The Pleiades cluster is a bright nearby grouping of stars visible to the naked eye even from moderately light-polluted skies. It is estimated to be 440 light years away, which is why I say "nearby." In astronomical terms that's not too far away! It is also know as the Seven Sisters, named after the seven daughters of Atlas and Pleione in Greek mythology. The main stars of this cluster are hot and blue, which is due to their relatively young age of about 100 million years old (1/50th the age of our Sun). The intense blue light given off by these stars illuminates a dust cloud that the stars are currently passing through.
This has been a challenging object for me, both in imaging and processing. My image above is the result of 70 exposures of 3 minutes each taken at ISO 800. It seems like even more time might be required to improve the results. I also need to work on my processing skills as it was difficult to really bring out the fainter details without raising the overall noise level too much.
Below is a NASA image map that identifies the major stars of the Pleiades.