Delphinus

No

• Fox
• Arrow
• Eagle
• Aquarius
• Pegasus

The dolphin (also dolphin, Delphinus Latin ) is a constellation near the celestial equator.

Description

The dolphin is a small but memorable summer constellation. Within the constellation of the stars Sualocin, Rotanev, Delta and Gamma Delphini form a diamond-shaped constellation, which in English is called " Job's Coffin ". The dolphin is north west of the bright star Altair in the Eagle (Aquila ) and thus can be easily found.

Due to its location on the celestial equator, it can be seen from all the inhabited world.

History

The dolphin is one of the classic 48 constellations of the ancient world, mentioned by Ptolemy.

The names Sualocin and Rotanev for the brightest stars go back to the Italian astronomer Niccolo Cacciatore, the successor of Giuseppe Piazzi at the observatory of Palermo. If you read the star names backwards, the result is " Nicolaus Venator " a Latin form of Cacciatores name. He added the name in 1814 in a star catalog and immortalized in this way two times in the sky. He was so far the only astronomer to which this succeeded.

Mythology

For mythological origin, there are two versions:

The sea god Poseidon courted the Nereid Amphitrite. Since these are not her virginity wanted to lose, she fled to the Atlas Mountains. Poseidon then sent several scouts, including a certain Delphinos. The finally stumbled upon Amphitrite and persuaded them to agree to the wedding. In gratitude, the god of the sea offset the image of a dolphin in the sky.

The second version is from the Greek singer Arion of Lesbos, who served at the court of Periander, ruler of Corinth. On a trip to Italy and Sicily, Arion came to wealth. On the drive home from Taranto, the crew of his ship conspired against him to take the treasure in itself. Facing death asked Arion a last request: he wanted to sing a dirge. The team gave him this. But while Arion sang, he jumped overboard and was rescued by a dolphin who was infatuated with the music. The dolphin sat Arion from the coast of Greece and disappeared.

Celestial objects

Stars

β Delphini ( Rotanev ), the brightest star in Dolphin is 80 light years away. He belongs to the spectral type F5 IV.

Double stars

The second brightest star, α Delphini ( Sualocin ), is a close binary star system. The brightness of each 3.86 m and 6.43 m add up to 3.76 m. With a current angular distance of 0.22 " they are not separable for visual observers. Both orbit each other in 17 years.

The star β Delphini ( 4.11 m ), which carries the proper names Rotanev, has a 5m bright companion ( together: 3.71 m), which surrounded him in 26.65 years. The maximum possible angular distance on the orbit is 0.65 ", the minimum spacing 0.185 " ( beginning of 2013 ). The distance is changing rapidly: it amounted to ' so will they, in 2010 to 0.37 " fall 2009 or 0.43.

γ Delphini, a binary star system in 105 light years away, is considered the most beautiful double star in the dolphin: In addition to the orange main star 4.3 m light ( γ1 Del, spectral type K1 IV ) is located in a little over 9 seconds of arc distance of 5.1 m bright, blue-white companion ( γ2 Del, spectral F7 V). Both stars are actually physically coupled to each other, the mutual orbital period could be extrapolated to 3250 years. Even a very small telescope may γ Delphini at 30 - to 40 -fold magnification separate.

A wide apart standing, but only optical double star is 18 Delphini. 18 Delphini has a planet (18 Delphini b).

The object NGC 6933 is fainter double star about 23 ' west of the globular cluster NGC 6934th

Variable Stars

R Delphini is a variable star of type Mira, which greatly changes its brightness over a period of 285.5 days

Messier and NGC objects

The globular cluster 7006 is extremely far away with 185,000 light years. To observe it, one needs an average telescope of 15 cm aperture.