The Pleiades, a bright open star cluster in Taurus with blue reflection nebulosity.
What It Is
M45, the Pleiades or Seven Sisters, is a bright open cluster in Taurus. Its hot blue-white stars are young by stellar standards and are loosely bound together by gravity within our Milky Way.
History
The Pleiades have been recognized since antiquity and have no single known discoverer. Galileo was the first known observer to examine the cluster telescopically, revealing many more stars than the handful visible to the unaided eye.
Science Notes
- NASA lists M45 at about 445 light-years away with an apparent magnitude of 1.6, making it one of the easiest Messier objects to see without a telescope.
- The cluster contains more than a thousand stars, although a small group of bright members visually dominates the view.
- The blue haze around stars such as Merope is reflection nebulosity: dust scattering the light of the bright cluster stars.
- NASA describes the Pleiades as younger than the Hyades but older than newborn stars in the Orion Nebula, making it a useful nearby example for studying stellar evolution.
- Modern distance measurements from Hubble, VLBI, and Gaia helped resolve the long-running Pleiades distance controversy.
- distance
- 445 light-years
- apparentMagnitude
- 1.6
- constellation
- Taurus
- objectType
- Open cluster
- starCount
- More than 1,000 loosely bound stars
- bestObserved
- December from mid-northern latitudes
