Delphinus

Delphinus is a moderately small and faint constellation which lies close to the southern vertex of the Summer Triangle asterism, near the star Altair in Aquila. It is highest in the evening sky in the months around July. Delphinus was one of the 48 constellations listed by the 2nd century astronomer Ptolemy

At its center is a grouping of fourth-magnitude stars, forming an asterism sometimes known as Job’s Coffin because of its box-like shape.

The name ‘Delphinus’ is Latin for ‘dolphin’, usually identified as the messenger of Poseidon, sent to entreat the sea nymph Amphitrite to marry him, According to Greek Mythology.

Delphinus is an interesting little constellation in the part of the sky which contains several other sea creatures nearby: Cetus the sea monster or whale, Pisces the fish, and Capricorn the sea goat. Several stories are told to account for this constellation.

Among the many tales, the story that seems to be the most prevalent is the one involving the famous lyric poet Airon. Airon, a native of Lesbos, an island in the Archipelago, went to Italy with Periander, king of Corinth. While he was there, he became quite famous and quite wealthy. After some time, he decided to return to his home for a visit and boarded a ship going that way. The sailors on the ship, jealous of his talent and hoping to get his great wealth, planned to kill him. When Airon learned of this plot, he asked if he might play a song for them on his lute, a stringed musical instrument much like a guitar, before he was put to death. As he played, the music attracted a number of dolphins to the ship. Airon immediately realized that these dolphins might be able to save him if he were in the sea, for he was surely going to die if he stayed on the ship. So he threw himself overboard into the sea, and one of the dolphins did come to his aid by carrying him safely to shore. When Airon got to the shore, he quickly went to tell King Periander what had happened. The rebellious sailors were ordered executed upon their return to port. To commemorate not only this one act by the dolphins, but the many times dolphins have helped save lives, Zeus placed their constellation, Delphinus, in the night sky.

The constellation’s two brightest stars are sometimes called Rotanev and Sualocin. These strange names first appeared in the Palermo Catalogue of 1814. Together, they spell out the name Nicolaus Venator backwards, which is the Latinized form of Niccolo Cacciatore, an observing assistant. They are the only example of stars named after a real person.

Delphinus is home to a number of notable deep sky objects, including the globular cluster NGC 6934 and the planetary nebula NGC 6891.

The Indian Name for Delphinus is ಧನಿಷ್ಟಾ (Dhanishtha)

Delphinus contains:

 

• Stars
  • Rotanev (mag 3.6)
  • Sualocin (mag 3.8)
  • ε-Del (mag 4.0)
  • γ²-Del (mag 4.2)
  • δ-Del (mag 4.4)
  • ζ-Del (mag 4.7)
  • ρ-Aql (mag 4.9)
  • γ¹-Del (mag 5.0)
  • κ-Del (mag 5.1)
  • 17-Del (mag 5.2)
  • η-Del (mag 5.4)
  • ι-Del (mag 5.4)
  • Musica (mag 5.5)
  • 16-Del (mag 5.5)
  • 13-Del (mag 5.6)
  • θ-Del (mag 5.7)
  • HD 200044 (mag 5.7)
  • HD 193472 (mag 5.9)
  • HD 196775 (mag 6.0)
  • 15-Del (mag 6.0)
  • 10-Del (mag 6.0)
  • HD 194012 (mag 6.2)
  • HD 193556 (mag 6.2)
  • HD 198404 (mag 6.2)
  • 1-Del (mag 6.2)
• Open Clusters
  None
• Globular Clusters
  • NGC 6934 (mag 8.9)
  • NGC 7006 (mag 10.6)
• Galaxy
  • NGC 6928 (mag 12.6)
  • NGC 6930 (mag 13.1)
  • NGC 6954 (mag 13.2)
  • NGC 6944 (mag 13.3)
  • NGC 6956 (mag 13.5)
  • NGC 6969 (mag 13.5)
  • NGC 7003 (mag 13.8)
  • NGC 7025 (mag 14.1)
  • NGC 6972 (mag 14.3)
  • NGC 6917 (mag 14.3)
  • IC 1320 (mag 14.5)
  • NGC 6927 (mag 14.5)
  • IC 1359 (mag 14.8)
  • NGC 6971 (mag 14.8)
  • NGC 6955 (mag 14.9)
  • NGC 6988 (mag 15.0)
  • NGC 6957 (mag 15.3)
  • IC 5080 (mag 15.6)