Astrophotographers must align their equatorial mounts to the North Star, Polaris. Polaris is currently the closest star to the celestial north pole and the objects in the night sky essentially rotate around this point. Mounts aligned to Polaris can effectively track these objects in right ascension (east/west) and declination (north/south). Similar to longitude and latitude on a globe, every point in the sky has a dedicated coordinate!
Polar alignment plays an important role in astrophotography and should be one of the first procedures that you master. Precise polar alignment ensures better Go-To/pointing accuracy, precise tracking/autoguiding, longer exposures, and round stars. These are all things that we strive to achieve -- and proper polar alignment is a great place to start. Alternatively, poor polar alignment is likely to lead to poor tracking accuracy which can severely limit your exposure times and introduce other frustrations and obstacles.
QHY PoleMaster Electronic Polar Scope
Luckily, there are several very easy ways to polar align your equatorial mount to a very accurate degree. Most mounts come with a built-in polar scope. These work well but aren't as highly recommended as other methods. When paired with the smartphone app called “Polar Scope Align”, using your polar scope can be a great way to start. Other ways include using a guide scope, guide camera and a program called SharpCap! This is a great way to polar align if you’re using an autoguiding system. Polar alignment in SharpCap can also be done through the main imaging scope. This is harder to do with longer focal length scopes and narrower fields of view.
The QHY PoleMaster is the most popular option and can result in sub-arc minute accuracy -- meaning you are polar aligned to a degree of accuracy comparable to the amount that Polaris moves in the night sky in 60 seconds!
Drift alignment is another method one can use when Polaris isn’t visible or is being blocked by a house or tree. The guiding software PHD2 can assist you in this method of polar alignment as well. Lastly, Celestron mounts offer their “All-Star Polar Alignment” which is another method of polar alignment for those who don't have a great view of Polaris. For a detailed explanation, visit Celestron’s guide here.
Polar alignment doesn't have to be difficult! Companies like QHY, iOptron, or the producers of SharpCap have really made this crucial step an easy one. For more polar alignment assistance, contact our experts here at High Point Scientific and we will be happy to offer our suggestions.
This Article was Last Updated on 07/24/2023
