The leaping dolphin is located on the edge of the Milky Way, between the two great birds, Cygnus, the swan and Aquila, the eagle. The constellation Delphinus has been recognized as a dolphin as far back as can be remembered, a testament to the congenial relationship between dolphins and humans since the dawn of time, not to mention the grouping of stars really does conjure up an image of a breaching dolphin. There are two myths regarding the origin of the constellation. The first says the dolphin was put in the sky by Neptune (Poseidon), as a reward for bringing him the beautiful Amphritite to take as wife. The second and most popular tale tells us the dolphin was put in the sky by Jupiter (Zeus), to commemorate the rescue of the famous Greek poet, Arion, who escaped from pirates on the back of a dolphin, back in the seventh century, BC.
The constellation's two brightest stars Sualocin and Rotanev, are simply the name Nicolaus Venator spelled backwards, the Latin translation of Niccolò Cacciatore, assistant director of the Palermo Observatory in Italy at the beginning of the 19th century. Since he was next in line to take over the observatory, he was presumably identifying with the alternate meaning of delphinus as "dauphin" meaning successor or inheritor. In an apparently surreptitious attempt to immortalise himself, he published the star names in the observatory's 1814 star catalogue, and it seems to have worked, since the names are still in use today.
Alpha Delphini (Sualocin) is a B9V blue/white main sequence star, with a magnitude of 3.77, located about 240 light years away. It is a binary system, with a dim companion star orbiting it at a distance of about one billion miles (12 AU).
Beta Delphini (Rotanev) is also a binary system, but there the similarities end. This system is much closer, only 95 light years away, and consists of two F5IV yellow subgiants with a combined magnitude of 3.62.
Epsilon Delphini is named Deneb Dulfim which simply means the tail of the dolphin. It is a B6IV blue subgiant with a magnitude of 4.03, fairly far away at a distance of about 350 light years.
Five stars with gas giant planets have been discovered so far in Delphinus, but only one of these is visible to the naked eye. The star is a G6III yellow giant designated 18 Delphini. It is quite distant at about 240 light years, with a huge gas giant planet about ten times larger than Jupiter. For more information on these and other extrasolar planets, visit NASA's New Worlds Atlas, and The Open Exoplanets Catalogue.
NGC 6934 is one of the 160 or so Globular Clusters that surround our Milky Way like a network of galactic suburbs, full of hundreds of thousands of stars. It is about 50,000 light years away, and with a magnitude of 8.8, a good target for a backyard telescope.
NGC 6891 is a planetary nebula about 7,000 light years away. With a magnitude of 10.7 it is a challenge for small scopes.
NGC 6905 is also called the Blue Flash Nebula for its distinctive bluish hue. It has a magnitude of 12.1, and is very far away at a distance of 5,000 light years.
|Winter: Orion Canis Major Canis Minor Monoceros Lepus Eridanus Taurus Auriga Camelopardalis Lynx Gemini Cancer|
|Spring: Hydra Sextans Crater Corvus Leo Leo Minor Ursa Major Ursa Minor Canes Venatici Coma Berenices Virgo Bootes|
|Summer: Draco Corona Borealis Hercules Ophiuchus Serpens Libra Scorpius Sagittarius Scutum Aquila Sagitta Vulpecula Lyra Cygnus|
|Autumn: Andromeda Perseus Pegasus Cassiopeia Cepheus Cetus Lacerta Delphinus Equuleus Capricornus Aquarius Pisces Aries Triangulum|
|Southern Skies: Centaurus Crux Lupus Corona Australis Piscis Australis Sculptor Tucana Fornax Dorado Columba Puppis Carina Vela|