date.


In the panel called Moon there are chosen the current parameters of the Moon, given by the astronomical annals.

Accuracy of calculations :
Same as for the Sun.

Panel called Current position Gives the current position of the Moon, i.e. the altitude, azimuth as well as apparent altitude, i.e. the altitude including the observer altitude, geocentric amendments, astronomical refraction including temperature and atmospheric pressure.

This table also includes the graphical visualization of Moon phases as well as calculation of the climax moment. It is worth mentioning that there is also calculated the azimuth of climax and it is not 180 degrees, as in other celestial bodies.

Similarly as in the case of the Sun, clicking "?" button causes the call of window with a detailed summary of the altitude amendments, also broken down by the amount of the upper and lower limb.

Mini visualization of the Moon

In the panel called "The current position" there is presented mini visualization of the Moon. This is not a simplification, but full visualization, with an accurate representation of phases and appearance of the Moon. Its apparent size and position, cause as we know due to libration the Moon is subject to some movements. So this is not always the same displayed sequence of pre-prepared images for the phase, but the appearance kept abreast.

The visualization of the Moon in a separate and independent window is also available.

Once called visualization window will be present (even when calling other programs) and will always show the current status. After closing the program, its all settings are saved, i.e. the size, location and whether during the start of main program it is to be shown.

Panel Moonrise and Moonset

In this table there are calculated moments of rises and sets of the Moon. Time and azimuth of moments of rise and set are calculated taking into account the altitude of the observer, actual radius of the Moon as well as refractions of the pressure and temperature.

In this panel, as in the "Sun" tab we can call numeric window of calculation of rises and sets of the Moon.

Panel called Astro-clock

Astro-clock panel, as in the SUN tab, is the graphical visualization of the exposure level during the whole day, along with charts of the course of the Sun and Moon.
The whole can be disabled by clicking on the image of Moon phases visualization.

Panel called Phases of the Moon

It shows the phases of the Moon for the month. Phases are calculated according to algorithms given in the book of Jeean Meusa called "Astronomical Algorithms", and then numerically corrected according to the choice of the theory DE404 or DE406.

As we know, the period between the selected phases (e.g. from New Moon to New Moon) is called synodic month. Literature states that it amounts to an average of 29d 12h 44m 2,8s. However, it is worth to know that in fact due to many factors, among others – change of the lunar orbit - in case of the gravitational effects of the Sun, the length of the month changes even up to 12 h. To see this, we can produce a statement of synodic months in a given year, along with statistics of the largest, smallest and average value for the given year.

Panel called Maximum declinations and Perigee and Apogee

It specifies the values calculated by numerical method according to the theory of DE404 or DE406 (depending on choice).

In the panel called Perigee and Apogee there are additionally available a compilation of the length of anomalistic months (from Perigee to Perigee),which as we know, is quite different from the average value, that according to the literature is 27d 13h 18m 33.1s.
In 2010 the difference was 3.8 day.

Panel Lunar node

As we know the Moon’s orbital plane is inclined to the place of Earth's orbit (ecliptic) by angle of about 5 degrees. The points of intersection of these planes are called nodes. Node, where the ecliptic width changes from negative to positive is called ascending node, while the node, where the width changes from positive to negative is called descending node.
Panel of ascending and descending nodes is available in the same place as the panel of the Maximum declinations and the selection of panel is implemented by the appropriate button.

And so, once we can have panel of maximum declinations and once ascending and descending nodes.
If anyone likes to have all the panels available, he/she can call small subprogram with the statement of the closest nodes.

In the Lunar node panel there is also available a summary of these phenomena, along with statistics of duration of the dragon month.

In the mentioned panels of the Moon phase, Maximum declinations, Perigee and Apogee, ascending and descending nodes, there were added additional buttons, thanks to which we can set these extreme and characteristic parameters, observing the effects even for the visualization of the Moon.

Here we can see the great educational values of this supplement. For example, a quick "jump by Moon after the Full Moon" allows us to observe how does the apparent appearance of the satellite change. The Moon gets extremely different size and changes its position as the result of libration.

Above we can see the sequence of visualization of the Full Moon. As we can see the Fullness is not equal to the Fullness.

And now, please quickly "jump" by the Moon on its Perigee and observe if the libration in the length perhaps does not revolve around one value.

and what is the conclusion?

