How To Polar Align A Telescope During The Day

Polar alignment means that you line up the telescope’s axis mount with the motion of the sky. This allows you to track the movement of objects in the night sky more accurately. 

This is done by aligning the mount with either the north or south celestial pole. You will need to learn to polar align your telescope if you want to track the sun or engage in astrophotography.

It is also an important task to complete if you want to see something specific at a certain time. 

Using a smartphone

Two companies, Sky and Telescope, collaborated to create an app called Planetarium. This app makes use of the internal compass and accelerometer in the phone to align with the sky.

There are other apps too, but you will need to ensure they display an equatorial grid such as Crosshair or Telrad field of view circle.

You will need to put your mount up facing the rough direction of the north. Attach the telescope to the mount and leave the lens cap off. This should be at a right angle to the polar axis on the mount, giving you a level surface to place your phone on. 

How To Polar Align A Telescope During The Day

Load the app on your smartphone and turn the brightness up to the maximum. Using elastic bands or duct tape, attach your phone to the lens cover.

Do not use anything metal to attach the phone, as this will interfere with the magnetism of the telescope. The phone screen should be facing up. 

Twist the altitude and azimuth knobs on your polar axis. The equatorial grid shown on your phone screen will change as you make the adjustments.

If you are located in the northern hemisphere, this will align with the southern celestial pole and vice versa. 

When the view of the planetarium is centered directly behind the crosshairs or inside the Telrad circle, you have successfully polar aligned your telescope. 

Using a protractor and a smartphone

For this method, you will need a 360-degree protractor. Put this on the tripod flange and line up the 0/360 line with the alignment hole. At the same time, ensure that the protractor and the center of the flange are aligned.

Find a sun-tracking app for your smartphone. The best app for Apple users is Sun Seeker, on Windows, it is Sun Tracker, and for Android phones, we suggest using Sun Surveyor. 

In the morning or evening, use this app to track the sun’s path of movement. 

Put a ruler on top of your protractor and make a radius following the path of the Sun. Place pins along this radial line. 

Pivot your tripod on the spot until the radius and the pin’s shadow are parallel or overlapping. Install the equatorial mount. You have now aligned the azimuth to north.

Use a GPS app on your smartphone to find the latitude of your current location.

You will also need an inclinometer app for your smartphone. This is essentially an app that turns your smartphone into a spirit level. Calibrate it on a level surface before attaching to the saddle of your telescope.

Change the mount’s inclination to set it according to your latitude. 

Using a compass and a polar scope

Place your mount on a level surface facing north. Use a compass and spirit level to confirm that you have done these steps correctly. 

Update the GPS details inside the mount’s controller to detect your current position and local time. Your next step is to align the polar scope reticule of the telescope. 

Take the dust caps off of both ends of the Right Ascension axis. Turn the declination axis and lower the position of the countershaft bar. This will allow you to see through the polar scope.

Using a compass, check the angle of the bisection on the RA axis. This is the line you will see on the horizon, far away.

Correct the inclination of the telescope mount and the altitude changes. You will need to use the latitude adjustment bolts, the altitude knobs, and the azimuth knobs. If you do this correctly, you can point the polar scope at the horizon. 

Using the sun

You will almost always be able to see the sun in the daytime. This makes it an easy and convenient object to determine your telescope’s polar alignment.

That being said, it is very dangerous for your eyes to look directly into the sun. This method should only be used with sufficient knowledge to keep yourself safe, and with the suitable equipment required. 

To do this, you will need the following equipment: a telescope, an equatorial mount, a handset (or computer control), a compass, some white paper, and a solar filter.

Your first step is to find magnetic north using your compass. You will need to set up the mount with the counterweight and the north leg facing north. The closer you get this to true north, the better your alignment will be. 

Using the handset or computer, point the scope at the sun. A tightly-fitting cap must be on the finder and you should not leave this unattended. It is vital to use a certified solar filter on the scope to protect your eyesight and your equipment.

Use the azimuth and altitude bolts on your telescope to move the position of the head. Try not to move the Right Ascension of the mount or the declination controls. Try to center the Sun in the field of view. 

Refine the positioning of the telescope so that the Sun is centered. Use the telescope’s ground shadow to do this, or allow small amounts of light into the telescope.

Lock in the positioning of the telescope mount. Watch your target and monitor its position. If it drifts north or south, you have not polar aligned it correctly. 

German mount

Set the declination of the telescope mount to +90 degrees, also known as zero position.

Follow the instructions given for the smartphone polar alignment. 

Gordon Watts

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