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"THE EARTH CENTERED UNIVERSE" "THE EARTH CENTERED UNIVERSE" "THE EARTH CENTERED UNIVERSE"
Sky Visualization Software Sky Visualization Software Sky Visualization Software
User's Manual User's Manual User's Manual
Version 1.1
Shareware and Registered Versions
Released in March 1992
for Microsoft(R) Windows 3.0
Written by:
David J. Lane
4-26 Randall Avenue
Halifax, Nova Scotia
Canada B3M 1E2
Compuserve E-Mail: 71601,247
Internet E-Mail: lane@oceanroutes.ns.ca
Manual Revision 1.0
TABLE OF CONTENTS TABLE OF CONTENTS TABLE OF CONTENTS
1. Getting Started ..................................4
1.1 Registration of ECU .............................4
1.2 System Requirements .............................5
1.2 Installation Instructions .......................6
1.3 Starting ECU ....................................7
2. Introduction .....................................7
2.1 The Status Display ..............................8
2.2 The Sky Display .................................9
2.3 Mouse Operations ................................10
2.3.1 Left Mouse Button .............................10
2.3.1 Right Mouse Button ............................11
2.4 On-Screen Controls ..............................11
3. Menu Selections ..................................12
3.1 File Menu .......................................13
3.1.1 Open... .......................................13
3.1.2 Save ..........................................13
3.1.3 Save As... ....................................14
3.1.4 Exit ..........................................14
3.2 Edit Menu .......................................14
3.3 Set Menu ........................................14
3.3.1 Time ..........................................14
3.3.1.1 Enter Local Time ............................14
3.3.1.2 Enter Universal Time ........................15
3.3.1.3 Use System Time .............................15
3.3.1.4 Local Time Format ...........................15
3.3.1.5 Daylight Savings ............................15
3.3.2 Geographic Location ...........................15
3.3.2.1 By Latitude/Longitude .......................15
3.3.2.2 By City/Town ................................16
3.3.3 Solar System ..................................16
3.3.3.1 High Accuracy Calculations ..................16
3.3.3.2 Precess to Sky Display ......................17
3.3.3.3 Nutation ....................................17
3.3.3.4 Aberration ..................................17
3.3.3.5 Light Travel Time ...........................17
3.3.3.6 Observer's Parallax .........................17
3.3.4 Define Comet Orbit ............................18
3.3.5 Sky Background Color ..........................19
3.4 Field Menu ......................................19
3.4.1 Magnitude Limits... ...........................19
3.4.2 Object Selection... ...........................19
3.4.3 Planets... ....................................20
3.4.4 Sun ...........................................20
3.4.5 Moon ..........................................20
3.4.6 Grid ..........................................20
3.4.7 Lines/Points ..................................20
3.4.8 Labels ........................................21
3.4.9 Zoom In Full ..................................21
3.4.10 Zoom Out Full ................................21
3.5 Center Menu .....................................21
3.5.1 On RA/Dec... ..................................21
3.5.2 On Constellation... ...........................22
2
3.5.3 On Bright Star... .............................22
3.5.4 On Messier Object... ..........................22
3.5.5 On Solar System Object ........................22
3.5.6 On Point on Horizon ...........................22
3.5.7 On Database Search... .........................23
3.6 Animation Menu ..................................23
3.6.1 Start .........................................24
3.6.2 Stop ..........................................24
3.6.3 Forward One Step ..............................24
3.6.4 Reverse One Step ..............................24
3.6.5 Trails On .....................................24
3.6.6 Maximum Trails... .............................24
3.6.7 Lock On Current RA/Dec ........................25
3.6.8 Lock On Current Azim/Alt ......................25
3.6.9 Lock On Solar System Object ...................25
3.6.10 Time Direction ...............................25
3.6.11 Time Step ....................................25
3.6.12 Animation Speed... ...........................26
3.7 About Menu ......................................26
4. Databases ........................................26
4.1 Stellar Database ................................26
4.2 Deep Sky Database ...............................27
5. Identify Objects .................................31
6. Printing Star Charts .............................31
7. The Future of ECU ................................32
3
1. Getting Started 1. Getting Started 1. Getting Started
Thank you for choosing to try "The Earth Centered
Universe", ECU for short. ECU is a Sky Visualization
Program capable of simulating many of the phenomenon of the
country night sky. This includes the stars, planets, sun,
and moon, comets, and "deep sky" objects. ECU is designed
as an observing tool for the observing amateur astronomer,
but is equally useful to the "armchair" astronomer or other
interested person.
Many of the concepts and terms used in this manual are
common in amateur astronomy, but may not be familiar to all
users. The author recommends the purchase of a good
beginner book in astronomy as a guide to the understanding
of the concepts provided by this program. An excellent
beginner's book is: NIGHTWATCH: An Equinox Guide to Viewing NIGHTWATCH: An Equinox Guide to Viewing NIGHTWATCH: An Equinox Guide to Viewing
the Universe the Universe the Universe by Terence Dickinson, which is available in
most well stocked bookstores or libraries.
ECU is designed to operate on a PC from within the
Microsoft(R) Windows 3.0 environment. This environment
provides all of the "tools" necessary to support a highly
graphical program like ECU. This manual assumes the user is
familiar with the operation of typical Windows 3.0 programs.
ECU was written, because of the obvious lack of good,
reasonably priced astronomy programs. Most "commercial"
software products (and the author has purchased three of the
high profile programs) suffer from very awkward (not
intuitive at all) user interfaces and ssllloooowwwww ssllloooowwwww ssllloooowwwww
operation (especially without a math processor). ECU,
therefore, attempts to fill an obvious need.
1.1 Registration of ECU 1.1 Registration of ECU 1.1 Registration of ECU
A large amount of effort in software development has
gone into this, the first release, of "The Earth Centered
Universe". This included a round of beta testing and user
feedback which resulted in many changes and a wish list from
Earth to the Moon.
In order to ensure that ECU is supported and greatly
improved in the future, I ask that you register ECU.
Registration will bring a laser printed manual and an
enhanced version of ECU. This enhanced version includes
several databases, which are too large to distribute by
normal shareware methods (bulletin board systems). Also,
several computational enhancements (which require one of the
database files) are enabled in the REGISTERED VERSION.
4
I ensure you that the SHAREWARE VERSION is not not not
"crippled" software. It only lacks some of the advanced
features, such as identification of stars, descriptions of
"deep sky" objects, ultra-high accuracy solar system
calculations (lower accuracy versions are included), comets,
etc. The executable file is the same.
A form is provided at the back of this manual for
registering ECU.
The author would be most pleased in hearing your
comments and suggestions for improvements of ECU or this
manual. ECU is a SHAREWARE product, thus is user supported.
I can be reached at any of the addresses (post office and e-
mail) listed on the cover page of this manual.
1.2 System Requirements 1.2 System Requirements 1.2 System Requirements
As stated in section 1.0, ECU operates within the
Microsoft(R) Windows 3.0 environment. It will not run under
DOS alone. However, it has been tested for operation in the
soon to be released OS/2 2.0. The minimum system
requirements are listed below:
Hardware: 286/386/486 100% PC Compatible Computer
Math Co-processor: 80x87 supported, but not required
Software: DOS 3.x or higher
Microsoft Windows 3.0 or higher
(standard or enhanced mode)
Memory: Minimum 600K bytes free from
within Windows
Disk Capacity: SHAREWARE VERSION - 450K bytes
REGISTERED VERSION - 1.8M bytes
WITH FULL SAO STAR DATABASE - TBD
Graphics Card: An EGA or better graphics card
Monitor: Color required for good screen displays
Mouse: Windows compatible
ECU has been tested with slower 286-based computers and
operates perfectly satisfactorily with them. In fact it
operates faster on a 286 computer than many commercial
programs operate on the author's 386!
