The Owl Nebula, also cataloged as Messier 97 and NGC 3587, is a planetary nebula that presents a rounded, softly glowing disk spanning roughly 3.3′ across the sky. Its two darker interior patches, which give the object its owlish appearance, emerge only after considerable integration time, making this a rewarding but demanding deep-sky target. Because the nebula shines strongly in the OIII and H-alpha emission lines, narrowband filters dramatically boost contrast and reveal the characteristic “eyes” against the surrounding halo. With a modest apparent diameter and low surface brightness, patient long-exposure imaging under dark skies delivers the most detailed and satisfying results.
Names and Catalog numbers
- Owl Nebula
- M 97 (Messier 97)
- NGC 3587
- PK 148+57.1
- PN G148.4+57.0
Position and the cosmic neighborhood
The Owl Nebula sits within Ursa Major at a right ascension of 11h 14m 47.7s and a declination of +55° 01′ 08″, high in the northern sky and circumpolar for many mid-northern observers. This placement near the bowl of the Big Dipper makes it easy to locate and frame throughout much of the year, and it shares the field with the nearby edge-on galaxy Messier 108, offering imagers the chance to capture both a planetary nebula and a galaxy in a single wide-field composition. Its high northern declination keeps it well above the horizon for long stretches, ideal for accumulating the deep exposures this faint target requires.
Nice to Know
- The two dark interior hollows that resemble an owl’s eyes are the nebula’s signature feature and only become visible in deeper, well-processed astrophotographs.
- It spans about 3.3′ on the sky yet measures only around 2 light-years in true physical diameter.
- Narrowband OIII and H-alpha filters are especially effective here, cutting through light pollution and enhancing the delicate structure.
- Conveniently located near the Big Dipper, it can be paired with the nearby galaxy Messier 108 for a striking dual-object frame.
Brightness, distance and size
The object has an apparent magnitude of 15.8 mag, it lies about 2,030 light-years from Earth and spans roughly 2 light-years across. On the sky it appears about 3.3′ in size.
