The HD 136118 theme is a theme that has captured the interest of many people over time. Since its emergence, HD 136118 has been the subject of debates, discussions and numerous investigations. Its relevance extends to different fields, since it has an impact on society, the economy, technology and many other areas. HD 136118 is a topic that has evolved and adapted to social and cultural changes, always remaining at the forefront of public attention. In this article, we will explore the different aspects of HD 136118 and its importance in today's world.
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Serpens |
Right ascension | 15h 18m 55.47227s[1] |
Declination | −01° 35′ 32.5926″[1] |
Apparent magnitude (V) | 6.93[2] |
Characteristics | |
Evolutionary stage | main sequence[3] |
Spectral type | F7V[4] |
B−V color index | 0.553±0.007[2] |
Astrometry | |
Radial velocity (Rv) | −3.07±0.13[1] km/s |
Proper motion (μ) | RA: −123.024(31) mas/yr[1] Dec.: 22.180(30) mas/yr[1] |
Parallax (π) | 19.8116±0.0341 mas[1] |
Distance | 164.6 ± 0.3 ly (50.48 ± 0.09 pc) |
Absolute magnitude (MV) | 3.60[5] |
Details | |
Mass | 1.84±0.23[6] M☉ |
Radius | 1.70±0.02[7] R☉ |
Luminosity | 3.717±0.018[7] L☉ |
Surface gravity (log g) | 4.08[5] cgs |
Temperature | 6,148+38 −43[7] K |
Metallicity | −0.06±0.01[2] dex |
Rotational velocity (v sin i) | 8.5[5] km/s |
Age | 3.5±0.4[2] Gyr |
Other designations | |
BD−01° 3045, HD 136118, HIP 74948, SAO 140452[8] | |
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.[2] It is located at a distance of 165 light years from the Sun based on parallax,[1] and is drifting closer with a radial velocity of −3 km/s.[2]
This object is an F-type main-sequence star with a stellar classification of F7V.[4] The absolute visual magnitude of this star suggests that it has begun to evolve away from the main sequence.[3] The abundances of the stellar atmosphere are similar to the Sun, and it has only a modest level of chromospheric activity.[9] HD 136118 has 84% more mass compared to the Sun,[6] and is 70%[7] larger in radius. The star is an estimated 3.5[2] billion years old and is spinning with a projected rotational velocity of 8.5 km/s.[5]
The astronomer Debra Fischer discovered a substellar companion, originally thought to be a very massive exoplanet, which was announced on February 7, 2002.[3] Designated HD 136118 b, it is orbiting the host star with a period of 3.25 years.[9] This object has a minimum mass of 11.9 MJ.[3] On November 25, 2009, its inclination was calculated to be 163.1° and its true mass 42 MJ, classifying it as a brown dwarf.[9] 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.[10][11]
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° |
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