| Emission nebula | |
|---|---|
| Planetary nebula | |
 | |
| Observation data: J2000.0epoch | |
| Right ascension | 19h 05m 55.6s[1] |
| Declination | −05° 59′ 32.9″[1] |
| Distance | 6,500 ly (2,000[2] pc) |
| Apparent magnitude (V) | 11.9[3] |
| Apparent dimensions (V) | 0.43′ |
| Constellation | Aquila |
| Physical characteristics | |
| Radius | 0.4 ly |
| Absolute magnitude (V) | 0.4 |
| Designations | Glowing Eye Nebula,GSC 05140-03497,PK 029-05 1,PN Th 1-J,CSI-06-19031,HD 177656,PMN J1905-0559,PN Sa 2-382,EM* CDS 1043,HuLo 1,PN ARO 101,PN G029.2-05.9,GCRV 11549,IRAS 19032-0604,PN VV' 477,SCM 227,GSC2 S3002210353,2MASX J19055556-0559327,PN VV 219,UCAC2 29903231 |
| See also:Lists of nebulae | |
NGC 6751, also known as theGlowing Eye Nebula,[2] is aplanetary nebula in theconstellationAquila. It is estimated to be about 6,500light-years (2.0 kiloparsecs) away.[2]
NGC 6751 was discovered by the astronomerAlbert Marth on 20 July 1863.[4]John Louis Emil Dreyer, the compiler of theNew General Catalogue, described the object as "pretty bright, small".[4] The object was assigned a duplicate designation, NGC 6748.[4][5]
The nebula was the subject of the winning picture in the 2009 Gemini School Astronomy Contest, in which Australian high school students competed to select an astronomical target to be imaged byGemini.
NGC 6751 is an easy telescopic target fordeep-sky observers because its location is immediately southeast of the extremely red-colored coolcarbon starV Aquilae.
NGC 6751, like allplanetary nebulae was formed when a dyingstar threw off its outer layers of gas several thousand years ago. It is estimated to be around 0.8 light-years in diameter.[6]
NGC 6751 has a complexbipolar structure. There is a bright, inner bubble (shown in the photo), as well as two fainter halos. (The outer halo, with a radius of 50″ is extremely faint and is broken, while the inner halo with a radius of 27″ is roughly spherical).[2] On both the west and east sides of the inner shell, knots can be seen that are surrounded by faint "lobes".[2] These lobes are actually a ring, and the eastern side is nearer than the western side.[2] As a whole, the system is approaching the Solar System with a heliocentricradial velocity of −31.7 km/s.[2]
The central star of the nebula has a similar spectrum to aWolf–Rayet star (spectral type [WC4]),[1] and has aneffective temperature of about 140,000 K and a radius of about 0.13 R☉. It is losing mass at a rate of1×10−6 M☉ per year, and its surface composition is mostlyhelium andcarbon.[2]
The winning image of the 2009 Gemini Astronomy Contest shows a nebula at the top left of NGC 6751.[7] This 80 x 40 arcsec nebula was discovered in 1990 by Hua & Louise at the Newton focus of the Foucault telescope, 120cm in diameter atObservatoire de Haute Provence (O.H.P.) Saint Michel l'Observatoire.[8]
Media related toNGC 6751 at Wikimedia Commons
