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Showing posts from April, 2020

Pareidolia - seeing things that aren't there

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Do you suffer from pareidolia? Nearly everyone sees objects in clouds. Some people see faces in toast. My wife says that, as a child, she used to see teddy bears' faces in knot patterns in her bedroom's wood panelling. Your brain is very good at making out objects in backgrounds, even when the object isn't actually there. It doesn't have to be images that our brains try to make sense of. Norwegian farmers feared the Fossegrime, a spirit that lived in waterfalls, luring people through sound. In the white noise coming from rushing water, our brains can nearly make out speech. Victims of the Fossegrime, looking for the source, would come nearer and nearer the dangerous waters, eventually to be taken by the malevolent spirit. The Moon is a fertile source of pareidolic images. A while back I wrote a piece on the "Lunar X" , as well as a few other features. Certainly, everyone has heard of the man in the Moon. That image doesn't stand out quite so much here in

Scotch College Observatory photo

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My mate Mal has always been a photographer, right from when I met him at primary school in 1974. This wasn't taken then, though, I think it would have been about 1978, and I think he was mucking around with some high-contrast film. I might look casual, but I must have been teetering on a ladder! The dome is my secondary school's observatory (yes, I went to Scotch College, don't judge me). I was in the Astronomy club from the very first year I was there.  I spent so much time in the observatory with a handful of mates - several of which I'm still friends with. It was, I guess, a bit of an escape from the harsh environment that was secondary school in the 1970s. We had observation nights every term or so, and the scope in the dome was a 4" Unitron on a clockwork driven equatorial mount. We also had a 6" Newtonian reflector on an equatorial mount which was itself on a mobile pier, as well as a Brass Monster - a refractor on a wooden tripod. I was never a huge fan

The Bat and Squid Nebulas from Germany

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Here's a photo from a friend, Pete, who lives in Germany. It's a story of collaboration between different objects. Peter got into astrophotography in 2014, and has steadily developed has talents and equipment ever since. Like most of us, he started with a DSLR, but now uses a dedicated astrophotographic sensor. He also has two triplet refractors that he uses from a fixed pier. The first collaboration is the object itself. Clearly, there are two separate structures here. The red nebula is Sh2-129, or the Flying Bat. The blue nebula is the very recently (2011) discovered Ou4, or the Squid.  Apparently, both occupy the same area in space - one is not behind the other. The only sad part is that you can't see any of this from Australia. The Squid Nebula gets its shape from jets from the triple star system in its middle. The blue shock-waves are rich in ionised Oxygen, which is very dim. It's no surprise that the Squid was only discovered in 2011. In contrast, the Bat is very

Carina from home during lockdown

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As you probably know, I do most of my astrophotography from the ASV's excellent dark sky site in Central Victoria. To make my narrowband images, I combine black and white photos taken using filters to make a full false-colour image. But with the Coronavirus, the dark sky site has been closed. I have to take photos from my light-polluted back yard. To quote Edmund Blackadder, "needs must when the devil vomits in your breakfast". Last Monday, the first half of the night was forecast to be clear, so I set up in the back yard and went for the Carina Nebula. This is a bright nebula and therefore less affected by light pollution. After my setup routine, including polar aligning, focusing and framing up the nebula, I started getting images. My first batch was a stack with the Oxygen filter. Oxygen is naturally a blue colour, and I normally present it as blue in the final image. I've attached the Oxygen photo.   Next, I started on my Sulphur filter. I intended to map this to

Comet Hale-Bopp from 1997

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What do you do when you're stuck inside and can't go to any dark sky sites? You rummage through old photos. This photo was taken in April 1997 - just over 23 years ago now. My wife and I were living in Bergen in Norway while Jan did a post-doctoral fellowship at the University there. I had little to do apart from do a series of Language and Culture course and act as a tour guide for visiting friends, including Marilyn. Like me, Marilyn is a birdo and an astronomer. However, at that stage I wasn't into birds. It was Marilyn's visit that set me on that particular course, and she became my much-respected birding mentor. But that's not what I'm talking about here. The comet behind the three of us is C/1995 O1 Hale-Bopp. This is probably the most well-known comet after Halley, and it was observed for over a year during its bright and spectacular 1997 flyby. Most comets are periodical, meaning they return regularly. This is because they're in orbit around the sun

