Ontario Telescope Astronomy Journal

Guide scope or off-axis guider: a PHD2 guide graph reporting 0.41 arcsecond RMS beside elongated stars from the same night

Your Guide Graph Is Lying to You

astrophotography Stephen Mallia
May 2025 night sky calendar: Mars meets the Beehive, the Eta Aquariid peak, the four moon phases and the dark-sky window

May 2025 The night sky this month. Galaxy season wraps up.

astrophotography - S. Mallia
Ritchey-Chretien, Schmidt-Cassegrain, Newtonian and refractor telescope designs ranked from narrow field to wide field

Choosing the Right Telescope: Understanding RC, SCT, Newtonian, and Refractor Designs for Astrophotography

astrophotography - S. Mallia