IAU designated constellations by area

Hydra is the largest constellation, covering more than 1⁄32 of the night sky and 19 times the area of Crux, the smallest constellation.

The International Astronomical Union (IAU) designates 88 constellations of stars. In the table below, they are ranked by the solid angle that they subtend in the sky, measured in square degrees and millisteradians.

These solid angles depend on arbitrary boundaries between the constellations: the list below is based on 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, there was no standard list of the boundaries of each constellation.

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 (e.g., for epoch J2000) are already somewhat skewed and no longer perfectly vertical or horizontal. This skew will increase over the centuries to come. However, this does not change the solid angle of any constellation.

Rank Abbrev. Constellation Solid angle
("Area")
(sq. deg.) [1] 		Solid angle
(millisteradians) 		Per­cent­age Right ascension
(hours & mins) [2] 		Decli­nation
(degs & mins) [3] 		Quad [4]
01 Hya Hydra 1302.844 396.869 3.16% +11 36.73 −14 31.91 SQ2
02 Vir Virgo 1294.428 394.305 3.14% +13 24.39 −04 09.51 SQ3
03 UMa Ursa Major 1279.660 389.807 3.10% +11 18.76 +50 43.27 NQ2
04 Cet Cetus 1231.411 375.109 2.99% +01 40.10 −07 10.76 SQ1
05 Her Hercules 1225.148 373.201 2.97% +17 23.16 +27 29.93 NQ3
06 Eri Eridanus 1137.919 346.630 2.76% +03 18.02 −28 45.37 SQ1
07 Peg Pegasus 1120.794 341.413 2.72% +22 41.84 +19 27.98 NQ4
08 Dra Draco 1082.952 329.886 2.63% +15 08.64 +67 00.40 NQ3
09 Cen Centaurus 1060.422 323.023 2.57% +13 04.27 −47 20.72 SQ3
10 Aqr Aquarius 979.854 298.481 2.38% +22 17.38 −10 47.35 SQ4
11 Oph Ophiuchus 948.340 288.881 2.30% +17 23.69 −07 54.74 SQ3
12 Leo Leo 946.964 288.462 2.30% +10 40.03 +13 08.32 NQ2
13 Boo Boötes 906.831 276.237 2.20% +14 42.64 +31 12.16 NQ3
14 Psc Pisces 889.417 270.932 2.16% +00 28.97 +13 41.23 NQ1
15 Sgr Sagittarius 867.432 264.235 2.10% +19 05.94 −28 28.61 SQ4
16 Cyg Cygnus 803.983 244.907 1.95% +20 35.28 +44 32.70 NQ4
17 Tau Taurus 797.249 242.856 1.93% +04 42.13 +14 52.63 NQ1
18 Cam Camelopardalis 756.828 230.543 1.83% +08 51.37 +69 22.89 NQ2
19 And Andromeda 722.278 220.018 1.75% +00 48.46 +37 25.91 NQ1
20 Pup Puppis 673.434 205.140 1.63% +07 15.48 −31 10.64 SQ2
21 Aur Auriga 657.438 200.267 1.59% +06 04.42 +42 01.68 NQ2
22 Aql Aquila 652.473 198.755 1.58% +19 40.02 +03 24.65 NQ4
23 Ser Serpens[5] 636.928 194.019 1.54% +16 57.04 +06 07.32 NQ3
24 Per Perseus 614.997 187.339 1.49% +03 10.50 +45 00.79 NQ1
25 Cas Cassiopeia 598.407 182.285 1.45% +01 19.16 +62 11.04 NQ1
26 Ori Orion 594.120 180.979 1.44% +05 34.59 +05 56.94 NQ1
27 Cep Cepheus 587.787 179.050 1.42% +02 32.64 +71 00.51 NQ4
28 Lyn Lynx 545.386 166.134 1.32% +07 59.53 +47 28.00 NQ2
29 Lib Libra 538.052 163.900 1.30% +15 11.96 −15 14.08 SQ3
30 Gem Gemini 513.761 156.501 1.25% +07 04.24 +22 36.01 NQ2
31 Cnc Cancer 505.872 154.097 1.23% +08 38.96 +19 48.35 NQ2
32 Vel Vela 499.649 152.202 1.21% +09 34.64 −47 10.03 SQ2
33 Sco Scorpius 496.783 151.329 1.20% +16 53.24 −27 01.89 SQ3
34 Car Carina 494.184 150.537 1.20% +08 41.70 −63 13.16 SQ2
35 Mon Monoceros 481.569 146.694 1.17% +07 03.63 +00 16.93 NQ2
36 Scl Sculptor 474.764 144.621 1.15% +00 26.28 −32 05.30 SQ1
37 Phe Phoenix 469.319 142.963 1.14% +00 55.91 −48 34.84 SQ1
38 CVn Canes Venatici 465.194 141.706 1.13% +13 06.96 +40 06.11 NQ3
39 Ari Aries 441.395 134.457 1.07% +02 38.16 +20 47.54 NQ1
40 Cap Capricornus 413.947 126.095 1.00% +21 02.93 −18 01.39 SQ4
41 For Fornax 397.502 121.086 0.96% +02 47.88 −31 38.07 SQ1
42 Com Coma Berenices 386.475 117.727 0.94% +12 47.27 +23 18.34 NQ3