If we want to see The ascending and descending nodes, Maximum declinations, Perigee and Apogee as well as The Lunar phases in the annual statement, as provided by an astronomical annals, then look:

In all cases we can choose the year and also the theory (DE404 or DE406) according to which the data are to be counted..

All of these statements can be viewed in a web browser with induced together with the statement, even in a period of 100 years.
Above we can see example reports :

Lunar Phases year 2011 amount of the years 10
Maximum declination 2011 amount of the years 10
Perigee and Apogee 2011 amount of the years 10
Asceding and descending nodes 2011 amount of the years 10

As in the Sun tab, also here we have the tools to calculate the time, for a given altitude or azimuth of the Moon. There is also a subprogram enabling the designation of time for these two variables (h,Az) at the same time.

The search for a narrow crescent of the Moon

For sure, each of us has seen the Moon 36h, but seeing 24h or even younger Moon is possible and certainly very exciting. If we want to grab as youngest Moon as possible, then immediately after the New Moon we must ambush after sunset and of course in the spring, because then the ecliptic is titled at a large angle in comparison to the sunset of the Autumn season. Below, there is the slope of the ecliptic at sunset in autumn and spring.

When looking for a narrow crescent the helpful thing can be application which allows us to draw up a statement of the days on which such observation is possible. The report is prepared in html format or base of time-sites, which is a base we can call anywhere in AlmSun.

On the occasion of the creation of base of time-sites there is created a report in the html format, which we can be opened in IE.
Example report of html looks like this: M_Warsaw, PL_1990_10.html

The maximum declination of the Moon

As we know the absolute value of the maximum declination of the Moon in a series of 18 years varies in the range of approximately 23.5-5.1 do 23.5+5.1.

Charts of declination and ecliptic latitude, distance from Earth, libration etc.

Mechanism of changes in the maximum declination of the Moon can be easily observed by analyzing the course of the declination and ecliptic latitude on a single chart.

Below, there is a special case, when the ascending node of the way of the Moon (When the ecliptic width changes from negative to positive) falls in the vernal equinox point (for accuracy, thing on the following chart is located in its vicinity)
Then the slope of the ecliptic to the equator and the inclination of the Moon’s way are added up and this way creates with equator the equal angle 23 °27' + 5 °9' = 28 °36'.
Then within a month the declination of the Moon varies from +28 °36' do -28 °36'

And here is the case when at the vernal equinox point there is descending node (it takes places when the ecliptic width changes from positive to negative). Then, in order to calculate the slope of the Moon’s way, we have to deduct 23 °27' k±t 5 °9'. The way of the Moon forms then an angle of 18°18' together with the plane of the equator, and therefore the declination of the Moon varies from +18°18' to -18°18'. We can also add that the time interval between successive passages of the Moon through the same node which is called the dragon month and is an average of 27.2122 d

Not less interesting is also the course of the diameter of the disc of the Moon or libration

However, the most interesting is the chart of the distance from Earth to the Moon in the range throughout the whole year.
The chart below shows how the distance from the Moon to the Earth changes in 2011.
An interesting situation occurs about 19.03.2011.

As we can see, apogee changes very slightly around the value of 405 thousands of kilometers, while the fluctations of perigee distances are very large. If anyone would like to have all charts together, then she/he can cause a subprogram...

Analysis of the parameters of the Moon

In this program there are available all parameters of the Moon together in the form of charts in the range of 3 months. By moving the mouse over the chart we can quickly change the date and time and maybe catch something interesting.

Window of the Moon visualization "listens" to this application. There is also available the description (this is for the beginner)thanks to which we can get to know what is the synodic, anomalistic and draconic month. What is the ascending node. What is apogee or perigee. In which extent changes the maximum declination of the Moon and what it all depends on, as well as what influence on the direct appearance of the Moon have librations. It is shown by the small visualization near the chart.

Visualization of the Moon - 3D

In this subprogram the visualization is full, of course, taking into account the apparent size of the Moon, together wit the simulation of the ashen light (near the New Moon) but primarily with the libration in latitude and longitude, being the sum of the components of the optical and physical libration..

An additional advantage of the program is the fact that we can always jump into a spaceship, fly away for a while and see the Moon from the other, darker way, for example during the New Moon. Observer positions can be changes at any range.

Simulation of the Earth – Moon system

Program of the simulation of Earth-Moon will allow us for immediate approximation of the phenomena associated with the phase of the Moon. The system can be rotated and brought closer in default way and thanks to that we can observe interesting systems.

