LOGIS-CIEL (window to the sky with planets)
by Alphonse POUPLIER
Attention! The constellations are always named by their international
abreviation in 3 letters. For ex. Great Bear = UMA. Use therefor the
initial menu for printing of constellation's tables and have it on your desk.
Note also through this menu the coordinates of observation places you will
Installing all the files of the diskette in a single directory of a hard disk
will improve speed while identifying objects or pointing with the window onto
an object or a constellation but not for initial calculations.
The program works without hard disk as well.
If your computer does not keep time and date, please give them at
initialisation. The program will propose them as default values.
When you are in the directory containing ALL THE FILES, type GB and ENTER to
obtain the menu.
Generaly, ENTER gives the following step of the program.
LOGIS-CIEL will allow you to observe the sky easily as it shows
in a square window 60 degrees wide (azimuth) and 60 degrees high
(altitude). (about a window 1 m x 1 m located 1 m in front of you)
You can modify that angle (ZOOM from 10 to 300 degrees ! ).
You also can print on paper the obtained screens. If you intend to do it,
when you are in DOS and BEFORE TO TYPE L, type GRAPHICS if your screen is
with a clear background. If your screen is with a dark background, type
GRAPHICS/R. When the window is to your liking, in order to have a hard copy,
press Shift PrtScr until the printer starts.
You will see first the Sun, the Moon and the planets, then the stars
according to their magnitude (brightest ones first) and finaly the 110 Messier
objects (even if they are under the horizon) at the moment of observation
and from the observation point of which you have chosen the coordinates.
Every objects are located on the screen exactly as they are in a real window.
Will appear successively:
-the Sun ... like a sun....
-the Moon like an empty circle (to see its phase, itendify it)
-the planets like a small lozenge
-the stars like smaller or larger dots according to their magnitude
-the Messier objects like very small circles.
The figure mentioned at the lower edge of the window is the azimuth on which
the window is centered.
The figure mentioned at the left edge of the window is the altitude on which
the window is centered.
You will easily identify all of those objects or point (automatically
center) the window. (see below)
The first question you'll have to answer to is about the type of screen you
have. The program was indeed developed to give a realistic representation
of the sky: Bright objects on dark background during the night and, in
daylight, the screen is bright and the objects appear dark.
MENU FOR CHOICE OF DATA
ENTER to keep a DATUM and go to the following one. H Help
P to get POSITIONS OF SUN, MOON, PLANETS C to CONTINUE
E to get POSITIONS OF OTHER OBJECTS D for DOS
Each datum can be changed and has to be confirmed by ENTER.
Originaly, default coordinates are of Uccle-Observatory in Belgium but you
will easily save others. The program proposes you that saving after each
If you give a few letters of an existing location name of the list, you get
directly its coordinates.
Your answers to the questions concerning latitude and longitude, may be
approximate. For example, +4000 for latidude and 28500 for longitude will
give a good idea of the sky for New-York
Do n't forget + or - before latitude.
There are 3 figures for degrees of longitude because it is an EAST longitude
which can go up to 360 degrees. This is a method recommended by the
International Astronomical Union.
Don't forget to give the time in universal time and not in local time.
The higher the magnitude limit, the more numerous the stars on the screen,
but the longer the time for the preliminary calculations.
Once preliminary calculations are finished, everything will be fast.
You will be able to interrupt at any time the showing of the stars in the sky.
Each datum can be replaced by H, P, E, C, or D.
H gives the Help-Menu.
P allows you to see in 2 seconds, before to enter the calculations, the
position of Sun, Moon and planets.
It is calculated from jan. 1st 1900 to dec. 31st 2100.
You can see, namely for Sun and Moon, if they are risen.
E gives the position of the other objects (for year 2000 and valid for many
Searching is made by name or constellation and FOR CHOSEN "MAGNITUDE LIMIT"
AND "MESSIER Y or N" ONLY.
You can see, for example, if ORIon is risen.
C starts the calculations and shows the window. Be sure to have given correct
data and specialy magnitude limit. Time for calculations will depend on it.
When the calculations are finished you can contemplate your sky...
Press ENTER as many times as necessary to obtain the small menu.
ORIENTATE the window to your liking, using the arrows ( 5 degrees at a time)
or using PgUp, PgDn, Home, End ( 30 degrres at a time), from the left to the
right (azimuth) or up and down (altitude).
It's not necessary to wait for the window to be filled up again before moving
it onto a new orientation.
