The Dragonfly Cluster, also cataloged as NGC 457, is a bright open star cluster in Cassiopeia that makes a rewarding target for astrophotographers of all levels. Shining at magnitude 6.4 and spanning an angular size of about 15′, it fits comfortably into the field of most small refractors and telephoto setups. Its scattered arrangement of stars invites relatively short exposure sequences, since the brightest members can quickly saturate and lose their color if pushed too hard. Careful exposure balancing rewards imagers with a rich palette of stellar hues set against a modest scattering of fainter background suns.
Names and Catalog numbers
- Dragonfly Cluster
- C 13 (Caldwell 13)
- NGC 457
- Mel 7 (Melotte 7)
Position and the cosmic neighborhood
Positioned at right ascension 01h 19m 32.9s and declination +58° 16′ 41″, the Dragonfly Cluster sits high in the northern sky within the rich star fields of Cassiopeia, one of the most recognizable circumpolar constellations. Its location along the Milky Way means the surrounding frame is naturally dense with foreground and background stars, giving wide-field compositions plenty of context and depth. Because Cassiopeia rides high for northern observers, NGC 457 stays well clear of the horizon murk for long stretches of the imaging night, making it an easy and reliable subject for both mosaics and single-object framing.
Nice to Know
- The cluster’s whimsical common name, the Dragonfly Cluster, reflects the winged, insect-like shape its star pattern suggests to many observers.
- It carries several catalog identities, including NGC 457, Caldwell 13 and Melotte 7, making it easy to locate across different star charts and planetarium software.
- At an estimated distance of about 7,920 light-years, the cluster spans a physical diameter of roughly 35 light-years across.
- With an integrated brightness of magnitude 6.4 and a compact 15′ angular size, it is a forgiving target that suits short focal lengths and modest exposures alike.
Brightness, distance and size
The object has an apparent magnitude of 6.4 mag, it lies about 7,920 light-years from Earth and spans roughly 35 light-years across. On the sky it appears about 15′ in size.