| Date & Time: | Dec 10 2021, 18:35 to 18:38 JST(+0900) |
| Composed 4shots with 5sec. exposed |
| Optical: | Meade 25cm(10") Schmidt Cassegrain (f=2500mm, F10.0) |
| with SBIG DSS7 Spectrometer |
| Auto-guided with Meade LX200 Equatorial |
| Cooled CCD Camera: | SBIG ST-402ME (Temp.: -25°C) |
| Location: | Ooizumi, Hokuto city, Yamanashi pref. |
Upper strip: taken spectrogram, Lower strip: stretched 3-pixel-width & pseudo-colored image
This page shows you the spectrum of WR136, a 7.5-magnitude Wolf-Rayet star located in the center of NGC6888.
Wolf-Rayet star, a blue giant nearing the end of its life, is leaking hydrogen gas from its surface.
As a result, the ionized helium, nitrogen, oxygen, carbon, etc. inside are exposed, and many of these emission lines can be observed.
In addition, the moving speed of these gases is very high, and the width of the emission line is widened due to the Doppler effect in the line-of-sight direction.
Wolf-Rayet stars are classified into WN, WC and WO types when the dominant emission line is ionized nitrogen, carbon, and oxygen, respectively.
This WR136 has been considered to be a type of WN because weak emission lines of hydrogen and strong helium lines are overlapped, and several emission lines of ionized nitrogen are observed.
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Position of Wolf-Rayet star WR136
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