Answer :
Objects such as the great nebula in andromeda were once called extragalactic nebulae. it is now realized that other galaxies much like our own.
What is nebula?
A nebula is a distinctively luminous region of the interstellar medium, which may be made up of cosmic dust, neutral, neutrally ionised, or molecular hydrogen. Nebulae are frequently areas where stars are being formed, as seen in the Eagle Nebula's "Pillars of Creation."
The gas, dust, and other material formations in these areas "clump" together to form denser regions, which draw in more matter and finally reach a density where stars can form. Planets and other planetary system objects are then supposed to be formed from the leftover material.
Learn more about nebula here:
https://brainly.com/question/9497068
#SPJ1