Auto Two Star Align
Introduced with NexStar hand control version 2.3 (first shipped with the NexStar
8i SE) and available in all newer versions, Auto Two Star Align is a cross
between the original NexStar Auto Align and Two Star Align. With Auto
Two Star Align, after entering the date, time and location information, you
select a star from a list of the brightest stars currently above the
horizon. You must then manually slew to that star. After
centering the first star the telescope will then automatically slew to a second alignment star.
After centering the second star the scope is aligned and ready to
- Power up the scope.
- Press ENTER to begin, use the Up and Down buttons (6 and 9 on the
keypad) to scroll to Auto Two Star and then ENTER again.
- The hand control will show either the current time or the time when
you last used the scope. The top line of the display will cycle
through the messages, "Enter if OK", and "UNDO to edit". If your
scope has a GPS module, the GPS receiver will shortly lock onto 3 GPS
satellites and update the date, time, and location. If you become
impatient waiting for a GPS link, or if you don't have a GPS module in
your scope, use the Up and Down buttons (6 and 9 on the keypad) to scroll
through the date, time, and location settings. If they are all correct,
press Enter to accept and proceed with the alignment. If they need
adjusted, press Undo and make any necessary corrections.
- The display will now prompt to Select Star 1. Decide which star
you will use, Up and Down buttons (6 and 9 on the keypad) to scroll to
that star and then press ENTER. For Northern Hemisphere use, Polaris
(the North Star) is an excellent choice.
- Use the arrow buttons to slew (move) to the star you selected.
Center the object in the finderscope and press ENTER. Then center
the object in the eyepiece and press ALIGN.
- The scope will now automatically slew to a second alignment star and
prompt you to center and then align, just as you did with the first star.
If this second alignment star is obstructed from view or if you would like
to use a different star to get wider separation from the first (which
improves GoTo accuracy), press Undo to skip to the next available star.
- After pressing ALIGN for the second star, you are finished.
- Auto Two Star Align is only used in alt-az mode - mounted right on top of the
tripod. When mounted equatorially on a wedge, the original Auto and
Two Star Align, as well as the new One Star and Solar System Align
(hand control version 4 or higher) are available.
- As with all the new NexStar alignment methods, Auto Two Star
Align does not care where the optical tube is pointed at the beginning
of the alignment.
- To get closer pointing for the second star, be sure to level the tripod before you start. Once the alignment is complete, GoTo and tracking are not
dependent upon the accuracy with which you leveled the tripod, so do not
spend time seeking perfect level - close is good enough.
- If you do not have a GPS-equipped telescope, be accurate to within a
couple of minutes when entering the time. Also, either select a city
within 50 miles or enter your longitude and latitude to within a degree or
- It is still important to select widely placed stars for alignment.
When selecting your first star, keep this in mind. Selecting a first
star high up in the sky will limit the possible separation of the
automatically selected second star.
- Be sure to center the objects with the same final movements as the
direction of the GoTo Approach. For example, if the scope normally
finishes a GoTo with the front of the scope moving right and up, you will
center both alignment stars in the eyepiece with the right and down arrow
buttons (the up/down arrows reverse at slew rates of 6 or lower).
For more details on this, refer to my book The NexStar User's Guide
or the other general alignment guides found here on my web site.