I have found the SeeStar S50 to be fantastic for variable star photometry and general night sky imaging.
For those of us with less spare time than we’d like, chronic back pain, and a willingness to allow our hobby to evolve (or some subset of these), devices in the category of “smart telescope” like the SeeStar, are something of a revolution.
The S50 field of view (0.73 x 1.29 degrees) is great for many deep sky objects (nebulae, star clusters, galaxies) variable stars, asteroids, some comets, Luna, and the Sun. My current primary use cases are deep sky objects and variable stars.
The fields in which variable stars appear are often themselves quite varied and beautiful and that deserves a separate post.
Below is a small gallery of some deep sky images I’ve taken with the S50 from my back yard over the last year or so, each with a catalog designation, name, constellation (unless obvious from the name) and total exposure time (from multiple 10 second images stacked by the device). Noise reduction has been applied to most via the SeeStar app.
Carl Sagan (Wikimedia)Christopher Hitchens (Vanity Fair)
I turned 62 on November 26th 2025.
Carl Sagan and Christopher Hitchens were both 62 when they died.
Sagan was born on November 9th 1934. He died on December 20th 1996 from pneumonia after a struggle with myelodysplasia, in which bone marrow stem cells fail to yield mature red, white blood cells and platelets.
Hitch was born on April 13th 1949 and died on December 15th 2011 after a battle with oesophageal cancer, and in the end, like Sagan, from pneumonia.
I remember a feeling of deep sadness and loss when I heard the news of Sagan’s death. I did not know of Hitch until about two years after he died but recall a retrospective sense of loss upon becoming familiar with his work.
Sagan was a scientist, author, presenter of the inspiring Cosmos series, co-founder of the Planetary Society, and the prototype of all future successful science communicators.
Hitch was a fearless journalist, writer and speaker, with an amazing recall of literature and history, an ironic wit, and blistering debating skills.
They were both great orators with a masterful grasp of the English language.
They both warned about the dangers of pseudoscience, irrationality and ideological thinking.
Both are sorely needed and missed at a time when opinions seem to carry as much weight as reasoned argument and the findings of Science.
They were not alive for long enough.
I wish they were still here.
Our world needs more like them.
For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. (Carl Sagan)
Take the risk of thinking for yourself. Much more happiness, truth, beauty, and wisdom will come to you that way. (Christopher Hitchens)
It’s my daughter’s birthday on October 25, which as I write, is today.
Happy birthday Heather!
I was idly thinking about my family’s birthdays while having a shower this morning (as you do), which either fall on the 25th (Heather) or the 26th (Karen, Nic and I) of some month.
I started thinking about the difference between the months of each birthday.
The difference between our son Nic’s birthday in February and my wife Karen’s in June is 4 months (6-2). So too between Karen’s and Heather’s (10-6).
The number of months between Karen’s and my birthday in November is 5 (11-6).
Completing the circle, between my birthday and Nic’s is 3 months, when moving from November to February (1 month each from Nov to Dec, Dec to Jan, Jan to Feb).
Curiously, within the same year, November back to February is 9 months (11-2), which is 32, 9 divided by 3 is 3, so 3 x 3 = 9, and so on. More simply, 12 -9 is 3. Three shows up in various ways.
The numbers 3, 4, 5 reminded me of the so-called “3, 4, 5” right-angled triangle, where two of the sides have length 3 and 4 with the diagonal (hypotenuse) having length 5.
The day before discovering V1935 Cen, John Seach discovered a nova in Sagittarius, on September 21. It was also discovered independently by two observers in Japan, as described in AAVSO alert notice 907.
V7994 Sgr has so far peaked at around magnitude 6.7 with a pre-outburst magnitude of less than magnitude 23 within a couple of days!
I made a visual estimate of the nova of 6.9 just before 11:30pm last night (September 26), Adelaide time (ACST) with 15×70 binoculars, using 7.1 and 6.8 magnitude comparison stars for reference.
The images above were taken with my Seestar S50 at around 8:30pm, the first resulting from additive stacking of 59 images on the S50. The second shows the nova in cross hairs after further processing and median stacking in Tycho Tracker. Sagittarius is a busy part of the sky!
V7994 Sgr is located near the boundary of Scorpius and Sagittarius, near the “stinger” of the scorpion.
The AAVSO finder chart below must be rotated at least 90 degrees clockwise to match the field above.
So far, as of September 27, 41 observations have been submitted to AAVSO, 19 of which are visual estimates (via telescope or binoculars) shown here (black), with my observation in cross hairs. A couple of observations from imaging devices are also included (green).
John Seach discovered a nova in Centaurus on September 22 2025 (see AAVSO alert notice 906), which appears to have peaked at magnitude 6.4 and is now fading below magnitude 8. Its pre-outburst magnitude was 16.7.
