NGC4490 · Cocoon Galaxy
| Chinese name | 茧状星系 |
|---|---|
| Type | Galaxy |
| Constellation | CVn |
| RA | 12h31m |
| Dec | +42° |
| Apparent magnitude | 9.8ᵐ |
| Hemisphere | Northern |
| Best season | Spring |
| Difficulty | Hard |
| Focal length | 长焦 1000mm+ |
About
The Cocoon Galaxy lies about 25 million light-years away in Canes Venatici and is a tidally disturbed galaxy undergoing vigorous starburst activity. It is interacting with the smaller companion NGC 4485, linked by a bridge of stars and gas, with tidal forces stretching the main galaxy into a cocoon-like irregular shape—broad at one end, tapered at the other—that gives it its name. Intense star formation turns its arms blue and fills them with red H II regions, while the core drives hydrogen-rich gas out into the halo. Its warped, irregular form is full of dynamism, a fine sample for studying galaxy interaction and starbursts. Deep long-focus imaging captures the main galaxy, companion and connecting bridge together.