Sh2-132 - Mgławica Lew

Two Wolf-Rayet stars sit inside this cloud - WR 152 (HD 211564) and WR 153 (HD 211853) - stars that have already blown off their own hydrogen envelopes and now expose interiors hot enough to ionise gas across dozens of light-years. Both are heading for the same ending that produced the Veil. On the timescale of this photograph, though, they are simply carving the cloud they were born in. The nebula lies on the Cepheus–Lacerta border, roughly 10,000 light-years away in the Perseus Arm of the Milky Way - about four times further than the Cygnus Loop. It spans some 250 light-years, which at that distance still works out to well over a degree on the sky, wider than two full Moons side by side. This is an SHO frame: sulphur in red, hydrogen in green, oxygen in blue, mapped the classic Hubble way. Sh2-132 is one of the few objects where that palette is honest work rather than a colouring exercise - the sulphur signal here is genuinely strong, so the third channel carries real structure instead of noise dressed up as colour. Oxygen is the opposite: weak, and concentrated in tight pockets around the hottest stars rather than spread across the cloud. Everywhere you see teal, you are looking at gas sitting close enough to a Wolf-Rayet wind to be stripped of two electrons and kept that way. The dark lanes threading through the frame are not gaps. They are cold dust in the foreground of the cloud, absorbing everything behind them - including one patch catalogued by Edward Barnard as B 369, more than a century ago, from photographic plates. Faint target, long project. Most of the integration went into sulphur, because that channel is where the image is either made or lost. Gear: William Optics UltraCat 76 · 365 mm f/4.8 William Optics UniGuide 50/200 + ASI 120MM ZWO ASI 2600MC Pro ZWO ASIAIR, EAF Pegasus NYX-88

Sh2-132 · Mgławica Lew