The images above were taken with my Seestar S50, the first resulting from additive stacking of 39 images on the S50. The second shows the nova (V1935 Cen) in cross hairs after further processing and median stacking in Tycho Tracker.
V1935 Cen is located near Alpha Centauri (aka Rigel Kentaurus) as shown in these Stellarium images for approximately 8:30pm Adelaide time (ACST).
Photometry (with Tycho Tracker) from the S50 images gave a visual band magnitude of around 8.1 at 8:15pm on September 26.
The AAVSO finder chart below must be rotated 90 degrees clockwise to match the field above. The bright star bottom is Alpha Centauri.
As I write this (the morning of September 27), 19 observations have been submitted to AAVSO, giving this early light curve, with my observation in cross hairs. Observations are visual estimates from telescopes of binoculars (shown as black) or visual band photometry from imaging devices (e.g. DSLRs, CCDs).
I set my alarm for 2:15am this morning to observe and image the total lunar eclipse visible from Australia. It started at around 2am and finished just before 5:30am, with totality from 3am, to around 4:20. This ABC News article gives a nice overview and a table with the relevant times.
I observed the last part of the partial phase and the early part of totality, with the unaided eye and 11×50 binoculars. I also took some images (above) and a seven minute time lapse (compressed to 14 seconds) near the onset of totality with my Seestar S50. A longer time lapse was impacted by cloud. Still, I was happy with what I saw and imaged, if a bit low on sleep. Clouds encroaching during the later stages of the eclipse.
The tail end of the eclipse through cloud (iPhone 13 images)
The light curves of the two recent bright southern novae, V462 Lup and V572 Vel, have developed somewhat since I last wrote about them, the first peaking at magnitude 5.2, now 11.1, and the second peaking at 4.8, now 10.3.
T CrB remains quiet and foreboding, low in the early NW evening sky, taunting us with its pre-eruption ellipsoidal variations.
Writing this update reminded me of a long-standing plan to write a nova distance calculator plug-in for VStar, based upon the rate of decline of a nova.
A 2020 ABC News article about a semi-trailer carrying chickens in Adelaide (of exactly the sort I recently wrote about in Estimated Witness) contains the following mind-bogglingly insane words:
The RSPCA attended the crash scene.
Spokeswoman Carolyn Jones said the chickens involved in the crash were taken to an Ingham’s processing facility at Burton in Adelaide’s north where their welfare would be assessed.
Up to 1,000 chickens died.
“Clearly a very distressing scene with so many crates that had toppled over and many birds that were loose,” Ms Jones said.
“We’ll be monitoring the welfare of the surviving and the injured birds.”
Umm. Their welfare would be assessed… At an Ingham processing facility…
It makes me feel so much better to know that the RSPCA was on the scene, and that Ingham and RSPCA were keeping an eye out for an unknown number of chickens’ welfare…
RSPCA Approved chicken. It’s in the name, along with their oxymoronically titled podcast: Human Food.
Up to 1000 chickens died. On the scene or in the “processing facility”? Ultimately I’d say 100% died except those who managed to run the hell away from the truck and didn’t get run over by a car.
Seriously!!
They were on their way to be slaughtered!
The only thing a chicken slaughterhouse “cares about” is whether or not it’s worth “processing” (euphemism alert!) a chicken or disposing of its dead or dying body! It’s all about the cost!
And who knows what the RSPCA cares about. Cute cats and dogs and bugger all else apparently. Kick a dog and we’ll prosecute you. But slaughter as many pigs, cows, sheep and chickens as you like. That’s fine. They’ll even approve the death of pigs and chickens so long as they “lived well” and were slaughtered “humanely”. Oh, and don’t export live sheep! Just kill them in Australia!
In December 2001 I soldered 25 red LEDs and 5 resistors onto a square of veroboard:
LED grid with PIC at right and Arduino at left (connected)PIC 16F84 microcontroller (source: Microchip)ATMEL ATMega 328PU microcontroller on Arduino dev board (source: Microchip)
then connected a locally produced PIC16F84 microcontroller development board via ribbon cable soldered to the veroboard, and a home-made power supply to it, wrote C code to create frames of patterns that changed over time, and used it as a Christmas decoration. It has been up each Christmas and New Year for the past 24 years at Christmas and New Year. The video below shows some of the patterns it has displayed.
Each time the code (or even just patterns) changed, the PIC microcontroller had to be removed from the development board, inserted into a programming board, and the binary (.hex format) including code and static data (e.g. pattern frames) uploaded to the device via a serial connection to the programmer board, then placed back into the development board .
