Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2023 January 5
See Explanation.  Clicking on the picture will download
the highest resolution version available.

Messier 45: The Daughters of Atlas and Pleione
Image Credit & Copyright: Stefan Thrun

Explanation: Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades or Seven Sisters open star cluster is well-known for its striking blue reflection nebulae. It lies in the night sky toward the constellation Taurus and the Orion Arm of our Milky Way galaxy. The sister stars are not related to the dusty cloud though. They just happen to be passing through the same region of space. Known since antiquity as a compact grouping of stars, Galileo first sketched the star cluster viewed through his telescope with stars too faint to be seen by eye. Charles Messier recorded the position of the cluster as the 45th entry in his famous catalogue of things which are not comets. In Greek myth, the Pleiades were seven daughters of the astronomical titan Atlas and sea-nymph Pleione. Their parents names are included in the cluster's nine brightest stars. This well-processed, colour-calibrated telescopic image features pin-point stars and detailed filaments of interstellar dust captured in over 9 hours of exposure. It spans more than 20 light-years across the Pleiades star cluster.

Tomorrow's picture: moon o'clock


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.