What magnification does the included eyepiece give?
The 32mm Omni Plossl eyepiece gives 47x (1500mm / 32mm), which Celestron calls excellent for locating and observing wide-field deep-sky objects. Celestron lists the highest useful magnification as 720x and the lowest as 43x.
Which phones work with StarSense Explorer?
Download the StarSense Explorer app before your first night out; Celestron says the app is large, so it recommends a Wi-Fi connection. The unlock code on the card in the box enables telescope control on up to 5 devices. Celestron says the app works with most modern smartphones and keeps a compatibility list on its site; on older phones the app can still be used, but it cannot be reinstalled once uninstalled.
How do I align my phone to the telescope?
To align the phone, which Celestron recommends practicing during the day, insert the low-power eyepiece, place the phone in the dock and turn the knobs at the bottom of the bracket until the camera view is centered, unobstructed, in the dock's mirror. Point the telescope at a very distant object, at least a quarter mile away, such as a streetlight, a license plate, a stop sign or a treetop, center it in the eyepiece, then slide the camera view until the same object sits in the crosshairs. If you have removed the phone from the dock since the last alignment, the app suggests aligning again.
How does the app find objects?
StarSense Explorer uses patented sky recognition technology and your smartphone to work out where the telescope is pointed: a Lost in Space Algorithm (LISA), like the ones satellites use to orient themselves in orbit, matches the star patterns the phone detects overhead to the app's internal database. Place your phone in the StarSense dock and launch the app. After you align the phone to the telescope's optics, a quick and easy procedure, Celestron says, the app lists the celestial objects currently visible. Pick one from the planetarium view or the Tonight's Best list and arrows appear on screen to guide you; the bullseye turns yellow when the telescope has detected stars but is not yet on target, and green when the object is ready to view in the low-power eyepiece. Celestron's app guide suggests stopping for a few seconds as you get close, so the telescope can sense the stars in its new position.
Can I use 2" eyepieces?
The 2" Crayford focuser, which Celestron says moves precisely and smoothly without focus shifting, comes with a 2" extension tube and a 2"-to-1.25" adapter, so you can use virtually any 1.25" or 2" eyepiece. Keep the extension tube in place for most eyepieces, or they will not reach focus; remove it for eyepieces that need a lot of inward travel, and you may need to remove it for an imaging camera. The adapter's internal brass compression ring protects eyepiece barrels. For a 2" eyepiece, remove the adapter and secure the eyepiece in the extension tube with its thumbscrews. A focus lock thumbscrew holds the sharpest focus, and a set screw adjusts the focus knobs' tension.
How long does the telescope need to cool down?
The best views come once the telescope reaches thermal equilibrium with the outside air. Celestron says to allow around one hour when moving it from a heated house, recommends storing it in a dry but unheated place such as a garage, and suggests taking it out at sunset so it is acclimated by dark. For the 12" Dob, Celestron names an optional USB Cooling Fan for Dobsonians that mounts on the rear of the mirror cell, blows air on the mirror and works with any USB power source.
How do I collimate the mirrors?
Collimation aligns the parabolic primary and the flat secondary mirror, and Celestron recommends checking it periodically. With the eyepiece removed and the included collimation cap in the focuser, you should see the whole primary mirror centered in the secondary, and the reflection of the secondary centered in the primary, whose center is marked with an adhesive ring. Celestron suggests collimating during the day, with the tube horizontal and pointed at a blank wall, and adjusting the secondary first with the three set screws in its holder, using the 2mm hex key. At night, a slightly defocused bright star at high magnification should show the secondary's shadow centered in the circle. On the 12" Dob, no tools are needed for the primary: loosen the three locking thumbscrews, adjust the three spring-loaded collimation thumbscrews one at a time, then retighten the locking screws until snug.
How long will my phone battery last?
The app keeps the phone's camera looking at the sky and its processor working, so it uses significant power; a fully charged phone should last several hours, but Celestron recommends bringing a charger to observe all night. It names its optional PowerTank Glow 5000, a USB power bank with a red flashlight, which straps to the two posts on the StarSense dock with its included bands.
What can I see from the city?
Celestron says that even from a light-polluted city the telescope can pick out Jupiter, Saturn, open star clusters like the Pleiades, double stars, the Orion Nebula and the Andromeda Galaxy, and that from even slightly darker skies hundreds of objects are within reach.
How do I transport it?
To transport the telescope, loosen the altitude tensioning knob and lift the tube off the base; the tube and base each have carry handles placed at the balance point. Dust covers are included for the front of the tube and the focuser, and Celestron recommends keeping them on when the telescope is not in use. The tube weighs 49.8 lbs, nearly 50 lbs, so Celestron says to bend your knees when lifting and to get help if it is too heavy to carry alone; the base weighs 33.8 lbs.
