[4] The Kepler spacecraft's first days of science activity revealed a series of transit events, in which some body (such as a planet) crosses in front of, and therefore dims, its host star.

[4] After the stellar parameters were established, the Kepler science team ran models and fits to ensure that Kepler-5's transit event was not a false positive, such as an eclipsing binary star.

Once the planetary nature of Kepler-5b was established, the Kepler team searched for the planet's occultation behind its star, hoping to find the temperature on its day side.

[1] Use of the Fibre-fed Echelle Spectrograph (FIES) at the Nordic Optical Telescope on the Canary Islands on June 4, 2009 provided data that was used to determine the star's stellar classification.

Keck Observatory's High Resolution Echelle Spectrometer (HIRES), which was used on June 3–6, 2009, and July 2–4, 2009, determined radial velocity measurements for the star, which helped to further define stellar parameters.

[1] The findings of the Kepler team, which also included planets Kepler-4b, Kepler-6b, Kepler-7b, and Kepler-8b, were announced at the 215th meeting of the American Astronomical Society of January 4, 2010.