Constellations > Dolphin

Dolphin is one of the tiniest constellations located in the northern sky. Latin “Delphinus” is translated as “dolphin”.

The constellation Dolphin represents a sea animal sent by Poseidon in search of the nerida Amphitrite, which he wanted to marry. It was listed in the second century by Ptolemy. It contains several interesting objects: globular clusters NGC 6934 and NGC 7006 and planetary nebulae NGC 6891 and NGC 6905.

Constellation dolphin

An object Designation Meaning of the name Object type Magnitude
one Beta Dolphin (Rotanev) “Venator” (reverse reading) Multiple star system 3.64
2 Alpha Dolphin (Sualokin) “Nikolaus” (reverse reading) Multiple star system 3.77
3 Gamma Dolphin No Double star 3.87
4 Epsilon Dolphin Dolphin Tail Blue-white giant 4.03
five Delta Dolphin No Binary star system 4.38

Facts, position and map

With an area of ​​189 square degrees, the constellation Dolphin is the 69th largest constellation. Found its place in the fourth quadrant of the northern hemisphere (NQ4). It can be found at latitudes between + 90 ° and -70 °. Neighbors with Aquarius, Pegasus, Arrow, Small Horse, Eagle and Fox.

Lat. title Delphinus
(in genus: Delphini)
Reduction Del
Symbol Dolphin
Right ascension from 20h 08m up to 21h 03m
Declination from + 2 ° 00 ‘to + 20 ° 30’
Square 189 sq. degrees
(69th place)
The brightest stars
(value <3m)

The brightest – Sualokin (α Del) – 3.77m

Meteor showers
  • No
Nearby constellations
  • Chanterelle
  • Arrow
  • Eagle
  • Aquarius
  • Small Horse
  • Pegasus
The constellation is visible in latitudes from + 90 ° to -69 °.
The best time to watch is summer.

Accommodates 5 stars with planets and no Messier objects or meteor shower. The brightest star is Beta Dolphin. It is included in the group of constellations of the Heavenly Waters along with Korma, Southern Fish, Eridanus, Little Horse, Dove, Carina, Compass and Sails. View the diagram of the constellation Dolphin with stars, objects and neighbors on a star map.

Constellation dolphin


There are two stories. In one of them, Poseidon’s messenger was a dolphin. God fell in love with the nymph Amphitrite and began to care for her. But she resisted in every possible way and hid among her sisters. Then he sent messengers, and it was the dolphin who found the nerida. Moreover, he calmed her down and escorted her to Poseidon, after which they got married. God thanked the animal by sending it to heaven.

Another story is about Apollo’s dolphin. It was the god of poetry and music. The dolphin was destined to save the poet and musician Arion, who lived on the island of Lesvos. The guy toured with a lyre in Italy and returned to Greece by ship. But the greedy sailors agreed to kill him and take the money he earned. Surrounded by the crowd, Arion asked for the last time to play the lyre and sing. The sailors agreed. The music was so beautiful that it attracted several dolphins. Arion decided to surrender to fate and jumped overboard. One of the dolphins picked him up and drove him to Greece. Later, Arion sentenced all sailors to death. The constellation Dolphin stands next to Lyra, because Arion was noted in this image.

Main stars

Explore the stars of the constellation Dolphin with detailed descriptions and characteristics.

Alpha Dolphin is the brightest multiple star in the constellation with a total apparent magnitude of 3.77. It is represented by seven objects: A and G (physical pair), B, C, D, E and F are optical binaries.

A and G are located about 241 light years away and are spectral types A and B9V.

The star also has the name Sualocin. So it was named by the astronomer from Italy Nicolo Cachatore. This is the romanized version of his name, written in reverse.

Beta Dolphin (Rotanev) is a double star found in 1873 by S.V. Burnham. At 1.8 billion years old, it is represented by a pair of stars of spectral types F5 III and F5 IV. It is a giant and subgiant, 101 light years distant. The stars revolve around each other with a period of 26.66 years and are separated by only 0.44 seconds.

The name “Rotanev” is the reverse surname of Venator (assistant to Giuseppe Piazzi) and means “hunter”.

Gamma Dolphin is a binary star located 101 light years distant. The main object is a yellow-white dwarf (F7V), and the companion is an orange subgiant (K1IV). Values: 5.14 and 4.27.

In 1999, a candidate for a planet was found in the orbit of the second body, but there has been no confirmation so far.

Delta Dolphin is a giant (A7IIIp) with a visual magnitude of 4.434. This is the Delta Shield variable.

Epsilon Dolphin is a blue and white giant (B6III) with a visual magnitude of 4.03 and a distance of 358 light years. It is a variable star, which periodically reaches 3.95 magnitude. From Arabic, ānabab ad-dulfīn means “dolphin’s tail”. The name was translated into Latin – “Cauda Delphini”.

Ro Orla (Tso Ke) is a white dwarf (A2V) with an apparent magnitude of 4.94 and a distance of 154 light years. “Tso Ke” in Mandarin translates as “left flag”. In China, “Left Flag” refers to the asterism formed by Ro Eagle and several stars in the constellation Sagittarius, and Ro Eagle itself is the Ninth Star of the Left Flag.

Age – 50 million years. Until 1992, the star belonged to the constellation Eagle, but then it passed to Dolphin.

Celestial objects

NGC 6934 (Caldwell 47) is a relatively large globular cluster near Epsilon’s star Dolphin. With a visual magnitude of 8.83, it is 50,000 light years distant. It was found by William Herschel on September 24, 1785.

Globular Cluster NGC 6934

Globular Cluster NGC 6934

NGC 6891 is a small planetary nebula near Rho Eagle. Visual magnitude – 10.5.

NGC 6905 (Blue Flash) is a small, bluish planetary nebula. It can be found with a 6-inch telescope.

NGC 7006 (Caldwell 42) is a globular star cluster 137,000 light years away (on the outskirts of the Milky Way). Visual magnitude – 10.6. Located near the star Gamma Dolphin.

This is part of the galactic halo – a spherical region of the Milky Way. Represented by dark matter, gas and random star clusters.

NGC 7006

NGC 7006

You can study the constellation Dolphin more closely if you use not only our photos, but 3D models and an online telescope. For an independent search, a static or moving map of the starry sky is suitable.

Constellations of the autumn sky

September Eagle Capricorn Swan Dolphin Small Horse Indian Microscope Peacock Arrow Chanterelle
October Aquarius Cepheus Crane Lizard Octant Pegasus Southern Fish
November Andromeda Cassiopeia Phoenix Fish Sculptor Toucan

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