Hercules (constellation)

Hercules constellation
Latin name	Hercules
Latin genitive	Herculis
Abbreviation	Her
Right ascension	15 h 48 m 30 s to  18 h 57 m 50 s
declination	+ 3 ° 40 ′ 25 ″ to  + 51 ° 19 ′ 27 ″
surface	1225.148 deg² rank 5
Completely visible	90 ° N to 38.0 ° S
Observation time for Central Europe	Spring, summer
Number of stars brighter than 3 mag	2
Brightest star (size)	β Herculis (2.78)
Meteor streams	Tau Herculids
Neighboring constellations ( clockwise from north )	Dragon Bear keeper Northern crown Snake (head) Snake bearer Eagle arrow lyre
swell	IAU ,

The Hercules ( Latin Hercules ) is a constellation of the northern sky.

description

The constellation of Hercules as seen with the naked eye

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.

In the direction of Hercules is the apex of our solar system . The sun with its planets moves, relative to its neighboring stars, at 20 km / s towards this “target point”.

history

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.

Around 1687, Johannes Hevelius combined a few stars between Hercules and the swan to form the constellation Cerberus , the three-headed hellhound. However, it did not prevail.

mythology

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 .

Celestial objects

Stars

B.	F.	Names or other designations	Vmag	Lj	Spectral class
β	27	Kornephoros , Ruticulus	2.78	148	G8 III
ζ	40		2.81	35	G0 IV
α	64	Ras Algethi	3.1 to 3.7	384	M5 Ib
δ	65	Sarin	3.12	79	A3 IV
π	67		3.16	367	K2 III
μ	86		3.42	27	G5 IV
η	44	Sophian	3.48	112	G8 III
ξ	92		3.70	135	G9 III
γ	20th		3.74	193	A9 III
ι	85		3.82	494	B3 IV
ο	103		3.84	347	B9 V
θ	91		3.86	759
τ	22nd		3.91	314	B5 IV
ρ	75		4.1	403	A0 + A0
	110		4.19
σ	35		4.20	314	B9 V
φ	11		4.23	204
	95		4.3	418	A5 + G8
G	30th		4.3 to 6.3	355	Mb III
	111		4.34
	102		4.37
λ	76	Maasym , Misam	4.4	approx. 370	K4 III
ν	35		4.41
ε	58	Cujam	4.57	163
ω	24	Kajam , Cujam	4.57	about 250	B9
	113		4.57
χ	1		4.60	52
e	69		4.64
	93		4.67
κ	7th	Marfik, Mirfak	4.7	367	G8 + K1
u	68		4.7 to 5.4	666	B3 III
υ	6th		4.72
	52		4.82
H	29		4.84
	42		4.86
	60		4.89
	106		4.92
A.	104		4.96
	98		4.96
	51		5.03
b	99		5.05
	87		5.09
	101		5.10	330
t	107		5.12
	70		5.13
i	43		5.15
f	90		5.17
l	45		5.22
s			5.24
	96		5.25
d	59		5.27
	105		5.30
	53		5.34
y	82		5.35
	2		5.35
	54		5.35
w	72		5.38
c			5.41
	112		5.43
	9		5.46
	89		5.47

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.

My Herculis is 27 light years away. It has about 1.1 times the mass of our sun and also has a yellowish glow.

Double stars

system	Vmag	distance
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.

The name Ras Algethi is of Arabic origin and means something like "the head of the kneeling man".

Variable stars

star	Vmag	period	Type
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 and NGC objects

Messier (M)	NGC	other	Vmag	Type	Surname
13	6205		6.5	Globular clusters
92	6341		9.5	Globular clusters
	6210		8.8	Planetary nebula
	6229		9.4	Globular clusters

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.

Exoplanets

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.

See also

• List of constellations

Web links

Commons : Hercules (constellation)  - Collection of images, videos and audio files

Individual evidence