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public  Greenwich, UK Greenwich, UK  ⓘ
TimezoneEurope/London
Sunrise: 7:25 
Transit: 12:14 
Sunset: 17:03
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All Constellations » Hercules » 

Rasalgethi - α1 Herculis (alpha1 Herculis)

Above the horizon.  Rise: 0:44 | Tran: 7:57 | Set: 15:09
Alt: 24.86°   Az: 261.78°   Direction: West

Rasalgethi, also designated as α1 Herculis (alpha1 Herculis), is a variable and multiple supergiant star of spectral class M5 in the constellation of Hercules.

Rasalgethi visual magnitude is 3.48. Because of its moderate brightness, Rasalgethi is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

Image of Rasalgethi - α1 Herculis (alpha1 Herculis) star
DSS2 image of Rasalgethi. The red arrow shows the motion of Rasalgethi during the next 10000 years (-1.00 arcmin in Right Ascension and 6.00 arcmin in declination);

Celestial Coordinates

Apparent

17h 15m 47s
+14° 21’ 47”
04h 31m 52s
21h 47m 40s

J2000

17h 14m 38s
+14° 23’ 25”

Galactic Coordinates

35.53°
27.82°

Finder Chart

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Finder chart for Rasalgethi - α1 Herculis (alpha1 Herculis).

Magnitude, Color, Spectral Class

3.48
Supergiant

-1.87
M5I
3886K

The red dot in the diagram below shows where Rasalgethi is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of Rasalgethi. Attribution: Richard Powell / CC BY-SA

Star System Properties

Rasalgethi is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the Rasalgethi double sysyem:

3.48
5.68
2.2
4.9 arcsec

Distance, Radial Speed, Proper Motion

Rasalgethi is distant 382.18 light years from the Sun and it is moving towards the Sun at the speed of 33 kilometers per second.

117.23
382.18
-33 km/s
-0.006 arcsec/y
0.036"/y

Alternative Designations

Rasalgethi
α1 Herculis
(alpha1 Herculis)
64 Herculis
SAO102680
SAO102680

Visibility from Your Location

Today's Rasalgethi - α1 Herculis (alpha1 Herculis) rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 75.6°
Max altitude: 52.9°
Azimuth: 284.4°