Here we can see the Earth and Moon during the Full Moon...

And here at the New Moon, in which we can see the invisible part of the Moon.


This tab basically consists of two panels :

Panel called Planets, in which there are given the parameters of Planets and Panel called The current position / rises and sets that gives the current position of Planets, azimuth, altitude also with compliance of the possible corrections (refraction, altitude of the observer) phase, the apparent diameter of the disc, brightness and in the case of Saturn - its current inclination (slope).

Program also shows the apparent sizes of Planets together with selection of the phase (in the case of Mercury, Venus and Mars) and inclination (in the case of Saturn), i.e. exactly what we can expect when we are going to look at the sky with our telescope.

In this panel, like in the "Sun" and "Moon" tab we can call the numerical calculations of sunrises and sunsets of Planets.

Planets visualizations

In the panel of Planets there are available full 3D visualizations of Mercury, Venus, Mars, Jupiter and Saturn. Visualization is 3D with the simulation of the apparent size of Planet, rotation, phase and in the case of Jupiter and Saturn also taking into account the inclination and moons.

Planets can be seen from Earth, but also from any point in space.

Planets tab is additionally supplemented by charts of brightness and angular diameter

as well as the chart of the Saturn's inclination in the given period of time – respectively in the range of the year 2, 3, 6, 12, 24, and 48 years.

You can also view the course of the position of moons of Jupiter in the form of a monthly chart

Chart of the estimated visibility of Planets on a specific geographic position

In the application there are also available charts of maximum apparent altitude of Planets.

Is Mercury more visible in the southern or north hemisphere? Or maybe it does not matter? In any case, we can quickly check it using this application.

Astro-calendar (hourglass)

In the tab called "Planets" there is also available the already mentioned Astro-calendar, i.e. graphical representation of the distribution of the whole year, with selection of rises and sets of the Planets.

Identifications of the individual charts can be made by colors, but by hovering the mouse on the chart. In this situation, in the "Planet" panel there will appear the information on which chart is which.

Of course, in order to achieve full transparency, each chart can be turned on separately. Interpretation of the lines of rises and sets should not pose too much difficulty.

In the above Astro-calendar, without additional calculations it can be seen immediately when there will be favorable conditions for observing the Planet.
On this occasion, we can also mention about the application properties.
Every movement of the mouse results in:

  • Showing the date and time under the mouse in the "Time" panel
  • Calculation of the Sun altitude and day length, also civil (from dawn to dusk) for the above date and time
  • Calculation of the Planet altitude
  • Calculation of the sunrises and sunsets of the Planets
Is someone does not like such a "pointing" by mouse, he/she can always turn on the fields with the possibility to manually set the date and time.
Astro-calendar can also be generated according to the midnight, conforming it to those presented in the Astronomy Annals.

Lines of rises and sets look quite interestingly at high latitudes, such as Spitzbergen, as on the following example.

Geographic coordinates can be changed by selecting a known database or visual map of the world.

Planets configuration

In the subprogram called Planets Configurations there is presented a detailed list of specific moments of Planets configuration.

If someone is not very versed in what’s going on with these configurations, he/she can always call the program called "Solar System Simulaton", which in this case will call with the view from the top in order to bring the matter closer.

The supplement of application is a list of Mars oppositions over the next 50 years. The nearest big opposition, the one which will be in 2003, will take place only in 2050.

It will look like that:

html report :
Planets configuration Year 2012

Planets configuration - Angular distances between Sun, Moon and Planets

Object conjunction

HTML report :
Conjunction 2012

Transit of Mercury and Venus

Report html Transit of Mercury and Venus

Solar System Simulation

The tab also has the Solar System Simulation. The central point of the System is of course the Sun and we as observers may view it from all sides and from any distance, also in the equatorial system.


At the first glance, it resembles Skymap...
But not, the program’s author intention was not to copy this known program. The program is used for something else, namely the analysis of rise or set of the Sun or Moon and a detailed simulation of the solar eclipse. As we can see the map is characterized by rectangular coordinates. Do you want to see the sunrise?
Just click on the button W under FindSun and then time start and...wait. In the moment, there will appear the top disc of the Sun. In the Sun table we can additionally read the azimuth and altitude of the Sun (the calculated and apparent) as well as top (hg) and bottom (hd) kedge of the Sun. When the solar disc will be seen in its entirety, please note that the disc is in an ellipse. With the major axis equal to the diameter of the disc, and small Dp = hg-hd. Please test how the size of the ellipse changes depending on atmospheric pressure and air temperature.