The use of a math co-processor is supported, but not
required. With most commercial programs, this statement
means that it works, but is untolerably slow! ECU's sky
drawing routines are written entirely in integer math, thus
operate quickly with or without the math processor. During
development, the author's computer did not have a math co-
processor.
The math processor, however, does speed up planet, sun,
moon, and comet orbit calculations significantly.
5
1.2 Installation Instructions 1.2 Installation Instructions 1.2 Installation Instructions
ECU is distributed as one file (ECU.ZIP ECU.ZIP ECU.ZIP) in ZIP ZIP ZIP
compressed format. Any ZIP extraction program, such as
PKUNZIP PKUNZIP PKUNZIP from PKWare, Inc., can be used to extract the
individual files from the compressed file. The compressed
file contains the following files for the SHAREWARE and
REGISTERED VERSIONS:
SHAREWARE VERSION
ECU.EXE - the main executable program file
ECU.CFG - the default configuration file
SAO1.ECU - the main star file
SAC1.ECU - the main "deep sky" object file
CONS.ECU - the constellation data file
LABELS.ECU - the text labels data file
LOCATION.ECU - the geographic location data file
MANUAL.TXT - this manual
REGISTERED VERSION
ALL ABOVE FILES PLUS:
SAO2.ECU - the secondary star file
SAC2.ECU - the secondary "deep sky" object file
PTERMS.ECU - the orbital terms used for high accuracy
calculations
PINDEX.ECU - the index file for PTERMS.ECU
Installation of ECU is straight forward. The example
below assumes the use of PKUNZIP PKUNZIP PKUNZIP (it must be in the path),
that your hard disk is drive 'C', and your floppy disk is
drive 'A'. You can install ECU from DOS or from a "DOS
Window" within Windows 3.0.
TYPE TYPE TYPE
1. Log to your hard disk: C: <return> C: <return> C: <return>
2. Make a directory to store ECU: MD \ECU <return> MD \ECU <return> MD \ECU <return>
3. Change to the ECU directory: CD \ECU <return> CD \ECU <return> CD \ECU <return>
4. Install the ECU disk in drive 'A'
5. Extract the files from ECU.ZIP: PKUNZIP A:ECU <return> PKUNZIP A:ECU <return> PKUNZIP A:ECU <return>
6. Start Windows: WIN <return> WIN <return> WIN <return>
(ignore if already running)
7. Start the "File Manager" use the mouse use the mouse use the mouse
8. Open the ECU directory such that the ECU.EXE file is
visible.
9. Arrange the screen so that ECU.EXE and a suitable program
group in the "Program Manager" are both visible.
10.Drag ECU.EXE from the "File Manager" to the "Program
Manager". A colorful Icon should appear.
11. Proceed to section 1.3: Starting ECU.
6
1.3 Starting ECU 1.3 Starting ECU 1.3 Starting ECU
ECU is started by double-clicking the ECU Icon.
Loading ECU typically takes less than 15 seconds, however,
the SHAREWARE version takes somewhat longer the first time
it is started. This is because the file MATH.ECU needs to
be created. This file is used by ECU to speed up its sky
drawing functions. It is not distributed in the SHAREWARE
version so as to reduce the "download" time (and therefore
the cost) of ECU from bulletin boards. Subsequent startups
will occur normally.
Before the "main window" appears, several data files,
plus the configuration file are loaded into memory. If any
problem is encountered while loading ECU (due to bad or
missing files, not enough memory, etc.), a small dialog box
displaying a descriptive message is displayed on the screen.
Pressing 'OK' will return control to Windows 3.0.
If all is successful, the opening screen will appear
greeting the user with a colorful display of the
constellation of ORION.
At this time, only one copy of ECU can be running at
any one time. If the user attempts to run a second copy of
ECU, a small dialog box will appear describing the problem.
The ECU "main window" always begins centered on the
screen, however, it is designed it operate "full screen".
Press the "maximize" button to facilitate this.
By default, ECU always uses the configuration file
"ECU.CFG" located in the current directory. If a file name
is specified on the command line, ECU uses the specified
file. This is useful for setting up ECU 'icons' to quickly
bring up saved astronomical events.
I suggest you read sections 2. and 3. next, which
introduce the operation of the program, and address all of
the menu selections. If you just want to explore, that's
fine, too. I think you will find ECU quite intuitive.
Section 4. then describes the built-in databases.
2. Introduction 2. Introduction 2. Introduction
This section assumes that ECU is installed and is
running. As indicated in Section 1.3, ECU runs optimally
"full screen", which is obtained by pressing the "maximize"
button.
7
Mouse operations are integral to the operation of ECU,
and will be described in Section 2.3. The on-screen
controls, such as the check boxes and scroll bars will be
described in Section 2.4 and the menu selections in Section
3. But first, the on-screen status displays and sky display
area will be described.
2.1 The Status Display 2.1 The Status Display 2.1 The Status Display
The left portion of the ECU window is used up by the
status display area. This area is contains the following
items:
a) Geographic Location Geographic Location Geographic Location - the top line shows the city where
the observer is located. If a city was not selected
(but rather a specific latitude/longitude was entered),
the message "By Lat/Long" will be displayed.
Immediately below, the latitude (Lat) and longitude
(Long) of the observer is displayed as degrees and
minutes. Positive latitudes are North of the equator
and positive longitudes are West of the Greenwich
meridian. To set your geographic location, see section
3.3.2, which describes the "Set -> Geographic Location"
menu selections.
b) Local Mean Time (LMT) Local Mean Time (LMT) Local Mean Time (LMT) - contains the date and time of
the local civil time. The date is always in the format
year/month/date. The time is either displayed as hh:mm
in 24 hour time or hh:mmpm in am/pm format. See
section 3.3.1.4.
c) Greenwich Mean Time (GMT) Greenwich Mean Time (GMT) Greenwich Mean Time (GMT) - contains the date and time
at the Greenwich meridian. The date is always in the
format year/month/date. The time is always displayed
as hh:mm in 24 hour time format.
d) Right Ascension (RA) Right Ascension (RA) Right Ascension (RA) - contains the right ascension of
the center of the sky display. It is formatted in
hours and minutes as hh:mm.m.
e) Declination (Dec) Declination (Dec) Declination (Dec) - contains the declination of the
center of the sky display. It is formatted in degrees
and minutes as +dd mm'.
f) Azimuth (Azim) Azimuth (Azim) Azimuth (Azim) - contains the azimuth of the center of
the sky display. The azimuth is the angle, in degrees
and minutes, from the Northern horizon towards the East
at the current Date and Time and Geographic Location.
g) Altitude (Alt) Altitude (Alt) Altitude (Alt) - contains the altitude of the center of
the sky display. The altitude is the angle, in degrees
and minutes, measured vertically from the horizon at
the current Date and Time and Geographic Location.
8
h) Field Size (Field) Field Size (Field) Field Size (Field) - contains the number of vertical
degrees currently shown in the sky display. The
minimum field size is 1 degree and the maximum is about
60 degrees.
i) Magnitude (Mag) Magnitude (Mag) Magnitude (Mag) - contains the minimum magnitude for
which stars are displayed in the sky display. This
number is usually the same as that set in the "Set ->
Magnitude Limits..." menu selection. If the field size
is larger than 25 degrees the minimum stellar magnitude
is 6.5 and if larger than 45 degrees, the minimum is
5.5. See section 3.4.1, which describes the "Set ->
Magnitude Limits..." menu selection.
2.2 The Sky Display 2.2 The Sky Display 2.2 The Sky Display
The right portion of the ECU window is the sky display
area. The sky display area displays celestial objects using
one of two "projections". These two projections were
selected for speed of their speed of calculation, however
there is some distortion at the limits of their usefulness.
