NGC 6309

NGC 6309, also known as the Box Nebula, is a planetary nebula located in the constellation Ophiuchus. It was discovered by the German astronomer Wilhelm Tempel in 1876.^[4] It has a luminosity of about 1800 times that of the Sun.^[1][2][5] The distance to this nebula is not well known, but it is assumed to be about 6,500 light-years or 2,000 parsecs.^[6]

NGC 6309

Emission nebula
Planetary nebula
NGC 6309 as seen through the Hubble Space Telescope
Observation data: J2000 epoch
Right ascension	17h 14m 04.3s[1]
Declination	−12° 54′ 38″[1]
Apparent magnitude (V)	11.5[2]
Apparent dimensions (V)	0.32′[2]
Constellation	Ophiuchus
Designations	PK 9+14.1, HD 155752, Box Nebula[3]
See also: Lists of nebulae

NGC 6309 is a quadrupolar nebula, with two pairs of lobes. Surrounding the pair is a spherical shell. The spherical shell formed before the four lobes.^[6] The square-like shape of the nebula gives it the nickname "Box Nebula".

The central star of the planetary nebula is an O-type star with a spectral type of O(He).^[7]

See also

• List of NGC objects (6001–7000)