Kepler-39b

Kepler-39b (formerly known as KOI-423b), is a confirmed extrasolar object (either a Jovian planet or brown dwarf because of its mass) discovered orbiting the F-type star Kepler-39.

The location of the subgiant star in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth.

[1] Although Kepler-39b and COROT-3b have similar characteristics (in terms of host star and mass), COROT-3b lies on the predicted size of what a planet of its character should look like.

[4] In 2022, the radius of Kepler-39b was improved based on direct parallax measaurements by the Gaia spacecraft, which allows the distance to the host star to be known.

A team of astronomers, hoping to learn more about hot jupiter planets and brown dwarfs, selected four F-type stars from the Kepler Input Catalog flagged as host to a Kepler Object of Interest (a transiting object that could possibly be a planet).

Using three quarters of Kepler's data, the science team conducted a follow-up investigation in using the SOPHIE échelle spectrograph at the Haute-Provence Observatory in southern France, observing stars Kepler-40, Kepler-39, KOI-552 and KOI-410.

These radial velocity measurements conclusively eliminated the possibility that the observed dips in Kepler-39's brightness were caused by the movements of binary stars and confirming the existence of planet Kepler-39b in the process.

[1] The astronomers submitted the discovery paper to Astronomy and Astrophysics on June 16, 2011 with François Bouchy as the leading author.