When displaying the sky from -45 to +45 degrees
Declination, a simple modified Mercator projection is used.
This projection causes the objects at high Declinations to
be distorted (spread-out), most noticeable in constellations
like Ursa Major (the big dipper). This is the same
distortion that makes Canada appear much larger than the
United States on world maps with similar projections (Canada
is only about 10% larger).
When displaying the sky either North of +45 or South of
-45 degrees in Declination, the Zenithal Equidistant Zenithal Equidistant Zenithal Equidistant
Projection Projection Projection is used. This projection is quite good, but does
spread out objects a bit at low Declinations.
With both projections, North is always up (South is
down) and East is to the right (West is to the left).
The objects and items displayed in the sky display area
are listed below. Each will be discussed in detail in
sections 3. and 2.4 by the specific menu selection or screen
resource which controls their operation.
a) Grid Grid Grid - the coordinate grid helps illustrate the sky
projections just described. Lines of Right Ascension
are drawn every hour (course grid) or every 20 minutes
(fine grid). Lines of Declination are drawn every 10
degrees (course grid) or every 5 degrees (fine grid).
9
b) Stars Stars Stars - stars are displayed as varying sized dots
according to the star's brightness. The larger the
dot, the brighter the star.
c) Lines Lines Lines - there are many lines displayed by ECU. These
include the constellation lines, horizon line, and
ecliptic line. Markers are also displayed at the
Zenith (the overhead point) and the North and South
poles.
d) Labels Labels Labels - there are text labels displayed for solar
system objects, bright stars names, Messier objects,
constellation names, and labels for the ecliptic and
horizon lines, and markers.
e) Solar System objects Solar System objects Solar System objects - the planets, sun, moon, and
comets are displayed. The sun and moon are displayed
to their correct size and the phase of the moon is
shown. Planets are displayed as either a point or by
their standard symbol. Comets as displayed as points.
Comets are not available in the SHAREWARE VERSION of
ECU.
f) Deep sky objects Deep sky objects Deep sky objects - deep sky objects are displayed in
six different categories. These are Galaxies, Open
Clusters, Globular Clusters, Bright Nebulae, Planetary
Nebulae, and Other; each displayed using a different
symbol.
2.3 Mouse Operations 2.3 Mouse Operations 2.3 Mouse Operations
The mouse forms a vital part of the ECU user interface
and has many uses from within ECU. The cursor (the shape of
the mouse pointer) is used to inform the user of how the
mouse is currently being used. If it is a cross-hair, it is
used for selecting a window, identifying an object,
centering, or measuring an angle. The cursor is always a
cross-hair while in the sky display area. If it is an
arrow, it is used for operating the scroll bars or buttons.
Each mouse button will be described separately in the
next two sections.
2.3.1 Left Mouse Button 2.3.1 Left Mouse Button 2.3.1 Left Mouse Button
The left mouse button, while the cursor is in the sky
display area, is used for the following functions.
a) Select an object Select an object Select an object - if the left mouse button is pressed
(and released) within a few pixels of the center of an
object, a dialog box, called the "Identify Object"
dialog box, will appear identifying and describing the
10
object. Section 5. details the contents of the
"Identify Object" dialog box. A cross-hair will appear
on the screen identifying the object currently
selected. The dialog box is always placed in the
diagonally opposite corner from the object selected, so
that it doesn't cover the object selected. The dialog
box can, of course, be moved about the screen as the
user wishes.
If more than one object is in the vicinity, the
"Next" button can be pressed to update the dialog box
with new information for the next object.
The dialog box can be terminated in four ways. If
the "Quit" button is pressed, the dialog box will
terminate immediately. If another object is selected,
the current dialog box will be replaced with a new one.
If the left mouse button is pressed while the cursor is
not near an object, the dialog box will terminate.
Finally, the <ESC> key can be pressed.
b) Zoom a window Zoom a window Zoom a window - the second function performed by the
left mouse button is its ability to draw a rectangle on
the screen which is used to re-position and re-scale
the sky display. The rectangle is drawn by positioning
the mouse at one corner, dragging the mouse (with the
left mouse button pressed) to another corner, and then
releasing the button. The center of the rectangle
defines the new display center and the vertical height
is used to scale the display.
2.3.1 Right Mouse Button 2.3.1 Right Mouse Button 2.3.1 Right Mouse Button
The right mouse button, while the cursor is in the sky
display area, is used for the following functions.
a) Center the mouse position Center the mouse position Center the mouse position - if the right mouse button
is pressed (and released), the current mouse position
will become the center of the sky display at the
current scale. This feature is very useful for quickly
"panning" about the sky.
b) Measure an angle Measure an angle Measure an angle - the second function performed by the
right mouse button is its ability to measure angles on
the sky. Angles are measured by positioning the mouse
at one location, dragging the mouse (with the right
mouse button pressed) to another location, and then
releasing the button. A dialog box will appear which
displays the angular measure between the two points in
degrees.
2.4 On-Screen Controls 2.4 On-Screen Controls 2.4 On-Screen Controls
11
The on-screen controls include the scroll bars, zoom
buttons, check boxes, and time step arrows and buttons.
Each is described below:
a) Scroll Bars Scroll Bars Scroll Bars - Two scroll bars are used to rapidly move
the center of the sky display about the celestial
sphere. The vertical bar is used to change the
Declination. +90 degrees is at the top; -90 degrees is
at the bottom. Pressing the end arrows will move the
pointer (and the sky display) by one degree and
pressing along the bar will move the pointer by 10
degrees. The horizontal bar is used to change the
Right Ascension. 23 hours 59 minutes is at the left; 0
hours is at the right. Pressing the end arrows will
move the pointer by 4 minutes and pressing along the
bar will move the pointer by one hour. When sliding
the scroll bars by dragging the pointer, observe at the
Right Ascension and Declination displays to know when
to stop.
b) Zoom buttons Zoom buttons Zoom buttons - the zoom buttons, identified as "zoom
in" and "zoom out", are used to change the scale of the
sky display. Each press of the respective button
changes the scale by a factor of two.
c) Check boxes Check boxes Check boxes - the six check boxes: Stars, Deep Sky,
Solar System, Grid, Lines, and Labels are used to
toggle whether the respective item is displayed in the
sky display.
d) Time step arrows and buttons Time step arrows and buttons Time step arrows and buttons - the time buttons "+" and
"-" are used to change the current time by the amount
shown at the immediate left. Pressing the black arrows
causes the amount at which the time changes to be
altered in steps from a minimum of 1 minute to a
maximum of 4 years.
3. Menu Selections 3. Menu Selections 3. Menu Selections
The menu selections control most of the features of ECU
and are divided into seven categories as listed below. Each
is described in detail in the identified sections:
a) File File File - the file menu handles the loading and saving of
the configuration settings of ECU (see section 3.1).
b) Edit Edit Edit - edit allows the last operation to be nullified
(see section 3.2).
c) Set Set Set - the set menu allows the time, geographic
location, sky display color, comet orbits, and
calculation settings to be adjusted (see section 3.3).
12
d) Field Field Field - the field menu controls if and how the stars,
deep sky objects, planets, sun/moon, grid, lines, and
labels are displayed. It also allows for a full "zoom
in" or "zoom out" (see section 3.4).
e) Center Center Center - the center menu allows many ways to set the
center of the sky display. These ways include
centering on a specified Right Ascension/Declination, a
constellation, a bright star, a Messier object, a Solar
System object, a point on the local horizon, or by a
text search of the databases (see section 3.5).
f) Animation Animation Animation - the animation menu controls the various
features of the animation mode (see section 3.6).
g) About About About - the about menu lists the program credits, the
version number, etc. (see section 3.7).
Many of the common menu items have "short cut" keyboard
keys to allow quick access to their features. The keys used
are identified by an _________ underline under the key used. The Alt
key is to be pressed in conjunction with the identified key.
