The Scruffy Astronomer

31 May 2019 Recently we heard that there was a typo on the new Australian $50 note. The $50 note features David Unaipon on one side and Edith Cowen on the other. As a security feature, the note includes microtext (which is a technical term for “really really small writing”) that relates to both of these people. Ms Cowen was Australia's first woman in parliament. On her side of the note, the microtext is an excerpt from her maiden speech, which was delivered in the Western Australian Legislative Assembly on 21 July 1921. Unfortunately, the text as printed on the note contains a typo. In several places, the word “responsibility” has been mis-spelled “responsibilty”. The showroom here has a number of microscopes set up for display, including a couple that hook up to a computer for photography. Being the geek type (all my friends gasp and say “NO!!”) I decided to see for myself. This photo shows the typo quite nicely. To take the photo, I used a Celestron Handheld Digital

29 May 2019 Some of you will have heard about this already, but we've got a Lunt LS230 solar telescope on the floor. This is a nine inch refractor, specifically for observing the surface and prominances of the Sun. Actually, it's the world's largest solar telescope, and only ten have been manufactured. Want one? Normally we warn people to never (and I mean NEVER) use an unmodified telescope to look at the sun. Clearly it's not going to do your eyes any good at all. there are a couple of ways you can do it though. First, a strong neutral density filter (like a decent chunk of welder's glass) will turn the brightness down sufficiently so you can look directly at the Sun. This is called "white light" observation, as you see all the visible frequencies (that's what a neutral density filter does). Observing in white light, you can see sunspots as grey patches, including an umbra and penumbra. The rest of the Sun is just a featureless white plain.

27 May 2019 Yikes! Did NASA just dust New York? No, they didn’t. Don’t worry. It was all an exercise. But it makes a fun read! Recently NASA and JPL hosted a conference on planetary defence – against near-Earth objects, that is, not aliens. Part of the five-day conference was a simulation of the discovery of an object on a collision course with Earth. Each day, more information was presented, and experts were asked what the best course of action would be, including options to deflect or “disrupt” the asteroid. They also discussed what would be at risk, and how to manage and mitigate damage. The hypothetical narrative that the experts were subjected to was this: In March 2019, the asteroid is discovered, and is estimated to have an impact probability of 1 in 100. At this point, most of the effort is focused on determining the fine orbit, and the size and mass of the asteroid. By July 2019, additional information has increased the probability of impact to 1 in 10. This is whe

24 May 2019 Bill (er, that's me) has done a new video for the Optics Central YouTube channel. This time I've unboxed a CGX 800, which is a Celestron CGX equatorial go-to mount with a Celestron 8" Cassegrain telescope on top. Not the biggest scope and mount we have, but plenty large enough. The video is in three parts. Part 1 is me showing off the three rather large cardboard boxes, and then opening each in turn. Like a kid at Christmas, I take out all the parts and spread them all over the floor in the showroom. In Part 2 I get all those pieces and build the tripod, mount and telescope, going through all the parts in turn. In Part 3 I turn the mount on and show a little about how it's aligned. Of course I wasn't able to do a great job for this part because it's during the day and we're indoors! I hope you get the idea though. For astrophotographers, however, I didn't go through the Celestron "precise polar alignment" routine

20 May 2019 Did you say a UFO? A few evenings ago a number of ASV members helped out at the Melbourne Montessori School for their Astronomy night. AstroBlake organised the evening, assisted ably by Sadie, Mark and Tara. Telescopes were provided by the Iscaro family, Russell, Neil, and Steve (as well as four Dobsonians provided by saxon). Unfortunately the one thing that was beyond our control was the weather, and it clouded over before Jupiter rose. But we did get some good views of the Moon and a few clusters like the Jewel Box. But what about the UFO? And as you can see, the kids found it engaging - the three round the 10" Dob were watching the Moon drifting past as displayed on my phone, which was attached using a saxon ScopePix. At least one of the kids there wants to get his own scope and liked the Dobsonian. He told me he's got enough saved already for more than half of it. Remember, no Nobel Prize winner started off with a Playstation! Neil Creek gave a

