K-type giant star in the constellation Eridanus
Location of HD 11343 (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 01 50 06.33044 |
| Declination | −54° 27′ 53.8624″ |
| Apparent magnitude (V) | 7.88 |
| Characteristics | |
| Evolutionary stage | Red-giant branch star |
| Spectral type | K2III/IV |
| B−V color index | 1.10 |
| J−H color index | 0.556 |
| J−K color index | 0.722 |
| Astrometry | |
| Radial velocity (Rv) | 6.61 km/s |
| Proper motion (μ) | RA: 110.617 mas/yr Dec.: −46.798 mas/yr |
| Parallax (π) | 6.4964 ± 0.0156 mas |
| Distance | 502 ± 1 ly (153.9 ± 0.4 pc) |
| Absolute magnitude (MV) | 1.240+0.275 −0.225 |
| Orbit | |
| Primary | HD 11343 A |
| Companion | HD 11343 B |
| Semi-major axis (a) | ~2600 AU |
| Details | |
| HD 11343 A | |
| Mass | 1.17±0.28 / 2.009±0.115 M☉ |
| Radius | 7.83±1.02 R☉ |
| Luminosity | 25.1+5.8 −5.6 L☉ |
| Surface gravity (log g) | 2.70±0.20 cgs |
| Temperature | 4670±100 K |
| Metallicity | −0.15±0.08 dex |
| Rotational velocity (v sin i) | 1.3±0.9 km/s |
| HD 11343 B | |
| Mass | 0.680+0.078 −0.083 M☉ |
| Radius | 0.698+0.062 −0.060 R☉ |
| Surface gravity (log g) | 4.58+0.11 −0.09 cgs |
| Temperature | 4351+142 −113 K |
| Other designations | |
| CD−55 412, CPD−55 351, Gaia DR3 4912062772547406976, GC 2232, HD 11343, HIP 8541, SAO 232538, PPM 331373, TIC 231019255, TYC 8482-1124-1, GSC 08482-01124, 2MASS J01500631-5427539 | |
| Database references | |
| SIMBAD | data |
HD 11343 (HIP 8541) is a wide binary system between HD 11343 A, a K-type borderline giant star, and HD 11343 B, a red dwarf companion, located in the southern constellation of Eridanus about 500 light-years (150 pc) distant. Two gas giant exoplanets are known to orbit the primary star.
Stellar characteristics
The HD 11343 system has an apparent magnitude of 7.88, making it too faint to be visible by the naked eye from Earth under most circumstances, but can be observed using binoculars as an orangish dot near Achernar.
The primary component, HD 11343 A, is a red-giant branch star slightly more massive than the Sun (albeit one estimate places its mass at a significantly higher 2.0 M☉), but approximately eight times as large in radius and 25 times as luminous. It has an effective temperature of 4,670 K (4,400 °C; 7,950 °F), corresponding to its spectral type of K2, and is slightly metal-poor, with an iron content 71% that of the Sun.
During a 2021 survey searching for binaries within data from Gaia EDR3, the star was found to be orbited by a 13th-magnitude M-dwarf, designated HD 11343 B. It is about 70% as large as the Sun both in mass and radius, is slightly cooler than the primary red giant at 4,351 K (4,078 °C; 7,372 °F), and is situated at a separation of roughly 2,600 astronomical units (0.041 ly) from its brighter companion.
Planetary system
In 2016, a super-Jupiter planet orbiting HD 11343 A was discovered from radial-velocity observations, alongside three other substellar companions to giant stars, namely HIP 74890 b, HIP 84056 b, and HIP 95124 b. This planet, HD 11343 b, is estimated to be slightly larger than Jupiter and has a mass of 5.7 MJ, close to the initially estimated minimum of 5.5 MJ. It revolves around its host star at a semi-major axis of 2.8 AU (420,000,000 km), around where the asteroid belt would lie in the Solar System, every 1,585 days (4.34 years) in a mildly eccentric orbit.
Another planet, HD 11343 c, was discovered in 2022 closer to HD 11343 A, also using the radial-velocity method. The planet is reportedly a Jupiter analog, larger than the previous planet but likely considerably less massive, with a minimum mass of 0.804 MJ. It orbits its star at a distance of 0.923 AU (138,100,000 km) every 228.5 days (0.626 years). Due to the faintness of the astrometric signals it produces, its orbital inclination cannot be well-constrained. The discovery paper for HD 11343 c notably presents a higher mass (7.71+0.73
−1.19 MJ), semi-major axis (3.729 AU), orbital period (5.07 years), and eccentricity (0.360) for HD 11343 b.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥0.804 MJ | 0.923 −0.022 |
228.5 −3.8 |
0.169 −0.102 |
— | ~1.24 RJ |
| b | 5.7 −1.1 MJ |
2.80 −0.25 |
1585 −40 |
0.122 −0.067 |
73.0 −16.0° |
~1.13 RJ |
Footnotes
- Calculated from star's luminosity.
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ "HD 11343". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 September 2024.
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Xiao, Guang-Yao; et al. (1 May 2023). "The Masses of a Sample of Radial-velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics. 23 (5): 055022. arXiv:2303.12409. Bibcode:2023RAA....23e5022X. doi:10.1088/1674-4527/accb7e. ISSN 1674-4527.
- ^ Feng, Fabo; Butler, R. Paul; Vogt, Steven S.; Clement, Matthew S.; Tinney, C. G.; Cui, Kaiming; Aizawa, Masataka; Jones, Hugh R. A.; Bailey, J.; Burt, Jennifer; Carter, B. D.; Crane, Jeffrey D.; Dotti, Francesco Flammini; Holden, Bradford; Ma, Bo; Ogihara, Masahiro; Oppenheimer, Rebecca; O’Toole, S. J.; Shectman, Stephen A.; Wittenmyer, Robert A.; Wang, Sharon X.; Wright, D. J.; Xuan, Yifan (1 September 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (1): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. ISSN 0067-0049.
This article incorporates text from this source, which is available under the CC BY 4.0 license.
- ^ Jones, M. I.; et al. (2016). "Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars". Astronomy & Astrophysics. 590: A38. arXiv:1603.03738. Bibcode:2016A&A...590A..38J. doi:10.1051/0004-6361/201628067. ISSN 0004-6361.
- ^ Stassun, Keivan G.; et al. (1 October 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
- Zarenski, Ed (2004). "Limiting Magnitude in Binoculars" (PDF). Cloudy Nights. Archived (PDF) from the original on 21 July 2011. Retrieved 6 May 2011.
- El-Badry, Kareem; Rix, Hans-Walter; Heintz, Tyler M (20 July 2021). "A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties". Monthly Notices of the Royal Astronomical Society. 506 (2): 2269–2295. arXiv:2101.05282. doi:10.1093/mnras/stab323. ISSN 0035-8711.
- "HIP 8541 Overview". NASA Exoplanet Archive. Retrieved 21 September 2024.
- "HD 11343 c - NASA Science". Retrieved 21 September 2024.
- "HIP 8541 b - NASA Science". Retrieved 21 September 2024.
External links
- HD 11343 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- Extrasolar Planets Encyclopaedia links: HD 11343 b, c