Hercules (Her) is a constellation named after Hercules, the Roman mythological hero adapted from the Greek hero Heracles. Hercules was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations today. It is the fifth largest of the modern constellations.
Hercules has no first or second magnitude stars. However, it does have several stars above magnitude 4. Alpha Herculis (α Her, α Herculis), traditionally called Rasalgethi, is a binary star resolvable in small amateur telescopes, 400 light-years from Earth. The primary is an irregular variable star; it is a red giant with a minimum magnitude of 4 and a maximum magnitude of 3. It has a diameter of 400 solar diameters. The secondary, which orbits every 3600 years, is a blue-green hued star of magnitude 5.4. Its common name means "the kneeler's head". Beta Herculis (Beta Her, β Herculis, β Her), also called Kornephoros, is the brightest star in Hercules. It is a yellow giant of magnitude 2.8, 148 light-years from Earth. Its traditional name means "club-bearer". deltoide 5512 is a double star divisible in small amateur telescopes. The primary is a blue-white star of magnitude 3.1,and is 78 light-years from Earth. The optical companion is of magnitude 8.2. Gamma Herculis (γ Herculis, γ Her) is also a double star divisible in small amateur telescopes. The primary is a white giant of magnitude 3.8, 195 light-years from Earth. The optical companion, widely separated, is 10th magnitude. Zeta Herculis (ζ Her, ζ Herculis) is a binary star that is becoming divisible in medium-aperture amateur telescopes, as the components widen to their peak in 2025. The system, 35 light-years from Earth, has a period of 34.5 years. The primary is a yellow-tinged star of magnitude 2.9 and the secondary is an orange star of magnitude 5.7.
Hercules contains two bright globular clusters: Messier 13 (M13), the brightest globular cluster in the northern hemisphere, and Messier 92 (also known as M92 or NGC 6341). It also contains the nearly spherical planetary nebula Abell 39. M13 lies between the stars η Her and ζ Her; it is dim, but may be detected by the unaided eye on a very clear night.
According to Gavin White, the Greek constellation of Hercules is a distorted version of the Babylonian constellation known as the "Standing Gods" (MUL.DINGIR.GUB.BA.MESH). White argues that this figure was, like the similarly named "Sitting Gods", depicted as a man with a serpent's body instead of legs (the serpent element now being represented on the Greek star map by the figure of Draco that Hercules crushes beneath his feet). He further argues that the original name of Hercules - the 'Kneeler' - is a conflation of the two Babylonian constellations of the Sitting and Standing Gods...
Draco | Boötes | Corona Borealis | Serpens Caput | Ophiuchus | Aquila | Sagitta | Vulpecula | Lyra
Lists of stars by constellation
WallHapp Catalogue (WH)
LISTS OF STARS IN Hercules
WallHapp Catalogue (WH)