43 CMa Canis Major 380.118 115.791 0.92% +06 49.74 −22 08.42 SQ2
44 Pav Pavo 377.666 115.044 0.92% +19 36.71 −65 46.89 SQ4
45 Gru Grus 365.513 111.342 0.89% +22 27.39 −46 21.11 SQ4
46 Lup Lupus 333.683 101.646 0.81% +15 13.21 −42 42.53 SQ3
47 Sex Sextans 313.515 95.502 0.76% +10 16.29 −02 36.88 SQ2
48 Tuc Tucana 294.557 89.727 0.71% +23 46.64 −65 49.80 SQ4
49 Ind Indus 294.006 89.559 0.71% +21 58.33 −59 42.40 SQ4
50 Oct Octans 291.045 88.657 0.71% +23 00.00 −82 09.12 SQ4
51 Lep Lepus 290.291 88.428 0.70% +05 33.95 −19 02.78 SQ1
52 Lyr Lyra 286.476 87.266 0.69% +18 51.17 +36 41.36 NQ4
53 Crt Crater 282.398 86.023 0.68% +11 23.75 −15 55.74 SQ2
54 Col Columba 270.184 82.303 0.65% +05 51.76 −35 05.67 SQ1
55 Vul Vulpecula 268.165 81.688 0.65% +20 13.88 +24 26.56 NQ4
56 UMi Ursa Minor 255.864 77.941 0.62% +15 00.00 +77 41.99 NQ3
57 Tel Telescopium 251.512 76.615 0.61% +19 19.54 −51 02.21 SQ4
58 Hor Horologium 248.885 75.815 0.60% +03 16.56 −53 20.18 SQ1
59 Pic Pictor 246.739 75.161 0.60% +05 42.46 −53 28.45 SQ1
60 PsA Piscis Austrinus 245.375 74.745 0.59% +22 17.07 −30 38.53 SQ4
61 Hyi Hydrus 243.035 74.033 0.59% +02 20.65 −69 57.39 SQ1
62 Ant Antlia 238.901 72.773 0.58% +10 16.43 −32 29.01 SQ2
63 Ara Ara 237.057 72.212 0.57% +17 22.49 −56 35.30 SQ3
64 LMi Leo Minor 231.956 70.658 0.56% +10 14.72 +32 08.08 NQ2
65 Pyx Pyxis 220.833 67.270 0.54% +08 57.16 −27 21.10 SQ2
66 Mic Microscopium 209.513 63.821 0.51% +20 57.88 −36 16.49 SQ4
67 Aps Apus 206.327 62.851 0.50% +16 08.65 −75 18.00 SQ3
68 Lac Lacerta 200.688 61.133 0.49% +22 27.68 +46 02.51 NQ4
69 Del Delphinus 188.549 57.435 0.46% +20 41.61 +11 40.26 NQ4
70 Crv Corvus 183.801 55.989 0.45% +12 26.52 −18 26.20 SQ3
71 CMi Canis Minor 183.367 55.857 0.44% +07 39.17 +06 25.63 NQ2
72 Dor Dorado 179.173 54.579 0.43% +05 14.51 −59 23.22 SQ1
73 CrB Corona Borealis 178.710 54.438 0.43% +15 50.59 +32 37.49 NQ3
74 Nor Norma 165.290 50.350 0.40% +15 54.18 −51 21.09 SQ3
75 Men Mensa 153.484 46.754 0.37% +05 24.90 −77 30.24 SQ1
76 Vol Volans 141.354 43.059 0.34% +07 47.73 −69 48.07 SQ2
77 Mus Musca 138.355 42.145 0.34% +12 35.28 −70 09.66 SQ3
78 Tri Triangulum 131.847 40.163 0.32% +02 11.07 +31 28.56 NQ1
79 Cha Chamaeleon 131.592 40.085 0.32% +10 41.53 −79 12.30 SQ2
80 CrA Corona Australis 127.696 38.898 0.31% +18 38.79 −41 08.85 SQ4
81 Cae Caelum 124.865 38.036 0.30% +04 42.27 −37 52.90 SQ1
82 Ret Reticulum 113.936 34.707 0.28% +03 55.27 −59 59.85 SQ1
83 TrA Triangulum Australe 109.978 33.501 0.27% +16 04.95 −65 23.28 SQ3
84 Sct Scutum 109.114 33.238 0.26% +18 40.39 −09 53.32 SQ4
85 Cir Circinus 93.353 28.437 0.23% +14 34.54 −63 01.82 SQ3
86 Sge Sagitta 79.932 24.349 0.19% +19 39.05 +18 51.68 NQ4
87 Equ Equuleus 71.641 21.823 0.17% +21 11.26 +07 45.49 NQ4
88 Cru Crux 68.447 20.850 0.17% +12 26.99 −60 11.19 SQ3
Notes
  1. ^ The total solid angle of all constellations is the total solid angle of the sky, which is exactly 4π steradians, or 4π × (180/π)2 = 129,600/π square degrees, or approximately 41,252.961 square degrees. The figures in the table do not sum precisely to this number due to rounding errors, which vanish when the areas are rounded instead to one decimal place.
  2. ^ Average of the most eastward and most westward RA.
  3. ^ Average of the most northern and most southern declination.
  4. ^ "Quad" designates the quadrant of the sky as N for North or S for South, Quadrants 1 (0h –6h ), 2 (6h –12h ), 3 (12h –18h ), or 4 (18h –0h ).
  5. ^ Serpens is divided into two parts:
    Serpens Caput ("Serpent's Head"; 428.484 sq. deg.; midpoint: RA: 15 46.49, Dec: +10 58.20), and
    Serpens Cauda ("Serpent's Tail"; 208.444 sq. deg.; midpoint: RA: 18 07.60, Dec: -04 51.73)