In 1994, Hubble detected particular gaz prominents from the young star named Herbig Haro 47, or HH47. The speed of the gaz located at only 1,500 light years has been calculated: it goes at 150km per second.
The spatial telescope has regularly taken pictures of the resulting nebula, between 1994 and 2008, that is to say during 15 years.
Result is that this is the very first time that we can observe the evolution of a nebula!
This show, very easily understandable, is exceptionnal because we never saw such an object changing in the sky before.
Click on the link and enjoy the show!
NASA, ESA, & P. Haritgan (Rice U.)