- A Hipparcos Census of the Nearby OB Associations (iopscience.iop.org)
A comprehensive census of the stellar content of the OB associations within 1 kpc from the Sun is presented, based on Hipparcos positions, proper motions, and parallaxes. It is a key part of a long-term project to study the formation, structure, and evolution of nearby young stellar groups and related star-forming regions. OB associations are unbound “moving groups,” which can be detected kinematically because of their small internal velocity dispersion. The nearby associations have a large extent on the sky, which traditionally has limited astrometric membership determination to bright stars (V ≲ 6 mag), with spectral types earlier than ∼B5. The Hipparcos measurements allow a major improvement in this situation.
- United States Attorney General (Wikipedia)
The United States attorney general (AG) is the head of the United States Department of Justice (DOJ) and is the chief law enforcement officer of the federal government of the United States. The attorney general serves as the principal advisor to the president of the United States on all legal matters. The attorney general is a statutory member of the Cabinet of the United States.
