| 1. | Many objections can be raised to this picture of planetary nebula formation .
形成行星状星云的这一图像可能会引起许多异议。 |
| 2. | Planetary nebulae are a type of isolated gaseous nebulae possessing a fair degree of bilateral symmetry .
行星状星云是一类孤立的气体星云，具有相当程度的双侧对称性。 |
| 3. | M2 - 9 is a typical butterfly shaped planetary nebula
M2 - 9是蝴蝶状行星状星云 |
| 4. | Don t confuse nebulae with planetary nebulae , which we will discuss in
注：不要把星云和将在 |
| 5. | Planetary nebulae are not as airy and tranquil as their images suggest
行星状星云并不如影像中所显现的那麽飘逸宁静。 |
| 6. | Bipolar planetary nebula
双极行星状星云 |
| 7. | The spectacular planetary nebula helix nebula is the death of a star disguised as a butterfly
色彩斑斓的行星状星云螺旋星云，正是恒星死亡所化身的蝴蝶。 |
| 8. | " butterflies in the starry sky " will present these beautiful planetary nebulae and their evolution
将会介绍这些美丽的行星状星云，与及它们的形成和演化过程。 |
| 9. | It will evolve into a cosmic butterfly - a spectacular planetary nebula in the starry sky
不过，太阳的死亡绝不平淡，它会化为星空蝴蝶成为夜空中灿烂的行星状星云。 |
| 10. | His book " cosmic butterflies " on planetary nebulae is one of the best - selling books published by the cambridge university press
他在二一年所写的cosmic butterflies ，更成为剑桥大学出版社的畅销书。 |
