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BD-11 4672

BD−11 4672 is a single star with a pair of orbiting exoplanets in the southern constellationofScutum, the shield. The designation BD−11 4672 comes from the Bonner Durchmusterung star catalogue, which was published during the nineteenth century in Germany. With an apparent visual magnitude of 9.99,^[3] the star is much too faint to be viewed with the naked eye. It is located at a distance of 89 light years from the Sun, as determined from parallax,^[2] but is drifting closer with a radial velocity of −87.5 km/s.^[5] This was recognised as a high proper motion star by German astronomer Max Wolf in 1924^[8] and is traversing the celestial sphere at an angular rateof0.401 arcsec yr⁻¹.^[9]

The spectrum of BD−11 4672 matches a K-type main-sequence star, an orange dwarf, with a stellar classification of K7 V.^[4] Its age is not well constrained, but is probably older than the Sun. It is a metal-poor star, showing an iron abundance that is 35% of solar.^[6] No significant flare activity was detected.^[10] The star shows evidence of a Sun-like magnetic activity cycle with a period of 7–10 years.^[3] It has 65% of the mass and 64% of the radius of the Sun. The star is radiating 16% of the luminosity of the Sun from its photosphere at an effective temperature of 4,550 K.^[3]

Planetary system[edit]

In 2010, a team of astronomers led by astronomer C. Moutou of the High Accuracy Radial Velocity Planet Searcher performed a radial-velocity analysis, which led to the suspicion of a gas giant exoplanet in orbit around BD−11 4672.^[4] The existence of this exoplanet was confirmed in 2014.^[11] In 2020, a second exoplanet was detected on an interior and much more eccentric orbit near the inner edge of the Star's habitable zone.^[3]

See also[edit]

• list of exoplanets discovered in 2014 (BD-11 4672b)
• list of exoplanets discovered in 2020 (BD-11 4672c)

References[edit]