BD−11 4672

Orange dwarf in the constellation Scutum From Wikipedia, the free encyclopedia

BD−11 4672 is a single star with a pair of orbiting exoplanets in the southern constellation of Scutum, 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 rate of 0.401 arcsec yr−1.[9]

Right ascension18h 33m 28.832s[2]
Declination−11° 38 09.72[2]
Quick facts Constellation, Right ascension ...
BD−11°4672
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scutum[1]
Right ascension 18h 33m 28.832s[2]
Declination −11° 38 09.72[2]
Apparent magnitude (V) 9.99±0.05[3]
Characteristics
Evolutionary stage main sequence[3]
Spectral type K7 V[4][3]
Apparent magnitude (B) 11.21±0.10[3]
Apparent magnitude (J) 7.651±0.023[1]
B−V color index 1.263±0.009[1]
Astrometry
Radial velocity (Rv)−87.515±0.0011[5] km/s
Proper motion (μ) RA: −288.440 mas/yr[2]
Dec.: −235.615 mas/yr[2]
Parallax (π)36.7534±0.0157 mas[2]
Distance88.74 ± 0.04 ly
(27.21 ± 0.01 pc)
Details[3]
Mass0.651+0.031
0.029
 M
Radius0.639+0.020
0.022
 R
Luminosity0.157+0.019
0.017
 L
Surface gravity (log g)4.642+0.027
0.025
 cgs
Temperature4,550±110 K
Metallicity [Fe/H]−0.48±0.07[6] dex
Rotation~25 d
Rotational velocity (v sin i)1.0±0.5 km/s
Age7.4+4.5
4.9
 Gyr
Other designations
BD−11 4672, GJ 717, HIP 90979, PPM 234703, Wolf 1462, TYC 5699-2129-1, GSC 05699-02129, 2MASS J18332885-1138097, Gaia DR2 4154598526336121600[7]
Database references
SIMBADdata
Exoplanet Archivedata
Close

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

In 2010, a team of astronomers led by astronomer C. Moutou [fr] 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]

More information Companion (in order from star), Mass ...
The BD−11 4672 planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination
(°)
Radius
c ≥15.37+2.97
−2.81
 M🜨
0.30±0.01 74.20+0.06
−0.08
0.40+0.13
−0.15
b ≥0.65+0.05
−0.06
 MJ
2.36±0.04 1634+13
−14
0.05+0.05
−0.03
Close

See also

References

Related Articles

Wikiwand AI