planetary nebula造句
1 The result is called, somewhat misleadingly, a planetary nebula.
2 NGC 2818 is a beautiful planetary nebula, the gaseous shroud of a dying sun - like star.
3 Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round.
4 The Cat's Eye Nebula (NGC 6543) is a planetary nebula in the constellation of Draco.
5 The label "planetary nebula" is another astronomical misnomer, as the objects are completely unrelated to planets.
6 A classic planetary nebula, the Cat's Eye (NGC 6543) represents a final, brief yet glorious phase in the life of a sun-like star.
7 This particular planetary nebula, pictured above and designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure.
8 While the planetary nebula phase is thought to last for around 10, 000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50, 000 to 90, 000 years.
9 Then, for a relative blink of about 1, 000 years or less, the star becomes a planetary nebula.
10 Many objections can be raised to this picture of planetary nebula formation.
11 The white dwarf star at the center of this planetary nebula may be accompanied by a second-generation world, formed from the debris of the dying star's original planets.
12 It is one of the best examples of a planetary nebula and a favorite target of amateur astronomers.
13 And it is these that are helping scientists to resolve the outstanding mysteries of the complex shapes and symmetries of planetary nebula.
14 they needed to show that the molecules are in space, that they have a unique and interesting molecular structure,[www.] and that they are associated with a faraway planetary nebula.
15 It was discovered by William Herschel on February 15, 1786, and was the first planetary nebula whose spectrum was investigated, by the English amateur astronomer William Huggins in 1864.
16 Data from theChandra X-ray Observatory revealed a bright central star surrounded bya cloud of multimillion-degree gas in the planetary nebula known as theCat's Eye.
17 Also known as Abell 21, this Medusa is an old planetary nebula some 1, 500 light-years away in the constellation Gemini.
18 The sands of time are running out for the central star of this hourglass-shaped planetary nebula.
19 Explanation: The sands of time are running out for the central star of this hourglass-shaped planetary nebula.
20 As for the spiral itself, current supposition is that this is the result of a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.
21 One of the fainter objects in Messier 's catalog, the Owl Nebula is a planetary nebula, the glowing gaseous envelope shed by a dying sun-like star as it runs out of nuclear fuel.