 |
The
Constellations |
The
Constellations |
In
colloquial usage, a constellation is what astronomers call an asterism: a group
of celestial bodies (usually stars) that appear to form a pattern in the sky or
appear visibly related to each other. Examples are Orion (which appears like a
human figure with a belt, often referred to as "The Hunter"), Leo (which
contains bright stars that outline the form of a lion), Scorpius (which can seem
reminiscent of a scorpion), and Crux (a cross). In
astronomy, however, a constellation is an area of the sky, and contains all the
stars and other celestial objects within that area. The International Astronomical
Union (IAU) divides the sky into 88 official constellations with exact boundaries,
so that every direction or place in the sky belongs within one constellation.
Most of these constellations are centred on the traditional constellations of
Western culture. Constellations are normally the product of human perception rather than astronomical realities. The stars in a constellation or asterism rarely have any astrophysical relationship to each other; they just happen to appear close together in the sky as viewed from Earth and typically lie many light years apart in space. However, there are some exceptions. The famous star pattern known as the Big Dipper in North America or the Plough in the UK is almost entirely created by stars that are genuinely close together in astronomical terms; they are known as the Ursa Major moving group. The grouping of stars into constellations is essentially arbitrary, as different cultures have seen different patterns in the sky, although a few of the more obvious ones tend to recur frequently, e.g., Orion and Scorpius. |
| List of Constellations by Area |
| Rank 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 | Family
[1] Her Zod Urs Per Her Wat Per Urs Her Zod Her Zod Urs Zod Zod Her Zod Urs Per Wat Per Her Her Per Per Ori Per Urs Zod Zod Zod Wat Zod Wat Ori Lac Bay Urs Zod Zod Lac Urs Ori Bay Bay Her Her Bay Bay Lac Ori Her Her Wat Her Urs Lac Lac Lac Wat Bay Lac Her Urs Wat Lac Bay Per Wat Her Ori Bay Urs Lac Lac Bay Bay Per Bay Her Lac Lac Her Her Lac Her Wat Her | Abbr HYA VIR UMA CET HER ERI PEG DRA CEN AQR OPH LEO BOO PSC SGR CYG TAU CAM AND PUP AUR AQL SER PER CAS ORI CEP LYN LIB GEM CNC VEL SCO CAR MON SCL PHE CVN ARI CAP FOR COM CMA PAV GRU LUP SEX TUC IND OCT LEP LYR CRT COL VUL UMI TEL HOR PIC PSA HYI ANT ARA LMI PYX MIC APS LAC DEL CRV CMI DOR CRB NOR MEN VOL MUS TRI CHA CRA CAE RET TRA SCT CIR SGE EQU CRU | Constellation Hydra Virgo Ursa Major Cetus Hercules Eridanus Pegasus Draco Centaurus Aquarius Ophiuchus Leo Boötes Pisces Sagittarius Cygnus Taurus Camelopardalis Andromeda Puppis Auriga Aquila Serpens [5] Perseus Cassiopeia Orion Cepheus Lynx Libra Gemini Cancer Vela Scorpius Carina Monoceros Sculptor Phoenix Canes Venatici Aries Capricornus Fornax Coma Berenices Canis Major Pavo Grus Lupus Sextans Tucana Indus Octans Lepus Lyra Crater Columba Vulpecula Ursa Minor Telescopium Horologium Pictor Piscis Austrinus Hydrus Antlia Ara Leo Minor Pyxis Microscopium Apus Lacerta Delphinus Corvus Canis Minor Dorado Corona Borealis Norma Mensa Volans Musca Triangulum Chamaeleon Corona Australis Caelum Reticulum Triangulum Australe Scutum Circinus Sagitta Equuleus Crux | Area
(sq. deg.) [2] 1302.844 1294.428 1279.66 1231.411 1225.148 1137.919 1120.794 1082.952 1060.422 979.854 948.34 946.964 906.831 889.417 867.432 803.983 797.249 756.828 722.278 673.434 657.438 652.473 636.928 614.997 598.407 594.12 587.787 545.386 538.052 513.761 505.872 499.649 496.783 494.184 481.569 474.764 469.319 465.194 441.395 413.947 397.502 386.475 380.118 377.666 365.513 333.683 313.515 294.557 294.006 291.045 290.291 286.476 282.398 270.184 268.165 255.864 251.512 248.885 246.739 245.375 243.035 238.901 237.057 231.956 220.833 209.513 206.327 200.688 188.549 183.801 183.367 179.173 178.71 165.29 153.484 141.354 138.355 131.847 131.592 127.696 124.865 113.936 109.978 109.114 93.353 79.932 71.641 68.447 | Percentage 3.16% 3.14% 3.10% 2.99% 2.97% 2.76% 2.72% 2.63% 2.57% 2.38% 2.30% 2.30% 2.20% 2.16% 2.10% 1.95% 1.93% 1.83% 1.75% 1.63% 1.59% 1.58% 1.54% 1.49% 1.45% 1.44% 1.42% 1.32% 1.30% 1.25% 1.23% 1.21% 1.20% 1.20% 1.17% 1.15% 1.14% 1.13% 1.07% 1.00% 0.96% 0.94% 0.92% 0.92% 0.89% 0.81% 0.76% 0.71% 0.71% 0.71% 0.70% 0.69% 0.68% 0.65% 0.65% 0.62% 0.61% 0.60% 0.60% 0.59% 0.59% 0.58% 0.57% 0.56% 0.54% 0.51% 0.50% 0.49% 0.46% 0.45% 0.44% 0.43% 0.43% 0.40% 0.37% 0.34% 0.34% 0.32% 0.32% 0.31% 0.30% 0.28% 0.27% 0.26% 0.23% 0.19% 0.17% 0.17% | RA:
