External links
- "HD 41004 A". The Extrasolar Planets Encyclopaedia. Retrieved 2008-07-21.
- "HD 41004 B". The Extrasolar Planets Encyclopaedia. Retrieved 2008-07-21.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pictor |
| Right ascension | 05h 59m 49.64736s [1] |
| Declination | −48° 14′ 22.8058″ [1] |
| Apparent magnitude (V) | 8.65 [2] (8.82 + 12.51) [3] |
| Characteristics | |
| Spectral type | K1V + M2V [4] |
| B−V color index | 0.887±0.013 [2] |
| Astrometry | |
| Radial velocity (Rv) | +42.5±0.5 [2] km/s |
| Proper motion (μ) | RA: −41.520±0.485 [1] mas/yr Dec.: +59.652±0.556 [1] mas/yr |
| Parallax (π) | 24.0437 ± 0.2635 mas [1] |
| Distance | 136 ± 1 ly (41.6 ± 0.5 pc) |
| Absolute magnitude (MV) | 5.60 [2] |
| Details [5] | |
| A | |
| Mass | 0.89±0.07 M☉ |
| Radius | 1.04+0.02 −0.03 [1] R☉ |
| Luminosity | 0.629±0.008 [1] L☉ |
| Surface gravity (log g) | 4.34±0.11 cgs |
| Temperature | 5,255±52 K |
| Metallicity [Fe/H] | 0.15±0.03 dex |
| Rotational velocity (v sin i) | 1.0±1.2 [6] km/s |
| B | |
| Mass | 0.4 [7] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 41004 is a visual binary [4] star system in the southern constellation of Pictor. It is too faint to be visible to the naked eye, having a combined apparent visual magnitude of 8.65. [2] The two components have a magnitude difference of 3.7, and share a common proper motion [4] with an angular separation of 0.30″ , as of 2018. [3] The distance to this system is approximately 136 light years based on parallax. [1] It is drifting further away from the Sun with a radial velocity of +42.5 km/s, having come to within 44.5 ly some 831,000 years ago. [2]
The primary, component A, is a K-type main-sequence star with a stellar classification of K1V [4] and a visual magnitude of 8.82. [3] Torres et al. (2006) classed it as a K1IV star, [6] suggesting it is a subgiant star that is evolving off the main sequence. It has 89% [4] of the mass of the Sun and 104% [1] of the Sun's radius. The star is radiating 63% [1] of the Sun's luminosity from its photosphere at an effective temperature of 5,255 K. [4] Its smaller companion, designated component B, is a red dwarf with spectral type M2V [4] and apparent magnitude 12.33. It has a projected separation of 23 AU from the primary. [4]
A planet, HD 41004 Ab, was discovered by Zucker et al., in but not published until 2004. It has a mass >2.56 times that of Jupiter. It orbits the primary star at a separation of 1.70 astronomical units, taking 2.64 years with a high eccentricity of 0.74.
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >2.56 MJ | 1.70 | 963 | 0.74 | — | — |
| Discovery | |
|---|---|
| Discovered by | Zucker et al. |
| Discovery date | 2004 |
| radial velocity | |
| Orbital characteristics | |
| Periastron | 0.0163 AU |
| Apoastron | 0.0191 AU |
| 0.0177 AU | |
| Eccentricity | 0.081±0.012 |
| 1.3283±1.2e-5 d | |
Average orbital speed | 145 km/s |
| 0.411 mas | |
| 178.5±7.8° | |
| 2452434.88±0.0029 JD | |
| Semi-amplitude | 6114±71 m/s |
| Physical characteristics | |
| Mass | ~16 MJ (most probable) [4] < ~25 MJ [4] |
HD 41004 Bb is a brown dwarf that at the time of the discovery was orbiting closer to the secondary star than any known extrasolar planet or brown dwarf (a=0.0177 AU), at only 145 km/s, because of its low-mass parent star, taking 1.3 days. Its orbit is circular despite the gravitational effect of HD 41004 A because of the tidal effect of the nearby star HD 41004 B. [9] A search for cyclotron radiation from the magnetosphere of Bb in 2020 did not find any, indicating the planet is either weakly magnetized, or the emission cone did not point to Earth at the time of observation. [10]
HD 6434 is a star in the southern constellation of Phoenix. Yellow dwarfs such as this are not very luminous, so at a distance of 138 light years it is not visible to the unaided eye. However, with binoculars it is readily visible under ideal observing conditions, having an apparent visual magnitude of 7.71. The star is drifting further from the Sun with a radial velocity of +23 km/s.
