STAR Atlas:PRO™ frequently asked questions - FAQs
When should I use Polar and Horizon views and how?
STAR Atlas: PRO (SAP) provides you with two main methods of drawing star charts, HORIZON MODE and POLAR MODE. These two options provide a wide range of choices in examining the sky, it is hoped that the information provided in this document will assist and help you to have great viewing.
Horizon Mode draw star charts like a planetarium that shows your entire Sky from horizon to horizon. The other charting mode, Polar Mode is a star atlas and can draw charts that orients charts so they appear much like those in a printed star atlas. Users may choose the charting mode that best suits their needs and switch between modes at any time when using STAR Atlas:PRO.
Following is an explanation of each charting mode with step by step procedures that demonstrate the different charting modes.
Polar Mode ( �Star Charting Mode� )
The Polar Mode allows the sky researcher to examine the sky at any time and in any part of the globe. It is not necessary to have the object you are seeking within your celestial view, that is you can examine the sky in any part of the globe at any time. There are no limits on the area of interest for this mode � moving the position on the chart is continuous over the whole globe.
Thus this view is optimally used when the user wishes to view the whole sky for objects of interest!
This Star Chart is oriented with the North or South Celestial Pole at top or bottom. Thus, if you are located in the Southern Hemisphere the North Pole is oriented toward the top of the chart. The opposite applies for the Northern Hemisphere.
To use Polar mode, open STAR Atlas: PRO; -
1. Click on [Chart Prefs] button on the main menu. This opens the menu which allows you to set the program as you wish.
2. Click on �Restore Defaults�, (near the bottom, right of the page).
3. Click on �POLAR VIEW� at the top, right hand corner of the page.
4. Click on �Redraw, bottom right. This will give you a view which depends on where you are and the �Field of View�
5. To orient yourself, click on [Zenith] on the Main menu. This will give you a view of the sky directly above you.
6. Click on [Locate] on the main menu.
7. Select an object which is not overhead e.g. NGC 5194.
8. Select [Field of View] on the main menu � 2 degrees
9. This will show a spiral galaxy. You can then download a picture of the object if this interests you, or you can view it through a telescope.
The four arrow keys on your keyboard will move the chart as desired. To orient yourself, if you are lost, it is helpful to go the Zenith [Main Menu ->Zenith] which is the point directly above you in the sky.
The next time you run STAR Atlas: PRO the chart will return to the last position you charted. To re-orient yourself, click on [Zenith] on the main menu.
Horizon Mode ( �Planetarium Mode� )
Displays the Sky with the Local Horizon in the same orientation as observed from your geographical location for the current date and time. This view is optimal when the viewer is exploring the sky in his or her local region and works well when used in conjunction with a telescope. The limitation here is the horizon for your current position.
When you switch to HORIZON MODE from POLAR MODE, a Horizon Chart is automatically displayed and two additional features may then be activated, the Sky Chart and Horizon Charts.
Sky Chart:
The Sky Chart displays the Observer�s entire Night Sky for the current date and time.The Sky Chart is always centred on the Observer�s Zenith (the point directly above the Observer) and has limited features compared to other charting modes. For example, when you right-click on the Sky Chart and choose Centre Chart an Horizon Chart is displayed for the area of the Sky Chart you selected, rather than actually centering the chart where you clicked.
To display the Sky Chart choose [Sky Chart] from STAR Atlas: PRO�s main menu.Horizon Charts ( North, South, East, West ):
This permits you to chart each Horizon direction (North, South, East, and West). To display an Horizon view, choose [Horizon] from STAR Atlas: PRO�s floating menu, then select the direction you want to view.To use Horizon mode, open STAR Atlas: PRO; -
1. Click on [Chart Prefs] button on the main menu. This opens the menu which allows you to set the program as you wish.
2. Click on �Restore Defaults�, (near the bottom, left of the page).
3. Click on �HORIZON VIEW� at the top, right hand corner of the page.
4. Click on �Redraw�, bottom left.
5. Click on [Sky Chart], on the main menu. This gives you the circular �SKY VIEW� which fills the screen.
6. To view the Horizon Charts you can either
i. Right click on the part of the SKY CHART you are interested in and click [Centre on Chart] or
ii. Click on [Horizon] on the main menu, then select the direction you would like to explore (North, South, East or West).
7. Click on [Locate] on the main menu.
8. Select an object which is not overhead e.g. NGC 5194.
9. This will give you an error message �The Object is below the horizon. Set Chart to POLAR MODE to chart objects below the horizon.
10. If this happens you can then go to the POLAR MODE as above.When in HORIZON MODE, the chart appears on the screen in such a way that you are at the bottom of the screen looking toward the direction stated in the view (this would be towards the south in the Southern view and can be identified by the �S� in the centre of the screen, near the bottom and coloured green.
The four arrow keys on your keyboard will move the chart as desired.
The limitation of these views is your horizon which is the whole of the horizon from your current position. This means 180 degrees of the earth, centred on your position. Of course the view on the computer screen is better than the actual area that can be visualised outside � this is restricted not only by the position of the earth but also the number of trees, buildings and hills in your area!
Horizon view at the maximum Field of View (150 degrees) displays the sky 75 degrees either side of centre.
The next time you run STAR Atlas: PRO, when the Horizon View is selected the chart will automatically return to the Sky Chart view, showing the entire Sky for the current instant in time. Once the Horizon Chart is displayed you regain all of STAR Atlas: PRO�s charting features that were disabled when you displayed the Sky Chart.