Yet another "test" image during full moon, stack of 27x900s bin1 with Halpha filter(7nm), no dark no flat, processed with Pixinsight.
Full-Res Image
Image Calibration
| Center (RA, Dec): | (303.080, 38.362) |
| Center (RA, hms): | 20h 12m 19.152s |
| Center (Dec, dms): | +38° 21' 44.069" |
| Size: | 40 x 32 arcmin |
| Radius: | 0.427 deg |
| Pixel scale: | 0.873 arcsec/pixel |
| Orientation: | Up is -0.646 degrees E of N |
Crescent Nebula
| Distance | 5,000.0 (ly) |
|---|---|
| Visual Brightness | +7.4 (mag v) |
| Apparent Dimension | 18 x 12 (arc min) |
NGC 6888, also known as the Crescent Nebula, Caldwell 27, Sharpless 105, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This portrait of the nebula uses narrow band image and shows emission from hydrogens. NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with abang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away.
