The Scruffy Astronomer

1 November 2019 This remarkable photo was published on the Australian Amateur Astrophotography Facebook page by Kelvin Hennessy. It’s a group of climbers on the Q1 building in Surfers Paradise with the full moon behind them. I had to ask Kelvin how he took it. Kelvin told me that he was inspired by Luke Taylor’s videos of the full moon rising behind the Cape Byron Lighthouse. He wanted to try has own version using the top of the Q1 building as a target. The telescope he used was a saxon 127mm FCD100. This is a triplet refractor which is normally used for astronomical work, as it has virtually no chromatic aberration. For Melbourne residents we have one in our showroom if you want to see it. I was surprised at the mount Kelvin used – it’s a saxon AZ3. You can see it in the photo that Kelvin sent me (and which I’ve brightened heavily). Kelvin says the mount works fine as long as it isn’t windy! I asked Kelvin how he planned the photo. For initial planning, he uses Photograp

30 October 2019 This is one of those rarer posts where I combine my two interests - birdwatching and astronomy. I've posted before about the surveys birders can help with. Birdlife Australia run a longitudinal survey called Birds on Farms ( https://www.birdlife.org.au/projects/woodland-birds-for-biodiversity/birds-on-farms-wl ). The intention is to get a better understanding of how birds interact with various forms of agriculture, particularly on rural and private properties. I like the citizen science aspect of these surveys. it's a way of making public use of my hobby. I'm not a top-level birder and can't reliably identify every one of the birds I hear. But you don't have to be an expert to get involved. Hear? Yes, most of the time, in a forest, especially, you don't see the birds, but instead hear them. Birds have distinct calls, of course, and most people know a Kookaburra when they hear one, but they also have alarm calls, contact calls, territorial calls,

Today’s message is an update on the Tawny Frogmouth nests in my local park. As far as I know, there are three nesting sites at Hays Paddock in East Kew. I’m sorry to have to report that one of the nests has failed. Nest failure isn’t uncommon with Tawnies. Even at the best of times the nest is flimsy, often nothing more than a dozen or so twigs laid across a horizontal fork in the branch. A strong gust of wind will dislodge the platform, sending the young chicks to the ground, but chicks can simply fall off, and I’ve heard that parents can even accidentally knock the chicks out of the nest. I’ve attached a photo of a typical Tawny Frogmouth nest. As you can see, there’s not much to see. I found two dead chicks at the base of the tree a few mornings ago. Being your typical birdo, I took a close-up photo of one of the chicks and asked on the Birding-Aus Facebook page to confirm my ID. The chick was about 10cm in length from beak to tail, and was covered in white down, with no feathe

28 October 2019 I've been busy blogging on lists lately. The latest one is the " top 10 telescopes for 2019 ". This is different to the Christmas gift list as I wasn't restricted by price (mwa ha ha!) In order to narrow it all down, I split the competition into categories, so I've chosen the following: Two basic scopes Two telescopes for viewing planets One telescope for viewing galaxies and nebulas One scope for short period astrophotography Three scopes for long period astrophotography (can you guess why?) One scope for terrestrial viewing One pair of astronomical binoculars Have a look at my choices and see if you agree or disagree. If you have any other suggestions, let me know in the comments. I'll be particularly interested in hearing from people who have bought scopes and what they think of them. Incidentally, I took the glamour photo of the Esprit 100 while making the unboxing video . Its proud owner knows who he is. He also kno

24 October 2019 Ever wondered what’s inside your binoculars? Take it from me, there’s some complicated stuff in there. The most important part of the binocular is the pair of prisms between the lenses. Without these, you’d be seeing upside-down. Design and quality of prisms can make a great difference to the quality of the image you see through the binoculars. They can also make a big difference to the look of the binoculars themselves. The older-style “porro” binoculars, with their characteristic zig-zag shape, have largely been displaced by “roof prism” binoculars, which have a straight-through look. This may or may not be a good thing, as while roof prism binoculars are more compact, more robust and easier to waterproof, most of them don’t provide as bright an image as their predecessors. Thanks to our friends at saxon, I got to pull a pair of binoculars apart and investigate the prisms inside them. I’ve written a blog about it (at http://www.opticscentral.com.au/blog/bi

23 October 2019 Remember a couple of weeks ago I posted my narrowband Helix photo? Well a while later, ASV member Geoff Healey posted a visible light photo of the same object. It's labelled "LRGB". Compare the two photos here. My photo (HOO) is an image captured using two filters that only pick up a pair of highly specific colours. One colour, a pinkish "Hydrogen" is displayed as red on the computer screen, and a teal "Oxygen" is displayed on both the blue and green pixels on the screen. If you look closely, they're quite different. Geoff's images is "true colour" and mine is "false colour". But there are a couple of other differences. You'll note that Geoff's image has lots more stars in it than mine. Geoff's camera accepts the whole spectrum, so it allows a lot more light in, including light near infra-red and ultra-violet. My filters accept light from the nebula but shut out a lot of the rest - to

