Quick Answer: What Telescope Do I Need for M81 and M82?
Both galaxies are visible in any telescope with at least 80mm (3-inch) aperture under dark skies. M81 is the brighter of the pair at magnitude 6.9, while M82 shines at magnitude 8.4. Through a 100mm refractor at 40–50×, M81 appears as a round diffuse glow with a bright core, and M82 is visible as a smaller, elongated patch nearby. A 150mm (6-inch) scope at 60–80× reveals M81's bright oval disc and M82's distinctive cigar shape with a mottled, uneven surface. An 8-inch (200mm) Dobsonian at 100–120× shows M81's spiral arms as subtle brightness variations around the core, while M82 reveals its chaotic, patchy structure with dark lanes cutting across its bright centre. Both galaxies are visible in 15×70 binoculars under dark skies as two distinct fuzzy patches.