Oh wow, I have a blog!

I'd forgotten I had this- time moved quickly; I had a new job, new hobbies, new friends. Totally forgot about my poor old blog.

So what's happened since then and now? Lots of things. Had a relationship, messed it up. Spent a lot of money on telescopes. Visited Lithuania twice (it's very nice, 9/10- would rate higher, but coffee is served in very small cups).

Got better at astrophotography too. Two years ago, I posted my pics of Messier 57, the Ring Nebula. Here's a more recent attempt using narrowband filters:



And here's a picture of the Western Veil Nebula in HaRGB (true colour plus fancy narrowband data for added zazz) that I'm quite happy with:


And that's really that so far. Perhaps I'll post more later.

Looking Up

I've always been interested in astronomy and have owned a couple of telescopes, but lately it's really taken over my life. Back in March, I wound up buying a Celestron Neximage 5, which is a sort of modified webcam that you attach to your telescope to take pictures of the moon and planets. These are high-brightness objects where the main obstacle to a good picture is the state of the atmosphere. Air currents cause the image to wiggle and waver like it's at the bottom of a pan of water just on the edge of boiling. To deal with this, you take lots and lots of very short exposure pictures- perhaps as high as a hundred frames every second. Once you have your pictures, you sort through for the best and digitally stack and mess with them to bring out the sharpness. Happily, there's a lot of cheap (even free!) software that will help automate the process of taking, aligning and stacking a thousand-plus frames of video.

My first photo of the moon

Jupiter, complete with red spot. Two moons can also be seen

Mars, or possibly a space potato. The polar cap is to the upper left, the dark triangular region is Syrtis Major Planitia

Montes Caucasus region, the moon.

Saturn, with the Cassini division plainly visible in the rings

Saturn at a lower power of magnification

My first few pictures lit off something of a fire in me, so I went out and got a much better mount than the one with my telescope (a Celestron Nexstar 6se- the mount's great for visual work, but for photography, a bit wobbly and doesn't track so well)  and also a second-hand 200mm Newtonian reflecting telescope from eBay.

Next came a new camera. The neximage 5 is well suited to bright planets and the moon, but not useful for dimmer objects like star clusters, nebulas and whatnot where you don't want high framerates but long exposures of several minutes. The Neximage 5 would rapidly build up a flood of thermal noise in the picture at that kind of exposure, so I picked up a cooled astronomical CCD camera to use for deep sky work.

The problem with long exposures, though, is that it requires extremely precise tracking- if the telescope doesn't perfectly follow the motion of the stars, they will start to streak the image. Partly this can be solved by a very accurate set-up of the telescope, so that its axis points towards the celestial north pole, near where Polaris, the pole star lives. Unfortunately that's tricky for me as I don't have good visibility to the north, as the house is in the way. I have to do a bit of messing around with what's called "drift alignment", which I haven't quite mastered yet. To help with any remaining inaccuracies, most astrophotographers use auto-guiding, where they have a smaller telescope fitted to the main one, and a second camera that takes an exposure every second and feeds it to a computer that checks the star positions between frames. If there's any drift, the computer sends commands back to the telescope mount telling it to shift position slightly to line things back up.

I don't have the ability to do auto-guiding yet, what with money and stuff (maybe next pay-day...) so I hadn't tried deep-sky astrophotography until last weekend. I'd gone out to take more pictures of Saturn, but it took me longer than I expected to set up, so by the time I was ready, Saturn had ducked behind the trees. Not wanting to totally waste the night, I decided to at least try the CCD camera just to get some experience working with it.

I'd only roughly aligned the mount (the goto contoller was telling me I was out by five times the apparent diameter of the moon!), so I knew I couldn't take long exposures. I hadn't planned on doing deep-sky work, so I hadn't had the camera's cooler switched on, so long exposures would wind up with lots of thermal noise anyway. It's almost bang-on the time of year where the nights are so short they never get properly dark and I really wasn't expecting much of anything. I set the goto controller to point to Messier-57 and stared into the eyepiece at a faint grey circle that may or may not have been my imagination. Yeah, not much of anything.

I swapped the eyepiece for the camera and started up Nebulosity on my laptop. Right there in the preview window was a ghostly grey ring. I might get something out of this after all!

Exposure to 10 seconds- keep them short to avoid streaking, but switch the camera to 4x4 binned mode, where 4x4 squares of pixels in the camera are added together to make one pixel in the image, producing a lower resolution image but with sixteen times the sensitivity to light. Take a sequence of five images and let's see!

A picture! Noisy and low-res, but a picture! M57, the ring nebula, and with colours right there in the picture!

I also took some dark frames to compensate for noise and also did a set of five images at 15 seconds exposure and 2x2 binning for more resolution at the cost of less sensitivity and more trailing of the stars.

Sure, the Hubble Space Telescope may have taken far better pictures, but they had a higher budget AND ASTRONAUTS. I had a few bits of silicon and some bent glass I bought off eBay!

Is this thing still on?

It has been a while since my last post.

Things have changed in the last nearly-two-years. I changed jobs, for starters. A colleague at my last job wound up killing himself. Although I doubt it was (solely) work-related, I decided it was yet another sign I might be happier elsewhere. It hadn't helped that I'd been involved in getting the guy recruited in the first place, yet learned more about him trying to find his next of kin for the police by reading his facebook page, than I had with him sat right there in the office for months.

This is the future, slam, slam, slam.

This morning, I managed to slam my dominant hand in the office door, resulting in blood and swearing. The pain was and still is remarkable and the insistent throbbing discomfort is exactly like what it feels like to be living in modern-day England, only in my hand. Hooray!

