Stingray Nebula

The Stingray Nebula, also Hen 3-1357, is a planetary nebula, cataloged by Karl Henize Gordon 1976. It lies in the constellation altar and is located at a distance of about 18,000 light-years. It is the youngest of all previously observed planetary nebulae. Is named the object after the stingrays ( Stingray english ), because the observable shape of the nebula resembles such a ray.

Structure

In the midst of the fog is a binary star system. The fog comes from a former red giant, which has since changed to the white dwarf. The remaining white dwarf has an estimated mass of 0.6 solar masses. It is accompanied by a second star. Because of their gravitational interaction both stars are connected by a fine trail of gas. The fog is very young and accordingly very small. It has only about one- tenth of the expansion of other known planetary nebula.

Dynamics

Sun-like stars evolve at the end of their life process to red giants. They repel their outermost layers into space forming the fog later. Meanwhile, such a star increasingly hotter. He brings through his radiation enhancing the desquamated gas to glow. As you watched him in the late 1960s for the first time, the central star was not hot enough that he could bring his gas to glow. Only since the mid -1980s, he creates this heating process.

Importance

The Stingray Nebula was formed only after the discovery of the original red giant, which is unprecedented. This could gain new insights. Researchers had the short transitional period of only 20 years is not expected in their models, in which the red giant became the planetary nebula. It was here more than 100 years of development.

Discovery history

In a 1976 published catalog Karl Gordon Henize classified the progenitor star of the Stingray nebula due to photographic plates from 1949 to 1951 as the star with H -alpha emission line. As recorded in 1971 spectra an AGB star, a red supergiant of type B1 or B2, and thus the precursor of a planetary nebula show the formation of the planetary nebula must have taken place after that date. First evidence for the formation of a planetary nebula in 1989 found by evaluation of IRAS data. 1993 could Parthasarathy et al. confirm with the International Ultraviolet Explorer, that it is now acted by a planetary nebula.