Folding solar panels for satellites

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Satellites need electricity to run electronics, mostly for communications and control systems, but also, if they're up there for scientific purposes, for whatever experiments they're doing. Most - not all - of these satellites use solar panels as power sources. You probably know that the Voyager spacecraft used nuclear cells for power. That's because they were travelling out of the solar system and sunlight out there is very weak. Space agencies have to transport large solar sails into orbit. Clearly, these can't be sent up all in one piece. The solar sail has to be broken down into components, the largest part being small enough to fit into a small capsule. But the real complication is figuring out how to assemble all these small parts using the very least amount of work.  If the panel is going to the ISS, some of the work can be done by astronauts, but even then, their time is very precious and work done outside is very difficult and dangerous. But most panels are des

Shaun's Carina

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Have a look at this shot of the Carina Nebula. It was taken by our mate Shaun. Shaun has been a photographer for ages, and has a pretty large collection of equipment to prove it. He's mostly been into wildlife and air show photos, but a long-time fascination with things astronomical led him to start his journey into astrophotography last year. Like me, Shaun uses an NEQ6 equatorial mount. Unlike me though, this was his first-ever mount. Clearly Shaun is not one of the faint-hearted. For a telescope, he started with a Sky-Watcher Star Travel 120 doublet refractor (which is the same as a saxon 1206) coupled with a DSLR. It wasn't long before he realised that he wanted to dive into the deep end with narrowband images. He tells me that these can show the wonders that exist in the universe - well beyond what our eyes can see. For the technically minded, the image was taken using a saxon 80mm FCD100 triplet refractor, coupled with a ZWO ASI1600GT. This is a relatively new camera from

Black Knight

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Remember last April, I was talking about space junk and the possibility of a " runaway Kessler Syndrome "? This is when the amount of space junk flying around means anything in orbit will be destroyed by debris. In the worst case scenario, humans could be stranded on Earth because of the Orbiting Cloud of Death . (I ought to write a SciFi novel with that premise.) If there's going to be a Kessler syndrome, the most likely cause will be debris created by satellites being destroyed by existing space junk. Wikipedia lists at least five instances where satellites have been damaged or destroyed in collisions with space junk or "micrometeoroids". As well, space shuttles and the ISS have been hit and damaged by tiny bits of debris. This photo was taken from the Space Shuttle in 1998. I think it's a thermal blanket from the same mission, not an alien spacecraft. Seriously. Search for "Black Knight satellite conspiracy theory". Another source of space junk

Frustrations of astrophotography

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Astrophotography can be frustrating. Right now, from the Earth’s perspective, Jupiter, Saturn and Mars appear close together in the sky. This conjunction is quite a pretty sight, although you have to get up early in the morning to see it, as it’s fairly low in the East. From my latitude (38° South), Jupiter is out on its own, blazing away higher than the others. Saturn and Mars are closer to each other, with Saturn slightly higher. Mars itself is clearly redder, but is similar in brightness to Saturn. The whole conjunction is wedged in between the constellations of Sagittarius and Capricorn.  My back yard faces East, but it’s up a hill and there are some tall trees blocking the view. Last night I woke up at about 3am so I thought I’d give it a whirl anyway. As it was a very wide field I decided to use my DSLR with a 70mm lens, which gave me the right sized view. I grabbed the tripod and stumbled out into the darkness.     Jupiter was blazing brightly, but it was through a tree. Mars an

Coronavirus lockdown: Park birds

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Well, our world is getting smaller. During the Coronavirus restrictions (in Victoria at least) we're requested not to travel unnecessarily. So my birding expeditions are restricted to Hays Paddock or other nearby dog walking parks. I can go to Chelsworth Park in Ivanhoe or up the Koonung Creek trail. I’ve been watching a White-faced Heron over the last couple of weeks. Each morning it patrols two ovals where I walk my dog. The ovals are watered overnight, and this leaves the ground quite wet. In turn, this brings creepy-crawlies to the surface where the Heron can nab them. A week or so back there was a second Heron there, but I’ve only seen the two on a couple of occasions. The same watering regimen seems to attract other grazing birds to the ovals. A couple of weeks ago there was a medium-sized mixed flock Australian White and Straw-necked. Ibis, particularly the White, are famous bin chickens, and in Sydney they’re quite a problem for people eating their lunch in parks. Here in M