Merrill’s Star and Minkowski 1-67 nebula

WR124 is a Wolf-Rayet star in the Sagitta (Arrow) constellation. It is surrounded by a nebula of expelled material known as Mi1-67 or Sh2-80. The star was discovered by Paul W. Merrill in 1938 as high velocity Wolf-Rayet star – its radial velocity is about 200km/s. Distance to WR124 was calculated to 10,900 light years and that corresponds to luminosity of 150,000 times the Sun luminosity. This data also allowed to calculate star current mass that is 9 solar masses, with a probable initial mass around 25 solar masses. WR124 star has blown away a large portion of its mass through the intense stellar winds of the Wolf-Rayet phase. Star surface temperature is 36,000K, so most of the energy is radiated in ultravioled wavelengths. Surrounding nebula is expanding at a rate over 150,000 km/s and is about 6 light years across, that gives its dynamical age of 20,000 years.

It is very interesting object, would be more interesting if it was closer to us 🙂 Picture below was made with 130mm refractor and QHY163M camera on EQ6 mount. It is stack 4×10 minutes frames made with hydrogen alpha filter. Nebula is really small, but according to Interstellarum atlas it can be accessed visually with large aperture and O filter.

Merrill’s Star and surrounding nebula – full frame
Merrill’s Star nebula and WR124 star – close up

Clear skies!

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