Constellations
 

Constellations & Asterisms
How to draw your own

Ok, this page contains the exact steps you will need to create your own line drawings (constellations, asterisms, pointer stars, nebulae, and so forth).

Setting up the User-Defined Data area

In the Data | User-Defined Data area choose the option "Snap to: Nearest star" as highlighted below. This way when you use a CONTROL+Left Mouse Click anywhere on a star it becomes your anchor point and a line is drawn to the star.

Initial settings
Data | Add User-Defined Data

Choose the correct settings!

Choose the Data class: Lines/Polygons as shown along with Object type: "Constellation Figure".  Actually you can make the lines ANY object type you want but Constellation Figure makes sense in this example.

The comment field is not necessary.  Pick a filename for your version of the constellation lines.  Here I chose the drive and folder "D:\my-constellations.txt" for the file.  This text file will be compiled into an SDB that will plot the lines you have created.

 

Label the stars if you find this helps.  Also turn off the fainter stars to avoid confusion. A setting of Stars Visible to about 4th or 5th magnitude is usually about right when drawing constellations or asterisms. This will keep you from inadvertently clicking on fainter stars.

 

View | Display Explorer | Star Properties.  See below limiting the stars to only 4th magnitude and brighter.

Shut off fainter stars
Avoid confusion

Turning on the Constellation Boundaries will also help you see what stars are found within the constellation you are working. See boundary marking Ursa Major below.

Constellation Boundaries
help you see the limits of the constellation

Now Ready to start drawing!

First you must designate the first star in the sequence. This is done by using CONTROL+SHIFT+Left Mouse Click which creates an initial "Move To command".

 

WARNING! It appears that nothing has happened when you use the CONTROL+SHIFT+Left Mouse Click issuing the Move To command.  The Move To command lifts the pen off the chart cleanly and drops an anchor. Again nothing happens when the Move To command is used!  Failure to include an initial and final Move To command will cause your lines to all be interconnected!

 

Now, pick the star Alkaid.  CONTROL+SHIFT+Left Mouse Click on this star.  It appears that nothing has happened!  However, in the Data | User-Defined Data area you now have a "MOVE TO" command with the coordinates of Alkaid. The Move To command is simply placing the pen on the first star in the sequence. If you don't start with a "Move To" you will have lines connected that you don't intend. You should always end with a Move To command also, that is CONTROL+SHIFT+Left Mouse Click on the last star in the sequence.

CONTROL+SHIFT+Left Mouse Click on the first star
Note: Command: MOVE TO
The first star stamped here for you

After placing your initial anchor (Move To) next CONTROL+Left Mouse Click on the star Mizar.  If you accidentally hit Alcor instead of Mizar you can remove the line by pressing F4 then try again.  F4 will continue to DELETE lines as long as you press it. That is you can REMOVE as many lines as needed by pressing F4 over and over again. 

 

NOTE: If you press F4 too many times you will also remove the initial anchor you had created by using the first CONTROL+SHIFT+Left Mouse Click!  If you have DELETED all of the entries in the User-Defined Data area go back and start again!

CONTROL+Left Mouse Click on the second Star

F4 DELETES lines that are mistakes!

Next CONTROL+Left Mouse Click on the star named Alioth.

CONTROL+Left Mouse Click on next star

See how simple!

Now when you have the Big Dipper asterism done if you wish to connect the other stars you will have to use the CONTROL+SHIFT+Left Mouse Click on the very last star in the sequence. If you don't use an initial and final anchor (Move To) additional stars added will be connected!  See below.  The line is drawn from Megrez not cleanly from Dubhe to the next star.  Press F4 DELETE once and the line disappears.

 

Use the  CONTROL+SHIFT+Left Mouse Click to anchor on Dubhe first.  Now you can CONTROL+Left Mouse Click on the next star and the line will be drawn from Dubhe correctly.  Watch the animation below!

