Double Double
| Lyra Double Double |
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| R.A. | E1a is 18h 44m 32.764s |
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| Dec. | +39° 37' 0.94" |
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| Mean Radial Velocity | - |
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| Magnitude | +5 to +6.43 |
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| Distance | 180 Ly |
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| Location | In Lyra, within Milky Way |
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| Other IDs | E1 Lyr,HIP91919,TYC 3122-03438-2 |
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| Element 1 and 2 | Spectral type F1,F1 |
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| Element 3 and 4 | Main sequence stars ,Spectral type F1 with A8 |
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| Orbital Period | 1165 and 585 years |
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| Scope | 8" Intes Micro mn-86 |
| Mount | EQ6 unguided. |
| Exposure | 5 x 0.3 sec for the hx516, 233 out of 459 frames for the webcam |
| Post-processing | Stacked in AA3 and registax |
| Filters | IR |
| Camera | toucam webcam ( above ) and Starlight Express hx516 ( below ) |
| Location | Claines |
| Date | 11th July 2005 |
The four stars are in two pairs separated by 3.5 arcmins, and so
they can just about be resolved with the unaided eye. Using a telescope reveals the two pairs, and all
the stars in this quadruple system are gravitationally bound to one another. The magnitude of the four
stars range from magnitude +5 to +6.43, and the two stars in each pair orbit each other about 2 arc-seconds apart.
The entire system is 180 light-years from us and the two pairs are 0.2 light-years apart or 13,000 AU apart .
Each member of the pair are themselves separated from the other by 160AU.
The top pair of stars , E1a and E1b are a slow binary system with 1165 year orbit: 5.0, 6.1; PA 350º and
separation 2.6", with magnitudes of +5.00 and +6.43.
The lower pair of stars , E2c and E2d are about twice as fast, with a period of 585 years: 5.2, 5.5; PA 83.5º,
separation 2.3", with magnitudes of +5.23 and +5.36.
