Stargazing

By Mark Hanna 06/04/2014


As I mentioned in an earlier post, after looking up at the night sky through binoculars for the first time over my summer holiday, I decided to buy a telescope this year. On the 27th of January, I went to see a show at the local observatory, Stardome, and ended up talking to one of the staff about the telescopes they had on sale. I came home the excited new owner of a “Celestron Powerseeker 114EQ”.

My new telescope

My new telescope

It’s a “Newtonian” telescope, also known as a “reflector”. It uses a mirror to gather light, as opposed to a “refractor” that uses a lens. The light comes in the front of my telescope and hits a concave mirror 114 mm in diamater at the other end of the tube, where it is bounced back up to a flat mirror near the opening that reflects the light out the side into the eyepiece. I have 3 eyepieces that give 45x, 90x, and 100x magnification.

My first target was Jupiter, which I’d got a brief glimpse of from one of Stardome’s much more expensive telescopes after the show I saw. When viewing it from home, I was thrilled to be able to make out its 4 Galilean moons, and tried taking a photo. It turns out, as you might be able to guess, that holding an iPhone 4 camera up against the eyepiece of a telescope in the dark, then holding it steady and pressing the “take a photo” button without bumping the phone, is actually pretty hard. I got very lucky though, and the first photograph I took clearly showed an overexposed Jupiter and its 4 largest moons:

Jupiter and the 4 Galilean moons. In no particular order: Io, Europa, Ganymede, and Callisto

Jupiter and the 4 Galilean moons. In no particular order: Io, Europa, Ganymede, and Callisto

Some time later, I was also lucky enough to take a recognisable photo of Saturn using the same technique:

Saturn. It appears on its side because of the angle I was viewing it from. Click through to see the full image.

Saturn. It appears on its side because of the angle I was viewing it from. Click through to see the full image.

That picture was taken with the highest magnification eyepiece, which has a lens only about 6 mm in diameter. It was really difficult to hold my phone steady for this, even with the trick I’d learned of using the iPhone headphones’ volume buttons as a remote for the camera app. After this, I decided I should look to see if I could buy an adapter to fit my iPhone directly onto my telescope, but while searching for one I found an article about how to make your own adapter. I didn’t follow the steps in that article, but I did decide to give it a shot. I found a piece of plastic, an old cover for part of a swimming pool pump, that fit perfectly over my telescope’s eyepiece, and put it together with a bunch of foamboard and glue to get the final product. Here are a few pictures of the process:

The first layer

The first layer

The plastic backing

The plastic backing

The second layer

The second layer

The 2 pieces combined

The 2 pieces combined

Trying it out. It was a bit heavy at this stage, and overbalanced my telescope

Trying it out. It was a bit heavy at this stage, and overbalanced my telescope

Cutting it down to size

Cutting it down to size

All trimmed down. After this I sanded the edges and it was good to go

All trimmed down. After this I sanded the edges and it was good to go

Using this new adapter and some astrophotography image processing software called Registax that lets me combine multiple images or frames of a video to form a single clean image, I’ve been easily able to take some clear images of Jupiter, the Moon, and Saturn:

Jupiter, with some of the cloud bands clearly visible. Click to see the full image.

Jupiter, with some of the cloud bands visible. Click to see the full image.

The waxing crescent Moon. Click to see the full image.

The waxing crescent Moon. Click to see the full image.

Saturn, rings and all. Click to see the full image.

Saturn, rings and all. Click to see the full image.

Registax also allows for a bit of processing to remove noise and sharpen the image. I’m not sure what I think of this yet, as I’m pretty much flailing blindly and to be honest it feels a bit like cheating, but here’s what came out the other end when I applied some of its filters to that Saturn image:

Processing image of Saturn to remove noise and sharpen it. Click to see the full image.

Processing image of Saturn to remove noise and sharpen it. Click to see the full image.

I also took some photos of Mars, but they’re all horribly overexposed and not really worth looking at. I’ve been having trouble seeing anything aside from just a circle of light when it comes to Mars. It’s tough using an iPhone 4 as a camera. It’s not possible to manually change settings like focus or exposure, and in order to take photos and videos of Jupiter that weren’t overexposed I had to lock the camera’s settings on the brightest part of the Moon (done not by tapping to focus like usual but by holding my finger on the spot for a second or so). Luckily Jupiter and the Moon are quite close in the sky at the moment so that wasn’t too much effort, but moving the telescope back and forth between the Moon and Mars was quite annoying. I’m sure there’s a better way that I’m yet to find. It possibly involves buying a decent camera.

One other thing I was finally able to do last night is resolve the Alpha Centauri system (the outermost of the 2 “pointers” that show the way to the Southern Cross) as a binary star system. I wasn’t able to photograph it though, the stars still appear very close together and my phone overexposed them to look like a single star. I guess that’s a challenge for another night.

I’m also quite looking forward to the upcoming total lunar eclipse on the 15th of April. Although I’ve read that the Moon is meant to turn a dark red during the totality of the eclipse, I’m not really sure what to expect when it comes to viewing or photographing it, which I find pretty exciting.