Second star in, looking left to right, at the handle of the Big Dipper (in Ursa Major). Alcor is a hot, white A5V main sequence star having a luminosity about 13 times that of the sun. Temperature of 8500 K, a diameter 1.7 times that of the sun, and a mass of about 2.2 solar masses. Alcor is a variable star, of the Delta scuti type.

ALCOR is an acronym for the ARPA Lincoln C-Band Observables Radar, a high-power, narrow-beam coherent, chirped monopulse tracking radar. It is part of the KREMS radar complex located at Roi-Namur in the Kwajalein Missile Range operated by the US Army in support of Anti-ballistic missile testing and space surveillance. It not only measures near-Earth target velocity, it's C-band allows simultaneous range and angle tracking on two targets (if equipped with beacons). It also is the primary weather measurement radar at Kwajalein, its data is used to predict the severity of weather on vehicle re-entry.