Using the Celestron Origin for Science

As the president of the American Association of Variable Star Observers (AAVSO), I was interested in learning whether the Celestron Origin Intelligent Home Observatory could proficiently measure the brightness of stars, a process known as photometry. To test Origin's ability, I selected BL Camelopardalis, a pulsating star that goes through a cycle in just 56 minutes. With a magnitude of 13, the star varies regularly by a fraction of a magnitude.

On December 20, 2023, after imaging the Veil Nebula and a few other deep-sky objects, I inputted the coordinates of BL Camelopardalis (3h44m +63d44m). After performing a swift autofocus, I captured a series of 10-second exposures over 66 minutes with the Celestron Origin. I received 406 images of the BL Camelopardalis and two nearby stars, a star with an accurately known magnitude called a "comp" star and a second star with an accurately known magnitude called a "check" star.

I used a program called AIP4win to obtain the stars' magnitudes. Within the software, I designated the three stars: BL Camelopardalis as the variable star, the "comp" star, and the "check" star, and then let the program read the brightness of each star in all 406 images. After exporting the data into Excel, I plotted the difference between BL Camelopardalis and the comp star (denoted as V-C1), alongside the difference between the check star and the comp star (C2-C1). The graph revealed a 0.25-magnitude variation in BL Camelopardalis, while the check star exhibited no discernible variation.

The random noise in the plot occurs from two factors: firstly, the variation in the number of star photons reaching the telescope within a given time frame fluctuates randomly, and secondly, atmospheric scintillation (commonly known as "twinkling") introduces additional random fluctuations. These random noises are entirely normal and anticipated in astronomical observations. I added a running average and a smoothed curve to the BL Camelopardalis data and a running average to the check star data. My 66-minute light curve shows somewhat more than a complete 56-minute cycle.

This was the easiest light curve I have ever made. The Celestron Origin's ability to zero in on the star, maintain tracking for over an hour, and save the data in FITS format made taking photometry data easy and efficient. As an old-school amateur astronomer, I felt a bit funny operating the Celestron Origin from the dining room table. Still, I was also delighted to take science data without the hassle.