Also, some menu items identify their keyboard equivalent to
the right in their menu item.
3.1 File Menu 3.1 File Menu 3.1 File Menu
The File File File menu allows the configuration settings of ECU
to be loaded (opened) and saved. Virtually every setting in
ECU is stored in the configuration file. This allows ECU to
be "set up" for a particular astronomical event and this
event saved to a configuration file for later quick
retrieval.
3.1.1 Open... 3.1.1 Open... 3.1.1 Open...
The Open... Open... Open... menu selection presents a dialog box
allowing a new configuration file selected, then
subsequently loaded. It defaults to file names with the
extension ".cfg". I will not detail the operation of this
dialog box, since it is identical to every other MS-Windows
application that has an Open... function.
3.1.2 Save 3.1.2 Save 3.1.2 Save
The Save Save Save menu selection saves the current configuration
settings to the current configuration file name. The
current file name is always displayed on the ECU Window
title.
13
3.1.3 Save As... 3.1.3 Save As... 3.1.3 Save As...
The Save As... Save As... Save As... menu selection saves the current
configuration settings to the file specified by the file
name selected in the dialog box presented. I will not
detail the operation of this dialog box, since it is
identical to every other MS-Windows application that has a
Save As... function.
3.1.4 Exit 3.1.4 Exit 3.1.4 Exit
The Exit Exit Exit menu selection is used to exit ECU. If the
configuration settings have changed, a message box appears
ensuring that the user wishes to exit without saving.
ECU can also be exited by "double-clicking" on the
Control-menu box or by selecting "Close" in the window's
system menu.
3.2 Edit Menu 3.2 Edit Menu 3.2 Edit Menu
The Edit Edit Edit menu currently has only one entry: Undo Undo Undo. The
Undo menu selection nullifies the last operation. This is
very useful when you have made a "slip of the mouse" and
wish to get back to where you were.
3.3 Set Menu 3.3 Set Menu 3.3 Set Menu
The Set Set Set menu allows the time, geographic location,
Solar System calculation settings, comet orbits, and sky
background color to be adjusted. Each is described in the
sections below.
3.3.1 Time 3.3.1 Time 3.3.1 Time
The time can be set in one of three formats: local
civil time, Universal time (GMT), or set to your pc's system
clock (using local civil time). The current time format
used is identified in the Time Time Time menu selections sub-menu, by
a check mark in front of the current mode. The following
sections describe the time settings.
3.3.1.1 Enter Local Time 3.3.1.1 Enter Local Time 3.3.1.1 Enter Local Time
The Enter Local Time Enter Local Time Enter Local Time menu selection presents a dialog
box allowing the user to enter the year, month, date, hour,
and minute in local time format. The year can be from 1000
to 3000 AD and the hour must be in 24 hour format. The time
is always initialized to the current time.
14
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing the time, is
accomplished by pressing 'Cancel'. If an error is detected
when ending the dialog box, a 'beep' will sound and the
cursor will be placed at the offending field.
3.3.1.2 Enter Universal Time 3.3.1.2 Enter Universal Time 3.3.1.2 Enter Universal Time
Entering the Universal time is accomplished identically
to entering the local time.
3.3.1.3 Use System Time 3.3.1.3 Use System Time 3.3.1.3 Use System Time
Selecting Use System Time Use System Time Use System Time causes ECU's time base to
become synched to the pc's system clock. This will cause
the sky to update automatically once per minute, therefore
simulating the actual sky's movements.
3.3.1.4 Local Time Format 3.3.1.4 Local Time Format 3.3.1.4 Local Time Format
The local mean time (LMT) display in the status area is
displayed in either 24 hour or am/pm format. The Local Time Local Time Local Time
Format Format Format menu selection is a sub-menu of AM/PM AM/PM AM/PM and 24 Hour 24 Hour 24 Hour
selections, each selection setting the respective format.
The current format is identified by a 'check mark'.
3.3.1.5 Daylight Savings 3.3.1.5 Daylight Savings 3.3.1.5 Daylight Savings
The Daylight Savings Daylight Savings Daylight Savings menu selection toggles whether the
current local time is to be interpreted as a daylight
savings time. It is used by ECU to convert from local time
to Universal time. If a 'check mark' is present, daylight
savings mode is enabled.
3.3.2 Geographic Location 3.3.2 Geographic Location 3.3.2 Geographic Location
The Geographic Location Geographic Location Geographic Location menu selection provides a sub-
menu containing two methods of entering a location on the
Earth's surface. These are By Latitude/Longitude By Latitude/Longitude By Latitude/Longitude and By By By
City/Town City/Town City/Town.
3.3.2.1 By Latitude/Longitude 3.3.2.1 By Latitude/Longitude 3.3.2.1 By Latitude/Longitude
The By Latitude/Longitude By Latitude/Longitude By Latitude/Longitude menu selection presents a
dialog box allowing the user to enter the latitude,
longitude, and time zone of the location used in the sky
display calculations. The latitude is entered as degrees
(North is positive, South is negative) and minutes. The
15
longitude is also entered as degrees (West of the prime
meridian is positive, East is negative) and minutes. The
time zone is entered in hours West of GMT (enter a negative
for the Eastern hemisphere). The location is always
initialized to the current location.
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing the location, is
accomplished by pressing 'Cancel'. If an error is detected
when ending the dialog box, a 'beep' will sound and the
cursor will be placed at the offending field.
3.3.2.2 By City/Town 3.3.2.2 By City/Town 3.3.2.2 By City/Town
The By City/Town By City/Town By City/Town menu selection presents a dialog box
allowing the user to select the location from a set of pre-
defined locations. A list box is presented containing the
available list. The user is to select the desired location,
then exit the dialog box.
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing the location, is
accomplished by pressing 'Cancel'.
If your location is not in the list of available
locations, you can use a text editor (the Windows NotePad NotePad NotePad
will do fine) to edit the file LOCATION.ECU. The file
format is quite simple, as shown by the sample entries
below:
49.0 59.0 3.5 Corner Brook NFLD
53.3 60.1 4 Goose Bay, LAB
47.5 52.9 3.5 St. John's NFLD
46.1 59.8 4 Sydney NS
The first three entries, which are separated by spaces,
are the latitude (decimal degrees North of the Equator),
longitude (decimal degrees West of the Prime meridian), and
time zone (hours West of GMT). The fourth entry is the name
of the location. The order of lines in the file does not
matter since ECU sorts the file in order when it is loaded.
3.3.3 Solar System 3.3.3 Solar System 3.3.3 Solar System
The Solar System menu selection provides a sub-menu
allowing several calculation options pertaining to the Solar
System to be changed. A 'check mark' in front of a menu
item indicates that it is enabled. Each menu item is
described below.
3.3.3.1 High Accuracy Calculations 3.3.3.1 High Accuracy Calculations 3.3.3.1 High Accuracy Calculations
16
This menu selection controls the precision of the solar
system calculations. The high accuracy calculations are not
available when using the SHAREWARE VERSION of ECU.
3.3.3.2 Precess to Sky Display 3.3.3.2 Precess to Sky Display 3.3.3.2 Precess to Sky Display
This menu selection controls whether the Solar System
object positions and the horizon line are to be adjusted
(due to the effect of precession of the Earth's axis of
rotation) to match the J2000.0 coordinates used by the sky
display.
3.3.3.3 Nutation 3.3.3.3 Nutation 3.3.3.3 Nutation
This menu selection controls whether the Solar System
object positions (except the comets) are to be corrected for
the effects of Nutation. Nutation is at maximum, a 9 arc-
second wobble in the precession circle primarily caused by
the gravitational pull of the Moon.
Nutation can only be calculated when the High Accuracy
Calculations selection is enabled.