[3] h m 11 36.73 13 24.39 11 18.76 01 40.10 17 23.16 03 18.02 22 41.84 15 08.64 13 04.27 22 17.38 17 23.69 10 40.03 14 42.64 00 28.97 19 05.94 20 35.28 04 42.13 08 51.37 00 48.46 07 15.48 06 04.42 19 40.02 16 57.04 03 10.50 01 19.16 05 34.59 22 07 59.53 15 11.96 07 04.24 08 38.96 09 34.64 16 53.24 08 41.70 07 03.63 00 26.28 00 55.91 13 06.96 02 38.16 21 02.93 02 47.88 12 47.27 06 49.74 19 36.71 22 27.39 15 13.21 10 16.29 23 46.64 21 58.33 23 00.00 05 33.95 18 51.17 11 23.75 05 51.76 20 13.88 15 00.00 19 19.54 03 16.56 05 42.46 22 17.07 02 20.65 10 16.43 17 22.49 10 14.72 08 57.16 20 57.88 16 08.65 22 27.68 20 41.61 12 26.52 07 39.17 05 14.51 15 50.59 15 54.18 05 24.90 07 47.73 12 35.28 02 11.07 10 41.53 18 38.79 04 42.27 03 55.27 16 04.95 18 40.39 14 34.54 19 39.05 21 11.26 12 26.99 | DEC:
d m -14 31.91 -04 09.51 +50 43.27 -07 10.76 +27 29.93 -28 45.37 +19 27.98 +67 00.40 -47 20.72 -10 47.35 -07 54.74 +13 08.32 +31 12.16 +13 41.23 -28 28.61 +44 32.70 +14 52.63 +69 22.89 +37 25.91 -31 10.64 +42 01.68 +03 24.65 +06 07.32 +45 00.79 +62 11.04 +05 56.94 +71 00.51 +47 28.00 -15 14.08 +22 36.01 +19 48.35 -47 10.03 -27 01.89 -63 13.16 +00 16.93 -32 05.30 -48 34.84 +40 06.11 +20 47.54 -18 01.39 -31 38.07 +23 18.34 -22 08.42 -65 46.89 -46 21.11 -42 42.53 -02 36.88 -65 49.80 -59 42.40 -82 09.12 -19 02.78 +36 41.36 -15 55.74 -35 05.67 +24 26.56 +77 41.99 -51 02.21 -53 20.18 -53 28.45 -30 38.53 -69 57.39 -32 29.01 -56 35.30 +32 08.08 -27 21.10 -36 16.49 -75 18.00 +46 02.51 +11 40.26 -18 26.20 +06 25.63 -59 23.22 +32 37.49 -51 21.09 -77 30.24 -69 48.07 -70 09.66 +31 28.56 -79 12.30 -41 08.85 -37 52.90 -59 59.85 -65 23.28 -09 53.32 -63 01.82 +18 51.68 +07 45.49 -60 11.19 | Quad
[4] SQ2 SQ3 NQ2 SQ1 NQ3 SQ1 NQ4 NQ3 SQ3 SQ4 SQ3 NQ2 NQ3 NQ1 SQ4 NQ4 NQ1 NQ2 NQ1 SQ2 NQ2 NQ4 NQ3 NQ1 NQ1 NQ1 NQ4 NQ2 SQ3 NQ2 NQ2 SQ2 SQ3 SQ2 NQ2 SQ1 SQ1 NQ3 NQ1 SQ4 SQ1 NQ3 SQ2 SQ4 SQ4 SQ3 SQ2 SQ4 SQ4 SQ4 SQ1 NQ4 SQ2 SQ1 NQ4 NQ3 SQ4 SQ1 SQ1 SQ4 SQ1 SQ2 SQ3 NQ2 SQ2 SQ4 SQ3 NQ4 NQ4 SQ3 NQ2 SQ1 NQ3 SQ3 SQ1 SQ2 SQ3 NQ1 SQ2 SQ4 SQ1 SQ1 SQ3 SQ4 SQ3 NQ4 NQ4 SQ3 |
Notes
|
Text
and tables courtesy of Wikipedia |
Two
well-known constellations |
Ursa
Major - The Plough |
 |
Orion
- The Hunter |
 |
Illustrations
courtesy of Ian Morison - Jodrell Bank Centre for Astrophysics |
The
88 official constellations defined by the IAU (International Astronomical Union)
are mostly based upon those of the ancient Greek tradition, passed down through
the Middle Ages, which includes the 'signs of the zodiac,' twelve constellations
through which the sun passes and which thus have had special cultural significance.
The rest consist of constellations which were defined in the early modern era
by astronomers who studied the southern hemisphere's skies, which were invisible
to the Greeks. These areas are determined by constellation boundaries drawn up by Eugène Delporte in 1930 on behalf of the IAU and published in Délimitation scientifique des constellations (Cambridge University Press). Before Delporte's work, the precise boundaries of each constellation were only vaguely defined. Delporte drew the boundaries along vertical and horizontal lines of right ascension and declination; however, he did so for the epoch B1875.0, which means that due to precession of the equinoxes, the borders on a modern star map (eg, for epoch J2000) are already somewhat skewed and no longer perfectly vertical or horizontal. This skew will increase over the years and centuries to come. However, this does not change the area of any constellation. |