First Anchor on Dubhe
(CONTROL+SHIFT+Left Mouse Click on Dubhe)

Then a normal CONTROL+Left Mouse Click on the next star

So get it!?  Keep CONTROL+Left Mouse Clicking on the stars you want to include lifting the PEN where needed.  F4 DELETES lines you don't want.  When you are satisfied with the end result make sure you do a final CONTROL+SHIFT+Left Mouse Click on the very last star issuing a Move To!

 

Each constellation starts with the anchor MOVE TO (CONTROL+SHIFT+Left Mouse Click)  and ends up with another MOVE TO (CONTROL+SHIFT+Left Mouse Click) on the very last star in the sequence.

Animation showing how to do it!

Don't forget to start with the Move To and then end with another Move To (CONTROL+SHIFT+Left click). Failure to include the "Move To" commands will result in lines being drawn where you don't want them. Remember "F4" DELETES unwanted lines.

This is how it is done!
See how simple?

Make a mistake?

Mistake made, No Problem - F4!

Whoops!  Better use F4 (DELETE) and get rid of that line!

Drawing Summary

1) Setup the User-Defined Data (Data | User-Defined Data) section correctly
2) Find the first star of the constellation and anchor on
    it using CONTROL+SHIFT+Left Mouse Click creating a MOVE TO command
3) CONTROL+Left Mouse Click on each star you want connected with a line
4) Use F4 to DELETE lines that are mistakes
5) Re-anchor the pen wherever necessary. CONTROL+SHIFT+Left Mouse Click
   avoiding bad or unwanted lines.
6) Finally Anchor again CONTROL+SHIFT+Left Mouse Click on the very last star in the sequence.

 

When satisfied with the drawing use the EXPORT button to save the data.  You can also SAVE the document file using File Save As BEFORE you DELETE the User-Defined Data.  I recommend saving a document for each constellation as you go.  Then you can add them all together into a single text file!

When Done Export the text file!
This Text file is then made into and SDB

Compiling the data into an SDB

Once you have your text file created it can then be compiled into an SDB.  Use Data | Import and Browse your computer for the text file and press Compile

Data | Import

 

Here is the default Ursa Major definition as found in the Constellation Figures.txt file.

 

21 MOVE TO HIP 67301 13.79233056 49.31325000 30.00 Ursa major
22 LINE TO HIP 65378 13.39877753 54.92533732 30.00
23 LINE TO HIP 62956 12.90050072 55.95981118 30.00
24 LINE TO HIP 59774 12.25711412 57.03262557 30.00
25 LINE TO HIP 58001 11.89719332 53.69477247 30.00
26 LINE TO HIP 57399 11.76748865 47.77943745 30.00
27 LINE TO HIP 56034 11.48447316 39.33698916 30.00
28 LINE TO HIP 55219 11.30798009 33.09433621 30.00
29 MOVE TO HIP 57399 11.76748865 47.77943745 30.00
30 LINE TO HIP 54539 11.16105143 44.49845643 30.00
31 LINE TO HIP 50372 10.28492488 42.91431758 30.00
32 MOVE TO HIP 54539 11.16105143 44.49845643 30.00
33 LINE TO HIP 50801 10.37214221 41.49955423 30.00
34 MOVE TO HIP 58001 11.89719332 53.69477247 30.00
35 LINE TO HIP 53910 11.03069891 56.38246424 30.00
36 LINE TO HIP 48402 9.86843169  54.06435365 30.00
37 LINE TO HIP 46853 9.54750763  51.67670569 30.00
38 LINE TO HIP 44471 9.06042002  47.15646323 30.00
39 LINE TO HIP 44127 8.98674392  48.04158759 30.00
40 LINE TO HIP 46853 9.54750763  51.67670569 30.00
41 MOVE TO HIP 48402 9.86843169  54.06435365 30.00
42 LINE TO HIP 48319 9.84977927  59.03856708 30.00
43 LINE TO HIP 41704 8.50438801  60.71804967 30.00
44 LINE TO HIP 46733 9.52549205  63.06189055 30.00
45 LINE TO HIP 54061 11.06210886 61.75099407 30.00
46 LINE TO HIP 53910 11.03069891 56.38246424 30.00
47 MOVE TO HIP 54061 11.06210886 61.75099407 30.00
48 LINE TO HIP 59774 12.25711412 57.03262557 30.00
49 MOVE TO HIP 59774 12.25711389 57.03263889 30.00 end Ursa major

 

Your constellation text file for Ursa Major should resemble the above.