And what?
At what temperature we will observe a greater eliptic Sun, at high (in summer) or low (in winter)?
I would add that the apparent disc of Sun or Moon is recalculated each time taking into account all possible corrections, including refractions of the pressure and temperature.
We have similar fun while observing sunset (button Z). Please test a phenomenon. We have just observed the sunset, i.e. moment when the top disc of the Sun hid behing the horizon. Let us suppose that we are now on the board and in a few seconds we are able to climb the stairs to a higher floor, which is at the altitude of 3m (changing the observer altitude). Will we see a sunset again?

In a similar way we can have some fun with the Moon, but the best fun brings the simulation of solar eclipse. Of course, we can call cities and observe which city the phase of eclipse is the biggest.

In the program there are also stated Planets and Stars so it is a little like simplified map of the sky, but in a projection similar to Mercator.

Mini-map of the sky

On the SunSim tab there is an application thanks to which we can analyze the solar disc or other objects. However, the projectin s rectangular, which works in high approximations. When we „set off” it probably loses its sense as a view, therefore by the title of alternative we have similar application but more natural with a projection method. Such a minimap of the sky. So, the application in OpenGL is very fast, but more schematically there were indicated: Sun, Moon, Planets and 182 Stars, including 66 navigation stars.

Applications can be ran in two versions – as totally independent and dependent on the main program, as a window that is always on the top of listener of all settings - the main program, as well as other subprograms such as Astro-calendar – hourglass.


In this section, of course, there is information about Sun and Moon eclipses. Moments of eclipses are calculated on the basis of algorithms given by Jeean Meeus but are numerically corrected on the basis of DE404 or DE406 algorithms(depending on choice). Eclipse of the sun is calcularted for any location on Earth. The moment of the maximum phase is shown graphically. Do we want to see a simulation of the eclipse? No problem, just click go button and the program takes us into the SunSim tab and there we can fully see the simulations of the eclipse.

It is also worth to recall that also in this tab the database of cities is active. We can always call this base and look for the city, where there is maximum phase of eclipse.

We can also recall the map and look for such a geographical position in which there is the maximum phase of eclipse.

Eclipse can also be searched by the mouse across the globe. The closest eclipse will be seen on 20.03.2015, somewhere on the sea...

Sub-program has also features of the closest solar eclipse – partial or total. According to the program, the next total solar eclipse will be in Paris on September 3, 2081. I will not live anymore to see it then...

If one wishes to have all the eclipse in one statement, then he/she can use an application, that generates all the eclipses from the specified range (up to 1000 years) and create a file of events in the aforementioned format of cmf (time-site base) that can be opened at any moment.

After finishing the process, the correct cmf database is immediately opened, but we can open it in another application, for example, where we can see a lot more.

Description of records in the database include: the type of eclipse, date and time as well as description of the phase. If in the description there is "W" or " it means that the maximum phase of the local eclipse takes place before sunrise or after sunset. It does not mean that during the day it is not visible.

We can run a search only of the total eclipses and a large range, e.g. from year 2010 to 2110.

On the occassion of the creation of time-sites base there is also design a report in html format, which can be opened in IE.
Example html report looks like this: Z_Paris, FR_2011_400.html

Lanar Eclipse

ISS - Visible Passes

Calculate ISS positions

Asteroid (planetoids)



Tab called „Stars” – Stars are a small addition to the program. In the program there is implemented the base of 58 navigation Stars, supplemented with known and characteristic Stars, the total amount of 182. The panel can display the maximum of 24 Stars, not counting the first list reserved for the Sun and the last, which is the current position from the base of Stars.

The program allows you to view the brightest and currently visible Stars („W” button).
Stars can also be sorted according to the brightness.

Calendar sheet

The program is supplemented with calendar sheet with the name-list. If anyone wishes to add name-day, that are not included in the program, it can be done by appending it to the file called "name-day.txt".

Calendar has also the possibility to leave notes for any given day. It can be done by clicking on "Notes" button.

Notes can be put in the years 1960 - 2059. All information are stored in files called Notice.idx and Notice.mdb. Deleting these files will automatically generate the new and thus will reset the entire base.