HD 216770 is an 8th-magnitude star located approximately 124 light-years away in the constellation of Piscis Austrinus. It is an orange dwarf, and is somewhat dimmer and cooler than the Sun.
HD 121504 is an 8th magnitude star in the constellation of Centaurus. It is a yellow dwarf and remarkably similar to the Sun, only slightly brighter like α Centauri A. However, it is located at a distance of about 135 light years and thus is not visible to the unaided eye; binoculars or small telescope is required to see this star.
HD 114386 is a 9th magnitude star located approximately 91 light years away in the constellation of Centaurus. It is an orange dwarf, and rather dim compared to the Sun. It can be seen with a telescope or good binoculars.
HD 65216 is a triple star system with two exoplanetary companions in the southern constellation of Carina. With an apparent visual magnitude of 7.97 it cannot be readily seen without technical aid, but with binoculars or telescope it should be visible. The system is located at a distance of 114.7 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 42.6 km/s.
HD 202206 is a binary star system in the southern constellation of Capricornus. With an apparent visual magnitude of +8.1, it is too faint to be visible to the naked eye. It is located at a distance of 150 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +14.7 km/s.
HD 1237 is a binary star system approximately 57 light-years away in the constellation of Hydrus.
HD 11964 is a binary star system located 110 light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. The system is drifting closer to the Sun with a radial velocity of −9 km/s. Two extrasolar planets have been confirmed to orbit the primary.
HD 4113 is a dual star system in the southern constellation of Sculptor. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.88. The distance to this star, as estimated by parallax measurements, is 137 light years. It is receding away from the Sun with a radial velocity of +5 km/s.
HD 156846 is a binary star system in the equatorial constellation of Ophiuchus, positioned a degree SSE of Messier 9. It has a yellow hue and is just barely bright enough to be visible to the naked eye with an apparent visual magnitude of 6.5. The system is located at a distance of 156 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −68.5 km/s, and is predicted to come to within 85.0 light-years in about 476,000 years.
HD 92788 is a star in the equatorial constellation of Sextans. It has a yellow hue but is too dim to be visible to the naked eye, having an apparent visual magnitude of 7.31. The star is located at a distance of 113 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −4.5 km/s. Two planets have been found in orbit around the star.
HD 141937 is a star in the southern zodiac constellation of Libra, positioned a couple of degrees to the north of Lambda Librae. It is a yellow-hued star with an apparent visual magnitude of 7.25, which means it is too faint to be seen with the naked eye. This object is located at a distance of 108.9 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −2.2 km/s. It has an absolute magnitude of 4.71.
HD 142022 is a binary star system located in the southernmost constellation of Octans. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.70. The distance to this system is 112 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s.
HD 178911 is a triple star system with an exoplanetary companion in the northern constellation of Lyra. With a combined apparent visual magnitude of 6.70, it is a challenge to view with the naked eye. The system is located at a distance of approximately 161 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −38 km/s.
HD 196050 is a triple star system located in the southern constellation of Pavo. This system has an apparent magnitude of 7.50 and the absolute magnitude is 4.01. It is located at a distance of 165 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +61 km/s. It is also called by the Hipparcos designation HIP 101806.
HD 213240 is a possible binary star system in the constellation Grus. It has an apparent visual magnitude of 6.81, which lies below the limit of visibility for normal human sight. The system is located at a distance of 133.5 light years from the Sun based on parallax. The primary has an absolute magnitude of 3.77.
HD 162020 is a star in the southern constellation of Scorpius with a likely red dwarf companion. It has an apparent visual magnitude of 9.10, which is too faint to be visible to the naked eye. The distance to this system is 102 light-years based on stellar parallax. It is drifting closer to the Sun with a radial velocity of −27 km/s, and is predicted to come to within ~18 light-years in 1.1 million years.
HD 220689 is a single star in the equatorial constellation of Aquarius. It is a challenge to view with the naked eye, having an apparent visual magnitude of +7.74, but is readily viewed with a pair of binoculars. The star is located at a distance of 153 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s. A survey in 2015 has ruled out the existence of any additional stellar companions at projected distances from 26 to 305 astronomical units.
HD 106515 is a binary star in the constellation of Virgo.
HD 72945 and HD 72946 form a co-moving star system in the northern constellation of Cancer. HD 72945 is a binary star that is dimly visible to the naked eye as a point of light with an apparent visual magnitude of 5.91. At an angular separation of 10.10″ is the fainter companion star HD 72946 at magnitude 7.25. It is being orbited by a brown dwarf. The system as a whole is located at a distance of approximately 84 light years from the Sun based on parallax measurements.
