Largest Constellations

The largest constellations in the sky are Hydra, Virgo, Ursa Major, Cetus and Hercules. The largest northern constellations are Ursa Major, Hercules, Pegasus, Draco and Leo, and the southern ones are Hydra, Virgo, Cetus, Eridanus and Centaurus.

All these are Greek constellations, listed by Ptolemy in his Almagest in the 2nd century AD. They have been known since ancient times. The largest constellation that has not been known since antiquity is Lynx, which was created by the Polish astronomer Johannes Hevelius in the 17th century. Lynx is the 28th constellation in size with an area of 545 square degrees.

Hydra, the largest of the 88 modern constellations, measures 1303 square degrees and has the shape of a twisting snake that stretches from Cancer in the north to Libra and Centaurus in the south. In spite of its size, Hydra is not particularly prominent or easily recognizable. Its brightest star, the orange giant Alphard, has an apparent magnitude of 2.0, which makes it only moderately bright.

Virgo is much easier to find than Hydra because it is home to Spica, the 16th brightest star in the sky. Spica can be located by following the arc of the Big Dipper‘s handle. After Arcturus, it is the first bright star along the imaginary line.

Ursa Major, the largest northern constellation, is one of the most recognizable constellations in the sky. The Big Dipper asterism makes it easy for northern observers to find at any time of year. Six of the stars that form the asterism are of second magnitude and easily seen even in less than ideal conditions. Ursa Major is circumpolar to northern observers, which means that it never sets below the horizon. However, it remains mostly invisible to observers living south of latitude 30°S.

Like Hydra, Cetus is large, but not particularly prominent. Its brightest star, the orange giant Diphda (also known as Deneb Kaitos), has a visual magnitude of 2.02, which makes it slightly fainter than Alphard.

Hercules, the second largest northern constellation, is considerably easier to spot, as some of its stars form an asterism known as the Keystone, which marks Hercules’ torso. However, the constellation does not have any first or second magnitude stars. Its brightest star, Kornephoros, is a yellow giant with an apparent magnitude of 2.8.

Eridanus, the sixth largest constellation, is home to Achernar, the ninth brightest star in the sky. Achernar marks the end of the celestial river and is located at the southern end of Eridanus. The constellation’s northern end borders with Orion and Taurus.

Pegasus is easy to recognize because it is dominated by a prominent asterism known as the Great Square. The Great Square of Pegasus is formed by three bright stars in Pegasus — Scheat, Markab and Algenib — and Alpheratz, the brightest star in the neighbouring Andromeda.

Draco is located in the far northern sky. Like Ursa Major, it is circumpolar and never sets for northern observers. It is not a particularly bright constellation, but it can be found between the more recognizable Ursa Major, Ursa Minor, Hercules and Cygnus. The brightest star in Draco, the orange giant Eltanin, has an apparent magnitude of 2.23. The constellation is mostly invisible to observers south of latitude 15°S.

Centaurus, the ninth largest constellation, is located in the southern sky and cannot be seen from locations north of latitude 25°N. It is one of the brightest and most recognizable southern constellations. Its brightest stars – Alpha and Beta Centauri – are the 3rd and 11th brightest stars in the sky. The stars are known as the Southern Pointers because they help observers find Crux and true south.

Aquarius is relatively faint – its brightest star, Sadalsuud, a class G supergiant, has a visual magnitude of 2.87 – but can be spotted on a clear night near Pegasus and Pisces. Like other zodiac constellations, Aquarius lies on the ecliptic. It contains an asterism known as the Water Jar, from which the mythical Water Bearer pours water in a line of stars that ends with Fomalhaut, the brightest star in the constellation Piscis Austrinus, the Southern Fish, and 18th brightest star in the sky.

Ophiuchus and Leo, the 11th and 12th largest constellations, also lie on the ecliptic. Ophiuchus, the Serpent Bearer, borders Hercules on the northern end and Sagittarius and Scorpius on the southern. Its brightest star, Rasalhague, is a binary system with an apparent magnitude of 2.07. Ophiuchus divides the constellation Serpens into two parts – Serpens Caput and Serpens Cauda – representing the Serpent‘s head and tail.

