網址: https://upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Starburst_in_NGC_4449_%28captured_by_the_Hubble_Space_Telescope%29.jpg/2560px-Starburst_in_NGC_4449_%28captured_by_the_Hubble_Space_Telescope%29.jpg
網址2: https://et.wikipedia.org/wiki/Fail:Starburst_in_NGC_4449_(captured_by_the_Hubble_Space_Telescope).jpg