3.3.3.4 Aberration 3.3.3.4 Aberration 3.3.3.4 Aberration
This menu selection controls whether the Solar System
object positions (except the comets) are to be corrected for
the effects of Aberration. Aberration is the apparent
displacement of the position of an object due to the finite
speed of light (whatever that means?).
Aberration can only be calculated when the High
Accuracy selection is enabled.
3.3.3.5 Light Travel Time 3.3.3.5 Light Travel Time 3.3.3.5 Light Travel Time
This menu selection controls whether the Solar System
object positions (except the Moon) are to be corrected for
the effects of the Light Travel Time. The Light Travel Time
correction recognizes that the observer sees an object at
where it used to be in the past.
Light Travel Time corrections can only be calculated
when the High Accuracy selection is enabled.
3.3.3.6 Observer's Parallax 3.3.3.6 Observer's Parallax 3.3.3.6 Observer's Parallax
17
This menu selection controls whether the Solar System
object positions (except the comets) are to be corrected for
the effects of the Observer's Parallax. The Observer's
Parallax is the effort of an apparent shift of an objects
position for observers located at different locations on the
Earth. This effect is what causes the Solar Eclipses and
Occultations of the Moon to be only observable from certain
locations on the Earth's surface. Be sure to enable this
selection when simulating events which are location specific
like solar eclipses.
3.3.4 Define Comet Orbit 3.3.4 Define Comet Orbit 3.3.4 Define Comet Orbit
The Define Comet Orbit Define Comet Orbit Define Comet Orbit menu selection provides a sub-
menu of the four comets which can be defined. Each
selection is identical except for the comet number.
Each sub-menu selection presents a dialog box allowing
the orbital elements of a comet to be entered. The
following items can be entered.
a) Comet Name - a textual name that can be displayed next
to the comet in the sky display.
b) Date of Perihelion - the date of perihelion can be
entered as either decimal years or as year, month, and
decimal days. If the month is set to zero, the decimal
years are used and the month and date are ignored. If
the month is valid (1 to 12), the year, month, and date
are used.
c) Perihelion Distance - the distance of the comet to the
Sun in astronomical units (AU) at Perihelion.
d) Eccentricity - the eccentricity of the comet's orbit
from 0 to 1.
e) Longitude of Perihelion - the longitude, in degrees, of
the perihelion.
f) Longitude of Ascending Node - the longitude, in
degrees, of the ascending node.
g) Inclination of Orbit - the inclination of the orbit in
degrees.
h) Epoch of the Elements - the epoch of the elements,
either B1950.0 or J2000.0.
i) Magnitude Constants - the magnitude constants g and k,
are used to estimate the brightness of the comet. Each
comet has a different set of constants. Comet
brightness predictions are notoriously extremely
unreliable.
g) Enable Comet - this flag enables the comet for display.
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing the comet orbital
elements, is accomplished by pressing 'Cancel'.
18
3.3.5 Sky Background Color 3.3.5 Sky Background Color 3.3.5 Sky Background Color
The Sky Background Color Sky Background Color Sky Background Color menu selection provides a sub-
menu allowing the sky background to be set to either black
or white. I find the black background more pleasing, but
the white background is required for printing of sky charts.
The current mode is identified by the 'check mark'.
3.4 Field Menu 3.4 Field Menu 3.4 Field Menu
The Field Field Field menu controls various parameters pertaining
to the sky display. Each menu selection is described
separately in the following sections.
3.4.1 Magnitude Limits... 3.4.1 Magnitude Limits... 3.4.1 Magnitude Limits...
The Magnitude Limits... Magnitude Limits... Magnitude Limits... menu selection presents a
dialog box allowing the user to set the limiting magnitude
for stellar and deep sky objects. The magnitude is set by
dragging the scroll bars to the desired magnitude as
displayed immediately below each scroll bar.
The actual stellar limiting magnitude is dependant on
the field size, however, the setting here sets the upper
limit. If the deep sky magnitude limit is set to 20, all
objects will be displayed, even those whose magnitude is
unknown.
Pressing 'OK' exits the dialog box and activates the
new magnitude limits. Pressing 'Cancel' exits without
making any changes.
3.4.2 Object Selection... 3.4.2 Object Selection... 3.4.2 Object Selection...
The Object Selection... Object Selection... Object Selection... menu selection presents a
dialog box allowing the user to select which types of deep
sky objects are displayed. The dialog box has 7 check
boxes; one for each of Galaxies, Globular Clusters, Open
Clusters, Bright Nebulae, Planetary Nebulae, Other, and
Unknown Magnitudes. If the check box of the respective
object type is true, that type will be displayed (if deep
sky objects are also 'turned on').
Note that the 'Unknown Magnitude' type allows for the
display of objects whose magnitude is unknown, without
littering the display with hundreds (or thousands) of faint
objects, as would be the case if the limiting magnitude were
set to 20 as described in Section 3.4.1.
19
Pressing 'OK' exits the dialog box and activates the
new object selections. Pressing 'Cancel' exits without
making any changes.
3.4.3 Planets... 3.4.3 Planets... 3.4.3 Planets...
The Planets... Planets... Planets... menu selection presents a dialog box
which allows the user to control various display parameters
for the eight planets. The three entries for each planet
include a check box indicating if the respective planet is
displayed, a set of radio buttons which determines if it is
displayed as either a point or as the planet's symbol, and a
check box indicating if the planet's name is also displayed.
Pressing 'OK' exits the dialog box and activates the
new planets settings. Pressing 'Cancel' exits without
making any changes.
3.4.4 Sun 3.4.4 Sun 3.4.4 Sun
The Sun Sun Sun menu selection toggles whether or not the Sun
is displayed on the sky display. If marked by a 'check
mark', the Sun will be displayed (assuming the Solar System
objects are also 'turned on').
3.4.5 Moon 3.4.5 Moon 3.4.5 Moon
The Moon Moon Moon menu selection toggles whether or not the Moon
is displayed on the sky display. If marked by a 'check
mark', the Moon will be displayed (assuming the Solar System
objects are also 'turned on').
3.4.6 Grid 3.4.6 Grid 3.4.6 Grid
The Grid Grid Grid menu selection provides a sub-menu allowing
the resolution of the coordinate grid to be set. If 'Fine'
is selected, the grid will mark every 20 minutes in Right
Ascension and every 5 degrees in Declination. If 'Course'
is selected, the grid will mark every 1 hour in Right
Ascension and every 10 degrees in Declination. A 'check
mark' marks the current setting.
3.4.7 Lines/Points 3.4.7 Lines/Points 3.4.7 Lines/Points
The Lines/Points Lines/Points Lines/Points menu selection provides a sub-menu
allowing the user to toggle the display of lines and points
on the sky display. These include the constellation lines,
ecliptic line, horizon line, zenith point, and celestial
20
pole points. The current state of each line/point is
indicated by a 'check mark' in front of the menu item.
3.4.8 Labels 3.4.8 Labels 3.4.8 Labels
The Labels Labels Labels menu selection provides a sub-menu allowing
the user to toggle the display of text labels on the sky
display. These include the constellation labels, bright
star labels, Solar System labels, Messier labels, horizon
line/zenith point labels (N,S,E,W, etc.), and ecliptic point
labels (VE - vernal equinox, SS - summer solstice, etc.).
The current state of each label is indicated by a 'check
mark' in front of the menu item.
3.4.9 Zoom In Full 3.4.9 Zoom In Full 3.4.9 Zoom In Full
The Zoom In Full Zoom In Full Zoom In Full menu selection causes the ECU sky
display to zoom in to the minimum allowable field size,
which is 1 degree in height.
3.4.10 Zoom Out Full 3.4.10 Zoom Out Full 3.4.10 Zoom Out Full
The Zoom Out Full Zoom Out Full Zoom Out Full menu selection causes the ECU sky
display to zoom out to the maximum allowable field size,
which is about 60 degrees in height.
