Delphinus is a minor constellation in the Northern Celestial Hemisphere near the celestial equator. Its name comes from the Latin translation of the Greek word for dolphin (δελφίς). It is one of the 48 constellations listed by Claudius Ptolemy in the 2nd century, and it is still one of the 88 current constellations recognised by the International Astronomical Union. It is one of the smallest constellations, with a size ranking of 69th.
The five brightest stars in Delphinus create a striking asterism that represents a dolphin, with four stars representing the body and one representing the tail. Vulpecula, Sagitta, Aquila, Aquarius, Equuleus, and Pegasus are its neighbours (clockwise from north). Delphinus is a small constellation with only two stars brighter than magnitude 4: Beta Delphini (Rotanev) at magnitude 3.6 and Alpha Delphini (Sualocin) at magnitude 3.8. |
Mythology
Delphinus is linked to two Greek mythological stories. Poseidon, the first Greek god, desired to marry Amphitrite, a lovely nereid, according to legend. She went to the Atlas Mountains, however, to protect her virginity. Her suitor then dispatched many searchers, one of which was a man named Delphinus. Delphinus happened upon Amphitrite and was able to persuade her to accept Poseidon's wooing. The god bestowed the image of a dolphin amid the stars as a token of his appreciation. The second story is about Arion of Lesbos, a Greek poet who was rescued by a dolphin in the seventh century BC. (Ridpath & Tirion 2017) He worked as a court musician in Periander's palace in Corinth. During his journeys to Sicily and Italy, Arion had collected a fortune. His wealth drove the crew of his ship to conspire against him on the way back from Tarentum. Arion, who was about to die, requested the last desire, which the crew granted: he wanted to sing a dirge. He did so, and in the process, he threw himself into the sea. He was saved there by a dolphin who had been captivated by Arion's song. Arion was taken to the Greek coast by the dolphin, who then left. (Schaaf 2012) |
Non-western Astronomy
The stars of Delphinus are placed within the Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ) in Chinese astronomy.
Delphinus was identified as a constellation by two Polynesian tribes. Te Toloa was the name given to it in Pukapuka, while Te Uru-o-tiki was the name given to it among the Tuamotus. (Makemson 1941)
Delphinus corresponds to Dhanishta's Nakshatra, or lunar mansion, in Hindu astrology.
The stars of Delphinus are placed within the Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ) in Chinese astronomy.
Delphinus was identified as a constellation by two Polynesian tribes. Te Toloa was the name given to it in Pukapuka, while Te Uru-o-tiki was the name given to it among the Tuamotus. (Makemson 1941)
Delphinus corresponds to Dhanishta's Nakshatra, or lunar mansion, in Hindu astrology.
Characteristics
Vulpecula to the north, Sagitta to the northwest, Aquila to the west and southwest, Aquarius to the southeast, Equuleus to the east, and Pegasus to the east are the constellations that surround Delphinus. With an area of 188.5 square degrees or 0.457 percent of the sky, it is the 69th largest of the 88 constellations. The IAU selected the three-letter acronym "Del" for the constellation in 1922. [9] A 14-segment polygon defines the official constellation borders, which were established by Eugène Delporte in 1930. The right ascension coordinates of these borders are between 20h 14m 14.1594s and 21h 08m 59.6073s in the equatorial coordinate system, while the declination coordinates are between +2.4021468° and +20.9399471°. Observers north of latitude 69°S can see the entire constellation. Between 69°S and 87°S, sections of the constellation rise above the horizon, but stars within a few degrees of the horizon are practically unobservable. |
Deep-sky objects
NGC 6891 – Planetary Nebula
NGC 6905 – Planetary Nebula
NGC 6934 – Globular Cluster
NGC 7006 – Globular Cluster
Main stars - 5
Bayer stars - 19
Stars with planets - 5
Stars brighter than Magnitude 3.00 - 0
Stars within 32 Ly - 2
Bordering
constellations
NGC 6891 – Planetary Nebula
NGC 6905 – Planetary Nebula
NGC 6934 – Globular Cluster
NGC 7006 – Globular Cluster
Main stars - 5
Bayer stars - 19
Stars with planets - 5
Stars brighter than Magnitude 3.00 - 0
Stars within 32 Ly - 2
Bordering
constellations
- Vulpecula
- Sagitta
- Aquila
- Aquarius
- Equuleus
- Pegasus