Hercules (constellation)

Hercules is the fifth largest of the 88 modern constellations. It was also one of Ptolemy's 48 constellations. It was named after the Roman name (Hercules) of the Greek mythological hero Herakles.

Notable features

Hercules has no first magnitude stars.

Mu Herculis is 27.4 light years from Earth.

The solar apex, i.e., the point on the sky which marks the direction that the Sun is moving in its orbit around the center of the Milky Way, is located within Hercules, close to Vega in neighboring Lyra.

Notable deep sky objects

Hercules contains two of the most conspicuous globular clusters: M13, the brightest globular cluster in the northern hemisphere, and M92.

Mythology

Hercules (Roman, Herakles in Greek mythology) was the demigod son of Zeus and Alcmene. One of the most widely known of the Greek heroes, he is best known for his superhuman strength, strong emotions, quickness to act, and often poorly thought out plans. Many stories are told of his life, the most important of which is the story of The Twelve Labours.

However, such visualisation was much later, as some parts require quite faint stars to be included, including those which have Flamsteed numbers but not Bayer designations. Earlier views of the constellation held it to be various things, predominantly a stag. Together with the constellation Sagitta, and the association of this area of the sky (the Zodiac of Scorpio) with Artemis, this may be the origin of the myth of the Cerynian Hind, one of The Twelve Labours of Herakles.

Graphic visualization

The stars of the constellation Hercules can be connected in an alternative way, which graphically shows the hero in an athletic pose and holding a club.

The hero's head is traced by a quadrangle of stars: π Her, η Her, ζ Her and ε Her known as the "Keystone" asterism. This quadrangle lies between two very bright stars: Vega in the constellation Lyra and α CrB (Gemma, or Alphecca) in the constellation Corona Borealis.

The hero's right leg contains two bright stars of the third magnitude: α Her (Ras Algethi) and δ Her (Sarin). The latter is the right knee.

The hero's left leg contains dimmer stars of the fourth magnitude which do not have Bayer designations but which do have Flamsteed numbers.

The star β Her belongs to the hero's outstretched right hand, and is also called Kornephoros.

The Globular Cluster M13 lies on the top of the hero's head, between the stars η Her and ζ Her. It is dim, but may be detected by the unaided eye on a very clear night.

Stars

Stars with proper names:

(α Her) Ras Algethi Rasalegti (64/α¹ Her) + 64/α² Her – double 2.78, 5.39
رأس الجاثي ra´s al-jaθiyy Head of the kneeler

(27/β Her) 2.78 Kornephoros ^* (or Rutilicus, see ζ Her)
(65/δ Her) 3.12 Sarin
(58/ε Her) 4.57 (or Cujam Caiam, Kajam, see ω Her)
(40/ζ Her) 2.81 Rutilicus

(7/κ Her) 5.0 Marfik Mirfak, Marsik (or Maasim, see λ Her)
< مرفق marfaq, mirfaq elbow

(76/λ Her) 4.41 Maasym Misam
< معصم ma^{c^şam} wrist

(24/ω Her) 4.57 Cujam Cujam, Caiam

Stars with Bayer designations:

20/γ Her 3.74; 91/θ Her 3.86; 44/η Her 3.48; 85/ι Her 3.82; 86/μ Her 3.42; 94/ν Her 4.41; 92/ξ Her 3.70; 103/ο Her 3.84; 67/π Her 3.16; 75/ρ Her 4.52; 75/ρ Her 5.47; 35/σ Her 4.20; 22/τ Her 3.91; 6/υ Her 4.72; 1/χ Her 4.60; 11/φ Her 4.23; 99/b Her 5.05; c Her 5.41; 59/d Her 5.27; 69/e Her 4.64; 90/f Her 5.17; 30/g Her 4.83; 29/h Her 4.84; 43/i Her 5.15; 47/k Her 5.48; 45/l Her 5.22; 28/n Her 5.63; 21/o Her 5.83; q Her 6.09; 5/r Her 5.10; s Her 5.24; 107/t Her 5.12; 68/u Her 4.80; 72/w Her 5.38; 77/x Her 5.83; 82/y Her 5.35; 88/z Her 6.78; 104/A Her 4.96

Stars with Flamsteed designations:

2 Her 5.35; 4 Her 5.73; 8 Her 6.13; 9 Her 5.46; 10 Her 5.74; 13 Her 7.67; 14 Her 6.61 – has a planet; 16 Her 5.72; 19 Her 6.70; 23 Her 6.41; 25 Her 5.53; 31 Her 7.14; 32 Her 6.87; 34 Her 6.44; 36 Her 6.92; 37 Her 5.77; 39 Her 5.92; 41 Her 6.55; 42 Her 4.86; 48 Her 6.59; 49 Her 6.51; 50 Her 5.73; 51 Her 5.03; 52 Her 4.82; 53 Her 5.34; 54 Her 5.35; 56 Her 6.06; 57 Her 6.27; 60 Her 4.89; 61 Her 6.19; 63 Her 6.20; 70 Her 5.13; 73 Her 5.70; 74 Her 5.51; 78 Her 5.66; 79 Her 5.76; 83 Her 5.56; 84 Her 5.73; 87 Her 5.09; 89 Her 5.47; 93 Her 4.67; 95 Her – double 4.96, 5.18; 96 Her 5.25; 97 Her 6.22; 98 Her 4.96; 100 Her – double 5.79, 5.83; 101 Her 5.10; 102 Her 4.37; 105 Her 5.30; 106 Her 4.92; 108 Her 5.61; 109 Her 3.85; 110 Her 4.19; 111 Her 4.34; 112 Her 5.43; 113 Her – double 4.5, 4.57

Reference

H.A. Rey, The Stars — A New Way To See Them. Enlarged World-Wide Edition. Houghton Mifflin, Boston, 1997. ISBN 0-395-24830-2.

External links

Hercules constellation