3.5 Center Menu 3.5 Center Menu 3.5 Center Menu
The Center Center Center menu allows the user to quickly center on
most objects in ECU's databases. This includes centering on
a specified Right Ascension/Declination, a constellation, a
bright star, Messier object, Solar System object, a point on
the local horizon, or on a text search of the databases.
When an object is centered on the sky display, a cross-hair
is used to mark it. Each centering menu selection is
described separately below.
3.5.1 On RA/Dec... 3.5.1 On RA/Dec... 3.5.1 On RA/Dec...
The On RA/Dec... On RA/Dec... On RA/Dec... menu selection presents a dialog box
allowing the user enter a specific Right Ascension and
Declination to center the sky display on. The Right
Ascension is entered as hours and minutes. The Declination
is entered as degrees and minutes.
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing the sky display, is
accomplished by pressing 'Cancel'. If an error is detected
21
when ending the dialog box, a 'beep' will sound and the
cursor will be placed at the offending field.
When the dialog box ends, ECU centers the sky display
at the coordinates entered.
3.5.2 On Constellation... 3.5.2 On Constellation... 3.5.2 On Constellation...
The On Constellation... On Constellation... On Constellation... menu selection presents a
dialog box allowing the user to select a constellation to
center the sky display on. A list box is presented
containing the available list of 88 constellations in
alphabetical order. The user is to select the desired
constellation, then exit the dialog box. ECU then centers
the sky display on the selected constellation.
3.5.3 On Bright Star... 3.5.3 On Bright Star... 3.5.3 On Bright Star...
The On Bright Star... On Bright Star... On Bright Star... menu selection presents a dialog
box allowing the user to select a bright star to center the
sky display on. A list box is presented containing the
available list of bright stars in alphabetical order. The
user is to select the desired bright star, then exit the
dialog box. ECU then centers the sky display on the
selected bright star.
3.5.4 On Messier Object... 3.5.4 On Messier Object... 3.5.4 On Messier Object...
The On Messier Object... On Messier Object... On Messier Object... menu selection presents a
dialog box allowing the user to select a Messier Object to
center the sky display on. A list box is presented
containing the available list of 110 Messier objects in
numerical order. The user is to select the desired object,
then exit the dialog box. ECU then centers the sky display
on the selected Messier object.
3.5.5 On Solar System Object 3.5.5 On Solar System Object 3.5.5 On Solar System Object
The On Solar System Object On Solar System Object On Solar System Object menu selection contains a
sub-menu of all the Solar System objects (Sun, Moon,
Planets, and Comets). The menu item selected is centered on
the sky display.
3.5.6 On Point on Horizon 3.5.6 On Point on Horizon 3.5.6 On Point on Horizon
The On Point on Horizon On Point on Horizon On Point on Horizon menu selection contains a sub-
menu of all the cardinal points on the local horizon plus
the Zenith (the overhead point). The menu item selected
becomes centered on the sky display.
22
3.5.7 On Database Search... 3.5.7 On Database Search... 3.5.7 On Database Search...
The On Database Search... On Database Search... On Database Search... menu selection is used to
search the ECU databases for a specified object. If a match
is found, the specified object is centered on the sky
display. The user is presented with a dialog box which
prompts for a line of text. If the 'OK' button is pressed,
the search commences. The line of text entered is
immediately converted to upper case to avoid ambiguities and
all spaces are removed. The object types which can be
searched for are listed below:
a) Constellations - the 88 constellations can be searched
by entering their complete formal name (eg. 'Ursa
Major').
b) Bright Stars - bright stars can be searched by entering
their complete formal name (eg. 'Deneb').
c) Stars - any star in the database can be searched by
entering its Smithsonian Astrophysical Observatory
(SAO) catalog number with the prefix 'SAO'. For
example, to find the SAO star number 49898, enter
'SAO49898'. Note that entering 'sao 49898' would be
just as effective because the case of the input and
spaces are ignored. Searching for SAO stars is not
available in the SHAREWARE VERSION of ECU.
d) Deep Sky Objects - deep sky objects can be searched by
entering either their primary name or 'Other Names:' as
stored in the SAC deep sky database (see Section 4.).
For example, the Andromeda Galaxy can be found by
entering either its official name 'NGC224' or its
common name (other name) 'M31'. Searching for deep sky
objects is not available in the SHAREWARE VERSION of
ECU.
If the search is not successful, a message box will
appear informing the user of this.
3.6 Animation Menu 3.6 Animation Menu 3.6 Animation Menu
The Animation Animation Animation menu controls all of the functions of
ECU's animation mode. The animation mode is used to
simulate astronomical events which are affected by changes
in the time. The animation mode has the following features.
a) Time can be automatically stepped in any step from 1
minute to 4 years.
b) Time can be stepped in either forward or reverse.
c) The time between time steps can be set from 0 to 60
seconds.
d) The solar system objects can be trailed with dots drawn
behind them.
23
e) The number of dots used in the trail can be set from 10
to 255.
e) The sky display can be made to 'lock' on any solar
system object, or point with reference to the local
horizon.
f) The time can be manually stepped, either forward or in
reverse.
g) All of the features of ECU can be used while the
animation mode is running due to the multi-tasking
nature of Windows, and thus of ECU.
Animation mode is best learned by experimentation,
however, the menu items which control the animation mode are
described in the sections below.
3.6.1 Start 3.6.1 Start 3.6.1 Start
The Start Start Start menu selection starts the animation mode. If
a 'check mark' preceeds the menu selection, animation mode
is running.
3.6.2 Stop 3.6.2 Stop 3.6.2 Stop
The Stop Stop Stop menu selection stops the animation mode. The
ESC key can also be used to stop the animation mode.
3.6.3 Forward One Step 3.6.3 Forward One Step 3.6.3 Forward One Step
The Forward One Step Forward One Step Forward One Step menu selection steps the time
forward by one time step. The time step is displayed to the
left of the time step buttons in the status area. This menu
selection can also be executed by pressing the '+' key or
the '+' button.
3.6.4 Reverse One Step 3.6.4 Reverse One Step 3.6.4 Reverse One Step
The Reverse One Step Reverse One Step Reverse One Step menu selection steps the time in
reverse by one time step. The time step is displayed to the
left of the time step buttons in the status area. This menu
selection can also be executed by pressing the '-' key or
the '-' button.
3.6.5 Trails On 3.6.5 Trails On 3.6.5 Trails On
The Trails On Trails On Trails On menu selection enables the drawing of
trails behind the Solar System objects. If the trails are
enabled, a 'check mark' will preceed this menu selection.
3.6.6 Maximum Trails... 3.6.6 Maximum Trails... 3.6.6 Maximum Trails...
24
The Maximum Trails... Maximum Trails... Maximum Trails... menu selection presents a dialog
box allowing the user to enter the number of trails (10 to
255) to be drawn behind Solar System Objects.
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing, is accomplished by
pressing 'Cancel'. If an error is detected when ending the
dialog box, a 'beep' will sound and the cursor will be
placed at the offending field.
3.6.7 Lock On Current RA/Dec 3.6.7 Lock On Current RA/Dec 3.6.7 Lock On Current RA/Dec
The Lock On Current RA/Dec Lock On Current RA/Dec Lock On Current RA/Dec menu selection causes the
animation mode to be locked on the current Right Ascension
and Declination. In fact, it turns 'lock mode' off. If
locked on the current RA/Dec, a 'check mark' will
immediately preceed this menu selection.
