Star Constellations: Pisces 'the Fish'
Created | Updated Apr 16, 2008
Taking the five loaves and the two fish and looking up to Heaven, Jesus gave thanks and broke the loaves. Then he gave them to his disciples to set before the people. He also divided the two fish among them all. They all ate and were satisfied, and the disciples picked up twelve basketfuls of broken pieces of bread and fish. The number of men who had eaten was five thousand.
- Mark 6: 41-44
Pisces the Constellation
| Latin: | Pisces ('fish') |
| Genitive: | Piscium |
| Short form: | Psc |
| Area: | 889 sq deg |
| Co-ordinates1: | 1h, +15° |
| Zodiac: | Yes |
| Origin: | Ancient |
Pisces shares its borders with Andromeda, Pegasus, Aquarius, Cetus, Aries and Triangulum. Quite a substantial size, Pisces ranks 14th of the modern 88 internationally recognised constellations. It's supposed to represent two fish joined at their tails, but tracing the stars from the asterism known as 'The Circlet' you end up with a snake-like creature bent in the middle. The bend is to the alpha star, Alrescha; this and a few others are below the ecliptic.
Due to its positioning bordering the ecliptic, Pisces is a member of the zodiac and an astrological sign, sometimes playing host to the planets, the Moon and the Sun.
Pisces is distinguishable because it contains the Vernal Equinox, the point where the Sun appears to cross the celestial equator into the northern hemisphere every year. Some people know this date as the first day of Spring. The gradual shift of the Earth on its axis is called precession, a 26,000 year wobble as the Earth rotates, and this has caused the Vernal Equinox to move into Pisces. Between 1500 BC and 500 BC the Vernal Equinox was in Aries.
Surprisingly, given its generous portion of the sky, there is just one Messier object, M74, which is a fabulous clockwise spiral galaxy around 32 million light years distant. Then there's the mindboggling Perseus-Pisces Supercluster of galaxies over 220 million light years away, which measures 300 million light years across.
Mythology
One story of the origin of Pisces the fish constellation concerns the gods of Olympus themselves. The god Typhon was a fearsome monster who all the other gods fled from when he stormed Mount Olympus. Even the mighty Zeus, who had morphed into the form of a ram, could not escape and he was imprisoned by Typhon. The goddess of love, Aphrodite (Venus) and her son Eros (Cupid) had transformed themselves into fish to swim to safety up the River Nile. Typhon was eventually defeated when Zeus trapped him by dropping Mount Etna on him. Being immortal, the god Typhon could not die, so he remains trapped beneath the earth, erupting when disturbed. The two fish were placed in the night sky as a reminder against complacency.
Stars
The scientific star names are simple to understand (if you know your Greek alphabet). For example: the 'alpha' star means that it is the brightest star in that constellation. The next brightest is designated 'beta', etc. Some stars have proper names as well; for example, alpha Piscium is Alrescha; others are known by their catalogue numbers or 'designation'.
That's the way it's supposed to work, but sometimes the measurements were a little off, or the stars are variable. In this case, the brightest star of Pisces is the eta designated star which is magnitude +3.6, followed closely by the gamma star, with the next brightest star the rather bizarrely designated omega. Omega is the last letter of the Greek alphabet and as such, the omega star should be the least bright of the whole constellation; in fact some constellations don't even reach an omega designation because there aren't that many stars in them! The iota star ranks behind the omega, then comes omicron, epsilon and theta before the alpha star, Alrescha, finally gets a look-in.
Star Table
| Star | Designation | Name or catalogue number | Magnitude | Distance (light years) | Spectral classification and/or comments |
| η Psc | Eta Piscium | 99 Piscium | +3.6 | 294 | Yellow giant |
| γ Psc | Gamma Piscium | 6 Piscium | +3.69 var | 126 | Yellow giant |
| ω Psc | Omega Piscium | 28 Piscium | +4.04 | 104 | Yellow-white dwarf |
| ι Psc | Iota Piscium | 17 Piscium | +4.13 var | 41 | Yellow-white dwarf |
| ο Psc | Omicron Piscium | 110 Piscium | +4.26 var | 142 | Yellow dwarf |
| ε Psc | Epsilon Piscium | 71 Piscium | +4.28 var | 199 | Yellow dwarf |
| θ Psc | Theta Piscium | 10 Piscium | +4.28 var | 165 | Orange giant |
| α Psc | Alpha Piscium | Alrescha | +4.3 var | 139 | Binary star system |
| δ Psc | Delta Piscium | 63 Piscium | +4.44 | 305 | Orange giant |
| ν Psc | Nu Piscium | 106 Piscium | +4.45 var | 368 | Orange giant |
| β Psc | Beta Piscium | Fum al Samakah | +4.48 var | 492 | Blue-white dwarf |
| λ Psc | Lambda Piscium | 18 Piscium | +4.5 var | 104 | White dwarf |
| τ Psc | Tau Piscium | Anunitum | +4.5 | 162 | Orange dwarf |
| φ Psc | Phi Piscium | 85 Piscium | +4.6 var | 377 | Binary star system |
| ξ Psc | Xi Piscium | 111 Piscium | +4.6 | 191 | Orange giant |
| υ Psc | Upsilon Piscium | 90 Piscium | +4.7 var | 311 | White dwarf |
| μ Psc | Mu Piscium | 98 Piscium | +4.8 var | 360 | Multiple star system |
| κ Psc | Kappa Piscium | 8 Piscium | +4.95 var | 162 | Multiple star system |
| ζ Psc | Zeta Piscium | 86 Piscium | +5.2 | 148 | Binary star system |
| π Psc | Pi Piscium | 102 Piscium | +5.5 | 110 | Yellow-white dwarf |
New General Catalogue (NGC)
The NGC catalogue was compiled by John Louis Emil Dreyer (the director of the Armagh Observatory from 1882 to 1916).
