Swimming, 13th August 2019

Posted on August 20, 2019 by james

Warm pool again, so no USRPT. “Fast fifty” of 41.28s. All of a sudden, 41s looks beatable!

USRPT distance this year: 165,800m
Total distance this year: 210,300m

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Swimming, 12th August 2019

Posted on August 20, 2019 by james

Another week, and the pool is still too warm. As I can’t really work on a proper USRT set, to amuse myself after doing my currently passes for my main set I’ve decided to have a couple of minutes rest and then do a single 50m swim as fast as I can go.

I did the first last time I swam and managed 42.16s, making the 42s barrier look quite breakable. Today my “fast fifty” was 41.69s. Something of a shock as I didn’t expect quite such an improvement, but I’ll take that. Now to see how much further I can get.

USRPT distance this year: 165,800m
Total distance this year: 208,500m

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Blobservatory Bitter

Posted on August 20, 2019 by james

Having spent so much time over the last *mumble* months building the observatory, my brewery (which stands right next door) has been sadly neglected. We have even reached the scandalous situation where my wife has occasionally had to actually buy beer from real shops!

Now I’ve I finally got around to getting in there and having a bit of a tidy up. As I posted my first proper image from the observatory (albeit not a great one) I decided that I should brew a beer to celebrate the observatory becoming properly functional. My choice of ingredients was a bit limited on the spur of the moment, but in the freezer I found some Challenger hops (who doesn’t keep hops in their freezer?) which seemed suitably space-themed to me, so that was where I started.

I ground a mix of pale, crystal and black malt (about seven and a half kilos in total — I’d forgotten how hard that is by hand)

Because I should consider my health, I added half a kilo of cornflakes

(not really, but it is flaked maize) and set it all up to mash in about 20 litres of water at 66C

An hour and a half later everything was rinsed through with another 25l of water to try to extract the last of the sugars

And into the boiler it went, with the first batch of hops

It takes a fair while to get 45l of water up to a boil even with two 2.4kW kettle elements, but it got there eventually and after another hour and a half I drew off the wort to leave to cool and got cleaned up. Sadly I don’t have a chiller to drop the temperature down to room temperature straight after the boil.

I’m just about to nip back out to wake some yeast up, and tomorrow I’ll measure the gravity and put it all in the fermentation cabinet for about ten days to a couple of weeks. Then I can bottle it and perhaps it should be ready to taste by the autumn equinox.

If it goes well I think space-related brews could become a bit of a theme. It’s tempting to make an 80/- style bitter so I can kick back and watch a Space-X launch with a pint of “Falcon Heavy” 😀

There are a number of other hops with space-related names, too. Galaxy is one, and I think Aurora too. I’m definitely seeing the beginnings of a plan here…

(I left the full recipe in the beer shack. I’ll fetch it tomorrow and add it to this post.)

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M27 revisited

Posted on August 20, 2019 by james

Whilst messing about with aligning my other mounts I decided I couldn’t pass up the opportunity to get a bit of imaging done with the first, despite not having spend any time improving the sky model, nor having any guiding, or dew heaters, or …

M27 has always been a favourite, so I slewed over to it, plate-solved and slewed to it again (seems like it must have moved) and started capturing a few short subs. I hadn’t done very many before discovering that the camera I was planning to use for the next alignment wasn’t working and I’d need to use the one I was imaging with so had to stop.

Nevertheless, I stacked what I was left with, it being my first DSO image in quite some years, and here’s what I got:

Nothing special. Needs more and longer subs, but I’m happy enough to get a clearly-identifiable image at this point.

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Telescope Polar Alignment, Part Two

Posted on August 20, 2019 by james

The computery side of my observatory is going to be Linux-based, as far as possible, so I’ve had it in the back of my head that I’d be running something like Kstars and Ekos to control the mount and other kit. I discovered that Ekos has a polar alignment system based on plate-solving and thought it would be worth a try to see if I could do better than I’d managed with PHD2.

So, back to the observatory having installed Kstars, all the necessary bits of INDI (from the Launchpad PPA), astrometry.net and the astrometry index files on the laptop (the latter taking several hours over my lightning fast ADSL connection). The plate-solving can be done over the net, but the network connection to the observatory isn’t great and it’s much faster to do locally.

Ekos takes three images near the pole, calculates the centre of rotation of the mount axis and how it needs to move to coincide with the celestial pole and then overlays a line on the camera image (which can be moved to line up with a handy star) to show what movement is required.

As with PHD I found this a bit awkward when both ends of the line don’t fit on the image, but as long as I got one end visible and adjusted the mount to move a star as far as possible in the right direction, it was just a case of repeating the process to narrow down the error. It took me a while to get the hang of it, but once I’d got my head around which directions the adjusters moved the star in any given direction it became easier.

Using this process I got the polar alignment error measurement down to less than one minute of arc and thus encouraged moved the camera over to the TS Optics Photoline 72 on the second NEQ6, achieving a similar degree of error quite quickly.