3.6.8 Lock On Current Azim/Alt 3.6.8 Lock On Current Azim/Alt 3.6.8 Lock On Current Azim/Alt
The Lock On Current Azim/Alt Lock On Current Azim/Alt Lock On Current Azim/Alt menu selection causes the
animation mode to be locked on the current altitude and
azimuth, with respect to the local horizon. This feature is
very useful for 'watching' a particular horizon as the
constellations rise or set, or as a planet such as Mercury
crests above the horizon. If locked on the current
Azim/Alt, a 'check mark' will immediately preceed this menu
selection.
3.6.9 Lock On Solar System Object 3.6.9 Lock On Solar System Object 3.6.9 Lock On Solar System Object
The Lock On Solar System Object Lock On Solar System Object Lock On Solar System Object menu selection presents
a sub-menu of all the Solar System objects (Sun, Moon,
Planets, and Comets). The menu item selected becomes locked
to the center of the sky display in animation mode. A
'check mark' will immediately preceed the Solar System
object locked.
3.6.10 Time Direction 3.6.10 Time Direction 3.6.10 Time Direction
The Time Direction Time Direction Time Direction menu selection presents a sub-menu
of the selections: Forward Forward Forward and Reverse Reverse Reverse. These selections
control the direction in which time is stepped when the
animation mode is running. A 'check mark' will immediately
preceed the time direction setting.
3.6.11 Time Step 3.6.11 Time Step 3.6.11 Time Step
25
The Time Step Time Step Time Step menu selection presents a sub-menu of the
selections: Increase Increase Increase and Decrease Decrease Decrease. These selections
increase or decrease, by one notch, the amount of the
animation mode time step. The current time step is shown as
the third sub-menu item. These two selections are
duplicates of the time step arrows in the status area.
3.6.12 Animation Speed... 3.6.12 Animation Speed... 3.6.12 Animation Speed...
The Animation Speed... Animation Speed... Animation Speed... menu selection presents a dialog
box allowing the user enter the number of seconds between
animation mode updates (0 to 60 seconds).
Ending the dialog box is accomplished by pressing the
'OK' button. Aborting, without changing, is accomplished by
pressing 'Cancel'. If an error is detected when ending the
dialog box, a 'beep' will sound and the cursor will be
placed at the offending field.
3.7 About Menu 3.7 About Menu 3.7 About Menu
The About About About menu has two entries. The first selection,
ECU... ECU... ECU..., presents a message box identifying ECU, its version
number, its copyright notice, and how to contact the author.
The second selection, Willman-Bell... Willman-Bell... Willman-Bell..., presents a
message box identifying that ECU contains source code that
which is copyrighted by Jeffrey Sax. The source code
referred to, provides high accuracy astronomical
calculations based on the algorithms described in the book:
Astronomical Algorithms by Jean Meuss Astronomical Algorithms by Jean Meuss Astronomical Algorithms by Jean Meuss (distributed by
Willman-Bell). The message given in the message box is a
requirement of distributing programs containing Jeffrey's
source code.
4. Databases 4. Databases 4. Databases
This section will describe the databases built-in to
ECU. ECU contains several databases. The databases which
will be covered in this section are the stellar database and
the deep sky database. Other databases include the label,
constellation line, and geographic location databases.
4.1 Stellar Database 4.1 Stellar Database 4.1 Stellar Database
The stellar database (files SAO1.ECU and SAO2.ECU) is a
sub-set of the Smithsonian Astrophysical Observatory (SAO)
Star Catalog. The entire catalog contains some 260,000
stars of which ECU uses the brightest 12,155 members of the
catalog, which includes all stars to magnitude 6.8.
26
The database contains the magnitude (visual, if
available), Right Ascension, Declination, catalog number,
and spectral classification of each star in the database.
The Right Ascension and Declination are in J2000.0
coordinates and are displayed on the sky display using this
epoch. The SHAREWARE VERSION of ECU does not know star's
catalog number or spectral classification.
4.2 Deep Sky Database 4.2 Deep Sky Database 4.2 Deep Sky Database
The deep sky database (files SAC1.ECU and SAC2.ECU)
contains a complete database of 10367 deep sky objects. The
members of the Saguaro Astronomy Club (SAC) (pronounced sa-
war-oh) of Phoenix, Arizona have provided much of the effort
to compile this database (database version 5.2). The
database includes the entire NGC catalog, plus other
interesting deep sky objects. Selected fields of the SAC
database were extracted for use in ECU. Only the object
type, magnitude, and position are available with the
SHAREWARE VERSION of ECU. These fields are described below:
a) Object Name - usually the NGC number, but for objects
with no NGC value, other catalogs are used. The
abbreviations listed below are used to represent the
other catalogs.
Abell - George Abell (planetary nebulae and galaxy clusters)
AM - Arp-Madore (globular clusters)
Antalova - (open clusters)
Bark - Barkhatova (open clusters)
B - Barnard (dark nebulae)
Basel - (open clusters)
Berk - Berkeley (open clusters)
Be - Bernes (dark nebulae)
Biur - Biurakan (open clusters)
Blanco - (open clusters)
Bochum - (open clusters)
Ced - Cederblad (bright nebulae)
Cr - Collinder (open clusters)
Czernik - (open clusters)
Do - Dolidze (open clusters)
DoDz - Dolidze-Dzimselejsvili (open clusters)
Dun - Dunlop (globular clusters)
Fein - Feinstein (open clusters)
Frolov - (open clusters)
Gum - (bright nebulae)
H - William Herschel (globular clusters)
Haffner - (open clusters)
Harvard - (open clusters)
He - Henize (planetary nebulae)
Hogg - (open clusters)
HP - Haute Provence (globular clusters)
27
Hu - Humason (planetary nebulae)
IC - 1st and 2nd Index Catalogs to the NGC
(All types of objects except dark nebulae)
Isk - Iskudarian (open clusters)
J - Jonckheere (planetary nebulae)
K - Kohoutek (planetary nebulae)
King - (open clusters)
Lac - Lacaille (globular clusters)
Loden - (open clusters)
LDN - Lynds (dark nebulae)
Lynga - (open clusters)
M - Messier (all types of objects except dark nebula)
Mrk - Markarian (open clusters and galaxies)
Mel - Melotte (open clusters)
M1 - Minkowski (planetary nebulae)
NGC - New General Catalog of Nebulae & Clusters of Stars.
(All types of objects except dark nebulae)
Pal - Palomar (globular clusters)
Pismis - (open clusters)
PK - Perek & Kohoutek (planetary nebulae)
RCW - Rodgers, Campbell, & Whiteoak (bright nebulae)
Roslund - (open clusters)
Ru - Ruprecht (open clusters)
Sa - Sandqvist (dark nebulae)
Sher - (open clusters)
Sh - Sharpless (bright nebulae)
SL - Sandqvist & Lindroos (dark nebulae)
Steph - Stephenson (open clusters)
Stock - (open clusters)
Ter - Terzan (globular clusters)
Tombaugh - (open clusters)
Ton - Tonantzintla (globular clusters)
Tr - Trumpler (open clusters)
UGC - Uppsala General Catalog (galaxies)
UKS - United Kingdom Schmidt (globular clusters)
Upgren - (open clusters)
vdB - van den Bergh (open clusters, bright nebulae)
vdBH - van den Bergh & Herbst (bright nebulae)
vdB-Ha - van den Bergh-Hagen (open clusters)
Vy - Vyssotsky (planetary nebulae)
Waterloo - (open clusters)
Westr - Westerlund (open clusters)
b) Other Name - contains other catalog designations that
the object is known by. The same abbreviations as in
a) are used.
c) Object Type - the type of object from the list below.