Galaxies
Galaxies are categorised by their shape:
- Spirals have 'arms' which rotate either clockwise (CW) or anti-clockwise (ACW) and they may have a central bar.
- Elliptical galaxies have no arms and are usually shaped like rugby balls.
- Lenticular galaxies are a mix between spiral and elliptical.
- Seyfert galaxies, named after their discoverer, American astronomer Carl Seyfert, have black holes at their core.
NGC Table
| Catalogue | Type | Magnitude | Distance (million light years) | Remarks |
| NGC 100 | Spiral galaxy | +14.6 | 41 | Edge-on |
| NGC 266 | ACW spiral galaxy | +13 | 99 | Barred |
| NGC 382 | Elliptical galaxy | +14.2 | 230 | Supernova 2000dk |
| NGC 383 | Lenticular galaxy | +12 | 230 | Pisces cluster |
| NGC 488 | CW spiral galaxy | +10.3 | 95 | Pisces cluster |
| NGC 507 | Elliptical galaxy | +13 | 225 | Interacting with NGC 508 |
| NGC 508 | Lenticular galaxy | +14.5 | 225 | Interacting with NGC 507 |
| NGC 514 | ACW spiral galaxy | +12 | 105 | Pisces cluster |
| NGC 520 | Starburst galaxy | +12 | 100 | Mid-range Merger |
| NGC 524 | Elliptical galaxy | +10.6 | 225 | Supernova 2000cx |
| NGC 660 | Seyfert galaxy | +15.5 | 24 | Post-merger/Polar ring |
Meteor Showers
Meteor showers occur when the Earth passes through the debris path left by the tail of a comet. There are a couple of meteor showers which appear to hail from Pisces, the Gamma Piscids during October, and the Upsilon Piscids of May. Neither of the events have had any spectacular shows recorded, the best ZHR (Zenithal Hourly Rate) so far is eight, the maximum count over one whole evening (six hours) was 17.
Extrasolar Planets in Pisces
Over 2,000 years ago the Greek philosophers Aristotle and Epicurus argued about whether there were other Earth-like planets orbiting distant suns. There have been five extrasolar planetary systems found in the constellation Pisces up to 2007; the first was discovered in 1998. One star, HD 217107, has at least two planets orbiting it, that we know of. Figures given in the table below are the length of the planet's orbital period around its parent star, which we know of as a year. The size of the extrasolar planet is compared to the mass of Jupiter, our Solar System's largest planet, known by astronomers as the 'Jovian scale'.
Extrasolar Planets Table
| Star name or catalogue number | Planet catalogue number | Planet size (Jovian scale) | Orbital period (Earth days) | Year of discovery | Comments |
| 109 Piscium | 109 Piscium b | 6.8 | 1,076 | 2000 | Super jovian |
| HD 4203 | HD 4203b | 1.65 | 401 | 2001 | Gas giant |
| HD 8574 | HD 8574b | 2.2 | 228 | 2002 | Gas giant |
| 54 Piscium A | 54 Piscium Ab | 0.23 | 62 | 2003 | Hot subjovian |
| HD 217107 | HD 217107b | 1.37 | 7.13 | 1998 | Hot Jupiter |
| HD 217107 | HD 217107c | 2.5 | 3,300 | 2005 | Gas giant |
Down to Earth
Astrology
Pisces is the 12th sign of the zodiac2 and astrologers today still use dates which are over 2,000 years out of date. So newspaper and magazine columnists say that Pisces covers the dates between 19 February and 20 March. However, currently (2008) the sun occupies Pisces between 15 March and 13 April.
If you believe in such things, the Piscean zodiacal sign has Jupiter as its ruling planet, white as its characteristic colour and chrysotile as its lucky jewel. Subjects of Pisces are said to be altruistic, highly sensitive and given to extremes of elation and depression.
Some famous Piscean people are: Douglas Adams (author); Alexander Graham Bell (telephone inventor); Albert Einstein (physicist); Yuri Gagarin (pioneering astronaut); George Harrison (musician); Sir Patrick Moore (astronomer/TV presenter); Samuel Pepys (diarist).
Pisces in Modern Culture
- Pisces Iscariot is an album by The Smashing Pumpkins.
- In the Dune universe of Frank Herbert, the Imperial House Corrino hail from the gamma star system of Pisces.
and Finally ...
Pisces Halcyon is a British author, poet and artist.
