Gamma-ray Observations of Galactic Sources with COSI

The Compton Spectrometer and Imager (COSI) is a wide-field-of-view Compton Gamma-ray satellite that will operate in the 0.2 - 5 MeV bandpass. COSI is a NASA Small Explorer mission planned for launch in 2027. The predecessor of the Small Explorer mission was a balloon-borne instrument that had a successful 46-day flight in 2016. With its high-purity germanium strip detectors, COSI can precisely map gamma-ray line emission, image gamma-ray sources, localize gamma-ray bursts, and provide polarimetry measurements of gamma-ray sources. These combined characteristics make COSI an exceptional instrument for galactic astronomy. In this presentation, we will discuss observations from the 2016 COSI-balloon flight of the Crab pulsar and Cygnus X-1, and also discuss how these observations can help inform us about what to expect from the upcoming COSI space mission.