In this application there can also be generated a shortened calendar for specific years in html format. Generated report looks like this : plik html

Reports (summaries) of data to the file

The program allows you to generate specific data to a file in a report form. It is a daily report of positions of the Sun, Moon and Planets as well as the annual report of rises and sets of the Sun and Moon.

Example reports :
Daily report of the position of the Sun, Moon, Mercury in the form of : table and data
Rising report : Sun and Moon
The AlmSun program for each report generating creates html files and opens it in the default browser.
Example reports in html format :

Sunrise and Sunset year 2011

Ephemeris generator

Ephemeris generator allows for possible expulsion of all important data to a text file in a table format or in the format of data, for example for aspiration to some other program. The way of data formattting can be changed. Ephemeris generator generates data for UT or TDT time and we can choose between three algorithms by which the calculations are performed : DE200 – the fastest, but less inaccurate,DE404 – relatively slow, but with professional precision and DE406 – the highest accuracy, provided that we have JPL files.

Example files generated by this program :

Html reports

To sum up. The AlmSun program generates reports and summaries in three formats. In text format, in data format (for aspiration for example to another application) and in html, for viewing. Html document usually opens automatically after generating of report in default browser.
Above, there is a list of applications that generate html reports, along with some examples :

Navigator (astro-navigation)

Navigator subprogram may be helpful for sailors on two issues. With its help it is possible to generate The Nautical Almanac for any year, virtually the same as the paper version of Her Majesty's Nautical Almanac Office. It is intended for those sailors, who want to play alone with conversions of amendments and calculation of the polar triangle. In one word - so solve it classically as it is taught in schools.
Those, who do not want to bother with the calculations, tables, arduous summing of corrections can take advantage of already finished program, that does all the calculation for them, providing the result at the end.
So, Navigator program is a complete tool that is used to determine A.L.P. Astronomical Line Position from the beginning, i.e. from the moment of measuring the altitude of a celestial body by sextant to calculate delta H, the difference of measured and calculated altitude, expressed in Mm. The program also includes illustrative map, showing how to put A.L.P on the map.

As it is known from the theory, positional lines can be assessed by measuring a celestial body at the time of its culmination. Then the calculations are greatly simplified, and from the measurement of the altitude we directly obtain the geographical latitude of the observation place, using the formula :

Phi = (90-h) + Dec

Also in this issue, the Navigator application comes with the help.
In the table below, there is also shown the main program with the same input data, in order to compare and show the correctness of the calculation of latitude using this method.

The Nautical Almanac Generator

Already mentioned generator of as astronomical yearbook - The Nautical Almanac allow generating of specified sides, whole year or a specified range of years with data of yearbook in three option. Only the left (nightly) sides with Planets and Stars, only right (daily) where the solar and lunar data are, or the whole.

Generated yearbooks, for example for the year of 2011, look like that:

Set color

Accuracy and speed of calculation - summary

In the program, depending on the application there were used 3 algorithms of calculations :

  • DE200 – Simple, fast and relatively accurate algorithms. Amateur and very popular. First published in the flagship position for every lover of astronomy called "Astronomical Formulae for Calculators"
  • DE404 – Professional calculation method, with the accuracy of calculations not really outgoing the summary published in the annals of astronomy.
  • DE406 – At the moment – the best and most accurate method of calculation. All astronomical yearbooks are based on that method. Unfortunately, the algorithms of calculation are not known.
    JPL for the years –3000 .. 3000 published the ephemeris for the Sun, Moon and Planets. So, the quality of the calculations is therefore dependent on the method of approximation.

For obvious reasons, the DE200 method was applied in the places where the application of accurate complicated method would be deprived of meaning. For example, when creating the analemma or graphical presentation of the Solar System.

Literature :

