|Designation|| Hen 3-1357|
|Right ascension||17h 16m 21.071s|
|Declination||-59° 29′ 23.64″|
|Type of object||Planetary nebula|
|Magnitude||Apparent Mag: +10.75|
|Distance from Earth||18,000 ly|
|Radial velocity||12.6±1.7 km/s|
|Proper motion|| RA: -0.8 mas/yr|
Dec.: -4.0 mas/yr
The Stingray nebula (Hen 3-1357, PN G331.3-12.1) is a planetary nebula in the constellation of Ara. It is thought by some to have formed recently, at some point between 1967 and 1990. The astronomer Karl Gordon Henize observed and classified a star at the centre of the nebula in 1967 but no nebula was spotted but later in 1990, the Hubble Space Telescope observed a nebula surrounding the central star.However, this may simply be due to the nebula being extremely faint and also extremely small dimensions on the night sky (roughly 1.8 arcseconds) and so it wasn't until Hubble that it was possible to detect it.
Properties and Structure
Located 18,000 light years away, the nebula is around 0.16 light years across (around 130 times larger than the Solar System) which is about ten times smaller than most planetary nebulae. There is a central white dwarf star in the nebula which has decreased in luminosity threefold since 1987. The star is joined by a companion star, making it a binary system. The gravitational attraction between the two stars is causing a "bridge" of green gas to form between them.
The radiation emitted by these two stars ionizes the gas enveloping the two stars causing it to glow. The colors in the image are due to the ionization of hydrogen (blue), nitrogen (red) and oxygen (green). The stellar wind generated by the central star has begun to blow away the surrounding material, creating bubbles. The red lines indicate where the "shock" of this stellar wind has hit the walls of these bubbles, heating the gas there up.
- Stingray Nebula (Hen 3-1357, PN G331) in Ara from constellation-guide.com
- PN G331.3-12.1 from simbad.u-strasbg.fr
- Stingray Nebula (Henize 1357) from esa.int
- The Stingray Nebula, a young planetary nebula in Ara. from annesastronomynews.com
- Stingray Nebula from nasa.gov