How to handle asterisms

What is an asterism? <-- Click here for details and complete list provided by TheSky

OK.  Now that you know how to draw your own constellation lines let's consider making an asterism within a constellation.  In order to accomplish this you will need to use two different object types in order to differentiate between them.  By using Constellation Figure then say Reference Line you can have two different attributes.  Better yet make a new object type called Asterisms first using the View | Display Explorer.  In the Goto: box type in User and you will be taken directly to the User-Defined object types.  See below.

Create new Asterism Object Type!

Use Display Properties on Type 1

Pick a different line type and/or color for your asterisms.

Different line type

And color

Change the Data | User-Defined Data section to use the newly created object type Asterism as shown. Also use a new file name for the asterisms!

Asterisms use new object type!

And new name!

So you draw the stars that make up the asterism using object type asterism and the constellation using object type constellation figure.  Below the green dashed lines are the asterism "The Big Dipper" and the red lines the constellation lines for Ursa Major.

And there you have it

Big Dipper Asterism

How about a new group called Pointers.  This can be another line type and turned on and off accordingly.  Be creative!

Pointer Stars

 

Summer Triangle Example

Here is how you can add the "summer triangle" asterism.  Set up the Add-User Defined Data area as per the above instructions first.

 

Next find the first star, in this case we will use Altair.  CONTROL+SHIFT+LEFT MOUSE click on the star Altair creating a Move To.  Using SHIFT KEY plus the left mouse click sets the starting anchor.

 

Then CONTROL+Left Mouse Click on the next star, Deneb in the example.  A line is drawn connecting the two using a Line To command. CONTROL+Left Mouse Click on the star Vega in the example below, another line is drawn.  Lastly, CONTROL+SHIFT+Left Mouse Click again on Altair dropping the anchor and lifting the pen so-to-speak.

See below.

  Summer Triangle Example
Done!

Again, also best to make a new line type to differentiate the "Asterism" from the constellations lines as per the above instructions.

 

Then just compile the text file into an SDB file.  Here is the text created by TheSky for this example.

 

;Copyright, Software Bisque, Inc.
>LABEL 1,30
>ALIAS 19,35
>RAHOURS 37,47
>DECDEGREES 49,60
>CATALOG CLASS=LINES
>LOADMEMORY
>IDENTIFIER Summer Triangle <----  CHANGE ACCORDINGLY!
>OBJECT TYPE 70 <----------------- First User Defined Object Type See Below
 

   1 MOVE TO      Altair            19.84644722   8.86894444 30.00
   2 LINE TO      Deneb             20.69053333  45.28033333 30.00
   3 LINE TO      Vega              18.61567500  38.78413889 30.00
   4 LINE TO      Altair            19.84644722   8.86894444 30.00
   5 MOVE TO      Altair            19.84644722   8.86894444 30.00

 

NOTE:  Object Type 54 is object type "Reference Line".  Refer to TheSky manual for a complete list of object types.  The object type used must be set to visible to see them.  If you use some other object type just make sure the object type used is set to visible using View | Display Explorer and find it listed there. 

 

HINT:  Just type in the name in the Go to: field and you will be taken directly to that object type there is no need to go digging for it.

 

If you are using your own object type these are accessed starting at Object Type "70" in the header definition above and the numbers go up from there.  See examples below showing custom object types I have created.

User-Defined Object Types
First entry "Simbad" = Object Type 70

You can also just just change this upon compiling the data using the Import dialog.  Also make the Identifier field clear here.  See below.

Compile the text into an SDB file
Note the name here and object type!
(Use Identifier field to name the SDB)

More complicated examples

Can I draw something more than just lines?  You bet.  Consider the following examples.

Taurus the Bull drawing
Courtesy Brian Rickard

Drawing of the Veil Nebula region in Cygnus done by me.

Wow,  25,000 points, nearly a full day of drawing!
Not for the faint at heart ;)