NGC 6572

NGC 6572 is the name of a planetary nebula in the constellation Ophiuchus. NGC 6572 has an angular size of 0.6 × 0.4 arcmin and a brightness of 8.1 mag. Its central star, a white dwarf, glows with an apparent magnitude of 13.6 mag. The distance is estimated to be 2,500 light-years, resulting in an expansion of about 0.1 × yields 0.15 light years from the apparent size.

Discovery

NGC 6572 was discovered in 1825 by the German astronomer Friedrich Georg Wilhelm Struve.

Description

NGC 6572 is a very young and therefore even a small, very bright planetary nebula whose central star has shed its shell of gas around 2,600 years ago. Currently, the gas cloud expands at a speed of about 15 km / s. The extremely hot central star is approximately 0.57 solar masses relatively low mass and stimulates the surrounding gas cloud with his hard UV radiation to shine. The dominant spectral lines CII, NII and OII give the nebula its intense turquoise color.

Visual observation

NGC 6572 is very easy to find because it is located almost exactly 3 ° south- south- east ( " 7 clock " ) of the star 72 Ophiuchi ( 3.73 mag). At 100 × magnification NGC 6572 falls by its remarkable brightness and the turquoise color at once, especially since there are no bright stars in the field of view. At 260 - fold magnification, the slightly oval shape of NGC 6572 is clearly seen, but the fog in the eyepiece as a whole remains structureless. The central star can not be determined in the eyepiece, it will probably completely outshone by the bright gas cloud.