HD 33636
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Orion |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 7.00[2] |
| Characteristics | |
| Spectral type | G0V_CH-0.3[3] |
| B−V Template:Engvar | 0.588 ± 0.016[2] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[1] km/s |
| Proper motion (μ) | RA: Script error: No such module "val". mas/yr[1] Dec.: Script error: No such module "val". mas/yr[1] |
| Parallax (π) | 33.7982±0.0529 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 4.71[2] |
| Orbit[4] | |
| Companion | HD 33636 B |
| Period (P) | Script error: No such module "val". yr |
| Semi-major axis (a) | Script error: No such module "val". |
| Eccentricity (e) | Script error: No such module "val". |
| Inclination (i) | Script error: No such module "val".° |
| Longitude of the node (Ω) | Script error: No such module "val".° |
| Periastron epoch (T) | Script error: No such module "val". |
| Argument of periastron (ω) (secondary) | Script error: No such module "val".° |
| Details | |
| Mass | 1.01 ± 0.02[5] Template:Solar mass |
| Radius | 0.97 ± 0.01[5] Template:Solar radius |
| Luminosity | 1.08 ± 0.003[5] Template:Solar luminosity |
| Surface gravity (log g) | 4.46 ± 0.02[5] cgs |
| Temperature | 5979 ± 28[5] K |
| Age | 2.5 ± 1.1[5] Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[3] | |
| Database references | |
| SIMBAD | data |
Script error: No such module "Check for unknown parameters".
HD 33636 is a G-type main-sequence star located approximately 96.5 light-years away in the Orion constellation. It is a 7th magnitude star with a metallicity of −0.05 ± 0.07. A likely substellar companion was discovered in 2002.[6][7]
Companion
HD 33636 b was discovered in 2002 by the Keck telescope in Hawaii using the radial velocity method.[6] It was independently detected at the Haute-Provence Observatory in France.[2] With this method it showed a minimum mass of 9.28 Jupiter masses, and was initially assumed to be a planet and labelled "HD 33636 b" (lower-case).[8]
In 2007, Bean et al. used the Hubble Space Telescope (HST) astrometry to find that this body has an inclination as little as 4.1 ± 0.1°, which yielded a true mass of Template:Jupiter mass. This is too high to be a planet. It was classified by this study as an M-dwarf star of likely spectral type M6V, "HD 33636 B" (upper-case).[9]
This picture was further revised in the 2020s. A 2023 study using astrometry from Hipparcos and Gaia found that the mass had likely been overestimated, and found a lower true mass of about Template:Jupiter mass. This would place HD 33636 b near the borderline between stars and brown dwarfs.[4] A 2024 study using Gaia astrometry even excluded the possibility of a companion mass greater than Template:Jupiter mass, instead finding a mass range more compatible with the initial minimum mass estimate. This study estimated a mass of about Template:Jupiter mass, near the borderline between brown dwarfs and planets.[7]
This object takes 2121 days or 5.807 years to orbit at a semimajor axis of 3.33 astronomical units (AU).[4]
References
<templatestyles src="Reflist/styles.css" />
- ↑ a b c d e Template:Cite Gaia DR3
- ↑ a b c d Script error: No such module "Citation/CS1".
- ↑ a b Template:Cite simbad
- ↑ a b c Script error: No such module "Citation/CS1".
- ↑ a b c d e f Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
Script error: No such module "Check for unknown parameters".