Asterism
Bright Nebula
Cluster with Nebulosity
Dark Nebula
Galaxy cluster
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Galaxy
Globular Cluster
Diffuse Nebula in a Galaxy
Globular Cluster in a Galaxy
Cluster with Nebulosity in a Galaxy
Cluster with Nebulosity in the LMC
Diffuse Nebula in the LMC
Globular Cluster in the LMC
Open cluster in the LMC
Nonexistent in RNGC
(means Sulentic and Tifft couldn't find it on the POSS
plates for inclusion in the RNGC)
Open Cluster
Planetary Nebula
Cluster with Nebulosity in the SMC
Diffuse Nebula in the SMC
Globular Cluster in the SMC
Open cluster in the SMC
Quasar
Unverified Southern Object
Multiple Star
d) Position - the object's position, Right Ascension and
Declination, in the J2000.0 epoch.
e) Magnitude - the object's brightness to the nearest
tenth. There are many objects which have no published
magnitude; they are listed as ??.?. Dark nebulae
obviously have no magnitude, so they are also listed as
??.?.
f) Description - a visual description of the object. Most
of these are from the NGC, some are from prominent
amateurs. Back issues of Deep Sky Magazine, Astronomy
magazine, Sky and Telescope magazine and Burnham's
Celestial Handbook are used as a source of some of
these descriptions. The descriptions use the
abbreviations from the NGC and Burnham's. They are
given below:
! remarkable object !! very remarkable object
am among n north
att attached N nucleus
bet between neb nebula, nebulosity
B bright P w paired with
b brighter p pretty (before F,B,L or S)
C compressed p preceding
c considerably P poor
Cl cluster R round
D double Ri rich
def defined r not well resolved, mottled
deg degrees rr partially resolved
diam diameter rrr well resolved
dif diffuse S small
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E elongated s suddenly
e extremely s south
er easily resolved sc scattered
F faint susp suspected
f following st star or stellar
g gradually v very
iF irregular figure var variable
inv involved nf north following
irr irregular np north preceding
L large sf south following
l little sp south preceding
mag magnitude 11m 11th magnitude
M middle 8... 8th magnitude and fainter
m much 9...13 9th to 13th magnitude
g) Size - the size of the object in minutes of arc (') or
seconds of arc (").
h) Class - the class of the object. Several professional
classification schemes are contained here.
Trumpler type for open clusters Trumpler type for open clusters Trumpler type for open clusters
Concentration
I. Detached, strong concentration toward the center
II. Detached, weak concentration toward the center
III. Detached, no concentration toward the center
IV. Not well detached from surrounding star field
Range in brightness
1. Small 2. Moderate range 3. Large range
Richness
p Poor (<50 stars)
m Moderately rich (50-100 stars)
r Rich (>100 stars)
An "n" following the Trumpler type denotes nebulosity in
cluster
Shapley-Sawyer concentration rating for globular clusters Shapley-Sawyer concentration rating for globular clusters Shapley-Sawyer concentration rating for globular clusters
The values range from 1 to 12, smaller numbers are more
concentrated clusters.
Vorontsov-Velyaminov type for planetary nebulae Vorontsov-Velyaminov type for planetary nebulae Vorontsov-Velyaminov type for planetary nebulae
1. Stellar
2. Smooth disk (a, brighter center; b, uniform brightness;
c, traces of ring structure)
3. Irregular disk (a, very irregular brightness;
b, traces of ring structure)
4. Ring structure
5. Irregular form similar to diffuse nebula
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6. Anomalous form, no regular structure
Some very complex forms may combine two types.
Hubble type for galaxies Hubble type for galaxies Hubble type for galaxies
E elliptical, E0 is roundest to E7 is flattest
subgroups; 'd'is dwarf, 'c'is supergiant,
'D' has diffuse halo
S Spiral, 'a' has tightly wound arms, 'b' has moderately
wound arms and 'c' has loosely wound arms
SB Spiral with central bar
Ir Irregular
5. Identify Objects 5. Identify Objects 5. Identify Objects
The identify objects dialog box contains various
information pertaining to the currently selected object.
The information common to all object types includes the
Right Ascension and Declination, and the Altitude and
Azimuth with reference to the local horizon. Each object
type is listed below with each one's specific information
displayed in the identify objects dialog box.
a) Sun - the sun's distance, in astronomical units; and
its size, in minutes of arc are displayed.
b) Moon - the moon's distance from the Earth, in
kilometres; its size, in minutes of arc; its age, in
days; and its phase are displayed.
c) Planets - the planet's magnitude; its distance from the
Earth, in astronomical units; its size, in seconds of
arc; and its phase (0 to 1) are displayed.
d) Comets - the comet's magnitude; and its distance from
the Earth and the Sun in astronomical units are
displayed.
e) Stars - the star's magnitude; and its spectral
classification are displayed.
f) Deep Sky Objects - the object's magnitude (if known);
its primary and other names; its description; its size;
and its object class are displayed. See section 4.2.
6. Printing Star Charts 6. Printing Star Charts 6. Printing Star Charts
ECU current does not currently support the direct
printing of star charts. However, the SHAREWARE graphics
program "Paint Shop", produces excellent charts with ECU.
The procedure that I use is listed below.
31
a) Start up Paint Shop.
b) Set up ECU as desired in "full screen" mode.
c) Switch Sky Background Color to White.
d) Use the Control Menu's "Switch To..." selection to
Select Paint Shop.
e) Use Paint Shop's "Capture" menu to grab ECU's full
screen, or part there of.
f) Use Paint Shop's "Print" selection to print out the
results.
7. The Future of ECU 7. The Future of ECU 7. The Future of ECU
The future of ECU depends on you. If you register it,
it gives me the signal that you are using it, which will
give me lots of incentive to improve it (if no one uses it,
why improve it?). Below is a partial list of the features
which are coming in future releases of ECU.
- add the position angle into moon phases
- add menu times for zoom to 10,20,and 40 degree field
- change the deep sky symbols
- add rise, set, and transit times to Identify Object mode
- add dialog boxes for label and lines settings
- add a flag for controlling calculation of atmospheric
refraction
- provide full EGA compatibility
- add Dreyer deep sky object description help dialog box
- add an observing list output of objects currently on the
screen
- add Earth's shadow for simulating lunar eclipses
- add ability to paste the screen to the clipboard
- add direct sky chart printing
- add planet empheris printer output
- add full Smithsonian Astrophysical Observatory (SAO) star
database (259k stars) integrated with Yale Bright Star
Catalog
- provide more realistic star brightness displays using a
combination of white/black and greys
- add a cross reference from SAO to star names, Flamsteed#,
and Bayer letter
- Hubble Guide Star Catalog CDROM support
- add text labels on the coordinate grid
- add ability for the user to add objects
- add ability to set the colors of nearly everything, plus
a red mode for dark adaptation in observatory use
- allow the user to add descriptions (an observing log) of
stars and deep sky objects
- add display of Jupiter's moons
- add display of Saturn's moons/rings
- add the SAC double star database support
32
REGISTRATION FORM
"The Earth Centered Universe"
for Microsoft(R) Windows 3.0
(ECU)
SHAREWARE VERSION 1.1
Released March 1992
NAME: _____________________________________________________
STREET: ___________________________________________________
CITY: _____________________________________________________
PROVINCE/STATE: ___________________________________________
POSTAL/ZIP CODE: __________________________________________
TELEPHONE NUMBER (S): _____________________________________
ECU Registration: $35US.................... _________
$40CDN................... _________
Optional Complete SAO Star Catalog:
(available by May 1, 1992)
$30US.................... _________
$35CDN................... _________
Minor upgrade: $10US.................... _________
$12CDN................... _________
Total: ( ) US or ( ) CDN............ _________
Disk size: ( ) 3.5" 1.44M ( ) 5.25" 1.2M
( ) 3.5" 720K
Payment may be made by postal money order or certified
check (Canadians may use a personal check) to:
David Lane
4-26 Randall Avenue
Halifax, Nova Scotia
Canada B3M 1E2
Please support the continued improvement of ECU by
registering it now!
33
*******************************************************************************
