Zeta Ophiuchi
Star ζ Ophiuchi |
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Image taken by the Spitzer Space Telescope . The pronounced bow shock wave can be clearly seen. | |||||||||||||||||||||
AladinLite | |||||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Snake bearer | ||||||||||||||||||||
Right ascension | 16 h 37 m 9.54 s | ||||||||||||||||||||
declination | -10 ° 34 ′ 1.5 ″ | ||||||||||||||||||||
Apparent brightness | 2.54 mag | ||||||||||||||||||||
Typing | |||||||||||||||||||||
B − V color index | +0.02 | ||||||||||||||||||||
U − B color index | −0.86 | ||||||||||||||||||||
R − I index | −0.04 | ||||||||||||||||||||
Spectral class | O9.5 V | ||||||||||||||||||||
Variable star type | Yes | ||||||||||||||||||||
Astrometry | |||||||||||||||||||||
parallax | (8.91 ± 0.20) mas | ||||||||||||||||||||
distance | (366.1 ± 8.2) ly (112.2 ± 2.5) pc |
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Visual absolute brightness M vis | −2.71 mag | ||||||||||||||||||||
Proper movement | |||||||||||||||||||||
Rec. Share: | (15.26 ± 0.26) mas / a | ||||||||||||||||||||
Dec. portion: | (24.79 ± 0.22) mas / a | ||||||||||||||||||||
Physical Properties | |||||||||||||||||||||
Dimensions | (20) M ☉ | ||||||||||||||||||||
radius | (8) R ☉ | ||||||||||||||||||||
Luminosity |
(68000) L ☉ |
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Effective temperature | (32500) K | ||||||||||||||||||||
Rotation time | 2 days | ||||||||||||||||||||
Age | 8 million a | ||||||||||||||||||||
Other names and catalog entries |
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Zeta Ophiuchi ( ζ Ophiuchi , also abbreviated to Zeta Oph , ζ Oph ) is a star in the constellation Snake Bearer , which with an apparent magnitude of 2.54 mag is one of the 100 brightest stars in the night sky. It is located just south of the celestial equator , so it is only visible from Europe in the summer half-year. Zeta Ophiuchi is a hot main sequence star of spectral class O9 V, about 370 light years from Earth , which appears reddish because of the light-absorbing interstellar dust that lies between it and the Earth. In fact, Zeta Ophiuchi would appear significantly brighter and would be one of the brightest stars if its light were not weakened by this layer of dust. The star is about halfway through its stellar evolution and will balloon to a supergiant in the next million years before ending its life in a supernova (Type II).
In the past, the star probably belonged to a binary star system with an even more massive partner. When this exploded in a Super Nova, Zeta Oph was thrown out of the system and a so-called high-speed (runaway star) . Due to its high speed relative to the interstellar medium , a pronounced bow shock wave forms in front of it .
Web links
- Zeta Ophiuchi - Runaway Star Plowing Through Space Dust
- Spektrum .de: amateur recordings [7]