Delphinus facts for kids
| Constellation | |
List of stars in Delphinus
|
|
| Abbreviation | Del |
|---|---|
| Genitive | Delphini |
| Pronunciation | Delfínus, genitive |
| Symbolism | dolphin |
| Right ascension | 20h 14m 14.1594s–21h 08m 59.6073s |
| Declination | +2.4021468°–+20.9399471° |
| Quadrant | NQ4 |
| Area | 189 sq. deg. (69th) |
| Main stars | 5 |
| Bayer/Flamsteed stars |
19 |
| Stars brighter than 3.00m | 0 |
| Stars within 10.00 pc (32.62 ly) | 3 |
| Brightest star | Rotanev (β Del) (3.63m) |
| Messier objects | 0 |
| Meteor showers | None |
| Bordering constellations |
Vulpecula Sagitta Aquila Aquarius Equuleus Pegasus |
| Visible at latitudes between +90° and −69°. Best visible at 21:00 (9 p.m.) during the month of September. |
|
The Delphinus constellation is like a tiny dolphin swimming in the night sky! You can find it in the Northern Celestial Hemisphere, which is the northern half of our sky. Its name comes from the Latin word for "dolphin," which itself came from the ancient Greek word "delphis."
Long ago, in the 2nd century, a famous astronomer named Ptolemy listed Delphinus as one of the 48 constellations he knew. Today, it's still one of the 88 official constellations recognized by astronomers worldwide. It's not a huge constellation, ranking 69th in size.
If you look closely, you'll see that five of its brightest stars form a special pattern, or asterism. This pattern looks just like a dolphin, with four stars making up its body and one star for its tail!
Delphinus is surrounded by other constellations. To its north is Vulpecula, to its northwest is Sagitta, and to its west and southwest is Aquila. You'll also find Aquarius to its southeast, Equuleus to its east, and Pegasus also to its east.
Even though it's small, Delphinus has some interesting stars. Only two of its stars shine brighter than a certain brightness level (called an apparent magnitude of 4). These are Beta Delphini, also known as Rotanev, and Alpha Delphini, called Sualocin.
Contents
Ancient Stories About Delphinus
The constellation Delphinus has two cool stories from Greek mythology connected to it.
Poseidon and the Dolphin
One story is about the powerful Greek god of the sea, Poseidon. He wanted to marry a beautiful sea nymph named Amphitrite. But Amphitrite wanted to stay free and ran away to the Atlas Mountains. Poseidon sent many helpers to find her, and one of them was a friendly dolphin named Delphinus.
Delphinus found Amphitrite and gently convinced her to accept Poseidon's proposal. Poseidon was so thankful to the dolphin that he placed its image among the stars for everyone to see!
Arion and the Musical Dolphin
Another tale is about a famous Greek poet and musician named Arion from Lesbos. He lived a very long time ago, around the 7th century BC. Arion was a court musician for King Periander of Corinth.
During his travels, Arion became very wealthy. On his way home by ship, the greedy crew decided to steal his riches and harm him. Arion asked for one last wish: to sing a final song. The crew agreed. As he sang a sad song, he jumped into the sea.
But guess what? A dolphin, charmed by Arion's beautiful music, rescued him! The dolphin carried Arion safely to the coast of Greece and then swam away. This amazing rescue is another reason why the dolphin is honored in the stars.
Delphinus in Other Cultures
People all over the world have looked at the stars and created their own stories and patterns.
In ancient Chinese astronomy, the stars of Delphinus were part of a larger group called the Black Tortoise of the North.
In Polynesia, island cultures also saw patterns in these stars. For example, people in Pukapuka called it Te Toloa, and in the Tuamotus islands, it was known as Te Uru-o-tiki.
In Hindu astrology, which is a traditional system of looking at the stars, Delphinus matches up with a special section of the sky called Dhanishta.
What Makes Delphinus Special?
Delphinus is a small constellation, but it has some interesting facts!
Where to Find Delphinus
As we mentioned, Delphinus is surrounded by other constellations. To its north is Vulpecula, and to its northwest is Sagitta. You'll find Aquila to its west and southwest, and Aquarius to its southeast. On its eastern side are Equuleus and Pegasus.
Size and Visibility
Delphinus covers about 188.5 square degrees of the sky. This means it takes up a tiny bit less than half a percent (0.457%) of the entire night sky. Out of all 88 constellations, it's the 69th largest.
