Telescope image of HD 136118 | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Serpens |
Right ascension | 15 18 55.47227 |
Declination | −01° 35′ 32.5926″ |
Apparent magnitude (V) | 6.93 |
Characteristics | |
Evolutionary stage | main sequence |
Spectral type | F7V |
B−V color index | 0.553±0.007 |
Astrometry | |
Radial velocity (Rv) | −3.07±0.13 km/s |
Proper motion (μ) | RA: −123.024(31) mas/yr Dec.: 22.180(30) mas/yr |
Parallax (π) | 19.8116 ± 0.0341 mas |
Distance | 164.6 ± 0.3 ly (50.48 ± 0.09 pc) |
Absolute magnitude (MV) | 3.60 |
Details | |
Mass | 1.84±0.23 M☉ |
Radius | 1.70±0.02 R☉ |
Luminosity | 3.717±0.018 L☉ |
Surface gravity (log g) | 4.08 cgs |
Temperature | 6,148+38 −43 K |
Metallicity | −0.06±0.01 dex |
Rotational velocity (v sin i) | 8.5 km/s |
Age | 3.5±0.4 Gyr |
Other designations | |
BD−01° 3045, HD 136118, HIP 74948, SAO 140452 | |
Database references | |
SIMBAD | data |
HD 136118 is a star in the Serpens Caput section of the Serpens constellation. The star is too dim to be readily visible to the naked eye, having an apparent visual magnitude of 6.93. It is located at a distance of 165 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −3 km/s.
This object is an F-type main-sequence star with a stellar classification of F7V. The absolute visual magnitude of this star suggests that it has begun to evolve away from the main sequence. The abundances of the stellar atmosphere are similar to the Sun, and it has only a modest level of chromospheric activity. HD 136118 has 84% more mass compared to the Sun, and is 70% larger in radius. The star is an estimated 3.5 billion years old and is spinning with a projected rotational velocity of 8.5 km/s.
Brown dwarf companion
The astronomer Debra Fischer discovered a substellar companion, originally thought to be a very massive exoplanet, which was announced on February 7, 2002. Designated HD 136118 b, it is orbiting the host star with a period of 3.25 years. This object has a minimum mass of 11.9 MJ. On November 25, 2009, its inclination was calculated to be 163.1° and its true mass 42 MJ, classifying it as a brown dwarf. Later studies in 2022 and 2023 found true masses of about 13-16 MJ, closer to the minimum mass, but still classifying the companion as a brown dwarf by most definitions.
Due to its high mass the object is likely to be very hot and possibly glowing faintly. The orbit of the object has a semimajor axis of 1.45 astronomical units from the parent star, taking 1,188 days (3.25 years) to complete one eccentric orbit.
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 16.5+1.7 −1.8 MJ |
2.353+0.046 −0.045 |
3.262+0.053 −0.051 |
0.35+0.027 −0.026 |
134.0+4.7 −7.5° |
— |
See also
References
- ^ 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.
- ^ 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.
- ^ Fischer, Debra A.; et al. (2002). "Planetary Companions to HD 136118, HD 50554, and HD 106252". Publications of the Astronomical Society of the Pacific. 114 (795): 529–535. Bibcode:2002PASP..114..529F. doi:10.1086/341677. JSTOR 10.1086/341677.
- ^ Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- ^ Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
- ^ Stassun, Keivan G.; et al. (2017). "Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes". The Astronomical Journal. 153 (3): 136. arXiv:1609.04389. Bibcode:2017AJ....153..136S. doi:10.3847/1538-3881/aa5df3. S2CID 119219062.
- ^ 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.
- "HD 81040". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
- ^ Martioli, Eder; et al. (January 2010). "The Mass of the Candidate Exoplanet Companion to HD 136118 from Hubble Space Telescope Astrometry and High-Precision Radial Velocities". The Astrophysical Journal. 708 (1): 625–634. arXiv:0911.4645. Bibcode:2010ApJ...708..625M. doi:10.1088/0004-637X/708/1/625. S2CID 119183677.
- Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.
- ^ Xiao, Guang-Yao; Liu, Yu-Juan; et al. (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. S2CID 257663647.
External links
- "Notes for star HD 136118". Extrasolar Planets Encyclopaedia. Archived from the original on November 6, 2007. Retrieved 2008-08-20.
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