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Showing posts from February, 2020

Fast radio bursts

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In January last year I wrote about Fast Radio Bursts, or FRBs. Now, there's an intriguing update. An FRB is a sudden flash of radio energy from … somewhere way, way out there, beyond our galaxy. They’re a little like a tame version of a Gamma Ray Burst, which is a slightly scary thing I wrote about a little more recently. FRBs are rare, and when I last wrote about them, they seemed random, with only two locations known to have produced more than one. Also, last time I wrote, I mentioned the new CHIME radio telescope in Canada, which was able to search large swaths of sky for these phenomena. Awesome image: CHIME   Well, the update is that CHIME (Canadian Hydrogen Intensity Mapping Experiment if you’re interested) is operational, and has been discovering FRBs hand over fist, including something really weird. One of the places we've detected FRBs, a galaxy about 500 million light years away, seems to be on a repeating cycle, of a bit over 16 days. For four days, the

Imaging at a dark sky site and in the city

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24 February 2020 Astronomy and astrophotography are always improved by going to a dark sky site. There's a bit of a debate amongst the astrophotography community about whether you can take good shots from light polluted areas. (There's really no argument, in truth, because Andy Campbell takes his photos from Burwood, which is, while not inner city, certainly not a dark sky site. Being a multiple international award winner, I think his shots probably do qualify as "good"!) This goes as much for visual astronomy as it does for astrophotography - possibly even more so. But rating visual astronomy locations is so subjective - because everyone is different, you can't make a genuine objective comparison like you can with astrophotography. Like, for example, what I've done here. Recently I stripped, modified and rebuilt my mount. Following that, I made a bunch of adjustments to tune it up. One of these adjustments required me to

Summer Birds on Farms survey

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You probably know that every three months I carry out bird surveys at a mate’s property in the Strathbogie ranges. The latest one was last weekend, and was the summer survey. Birdlife Australia has been running its birds on farms data gathering project for a few years now. The idea is twofold.  First, it encourages farmers and other rural people to become citizen scientists. This not only generates data for the project, but also educates the observers so they have a better understanding of the way birds interact with the farmed environment.  This aspect is of benefit to agriculture, as birds are often a good indicator of the health of the local environment. Knowing about the condition of the land can help land managers have healthier and more productive farms. Of course, the second benefit of the project is the generation of data over time. Understanding how bird numbers and diversity changes with weather conditions as well as time of year helps conserve the most critical habitat. It

Birds at Koonung Creek with Mickey the Lab

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Before coming in to work in the mornings, I walk the dog. Mickey the Lab likes to go to different places, and we decided to go to the Koonung Creek park, along the Eastern Freeway. It was a bright day, so I took my birding lens with me as well. The park is adjacent to the freeway, and so can be quite noisy in places, but that hasn't seemed to put the birds off. The place was quite busy that day. The grass at the western end where we began is interspersed with onion weed. Corellas, particularly Long-Billed, like to dig the corms up. I've written about these before. However, Galahs and Crested Pigeons favour this area as well. Because it was morning and we were walking roughly eastward, I didn't begin really looking for birds until after we turned back. There's little point photographing into the sun. The eastern end of the park is narrow and close to the freeway, and this is where it is noisiest. I've heard that birds who live in noisy areas tend to sing poorly, but

saxon 909EQ2 unboxing video

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Following a bit of a shuffle of display stock, I got the chance to make an unboxing video of a saxon Novo 909EQ2. This is the equatorial version of the Novo 909AZ3, and a very popular scope for the serious beginner.  My opinion about this scope is very high. It's got a good long 910mm focal length, which makes it suitable for planets (we like to say that to get a half-way decent view of Saturn's rings you need about a 90 time magnification - and even then it's a small image). It's also got a quite a passable 90mm aperture, which will show you the beginnings of the bright nebulas. Of course, clusters (open ones like the Jewel Box, or Globulars like Omega Centauri) will look very good in this scope, as they are not badly affected by light pollution. Of course, as you might know, I'm totally a refractor man, despite having been wowed by a big Dobsonian on the Orion Nebula a couple of months back. The only drawback (if you could call it that) for a beginner fo

Round 50c piece

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Most of my work colleagues, being the young kids they are, have never seen a round 50 cent piece, or even heard of them. It makes me feel a bit old. After all, they haven't been in circulation since 1967. (I've been in circulation a bit longer.) I came across one the other day in my father-in-law’s old coin collection, and decided to take a photo of it. To do this, I used a USB microscope, a Celestron Handheld Digital USB Microscope Pro . You can see the setup I used in the photo, with the microscope connected to our work laptop. I did have some trouble with the photo, because the coin is larger than the field of view of the microscope when it’s on its stand. You can see the setup here, including the image that was too large for the screen.   So, I had to hold the microscope in my hand and hover it above the coin. That meant I couldn’t get a really good steady square on shot, as my hand drifted about. So, being the geek that I am, I decided to use an astrophotographic technique

Gamma Ray Bursts

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But is it an existential threat? If you’re the anxious type, maybe you’re best not reading this… Image: NASA One of my favourite podcasters is John Green, who is known for his anxieties. He’s able to list and discuss the top 10 existential threats for humans. The other day he talked about one I hadn’t heard of before. A Gamma Ray Burst is (we think) the biggest bang in the universe. It takes the form of a focused blast of gamma rays, which are especially high energy particles. Humans only discovered GRBs when the US launched a satellite in the 1960s to monitor for Soviet nuclear tests. There are two types of GRB, neither one of which you’d like to be near, and both of which result in the creation of a black hole. The collapse of a huge star during a supernova can cause a “long” burst, of “up to a minute”. In this minute, the energy blasted into space is – get this – roughly the same as the energy our sun gives off in its entire lifetime . In January last year, NASA detected a

Zeiss Conquest Gavia unboxing video

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I haven't finished one for a while, I know, but I've put up a new unboxing video on the Optics Central YouTube channel! This one is a Zeiss Conquest Gavia 85, a spotting scope.     Mainly for birdwatchers, the Gavia zooms from 30 times to 60 times, looking through an 85mm objective. I had a fun time taking photos through it using my phone - our test target is a highly salubrious dumpster about 180 metres away on the other side of the car park. Incidentally, the bird on the box is indeed a Gavia Arctica - the Black-throated Diver (or if you're in the US, I believe they're known as the Black-throated Loon). I've never seen one - I've seen a Red-throated in Norway, will that do? You can see the video here .  You can find the whole of the Optics Central YouTube channel , including all the other times I've made a goose of myself.  Enjoy.

Paul Dodd's Horsehead

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Paul is one of my oldest friends. I was at school with him back in the 1970s. Paul is the lean-in type who has never done anything in a half measure, and is now an accomplished wildlife photographer. Like me, Paul has an interest in astronomy, and has always been fascinated with the idea of photographing the Horsehead Nebula. In order to do this, he got himself a telescope. Showing that lean-in personality again, it's a Celestron 1100 EdgeHD Scmidt-Cassegrain, mounted on a CGEM-II equatorial mount. This is a big scope, and big scopes have complications, as we found. The camera he used is a Nikon D810a, which is specifically for astrophotography, having the built-in IR filter modified to allow longer wavelengths to the sensor. This is important for the Horsehead as it's in a region rich in hydrogen, which emits light at this wavelength. Last week, I went with Paul and his wife Ruth (also a photographer) to the ASV's dark sky site. This was the scope's first