19 October 2019 We’ve just uploaded a new unboxing video . Optics Central’s astrophotographer, Bill has unboxed the latest version of the Sky-Watcher Star Discovery 127mm Maksutov. This is a small telescope with a lot of magnification, and the 2019 version has an updated handbox as well as built-in wi-fi. The scope itself is compact but has a long 1500mm focal length, making it a planetary specialist. You can see the larger planets in some detail, as well as seeing individual craters on the Moon. The scope comes on a computerised go-to mount, which now has built-in wi-fi, meaning you have a choice between controlling it with the hand box or by using the SynScan app on your smart device. Either way, you will be able to choose from a list of 42,000 objects, and the telescope will move itself to locate them for you. Go watch the video and see for yourself.

18 October 2019 The other day I read on the ABC website that our Milky Way galaxy is likely to be “eaten” by Andromeda . If there’s one thing I can’t stand, it’s clickbait. No, we’re not all about to die. First, it’s not expected to happen for another 4.5 billion years. So I wouldn’t be too fussed about it if I were you. Second, galaxies might look pretty substantial, but honestly, they’re not. Probably the most crowded place I can think of in the current universe would be a globular cluster, such as Omega Centauri (this is my shot). To give you an idea of how crowded these places are, Alpha Centauri, the closest star to the Earth, is about four light years away. The stars in a cluster like this are about one light year apart on average. Of course, in the densest part, they’re much closer - down to one light day apart. Life as we know it (Jim) in there just wouldn’t be possible. Star collisions here are a genuine possibility. Not only that, any planet would be torn away from

14 October 2019 You can do this! I've seen few photos of the Space Station taken with affordable gear before. This one is fantastic. Jim Hammond took this shot from his driveway in Oregon in the USA (yeah, I rarely post photos from outside of Oz). Jim's rig is a Sky-Watcher 102mm Maksutov on an EQ2 mount (www.opticscentral.com.au/skywatcher-102mm-eq-maksutov-cassegrain-telescope.html). The Mak has a mylar sun filter (like www.opticscentral.com.au/skywatcher-127mm-solar-filter-for-maksutov-cassegrain-telescopes.html), and on the back was a Nikon DSLR. Everything else was technique. Jim knew the exact moment the ISS was going to pass in front of the sun from transit-finder.com, given his location. On the day, Jim used a watch synchronised to the Internet. For Iridium flares, I've used my GPS. Jim needed a really fast shot or the image would blur. Experience suggested 1/1000s at ISO 400, but that depends on your scope. On continuous shooting, Jim's camera t

9 October 2019 This is the best time of year for NGC 253, the Sculptor Galaxy. Here’s a terrific image taken by our mate Adrian up at the ASV’s dark sky site a couple of weeks back. I was up there on the same night. Adrian uses a saxon 200DS Newtonian, which he got from Optics Central about a year back. It has a pretty fast focal ratio of 5, which means it’s good for photography. It’s on a saxon NEQ6 mount he got at the same time. You can see it below. This alone is a great setup. But he's upgraded it. Adrian has a ZWO ASI294MC, a colour camera with a “four-thirds” size sensor, similar to a DSLR but more sensitive to near-infrared colours. The large sensor combines with the scope's 1000mm focal length to give a nice wide field - which is good for large nebulas. On top of this an IR cut filter helps with that awful “star bloat”. Since buying the mount and scope, Adrian has added a laptop computer, which can replace the mount’s hand controller. Having the computer also me

This was originally five separate Facebook posts. It's been republished by the Astronomical Society of Victoria and in a couple of other places as well. Although I think it was originally a pile of notes that got saved after my university course in History and Philosophy of Science from the mid 1980s. 1: Introduction 4 October 2019 What happens when objective observation comes up against hubris? Hubris wins. At first. I'm going to spin out a yarn. It's quite a good one, about how humans figured out how the planets move through the sky. It also shows a lot about how humans began asking the big questions: of "what?" and more importantly "why?" That humans ask themselves these questions about pretty much everything is, I think, the thing that sets us apart. That these questions are unanswerable doesn't matter - it's a goal that drives our understanding, not only of astronomy, but in fields as diverse as psychology and economics. But it

Last weekend, I got up to the dark sky site. It was the first time I'd been up there on a weekend for about a year, due to work commitments. Normally, I go on a Wednesday night and there is rarely anyone else there. It was both a new moon and a long weekend. I was still surprised by how many people were up there; there were probably 20 people in total, including several kids. Most of them I knew already, and it was marvelous to catch up with them all again. That's one of the things I like about astronomy and the ASV, it's a very friendly bunch. The target for the evening was NGC 7293, the Helix nebula, and I intended to get a full narrowband photo, made up of sub-images taken through Hydrogen alpha, Oxygen III and Sulphur II filters. I set up on a pier, threw a towel over the scope to keep the sun off it and went and socialised while I waited for sunset. Once the stars began to come out, I did my polar alignment, set up my auto focus and found the target. It'