2026
March
5
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Jupiter, done properly
This evening (March 5) I used the 8-inch telescope to photograph Jupiter properly
(without the f/7 reducer, and with a camera with smaller pixels).
This is a stack of the best 25% of 9,105 video frames with a ToupTek 678 color camera.
I also had my first visual astronomy session, brief though it was, since both eyes fully
recovered from cataract surgery and the blurry spots that troubled me for a few weeks.
An ophthalmologist with whom I correspond about astronomy has suggested that they were
stray particles left over from removing the old lens, and adhering to the posterior
capsule or something near it, and they dissolved. We may never know, but they're gone.
I can truthfully describe the implanted lenses as better than new.
There are no unwelcome optical effects when I look through the eyepiece,
and even at 400×, which is almost too high a power for this telescope,
I get a much smoother view than even 20 years ago; the artificial lens doesn't
have the specks and spots that were always inherent in the natural one.
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2026
March
4
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Dual-booting Linux with Windows 11
On my do-everything 14-inch ThinkPad, which I take to the library and everywhere
else I do work, I needed to actually run Linux, not just WSL. So I set it up to
dual-boot. Lots of web pages tell you how to do this;
where I will mention some unobvious details.
It's not quite the same as dual-booting Windows 10 with Linux.
Most things are the same, but what has changed is that under Windows 11,
BitLocker disk encryption is more or less compulsory.
You can turn it off, but Windows updates are liable to turn it on again.
And I want to have it in place, so that if someone steals my laptop
or obtains the flash drive from it, they won't be able to read my data.
My first attempt was a disaster — Linux was happy as a clam (or penguin), GRUB worked so
that I could choose operating systems when booting, but Windows asked for the BitLocker recovery
key every time it booted. Fortunately I had my key available (I had to go home to get
it), but that wasn't acceptable. What was wrong?!
I searched online for answers and ended up completely undoing the Linux installation —
deleting the partition it was installed on, using bootsect to fix Windows
(subtle; it involved mounting the boot sector as drive S), and even hiding "ubuntu"
in the UEFI boot menu.
Well, toward the end of that process I found out what was wrong.
Windows demands the BitLocker key if Secure Boot is turned off in BIOS (UEFI).
The problem may not have been Linux at all!
But installing Linux with the wrong options can apparently cause Secure Boot to turn off,
and wiping out every last trace of Linux doesn't fix it.
So the second time, I did everything right:
- Used Disk Manager to shrink my main Windows partition, gaining a 128-MB free-space partition
into which to install Linux.
- Suspended BitLocker temporarily, knowing it would turn back on the next time Windows started up.
- Restarted and pressed F1 to get into the UEFI menu; made sure Secure Boot was turned on.
- Booted Linux Mint from a bootable USB drive and chose "Install Linux Mint."
- For the installation options I chose "Something else" and directed it to my 128-MB partition.
(It might well have found that if I had taken the default; I don't know; but that's how I've done
it in the past.)
- Also in the installation options, I made sure Secure Boot was enabled. This required
making up a password, which I stored away carefully though I don't know why I'll need it.
Linux is nowadays compatible with Secure Boot.
That gave me a successful Linux installation, with GRUB for choosing operating systems.
There were three remaining concerns.
Time zones: If Windows sets the system clock automatically (as mine does), Linux has to be told
to run on local time rather than UT (GMT), or it will reset the system clock several hours off.
Nowadays all you need is the command:
sudo timedatectl set-local-rtc 1
File sharing: Linux can't see a BitLocker-protected disk, and I think I like it that way.
(A stranger with Linux on a jump drive wouldn't be able to read my data either.)
Fortunately, my ThinkPad T490s has a strange provision for keeping a micro SD card installed
more or less permanently, though it's easy to get out, much like changing a SIM card in a phone.
I have a 256-GB card there, and both Linux and Windows can see it and write on it.
That's how I get files back and forth from one OS to the other.
I did not opt for Linux disk encryption, so I will limit the amount of confidential data
that I store in Linux. If this becomes a concern, I can presumably turn disk encryption on.
Mouse: You can't pair a Bluetooth mouse with more than one operating system;
don't try. Also, a recent-model Logitech mouse that supports both Bluetooth and USB wireless
turns out to have a complicated pairing process that I never got working as desired.
(Hint about Logitech mice: A full reset requires taking the battery out! It retains some
memory about pairing when switched off.)
What worked was to get the old, simple, plain-USB-wireless mouse (Logitech M310) from one of my other
computers. It emulates a wired mouse and has no pairing protocol.
The one spooky thing about the M310, which other Linux users have noted, is that sometimes the
mouse wheel doesn't work under Linux unless you take the battery out for a moment and put it
back in. Strange error in some Linux driver, I suppose, perhaps to be fixed in the future.
So that's how I spent a lot of time for two afternoons!
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2026
March
1
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Some astrophotography at last
Due to a remarkable spell of bad weather, I did no astrophotography at all in January, and only finally
got around to doing some on the last day of February.
My main goal was to test guiding software and a guidescope
(I'm trying out an unofficial fork of PHD2).
I had the Celestron 8 EdgeHD set up with the f/7 compressor and Altair 26C (24-megapixel) camera,
but the gibbous moon was in the sky, so the first thing I did was take a picture of the moon.
To be precise, I recorded 99 video frames, then stacked the best 75% (presumably 74 of them)
and turned up the color saturation to bring out differences in the minerals on different parts
of the moon's surface. Here's the result.
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It came out admirably sharp. I also have a higher-resolution version.
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Moon: Aristarchus
Here is the region of the lunar crater Aristarchus (a crater with a spooky reputation,
and possibly a history of outgassing, raising dust). This is taken the same way,
but not scaled down; this is full resolution. Stack of the best 50% of 2000 video frames.
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Moon: Mare Crisium
Favorable libration (an effect of non-circular orbits)
enabled me to see past Mare Crisium all the way to Mare Smythii, the dark spot right
on the edge of the visible moon. This picture is rendered in black-and-white (grayscale)
because parts of it were slightly overexposed and did not go through color correction
correctly. Stack of the best 50% of 1008 video frames.
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Jupiter
Although definitely not using the right optical configuration or camera, I decided
to see what my f/7 deep sky setup would get when I aimed it at Jupiter.
Not nearly as much detail as when I use the planetary camera at f/10,
but definitely something.
Satellite IV (Callisto) is visible; I brightened it up separately, since it is much darker
than the face of Jupiter.
By the way, I've decided to join the ranks of the astronomers
(many, since the time of Galileo) who call the first four satellites I, II, III, and IV,
as Galileo initially did, rather than Io, Europa, Ganymede, and Callisto, the names
proposed by Marius and Kepler but not widely used until the twentieth century.
If you want to know the reason, look up the mythology, and how Jupiter (Zeus)
acquired those four companions. Zeus is not an example of behavior to be emulated.
Although nobody ever talked about it, I suspect this may be why generations of
earlier astronomers were not particularly fond of that set of names.
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M78 and NGC 2071
Finally, an actual deep-sky image. Because of the bright moonlight, this is not a great picture,
but it proves that the equipment worked. Stack of 150 30-second exposures. These are two
reflection nebulae, clouds of dust that reflect the light of nearby stars. M78 is the larger one.
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