When the window is on the zenith, if you try to go up, you will see a change
of azimuth of 180 degrees. You can then, either descend in that new direction
with the horizon down or try to go up again and recover the previous azimuth.
When the window is against the zenith, its upper edge covers 180 degrees like
in a real window !
If you press I of IDENTIFY you will see a small finder-circle in the middle
of the screen. Move it first using "home", "end", "pgup", "pgdn" and then
using arrows for acurate positioning.
The circle will center itself on the reached object.
You will see then in the left part of the screen:
- its poetic name (for Messier-objects, Messier-nr + NGC-Nr )
- its greek letter
- its constellation
- its right ascension and its declination
- its magnitude (type like planetary nebulae for Messier-objects)
- its altitude and its azimuth
- for the Monn, its phase
If you press P of POINTING the window will automatically center itself either
on the selected O(bject) or on the selected C(onstellation) or on a given
A(zimuth) or on a star if you give its (B)ayer greek letter and its
In the first case, you may give only a few letters of the object name. The
program will give you the brightest object whose the name contains those
You also can give the HD Nr. For example 191692 = teta of Eagle (AQL).
Caution ! For Messier objects, you'll have to type M +3 figures.
For example: M003, M031
S(pecial) alows you to mark 2 points by a cross.
Let us suppose a NOVA, a COMET or an ASTEROID is anounced with its R.A.
and its Decl.
Two points are originaly marked by a cross: the Vernal and Autumnal ones.
You can replace the name and celestial coordinates of each of them by
those of the new object. You will then find them on the screen and have
the possibility to P(oint) them, I(dentify) them.
ENTER lets things unchanged.
If you press C and then the name of a CONSTELLATION (always by the 3
internationnal letters), your will surround by repeated ENTER the objects of
that constellation if appearing on the screen.
After having surrounded the objects of one or several constellations, type /
to recover the screen like it was before.
If you press Q, the eQuator will appear if it is throug the window.
If you press E, the Ecliptic will appear if it is throug the window.
For Ecliptic or Equator, the first time you will ask for one of them,
after a change of moment or observation place only, calculations
of screen coordinates take about 8 seconds.
The next times, it's immediate.
If you press M(eridian), if the meridian of the observation place is in the
window, it will appear in full line. It makes the orientation easier.
To supress that line, press /.
If you press L, you'll maybe have to be patient: The lines of EQUATORIAL
COORDINATES are traced STARTING FROM THE NEAREST CELESTIAL POLE and it can be
at some distance of the window.
Dots lines will appear for each hour of Right Ascension ( one dot every 2°,
one "o" every 10°, of Declination). The values are mentioned every 30°.
If you press Z of ZOOM you can chose the vision angle (10 degrees at a time)
- NORMAL Angle : 60° (F=44mm in 24x36)
- MINIMUM Angle : 10° This corresponds to a TELE of 291mm in 24x36.
- MAXIMUM Angle : 300° ( 180° is equivalent to a "Fish eye")
N.B. This angle shows the whole celestial hemisphere when the
window is centered on the Zénith !!!
- 90 degrees Angle (F=25mm in 24x36): When centered on 45° altitude, that
angle shows the celestial hemispherede from the horizon to the
zenith, embracing an angle 90° large !!!
1) I, C, E, Q, L functions work by any angle and in any direction.
Please try them with 300° angle and on the zenith. A delight !
2) Sun, Moon and planets appear even under the horizon !!!
If you press A, you will be proposed: A OTHER
Attention ! If you press A, you will have to give new location and
time of observation.
This will allow you to choice another magnitude limit and to take or
If you press B you can obtain the sky configuration a few hours
later or earlier (maximum: 24 hours) by adding or substracting a
number of hours (DECIMALISED). For example, for a quarter later,
Observe that way, for example, the motion of the Moon trough the
stars or the rise of ORION etc...
For any information, please contact the author.
He wishes to you marvellous observations by night (or day...) in the warmth
of your home, in any weather...
Alphonse POUPLIER eng. Univ. Liege
47 Chemin des Vignerons or 4 Hameau du Lac
B-5100 WEPION (Europe) F-04550 ESPARRON DE VERDON
tel. Belgium 081 460567 tel. France 92-771407
The technical datas on the stars are from
the "Catalog of the brightest stars" of F.OCHSENBEIN and J.L.HALBWACHS
Centre de Donnees Stellaires
Observatoire astronomique de Strasbourg
11 rue de l'Universite
F 67000 Strasbourg