  • Nautical Almanac Office, U. S. Naval Observatory, "Astronomical Almanac for the Year 1986", U. S. Government Printing Office, 1985.
  • Nautical Almanac Office, U. S. Naval Observatory, "Almanac for Computers, 1986", U. S. Government Printing Office
  • Meeus, Jean, "Astronomical Formulae for Calculators", 3rd ed., Willmann-Bell, Inc., 1985.
  • Moulton, F. R., "An Introduction to Celestial Mechanics", 2nd ed., Macmillan, 1914 (Dover reprint, 1970)
  • Taff, L. G., "Celestial Mechanics, A Computational Guide for the Practitioner", Wiley, 1985
  • Newcomb, S., "Tables of the Four Inner Planets, Astronomical Papers Prepared for the Use of the American Ephemeris and Nautical Almanac", Vol. VI. Bureau of Equipment, Navy Department, Washington, 1898
  • Lieske, J. H., T. Lederle, W. Fricke, and B. Morando, "Expressions for the Precession Quantities Based upon the IAU (1976) System of Astronomical Constants," Astronomy and Astrophysics 58, 1-16 (1977).
  • Laskar, J., "Secular terms of classical planetary theories using the results of general theory," Astronomy and Astrophysics 157, 59070 (1986).
  • Bretagnon, P. and G. Francou, "Planetary theories in rectangular and spherical variables. VSOP87 solutions," Astronomy and Astrophysics 202, 309-315 (1988).
  • Bretagnon, P. and Simon, J.-L., "Planetary Programs and Tables from -4000 to +2800", Willmann-Bell, 1986
  • Seidelmann, P. K., et al., "Summary of 1980 IAU Theory of Nutation (Final Report of the IAU Working Group on Nutation)" in Transactions of the IAU Vol. XVIII A, Reports on Astronomy, P. A. Wayman, ed.; D. Reidel Pub. Co., 1982.
  • "Nutation and the Earth's Rotation", I.A.U. Symposium No. 78, May, 1977, page 256. I.A.U., 1980.
  • Woolard, E.W., "A redevelopment of the theory of nutation", The Astronomical Journal, 58, 1-3 (1953).
  • Morrison, L. V. and F. R. Stephenson, "Sun and Planetary System" vol 96,73 eds. W. Fricke, G. Teleki, Reidel, Dordrecht (1982)
  • Stephenson, F. R., and M. A. Houlden, _Atlas of Historical Eclipse Maps_, Cambridge U. Press, 1986
  • Borkowski, K. M., "ELP2000-85 and the Dynamical Time - Universal Time relation," Astronomy and Astrophysics 205, L8-L10 (1988)
  • M. Chapront-Touze' and J. Chapront, "ELP2000-85: a semi-analytical lunar ephemeris adequate for historical times," Astronomy and Astrophysics 190, 342-352 (1988).
  • S. L. Moshier, "Comparison of a 7000-year lunar ephemeris with analytical theory," Astronomy and Astrophysics 262, 613-616 (1992)
  • J. Chapront, "Representation of planetary ephemerides by frequency analysis. Application to the five outer planets," Astronomy and Astrophysics Suppl. Ser. 109, 181-192 (1994)
  • J. L. Simon, P. Bretagnon, J. Chapront, M. Chapront-Touze', G. Francou, and J. Laskar, "Numerical Expressions for precession formulae and mean elements for the Moon and the planets," Astronomy and Astrophysics 282, 663-683 (1994)
  • James G. Williams, "Contributions to the Earth's obliquity rate, precession, and nutation," Astronomical Journal 108, 711-724 (1994)
  • Kazimierz M. Borkowski, "Astronomiczne obliczenia nie tylko dla geografów", UMK Toruń, maj 1990 r.
  • Jan Ludwig, "Astronawigacja dla zeglarzy", Gdynia 1984

The program takes up 300 MB, while the full set of DE406 files, which we can optionally use, takes about 200 MB. The program works with operating systems such as WinXP, Windows Vista and Windows 7.

Although the program has been tested repeatedly, it is inevitable that is may contain hidden errors. The author of the program, however, declares that he will try to remove them, if possible. In this case, the free amendment will be given to all those who bought the program. Free amendment will be also received in the situation when the program is expanded by the author. Each program is compiled individually for each owner.

If you want to buy this software mail to : astro_sybic@wp.pl (german, english or polish language)
or take a look eBay (phrase : AlmSun) sometimes it is put on auction.

Price of the program : 19 USD

Purchased program is compiled separately for each user, together with the key generated for his/her individual data (name and surname).
Key files are sent by e-mail.
The rest of data is available in the network, to which there will be sent link with mentioned files.

Complete AlmSun files without key file : Download

Calculated eclipse sequences : sequences

Optionally, you can upload files with DE406, DE422 or DE431 ephemeris, which can be downloaded from NASA website now.
The list of files is here : DE406 (While downloading, we have to ensure that Windows did not add the extension of *.txt. Names of files have to be like in the summary).
DE431 and DE422 :

Payment : PayPal or money transfer to my account.

More information : astro_sybic@wp.pl

Author : Rafal Tomasik

Actualization : 2023.02.14 (ver. 4.81)