I am in a bad mood, you see. Partly it's the announcement that the London Olympics will be protected by laser-guided hypervelocity cluster-missiles, presumably to blow up anything that doesn't have enough corporate sponsorship. Partly it's the miserable embarrassment we have for a government (and I'm including the loyal opposition in that). Partly it's how crap everything has become.

But mostly it's my hand hurting. That's a direct and immediate pain that takes all of my attention and is hard to ignore, unlike London boroughs farming their poor out to less expensive parts of the country, or the overly close attachment all our politicians have to people whose hideously disgusting personal wealth commands all their attention, unlike the ghastly poverty-stricken proles they pay lip-service to representing. Or the way the global economy seems to be committed to self-destructing. Or the way I'm nearly forty now and a sad and lonely speck in a sad and lonely world.

On a brighter note (magnitude -4 or thereabouts), here is a picture I took during last month's conjunction between the Moon and Venus. It's a bit rough as I was using my phone to take the pic as timing was everything.

Back Again

A busy day. Two software releases, goofing about with Google Fusion Tables, solving someone's problems with a phone I've never really used,  trying to work out whether I'm just imagining that everything changed in the one day I wasn't in the office on a work day, answering various customer and helpdesk queries, and triple-checking everything I type in case it gets all gibberishy.

 Next up, steam-mopping the floor a bit.

Tyred

The illness progresses apace. My nose is running like unto a tap whilst my brain is most decidedly not running at all. It keeps hitting breakpoints that I didn't set up and the stack trace seems to be for a different process entirely.

Yes, I am mixing my metaphors like I mix my drinks. Badly.

Given it took me an hour to fry three sausages, it was not the best time to get my car in to the garage for a Service and MOT. Four new tyres and the geometry realigned. I have to admit I Googled "tyre geometry realignment" to check that it wasn't a made-up thing because today they could probably have told me my Ring System needed a Cassini division and I would have gone for it. The only car where that might be an actual thing would be GM's old Saturn brand, which has gone the way of the Sega Saturn.

My face burns from the constant blowing of nose. Tomorrow, I must go to work and do a software release for one guy.

Flares Are Back!

Apparently I do requests now, as someone who shall remain nameless wanted me to post about this.


On Thusday night, I saw my first-ever Iridium flare! If you're too lazy to click on the link to Wikipedia (or they're SOPA'ed out again), I will explain it myself with lies and half-truths and everything.

Some years back, a bunch of rich idiots including but not limited to Bill Gates and Motorola decided that America knew what the world wanted in a mobile phone, namely a handset the size of a breezeblock that cost $3,000 minimum and a contract that would charge $10 a minute of calltime. 

The thing is that America is a big country that is sparsely populated for most of its territory. The cost of fitting conventional GSM towers all over the nation to give European-style levels of coverage would cost billions. BILLIONS! 

The solution? Well, how about bigger cells? Trouble is, for the shortwave frequencies that go furthest without needing huge antennas and frying the users head, the earth's curvature becomes a problem as the radio broadcasts only go out to the horizon. 

So, how do you see further over the horizon? From higher up. 

Instead of a network of hundreds of thousands of cell towers, they envisaged a network of seventy-seven satellites in low-ish Earth orbit, providing phone coverage not merely across the US, but ANYWHERE ON EARRRRTHHHH (and also in any nearby space stations). 

The seventy-seventh element in the periodic table is Iridium, so that's where they got the name. 

A couple of problems occurred. One was that Satellites are REALLY expensive, as are the rockets to launch them. The other was that GSM networks spread like crazy, even in poor countries that'd never had a fixed-line telephone network, as the cost of GSM kit was hugely less than millions of miles of copper cable. As more people bought GSM network gear, the cost went down and down and down. 

In the meantime, the cost of the satellites went up and up and up. Eventually, they had to settle on only sixty-six, but didn't rename the network to element 66, possibly because Dysprosium sucks as a name. 

Eventually, they launched their network and sold services to basically no-one outside of international news services and ultra-rich yachtsmen. They ran into financial difficulties and would have died a death if it hadn't been for a little old thing called war. 

The wars in Afghanistan and Iraq revealed that a lot of the fancy communications gear the US Armed forces had spent billions of moneys on was in a lot of ways pretty crap. All around them, embedded journalists were running round with phones that were more reliable, more rugged and more effective than the Army's own kit. The Pentagon immediately started throwing money at Iridium and everyone was happy except for the people who got bombed and shelled and stuff thanks to a phone call but they were all non-American and thus didn't count. 

Aaaaanyway, the interesting thing about Iridium is the satellites. Ignoring the one that crashed into a Russian Strela-2M communications satellite, the surviving Iridium satellites have one very interesting design feature, a pair of large, flat, mirror-finish radio antennas. 

Around dawn and dusk, passing Iridium satellites will reflect the sun's rays down to earth, appearing for a few seconds as a *really* bright moving star (up to thirty times brighter than Venus!). Some flares are visible in broad daylight! 

The great thing is they're predictable. I have an app on my Android smartphone that takes my GPS position and works out where and when I'll see a flare (actually it cheats and asks a web server to do the hard sums). Tonight, I went out at the appointed time (18:34), looked where the pointy thing said and waited. 

Out of nowhere, a star appeared. It got brighter until it looked like the main light of a plane without the wingtip lights or blinking anticollision lights; it moved steadily north-east and then faded down to invisibility again. 

I'd seen a half-tonne satellite seven hundred miles up while it was somewhere over the North Sea, a little south of Norway! 

And that was my evening.


For you kids too cool for smartphones, you can always try www.heavens-above.com as that'll do the same job as the app.