|Right ascension||15 h 48 m 30 s to 18 h 57 m 50 s|
|declination||+ 3 ° 40 ′ 25 ″ to + 51 ° 19 ′ 27 ″|
|Completely visible||90 ° N to 38.0 ° S|
|Observation time for Central Europe||Spring,
|Number of stars brighter than 3 mag||2|
|Brightest star (size)||β Herculis (2.78)|
clockwise from north )
Hercules is the fifth largest constellation in the sky. Since only three of its stars are brighter than the 3rd magnitude , it is not very noticeable. It can be found between the constellation of the lyre with the bright star Vega and the memorable northern crown . The best time to observe is early summer, as it is then highest in the sky.
Hercules contains two interesting globular clusters that can already be observed with binoculars.
The constellation is one of the classic 48 constellations of antiquity mentioned by Ptolemy . In the ancient Greeks, however, he was simply called "Engonasin" ("the kneeling"). Later the constellation was associated with various mythical figures, such as Prometheus , Theseus , Orpheus or Heracles (whom the Romans called Hercules). The interpretation as Hercules has been preserved.
The mythological origin of the constellation is unclear. The later identification with Heracles , the hero from Greek mythology endowed with enormous powers, has been preserved . Herakles was an illegitimate son of Zeus , who was given twelve tasks that were actually insurmountable. With strength and intelligence he was able to fulfill the tasks, whereby he brought down a number of monsters that are also immortalized in the sky, such as the lion , the cancer , the water snake and the dragon .
|B.||F.||Names or other designations||Vmag||Lj||Spectral class|
|β||27||Kornephoros , Ruticulus||2.78||148||G8 III|
|α||64||Ras Algethi||3.1 to 3.7||384||M5 Ib|
|ρ||75||4.1||403||A0 + A0|
|95||4.3||418||A5 + G8|
|G||30th||4.3 to 6.3||355||Mb III|
|λ||76||Maasym , Misam||4.4||approx. 370||K4 III|
|ω||24||Kajam , Cujam||4.57||about 250||B9|
|κ||7th||Marfik, Mirfak||4.7||367||G8 + K1|
|u||68||4.7 to 5.4||666||B3 III|
Beta Herculis , the brightest star in Hercules, is a yellowish shining star of the spectral class G8 at a distance of 148 light years .
The ancient Greek name Kornephoros means "club bearer". The star is also called the ruticulus.
|α||3.4 / 5.4||4.6 "|
|κ||5.0 / 6.3||27.5 "|
|95||5.0 / 5.2||6.3 "|
|100||5.9 / 5.9||14.2 "|
|ρ||4.5 / 5.5||4.2 "|
Alpha Herculis , the third brightest star in Hercules, is a binary star system 430 light years away. The main star is a red giant of the spectral class M5, with 500 times the diameter and 830 times the luminosity of our sun . Its surface temperature is relatively low at around 3000 Kelvin . It emits a large part of its radiation in the infrared . The companion star belongs to class G5. The system can be separated into single stars even in the smaller telescope and shows a very nice color contrast. The main star glows orange-red, the companion star appears greenish.
|α||3.0 to 4.0||90 to 100 days||Semi-regular|
|30th||4.3 to 6.3||70 to 90 days||Semi-regular|
|68||4.7 to 5.4||2.05 days||Beta Lyrae Star|
The main star of the Ras Algethi system is a semi-regularly variable star whose brightness fluctuates over periods of 90 to 100 days.
68 (u) Herculis is a variable star of the Beta-Lyrae type . It is an extremely luminous star 1200 light years away.
Messier 13 is considered to be the most impressive globular cluster in the northern sky. It is located about 25,000 light years away and consists of about 300,000 stars. Even in prism binoculars it appears as a misty spot. In the telescope it can be resolved into single stars. It is easy to find because it is in the upper third of the connecting line between the stars η and ζ (the right "box stars" of Hercules).
Messier 92 is a globular cluster about 30,000 light years away. It does not appear as extensive in the telescope as M13, but it is also a very worthwhile observation object.
NGC 6210 is a planetary nebula 3,000 light years away. With a diameter of 0.3 arc minutes , it is not very extensive. In the binoculars it only appears as a faint star. An irregular disc and the central star become visible in a telescope with an opening of 12 cm or more.
The exoplanet HD 149026 b in Hercules is one of the hottest known exoplanets with a temperature on the day side of over 2000 K. It orbits the star HD 149026 (8.15 mag, spectral class G0, 1.3 solar masses) in 2.87 days at a distance of 0.042 AU and, from our point of view, performs a transit. The exoplanet has a mass of about 0.4 Jupiter and a radius of about 0.7 Jupiter radii. The system is about 260 light years from Earth.