Summary
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]
| 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] |
| Distance | 88.74 ± 0.04 ly (27.21 ± 0.01 pc) |
| Details | |
| Mass | 0.651+0.031 −0.029[3] M☉ |
| Radius | 0.639+0.020 −0.022[3] R☉ |
| Luminosity | 0.157+0.019 −0.017[3] L☉ |
| Surface gravity (log g) | 4.642+0.027 −0.025[3] cgs |
| Temperature | 4,550±110[3] K |
| Metallicity [Fe/H] | −0.48±0.07[6] dex |
| Rotation | ~25 d[3] |
| Rotational velocity (v sin i) | 1.0±0.5[3] km/s |
| Age | 7.4+4.5 −4.9[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >0.65±0.05 MJ | 2.36±0.04 | 1634±14 | 0.05±0.05 | — | — |
| c | >0.04836+0.009 −0.0066 MJ |
0.3±0.01 | 74.2±0.08 | 0.4±0.15 | — | — |
See also edit
- list of exoplanets discovered in 2014 (BD-11 4672b)
- list of exoplanets discovered in 2020 (BD-11 4672c)
References edit
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g h i j k l m n o p q Barbato, D.; et al. (2020), "The GAPS Programme at TNG XXIV. An eccentric Neptune-mass planet near the inner edge of the BD-11 4672 habitable zone", Astronomy & Astrophysics, A68: 641, arXiv:2006.14393, Bibcode:2020A&A...641A..68B, doi:10.1051/0004-6361/202037954, S2CID 220055727.
- ^ a b c Moutou, Claire; et al. (March 2011), "The HARPS search for southern extra-solar planets: XXVI: Seven new planetary systems", Astronomy & Astrophysics, 527, arXiv:1012.3830, Bibcode:2011A&A...527A..63M, doi:10.1051/0004-6361/201015371, S2CID 118696125, A63.
- ^ a b Soubiran, C.; et al. (2018), "Gaia Data Release 2. The catalogue of radial velocity standard stars", Astronomy and Astrophysics, 616: A7, arXiv:1804.09370, Bibcode:2018A&A...616A...7S, doi:10.1051/0004-6361/201832795, S2CID 52952408.
- ^ a b Andreasen, D. T.; et al. (2017), "SWEET-Cat update and FASMA A new minimization procedure for stellar parameters using high-quality spectra", Astronomy & Astrophysics, A69: 600, arXiv:1703.06671, Bibcode:2017A&A...600A..69A, doi:10.1051/0004-6361/201629967, S2CID 119534579.
- ^ "BD-11 4672". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-09-27.
- ^ Wolf, M.; Reinmuth, K. (1925), "Einige bewegte Sterne in Scutum", Astronomische Nachrichten, 223 (14): 231, Bibcode:1925AN....223..231W, doi:10.1002/asna.19242231404.
- ^ Luyten, W. J. (June 1995), "NLTT Catalogue (Luyten, 1979)", VizieR Online Data Catalog, Bibcode:1995yCat.1098....0L.
- ^ Lammer, H.; et al. (2020), "A census of Coronal Mass Ejections on solar-like stars", Monthly Notices of the Royal Astronomical Society, 493 (3): 4570–4589, arXiv:2002.04430, Bibcode:2020MNRAS.493.4570L, doi:10.1093/mnras/staa504, S2CID 211076125.
- ^ Moutou, C.; et al. (2014), "The HARPS search for southern extra-solar planets", Astronomy & Astrophysics, 576: A48, arXiv:1412.6591, Bibcode:2015A&A...576A..48M, doi:10.1051/0004-6361/201424965, S2CID 118512899.
- ^ "Planet BD-11 4672 b", exoplanet.eu, retrieved 2024-01-05.