Eridana（Eridanus/ᵻ r ɪ d ə n ə s/) is a southern constellation, which symbolizes a river.Its name isPo RiverIt is also the Latin name of a river in Athens.This constellation is in the second centuryastronomerPtolemy One of the 48 constellations listed, it is still one of the 88 modern constellations.It is modern88 constellationsThe sixth largest in.[3]
Eridanus is one of the constellations in the southern sky, including the ancient Chinese star official: Tianyuan,Jiuzhou Shukou, Tianyuan, Jiuqi, Yujing andWater Commission, the largest constellation in the north-south span, is also one of the major southern constellations in the northern hemisphere in winter nights.Eridanus fromOrionStarting near the southern end, it winds and twists in TaurusCetusAndAplysiaIt flows between, until the southern sky comes closeHydraThe place.The constellation Eridanus lies between Cetus and Orioncelestial equatorIt extends southward to about declination - 60 °.Most of the stars in the whole constellation are dark, with only one star at the head and one star at the tail attracting attention.
The bright star at the southernmost tip of the constellation Eridanus isWater Commission IOnly the south of China can see it.The stars of this constellation have always been associated with various terrestrial rivers, includingEuphrates River、the NileAnd ItalianPo River。In the vast area south of 32 degrees north latitude, the complete constellation of Eridanus can be seen, including 79 stars brighter than 5.5, including one first-class star and three third-order stars.Included in the 200 bright stars list throughout the day are Water Commission I, β (127th), θ (154th) and γ (159th).Although most of the stars in the constellation of Eridanus are relatively weak, there are not many stars near this constellation, so people can still easily identify it.
Water Commission IIt is one of the 20 brightest stars in the whole day (ranking 9th) with a brightness of 0.45. Its Latin name Achernar comes from the Arabic word "Hewei". It is a big blue white star with a radius of 8 times the sun's radius and a surface temperature of 15000 Kelvin.Due to high-speed rotation, the equatorial radius is 50% longer than the polar radius.
Chinese name of γ - star in Eridanus“Tianyuan No.1”, named Acamar in the west, with an apparent magnitude of 3.24 and a distance of 93 light-years, it is a pair of binary stars with θ 2 in the constellation Eridanus.AscompanionThe apparent magnitude of θ 2 star is 4.42.
Ripple ε（Tianyuan IV）Similar to the sun, with at least one planet (similar toJupiter）。
It is said that one day, the son of Helios, the sun godPhaethon Driving his father's solar car in the sky.As Phaethon whipped the steed with a whip, the steed lost its normality and ran away from the heaven with the solar cart.The solar car skimmed over the clouds and hit the mountains, turning the earth into a sea of fire.Main GodZeusIn order to stop this disaster and avoid the destruction of the whole universeAlistair Danas RiverLi.At this time, the runaway solar car returned to the heaven, and the earth slowly returned to normal order.Later, Zeus moved the Eridanus River to the heaven and became the constellation of Eridanus in the sky.
Legend II
In early Greek mythology, the sun god was namedHelios(Later Greek mythology called him Apollo).He and the forest goddessClumeneHe had a son named Phaethon and five daughters.Once, Phaethon's companions humiliated him, saying that he was an illegitimate son.Phaethon Very angry, in order to prove that he is the son of the great sun god, he asked his father Helios.The kind father said to him: "My dear child! You are indeed my son, and I can help you to realize any wish you have." Fa Etong asked to drive his father's carriage to prove himself to his companions.Helios knew that not everyone could drive the chariot of Helios;But he also understood that a father should keep his word.He decided to let his son play with his carriage.After Phaethon jumped onto the carriage, the carriage took him to run wildly, and soon left the track in the sky and drove to the ground.
The earth suddenly became hot, the rivers began to dry up, and the forests burned.In order to save all living beings on the ground, Zeus, the main god, had to shoot lightning at Phaethon.Phaethon was caught off guard, hit by lightning, and fell intoPo RiverAnd die.The Helios family was in great sorrow. The sisters of Phaethon cried bitterly. Their bodies turned into poplar trees on the bank of the Po River, and their tears turned into tearsamber。In order to comfort Helios, Zeus moved the Po River to the heaven and became the constellation of rivers in the sky.
meteor shower
Announce
edit
This one is not noticeableMeteor groupIt was discovered by Gary Kronk when checking the 39145 radio meteors observed by Zdenek Sekanina in the 1960s. A total of six clusters appeared from August 2 to 27, with the maximum appearing on August 12,Radiant pointIt is located at 49.6 degrees of right ascension and - 4.9 degrees of declination.Its parent comet should be the periodic comet Pons Gambart (1827 II Pons Gambart), with very similar orbits, but the perihelion distance is about 0.2AU different, and the difference in orbital half length diameter is about 3.5 times.
Interestingly, although there is no visual data about this group of direct contacts, the American Meteor Association has observed strong activities at 8-10 degrees in the north.Dr. H.L. Alden and Ronald A. McIntosh observed activities in 1926 and 1929 respectively, similar to Franklin Institute in 1941, Charles E. Worley in 1954 and Eli Metzger in 1958.Cuno Hoffmeister listed 5406 radiation points in his "Meteor Nighttalk" published in 1948, and said that in 1937, heSouth West AfricaSimilar meteor clusters have also been observed.It can be concluded from the above that the August Borneo meteor shower is very old, so the radio group and the visual group may have been divided into two parts.
Comet Ponce Gambart has been observed for only one month, and its period is thought to be 57.5 years, but it has never been found again.In 1979, someone calculated the orbit of a comet that appeared in 1110, and found that this may be the last return of Comet Ponce Gambart. It seems that its period may be about 1000 years.
