HD 7449
HD 7449 A is the primary star of the binary star system HD 7449, about 126 light-years way. It is a main-sequence star belonging to the spectral class F9.5. It is younger than the Sun. The primary star is slightly depleted of heavy elements, having 80% of solar abundance.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 01h 14m 29.3222s[1] |
| Declination | −05° 02′ 50.6148″[1] |
| Apparent magnitude (V) | 7.48 |
| Characteristics | |
| Spectral type | F9.5V+M4.5 |
| B−V color index | 0.575 |
| Astrometry | |
| Radial velocity (Rv) | -19.824 km/s |
| Proper motion (μ) | RA: -164.483 mas/yr Dec.: -134.376 mas/yr |
| Parallax (π) | 25.8363 ± 0.0431[2] mas |
| Distance | 126.2 ± 0.2 ly (38.71 ± 0.06 pc) |
| Orbit[3] | |
| Primary | HD 7449 A |
| Companion | HD 7449 B |
| Semi-major axis (a) | 18 AU |
| Eccentricity (e) | <0.5 |
| Details[4] | |
| HD 7449 A | |
| Mass | 1.05±0.02 M☉ |
| Radius | 1.02±0.02 R☉ |
| Luminosity | 1.26±0.02 L☉ |
| Surface gravity (log g) | 4.44±0.02 cgs |
| Temperature | 6060±42 K |
| Metallicity | -0.11±0.01[5] |
| Age | 2.2±1.3 Gyr |
| HD 7449 B | |
| Mass | 0.2[3] M☉ |
| Temperature | 3000 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The stellar companion HD 7449 B, belonging to spectral class M4.5, was discovered in 2015.[6] A survey in 2017 has failed to find additional stars with masses above 0.35M☉ in the system.[7]
Planetary system
In 2011 one Jupiter-sized planet, HD 7449 A b on a very eccentric orbit around HD 7449 A was discovered utilising the radial velocity method.[5] The large eccentricity of the inner planet is caused by the stellar companion HD 7449 B.[3] The presence of additional bodies in the system has been suspected since 2011, and a brown dwarf on a poorly constrained, wide orbit was proposed in 2019.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| HD 7449 A b | 1.09+0.52 −0.19 MJ |
2.33+0.01 −0.02 |
1270+6 −12 |
0.80±0.08 | — | — |
| HD 7449 A c | >31 MJ | — | >15341 | — | — | — |
References
- "HD 7449". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 10 October 2020.
- 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.
- Rodigas, Timothy J.; Arriagada, Pamela; Faherty, Jackie; Anglada-Escudé, Guillem; Kaib, Nathan; Butler, R. Paul; Shectman, Stephen; Weinberger, Alycia; Males, Jared R.; Morzinski, Katie M.; Close, Laird M.; Hinz, Philip M.; Crane, Jeffrey D.; Thompson, Ian; Teske, Johanna; DíAz, Matías; Minniti, Dante; Lopez-Morales, Mercedes; Adams, Fred C.; Boss, Alan P. (2015), "MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). I. A BENCHMARK M DWARF COMPANION EXCITING a MASSIVE PLANET AROUND THE SUN-LIKE STAR HD 7449", The Astrophysical Journal, 818 (2): 106, arXiv:1512.04540, doi:10.3847/0004-637X/818/2/106, S2CID 51813840
- Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016), "Age consistency between exoplanet hosts and field stars", Astronomy & Astrophysics, 585: A5, arXiv:1511.01744, Bibcode:2016A&A...585A...5B, doi:10.1051/0004-6361/201527297, S2CID 53971692
- Dumusque, X.; Lovis, C.; Ségransan, D.; Mayor, M.; Udry, S.; Benz, W.; Bouchy, F.; Lo Curto, G.; Mordasini, C.; Pepe, F.; Queloz, D.; Santos, N. C.; Naef, D. (2011), "The HARPS search for southern extra-solar planets. XXX. Planetary systems around stars with solar-like magnetic cycles and short-term activity variation", Astronomy & Astrophysics, 535: A55, arXiv:1107.1748, Bibcode:2011A&A...535A..55D, doi:10.1051/0004-6361/201117148, S2CID 119192207
- Open Exoplanet Catalogue an open source database of all discovered extrasolar planets HD 7449
- Wittrock, Justin M.; Kane, Stephen R.; Horch, Elliott P.; Howell, Steve B.; Ciardi, David R.; Everett, Mark E. (2017), "Exclusion of Stellar Companions to Exoplanet Host Stars", The Astronomical Journal, 154 (5): 184, arXiv:1709.05315, Bibcode:2017AJ....154..184W, doi:10.3847/1538-3881/aa8d69, S2CID 55789971
- Wittenmyer, Robert A.; Clark, Jake T.; Zhao, Jinglin; Horner, Jonathan; Wang, Songhu; Johns, Daniel (2019), "Truly eccentric. I. Revisiting eight single-eccentric planetary systems", Monthly Notices of the Royal Astronomical Society, 484 (4): 5859–5867, arXiv:1901.08471, Bibcode:2019MNRAS.484.5859W, doi:10.1093/mnras/stz290, S2CID 118915974
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