My third mount (a HEQ5) however doesn’t have a view of the polar region so this method wasn’t going to be possible. I decided to leave it for the time being and consider what other options I might have.

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Telescope mount polar alignment

Posted on August 20, 2019 by james

The observatory having reached a point where it’s usable, the first job was polar alignment of the RA axis of the mounts. When setting up on a nightly basis I’ve always just tried to get Polaris in roughly the right place in the polar scope reticle, but now the mounts are on permanent piers I thought I should try something better.

It struck me that the easiest way to do this would be to ignore the PCs that are going to run the mounts long-term (because the display is in the warm room), fit a camera and telescope to the mount and plug them all into my laptop, allowing me to stand at the mount and adjust its position whilst looking at the laptop screen.

The first mount was one of the NEQ6s, with a Skywatcher ED80 and ASI174MM. I booted the laptop into Windows, started up Cartes du Ciel, EQMOD and PHD2. Once PHD2 had recognised the camera I spent a happy few minutes trying to find focus before realising that I’d need a fairly big extension because there just wasn’t enough backfocus. A 60mm T2 extension screwed onto the back of the drawtube and into the camera did the job nicely. I opened the alignment tool in PHD2, pointed the telescope where it needed to be (using CdC) and set about adjusting the mount according to the guide trace.

I don’t know why, but I found the whole process quite awkward. Partially I think it’s because the alt adjustment on the NEQ6 is just rubbish for UK latitudes. Not being able to see the circle shown as the target for moving the guide star because I wasn’t sufficiently close already was a pain, too. Especially when I could see only part of the circle and in fact I needed to be moving the mount in the opposite direction. Sometimes I’d think I was getting close only to find that the next test run showed the alignment as being much further away.

In the end I got to within about 5 arcminutes of the pole and decided that was as good as I could get, but I wasn’t really happy because I felt I should be able to do better.

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Lunar Eclipse, July 2019

Posted on August 13, 2019 by james

I’d forgotten I had these, but July this year found me in France for the lunar eclipse. By complete coincidence the second summer holiday in a row where I’d been able to watch a lunar eclipse. Sadly I was ill-prepared for this one and had only a compact camera to take a few photos that in the main didn’t come out very well.

Regardless I managed to watch the eclipse from shortly after moonrise (I had to wait for it to clear some trees to the south) to the end. I need to plan better for next time I think.

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Linux Mint 19 on an HP EliteDesk 800 G1 Mini

Posted on August 12, 2019 by james

I picked up a couple of these second-hand recently, to use in the observatory. They came with Windows 10 installed, but I don’t care about that. I want to run Linux Mint on them.

I tried a couple of times to install from my Mint 19 DVD, but just kept getting the error:

The 'grub-efi-amd64-signed' package failed to install into /target/

Something about UEFI seems to mess things up. It made no difference if I removed the Windows boot entry using efibootmgr from the live desktop, or even if I deleted the entire partition table from the disk. I always got the same error. It took me quite a while to find a solution. What finally worked was this:

Once the above error occurs, allow the install process to stop and then open a terminal window. In the window, use sudo to get a root shell (“sudo -s”). The first thing I needed to do was to edit /etc/hosts to add some of the hostnames that would be used later by apt-get. I don’t know if this is a problem specific to my setup or will generally be the case, but I added entries for packages.linuxmint.com, archive.ubuntu.com and security.ubuntu.com to the file, using another machine to look up the IP addresses (and just picking one where there were several). At the time of writing, I added:

208.77.20.11 packages.linuxmint.com
91.189.88.24 archive.ubuntu.com security.ubuntu.com

There’s a Canonical host used too, but I just ignored the errors about that in apt-get.

The next step is to run the following commands (all as root)

# mkdir -p /mnt/boot/efi
# mount /dev/sda2 /mnt
# mount /dev/sda1 /mnt/boot/efi
# for i in /dev /dev/pts /proc /sys; do mount -B $i /mnt$i; done
# chroot /mnt
# apt-get update
# apt-get install ubuntu-system-adjustments
# apt install --reinstall grub-efi-amd64-signed
# os-prober
# update-grub
# ^D

At that point I was able to restart the machine and it booted straight into Mint 19.

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Swimming, 9th August 2019

Posted on August 10, 2019 by james

Had a bit of barney with Mrs Indignant Triathlete today, who wasn’t chuffed to be asked to move into the slower lane to allow my son and I to swim in the faster one. She claimed to be able to swim a 1’20s 100m freestyle (which is faster than I can do it), clearly intending to suggest that it was me who should be in the slow lane. Only she then proceeded to swim 1’20s 50s compared with mine of about 48s and my son’s of something like ten seconds faster than that. Even including my rest interval I was faster than her over 50m. Hey ho.

USRPT distance this year: 165,800m
Total distance this year: 206,700m

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Swimming, 8th August 2019

Posted on August 10, 2019 by james

And another warm water day…

USRPT distance this year: 165,800m
Total distance this year: 204,900m

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