17 May 2019 Gratulerer med dagen! Today is Norwegian national day, or more specifically, Constitution day. Norway received its independence from Sweden in 1905. Over the last few months, several of our customers have been preparing for tours in Scandinavia, and especially Norway. The coastal steamer, known as the Hurtigruten, is very popular, and it's easy to see why. That's my daughter next to the M/S Nordlys, which was just approaching Kirkenes. Norway's scenery regularly ranks as 11 out of ten, especially along the West coast, with its islands and fjords. My personal favourite spot is called Aurlandsvangen, a small town near Flåm. There's a viewing platform up the mountain a way called Stegastein that looks over the Aurlandsfjord. I think it's the world's most beautiful spot. Check out the picture and prove me wrong. In order to enjoy the details of the scenery without having to lug heavy binoculars around, our customers have been buying compact b

While on our recent outback trip, we discovered that there are observatories set up in far flung places for people to visit. In Woomera, the Baker Observatory is in Carriwan Street (we got a bit lost and parked in Burrimul street and walked through). Their main building is a converted kindergarten. They have a 3.5 metre dome, which makes it quite large, and inside, they have a 14” Cassegrain telescope, which is an absolute monster. They’re open on Friday nights, but it’s best to check their Facebook page for weather details. In Andamooka, an opal mining area an hour or so up the road from Woomera, the skies are unbelievably clear. Conan Fahey is raising funds for an observatory by running night tours and classes. In particular, there’s the Mars Simulation Camp at the German Gully Mine. They also run a bookshop that specialises in Australian history, including indigenous history as well as astronomy and science fiction, amongst other subjects. The Andamooka Observatory has a web page

10 May 2019 Apart from being a birdo and an astrophotographer, I’m also a scout leader. One of the things we teach scouts is navigation, and the other day I was planning an exercise. It was pretty simple. The kids had to start at the kickoff spot on a footy oval, set the compass to a heading of 60°, and walk 100 steps in that direction. Then, they had to change direction, walking another 100 steps on heading of 300°. Finally they walk 100 steps due south. If they'd done it right, they should have found themselves back at the start. Planning it, I was armed with a very old Silva compass, which was awesome in its day. However, it wasn’t playing the game any more. The alcohol had evaporated out of the central cell so the needle wobbled all over the place rather than staying consistently north. I eventually got a reasonable result, but I couldn’t help wondering what would make the exercise better and more reliable. The answer was to use a pair of marine binoculars. The na

8 May 2019 What is colour? A strange question maybe... Recently I took a photo of NGC 6188. The Fighting Dragons of Ara is one of my favourite nebulas. I'd got a test shot last year in black and white, and really wanted more. I went up to the ASV dark sky site and got over 6 hours of images through my three narrowband filters. Then I roughly processed what I'd got on my computer. I used the free program Deep Sky Stacker to create stacked and aligned images from each filter, then recombined them in Photoshop using the "Hubble palette". Images taken through the Sulphur filter end up as red in the final image, Hydrogen goes to green and Oxygen goes to blue. This is a "false colour image". If you were there, it wouldn't look like that. If you could see it at all, it'd probably be pink. I put the photo on the ASV Facebook page, and there was some some discussion about the green colour. It's not that it's wrong, just ... unusual. One a

6 May 2019 I hadn't planned to prepare a post about the Eta Aquarids, because meteor showers can be, shall we say, "underwhelming"? However, it looks like this year, I'm wrong. The Eta Aquarids are quite spectacular, mainly due to their coming at the time of the new Moon, so the skies are dark. This meteor shower happens at the same time each year, as the Earth passes through the cloud of dust and grit left behind by Halley's Comet. Who would have thought that the vacuum of space is as full as stuff? The cloud forecasts for tomorrow morning for both Melbourne and Sydney are pretty reasonable. If you go outside at 4:30am or earlier (yes, you heard me) and look North East, the radiant (that's where the meteors appear to be coming from) is about 40° above the horizon. The meteors themselves won't be here, though. They'll appear all over the sky, so it's best to look in the darkest general areas. They're not a continuous thing, either. So

6 May 2019 Because I'm both a birder (who likes to take photos) and an astrophotographer, I'm always keeping an eye on the clouds. The other day I was walking the dog in the local park. It was humid and threatening to rain, and the clouds were fairly dramatic, as the picture shows. There was a thin band of dark, mid-level cloud starting to form ahead of a rain band, but above that was a large gap, with much higher cloud behind it. But there was a stripe across the sky, which was dark in the middle with light edges. What was it, and what caused it? It was an aeroplane approaching Tullamarine. It had been flying in the clear area between the two cloud layers and was just descending into the thin lower layer. My guess is that the plane's wings were pushing the air immediately below it downwards into the clear air below, while vortices at the end of the plane's wings were pushing the air there upwards into the layer above. The band of cloud must have been pretty thi