Astronomers use a short, three-letter code for each constellation. For Delphinus, it's "Del." This code was decided by the International Astronomical Union in 1922.
You can see the entire Delphinus constellation if you are anywhere north of 69 degrees south latitude. This means most people in the world can spot it!
Stars and Other Objects in Delphinus
Delphinus is home to many stars, even though it's a small constellation. It's located in a busy part of the Milky Way galaxy!
Bright Stars of Delphinus
The brightest star in Delphinus shines at a magnitude of 3.6. Remember, the lower the magnitude number, the brighter the star appears!
Four of its brightest stars – Alpha, Beta, Gamma, and Delta Delphini – form a diamond shape. This pattern is sometimes called "Job's Coffin."
Interestingly, two of these stars, Alpha and Beta Delphini, have unique names: Sualocin and Rotanev. These names are actually the Latinized name of an astronomer, Niccolò Cacciatore, spelled backward! He was a director at the Palermo Observatory in the 1800s.
Alpha Delphini (Sualocin)
Alpha Delphini is a blue-white star. It's about 241 light-years away from Earth. A light-year is the distance light travels in one year – that's incredibly far! This star is also a binary star, meaning it's actually two stars orbiting each other, but they look like one from Earth.
Beta Delphini (Rotanev)
Beta Delphini is officially called Rotanev. It's a white star that appears as a single point of light to our eyes. However, astronomers discovered in 1873 that it's also a binary star! If you have a large amateur telescope, you might even be able to see the two stars separately. They orbit each other every 27 years and are about 97 light-years from Earth.
Gamma Delphini
Gamma Delphini is a favorite among amateur astronomers because it's a beautiful binary star. One star is orange-gold, and the other is light yellow. You can see both stars with a small telescope! They are about 125 light-years away and take over 3,000 years to complete one orbit around each other.
Delta Delphini
Delta Delphini is another interesting star. It's also a spectroscopic binary, meaning astronomers can tell it's two stars by looking at their light, even if they can't see them separately.
Epsilon Delphini
Epsilon Delphini is sometimes called Deneb Dulfim, which means "tail of the Dolphin" in Arabic. Its brightness changes a little bit over time.
Zeta Delphini
In 2014, scientists found something amazing orbiting Zeta Delphini: a brown dwarf! A brown dwarf is like a "failed star" – it's bigger than a planet but not quite big enough to become a star. This brown dwarf is about 50 times the mass of Jupiter.
Other Notable Stars
- HR Delphini was a nova that suddenly became very bright in December 1967. A nova is a star that has a sudden, huge burst of energy, making it shine much brighter for a short time.
- Another nova, V339 Delphini, was seen in 2013. It was special because it was the first nova where scientists observed the creation of lithium, a light element.
- Musica (also known as 18 Delphini) is one of the stars in Delphinus that has a planet orbiting it!
Planets Beyond Our Solar System (Exoplanets)
Scientists have discovered planets orbiting stars outside our solar system, called exoplanets. Delphinus has a few!
TOI-6883 b
In 2024, the planet TOI-6883 b was discovered in the Delphinus constellation. It takes about 16 days to orbit its star. This planet is a bit bigger than Jupiter and about four times as massive. Citizen scientists helped confirm its discovery!
TOI-6883 c
Also in 2024, another planet, TOI-6883 c, was found in Delphinus. It orbits its star much faster, taking about 7.8 days. This planet is smaller than Jupiter, about 0.7 times its size, and has about a third of Jupiter's mass.
Deep-Sky Wonders
Delphinus is in a part of the sky rich with stars from the Milky Way, so it has many interesting "deep-sky objects" – things like nebulae and star clusters.
Nebulae
- NGC 6891 is a planetary nebula. This is a beautiful cloud of gas and dust that forms when a star like our Sun reaches the end of its life.
- NGC 6905, also called the Blue Flash Nebula, is another planetary nebula. It gets its name from the bright blue light it gives off.
Globular Clusters
- NGC 6934 is a globular cluster. This is a huge, tightly packed ball of thousands to millions of very old stars, all held together by gravity. It's about 52,000 light-years away from our Solar System.
- NGC 7006 is another globular cluster, but it's much farther away – about 137,000 light-years! It's located at the very edges of our galaxy.
See also
In Spanish: Delphinus (constelación) para niños
