This is a composite video of Comet 46/P Wirtanen done from 41 exposures of 30 seconds each.
They were taken on 2019-12-19, using a Vixen SXD mount converted to OnStep, a Celestron C8 with 0.6X reducer, and a Canon T4i DSLR. You can see the comet racing against the background stars.
An Artificial Star is a point source of light. It is used to simulate a real star indoors, so you can collimate your telescope's optics indoors and/or during daylight.
Commercial artificial stars, such as this Hubble Optics one, cost $25 or more, and their main feature is a small plate that has precision holes of 50 micron up to 250 microns.
You can make your own artificial star, which is very close in function to the commercial ones.
You can watch this short 4 minute video on how I did it, and read on for detailed instructions.
After nine months of modifying the OnStep open source telescope controller to run on the cheap STM32 ARM Cortex M3 microcontroller, it is time to reap the fruits of this long labour: I have an OnStep powered mount ...
Over the winter, I worked with Howard Dutton, the author of OnStep Telescope Controller, to make it work with the low cost STM32 ARM Cortex M3 microcontrollers. This involved writing a hardware abstraction layer (HAL), so adding different architectures in the future would not be too hard, as it was.
On Friday 11th of May, 2018, I gave the second part of my presentation on Islamic Astronomy's Legacy in Arabic Origin Of Modern Star Names. This was for the KW RASC.
The book is the first illustrated pictorial star atlas, and was very influential for centuries after it was authored. It spread widely from central Asia, throughout the Middle East, and to Europe. It was translated into many languages.
Here is the presentation slides, and audio recording:
One of the obstacles in using OnStep is the process of configuring it. A user should start with a spreadsheet that calculates certain parameters. The user is supposed to check that they lie between acceptable ranges mentioned in the spreadsheet.
