Viewing the universe has never been easier or as much fun
We had a group test recently on computerised telescopes and how they have now matured into almost mini-home observatories. A modern GoTo telescope is an extraordinary device with the ability to connect to a computer regardless of the operating system, to allow the user a greater degree of control and to upgrade the scope's abilities when necessary.
For the amateur astronomer, you won't find much better than the offerings from Celestron, in particular this model, the Celestron NexStar 5SE. This is a Schmidt-Cassegrain telescope with a 125mm objective diameter and a focal length of 1250mm. The Schmidt-Cassegrain element describes the corrector plate at the front of the telescope, where light is focused by the primary mirror, together with a smaller convex mirror located in the centre of the corrector plate. In essence, this means you'll get a better focal length in a compact design.
Speaking of which, this is a remarkably lightweight setup, including the tripod. The entire package weighs just under 8kg, and the mount can be removed from the tripod by unscrewing three bolts located underneath the top of the tripod. This of course means you'll easily be able to move the telescope to a remote location, should you so wish.
The 5SE comes with a 25mm eyepiece, which will give a magnification of around 50x. It's enough to see Jupiter and several of its moons on a clear night, as well some rather magnificent lunar observations and views of the inner planets. There's also a finderscope with a red LED dot projected in the centre to help align the telescope.
The computerised handset supplied is a Celestron NexStar+, a device that on its own can activate the motors to align the telescope to 40,000 objects in its database. Alignment is a simple enough affair, thankfully. All you need do is fit the eight AA batteries, power up the handset and start by entering the current time, date and your location either by the selecting the closest city or by entering the exact latitude and longitude. Once the basic information is entered, you can choose to align the 5SE in a number of ways. The Single Star align is quick and gets you up and running in minutes but is less accurate; the two-star align is far more accurate but takes a little longer. You can also auto-align or align using planets. Suffice to say, it's a comprehensive setup and thankfully all documented in the instructions.
The handset, though, has a few more tricks up its metaphorical sleeves. By connecting the accompanying RJ-11-to-serial cable to a PC, using the PCs serial port or a good serial-to-USB adapter, you can remote control the 5SE, update the firmware installed on the handset or use a third-party product such as Stellarium to greater improve the object database currently stored. There are even ports on the mount itself that can be used to connect a GPS module and an added camera control port.
We had no trouble connecting and communicating with the 5SE in Stellarium; it was a simple matter or loading the right GoTo script and setting the relevant COM port. Likewise, updating the firmware on the handset is conducted through a Java-based program that's both available on the Celestron website and on one of the three CDs. In this case, the 5SE was instantly found, and the latest firmware was downloaded, ready to be installed at a click of a button.
The trio of CDs that come with the 5SE include a PDF version of the manuals and instructions, TheSkyX First Light Edition astronomy software and NexRemote remote control software - all of which are compatible with Windows and Mac. The remote control software, once installed, will display a virtual handset identical to the one on the 5SE on the screen. From here you can control the telescope from the PC or laptop, without using the handset. But it also adds a text-to-speech function, which will talk you through the text displayed on the handset and provide any other information necessary.
The supplied software is certainly good enough for the task at hand and is simple to use. However, we felt that better control and a better astronomy software was already available with Stellarium. Plus Stellarium can be used on any OS, and thanks to the scripts already written for it, it can offer a better degree of remote control over the telescope.
Naturally, there are many other options and abilities the Celestron 5SE offers. You can attach a camera for astrophotography or a special webcam with a 1.25" fitting for filming astronomical events. And with the right hardware in place, you can control the telescope from virtually anywhere. In one instance, we connected the 5SE to a Raspberry Pi and left it outside while we retired to the warmth of our PC and opened a remote desktop session.
The Celestron NexStar 5SE is an excellent telescope, and the added benefit of its computerised functionality makes it even more alluring to both keen astronomers and computer enthusiasts alike, especially when combined with the right software. There's plenty to see and experiment with, and it would make for an ideal project and hobby for years to come. David Hayward
Ideal for the technical hobbyist and those looking for an interesting project.