Leo, the fifth largest northern constellation, is much easier to identify, with the bright Regulus (mag. 1.39) marking the Lion’s heart, Denebola (mag. 2.11) its tail and an asterism known as the Sickle representing its mane and shoulders. The Sickle looks like a backward question mark and is quite prominent in the spring sky. Regulus, located at the base of the question mark, is part of the Spring Triangle, a large spring asterism also formed by the bright stars Arcturus and Spica, which makes it even easier to locate Leo in the evening sky.

Below is the list of all 88 modern constellations ordered by size, from largest to smallest.

Constellation	Size (area in square degrees)	Quadrant
1. Hydra	1302.844	SQ2
2. Virgo	1294.428	SQ3
3. Ursa Major	1279.660	NQ2
4. Cetus	1231.411	SQ1
5. Hercules	1225.148	NQ3
6. Eridanus	1137.919	SQ1
7. Pegasus	1120.794	NQ4
8. Draco	1082.952	NQ3
9. Centaurus	1060.422	SQ3
10. Aquarius	979.854	SQ4
11. Ophiuchus	948.340	SQ3
12. Leo	946.964	NQ2
13. Boötes	906.831	NQ3
14. Pisces	889.417	NQ1
15. Sagittarius	867.432	SQ4
16. Cygnus	803.983	NQ4
17. Taurus	797.249	NQ1
18. Camelopardalis	756.828	NQ2
19. Andromeda	722.278	NQ1
20. Puppis	673.434	SQ2
21. Auriga	657.438	NQ2
22. Aquila	652.473	NQ4
23. Serpens	636.928	NQ3
24. Perseus	614.997	NQ1
25. Cassiopeia	598.407	NQ1
26. Orion	594.120	NQ1
27. Cepheus	587.787	NQ4
28. Lynx	545.386	NQ2
29. Libra	538.052	SQ3
30. Gemini	513.761	NQ2
31. Cancer	505.872	NQ2
32. Vela	499.649	SQ2
33. Scorpius	496.783	SQ3
34. Carina	494.184	SQ2
35. Monoceros	481.569	NQ2
36. Sculptor	474.764	SQ1
37. Phoenix	469.319	SQ1
38. Canes Venatici	465.194	NQ3
39. Aries	441.395	NQ1
40. Capricornus	413.947	SQ4
41. Fornax	397.502	SQ1
42. Coma Berenices	386.475	NQ3
43. Canis Major	380.118	SQ2
44. Pavo	377.666	SQ4
45. Grus	365.513	SQ4
46. Lupus	333.683	SQ3
47. Sextans	313.515	SQ2
48. Tucana	294.557	SQ4
49. Indus	294.006	SQ4
50. Octans	291.045	SQ4
51. Lepus	290.291	SQ1
52. Lyra	286.476	NQ4
53. Crater	282.398	SQ2
54. Columba	270.184	SQ1
55. Vulpecula	268.165	NQ4
56. Ursa Minor	255.864	NQ3
57. Telescopium	251.512	SQ4
58. Horologium	248.885	SQ1
59. Pictor	246.739	SQ1
60. Piscis Austrinus	245.375	SQ4
61. Hydrus	243.035	SQ1
62. Antlia	238.901	SQ2
63. Ara	237.057	SQ3
64. Leo Minor	231.956	NQ2
65. Pyxis	220.833	SQ2
66. Microscopium	209.513	SQ4
67. Apus	206.327	SQ3
68. Lacerta	200.688	NQ4
69. Delphinus	188.549	NQ4
70. Corvus	183.801	SQ3
71. Canis Minor	183.367	NQ2
72. Dorado	179.173	SQ1
73. Corona Borealis	178.710	NQ3
74. Norma	165.290	SQ3
75. Mensa	153.484	SQ1
76. Volans	141.354	SQ2
77. Musca	138.355	SQ3
78. Triangulum	131.847	NQ1
79. Chamaeleon	131.592	SQ2
80. Corona Australis	127.696	SQ4
81. Caelum	124.865	SQ1
82. Reticulum	113.936	SQ1
83. Triangulum Australe	109.978	SQ3
84. Scutum	109.114	SQ4
85. Circinus	93.353	SQ3
86. Sagitta	79.932	NQ4
87. Equuleus	71.641	NQ4
88. Crux	68.447	SQ3