I’ve used quite a few programmers over the years, starting with a parallel port programmer I built from a kit in conjunction with free software to write, read and verify bits written to the microcontroller. After parallel ports went the way of the dinosaur, and before USB ports were common, serial port pins were used to “bit bang” data to the microcontroller via a PIC pin, one bit at a time. Over time, serial ports became extinct too, and a USB to serial cable did not work as a replacement because the wires over which to bit bang data were absent. So, I kept an old Windows 95 laptop around for this purpose, since it still had serial port.
Compiled files (.hex files) had to be transferred to the laptop via a USB memory stick from one of a number of computers I used to write and compile the code on (Windows, Mac). Over time the C compiler had to change as well, from Hi-Tech to MPLAB.
I figured that one day the Windows 95 laptop was going to stop working or I would lose the only USB stick that worked with it.
So, in December last year (2024) I finally decided to change the microcontroller from a PIC 16F64 to an AVR based Arduino which has a cross-platform development environment and allows code to be read/written via a USB cable. That’s been the case for a decade or more now for many microcontroller and similar devices.
Although the General Purpose Input/Output (GPIO) pins changed, just 3 lines of the original C code had to be changed to get it to work with the Arduino! That’s is a testament to C. Had it been written in PIC assembly code (and I’ve written my share of machine-level code) or some now extinct special purpose language, or a compiler that’s no longer available or supported (or only on one operating system), a total rewrite would have been necessary.
To me, microcontrollers are like what microcomputers were 40 to 50 years ago, but with no operating system, except perhaps a bit of code that loads other code into a device. Early microcomputers (e.g. Apple I or II, TRS-80, Commodore Vic-20/64) didn’t have much of an operating system either. They just booted up into a read-eval-print loop (REPL) and called other code to load programs from tape or disk, display characters on the screen, play sounds and so on, often supported by specialised hardware.
The Arduino platform provides common pinouts irrespective of processor (e.g. AVR, ARM), a platform independent Integrated Development Environment (IDE), C++ as the development language, a common Application Programming Interface (API), a library of common code for many peripheral devices (e.g. keypads, LCDs), and a USB to serial programming and I/O route.
Before the Arduino, it was the wild west, like it was before the PC and Mac came to dominate. That diversity was interesting however, and 20 years ago I tried my hand at writing generic library code that was likely to work with multiple microcontrollers, and experimented with writing compilers (and interpreters) for various languages to run on microcontrollers. Starting from scratch is not necessary now.
The PIC16F84 had less than 100 bytes of RAM and less than 2K of non-volatile program (FLASH storage) and could run at between 4 and 10 MHz. I later replaced the PIC16F84 with the PIC16F628 which had more than 200 bytes of RAM, 3.5K of FLASH and had a clock speed of 20 MHz.
Optimising the code and patterns that were stored mattered a lot on these small devices!
Compare this with the AVR ATMega 328P used on the Arduino I switched to. It has 32K of program FLASH and 2K of RAM, although the clock speed is only 16 to 20 MHz. Still small by the standards of many microcontrollers now and orders of magnitude smaller when compared to the resources available on even the most modest laptop or smartphone today.
The AVR was made by ATMEL, which was eventually acquired by Microchip, maker of PIC microcontrollers, ironic because of the fierce rivalry between the two companies at one point, amusingly exemplified by this sticker:
The processor, clock speed, memory and on board peripherals in microcontrollers have improved significantly over time, and devices like the RPi PICO have more powerful processors (typically ARM based) and can be programmed either as an Arduino device or can run MicroPython, making it much easier to create more complex gadgets. But that’s for another post.
There’s a lot that can be explored in the world of microcontrollers, which are distinct from other small devices such as Raspberry Pi, NVIDIA Jetson, Beagle in at least one important way. The latter are full fledged computers that run an operating system, typically a variant of Linux.
Unless a microcontroller is running an interpreter, the code you write takes over the device completely. There may be a small boot-loader that loads the program to be run, but nothing like an operating system. Ultimately, when you program a microcontroller, the only code running is yours, compiled or assembled from a human-readable language into machine code. You control the vertical and the horizontal. If the device does nothing or if it does the wrong thing, it’s because there’s an error in your code or you wired something up incorrectly. Either way, it’s on you.
When I started writing for the PIC, it really wasentirely my code, nothing I had not written myself vs use of Arduino library code. In the case of this simple LED grid, it still is all my code. Either way, this complete control over a device is appealing in an age of bloated operating systems, an enormous emphasis upon cybersecurity, and wasted power.
Microcontrollers are also an example of so-called green computing. There is an emphasis on low power consumption and small footprint.
That’s a topic worth exploring more in an age of Blockchain and more recently, Large Language Models. For example, some machine learning models can be trained on a more powerful computer, then run on a less power hungry microcontroller.
Another topic worth exploring is zero-instruction set computing.
