Hercules, M13

June, 2021

Imaging: TS80 apo, ZWO ASI533 (100 gain, 0C), Neodymium
Subs: 284x60s (4.7h), darks, flats, and darkflats
Software: NINA, Phd2, PixInsight

(Additional notes below)



The Great Hercules Globular cluster, Messier 13. According to Wikipedia, Hercules is comprised of several hundred thousand stars. It is the largest globular cluster viewable in the northern hemisphere at about 145 LY in diameter. In dark skies, it might be just barely visible to the naked eye. Compared to our sun and its neighboring stars, the stars in the Hercules cluster are more than a hundred times denser (and sometimes collide with each other).

This is the first image with both my new TS Optics Photoline 80mm telescope and ZWO ASI533MC astrocamera. The TS80 is an apochromatic telescope. In contrast to my ST120 achromat, it focuses red, green, and blue simultaneously and produces tightly focused stars versus the horribly bloated blue messes from my earlier images. The ASI533 is a special purpose, cooled one-shot-color (OSC) camera. For deep space photography, the image is so dim that sensor noise is significant, so the ASI533 includes a TEC cooler that can keep the sensor at or below 0°C. This significantly reduces the noise in the image.