The Pleiades, also known as Messier Object 45, is an open star cluster located in the constellation of Taurus at a distance of 430 light years. It is one of the nearest star clusters to Earth and can easily be seen with the naked eye. In fact ancient Greek references to the star cluster occur as early as 750 B.C.. Some Greek astronomers even considered the Pleiades to be a distinct constellation. The star cluster is sometimes referred to as the Seven Sisters since the nine brightest stars were named after the Seven Sisters of Greek mythology (Alcyone, Electra, Maia, Merope, Taygeta, Celaeno, and Sterope) along with their mother Pleione and their father Atlas. In Japanese, the star cluster is referred to as “Subaru” (to unite). This is where the Japanese automaker derives its name and corporate logo.
The Pleiades star cluster is one of the most beautiful objects to observe in the night sky. It contains more than five hundred stars spread over a two-degree field (four times the diameter of the full moon). Most of these stars are hot, blue and extremely luminous. The cluster is currently passing through an unrelated cloud of dust once thought to have been the origin of the stars in the cluster. Since most of the stars found in the cluster formed in the last one hundred million years, it is thought that the dust originally present while stars were forming would have since been dispersed by radiation pressure. The dust reflects light from the stars in the cluster so faint nebulosity can be seen in and around the star cluster. This nebulosity can be seen in small telescopes under moderately dark skies but its true beauty takes on a whole new life if seen through a large telescope under very dark skies where the smallest wisps of dust can be seen alongside a background of many more of the fainter stars.
This object was captured from my favourite location near Foymount, Ontario under pristine skies. The seeing conditions and the transparency were ideal this night. The temperature was just warm enough to feel comfortable. The Milky Way cast shadows on the ground and the only sounds heard were those made by crickets. The view of the Milky Way would have given pause even to the most seasoned astronomer. It was a truly awe-inspiring night. Stars could be seen all the way down to one half degree above the horizon. I elected to use my Takahashi FSQ106 at prime focus to capture this object. Since it was the second object on the agenda that night, I only had enough time for just over one hour of exposure. I originally had only intended this to be a test of exposure length although when I processed the raw data, I realized I had data that I could actually work with. I have since focused on other objects in the night sky, but I intend to come back to this one next summer when it is again visible so that I can capture the remaining colour data.