HD 38529

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**HD 38529 A / B**
Observation data Equinox J2000.0
Constellation	Orion
Right ascension	05^h 46^m 34.9120^s
Declination	+01° 10' 05.496"
Apparent magnitude (V)	+5.94 / +13.35
Characteristics
Spectral type	G4IV / M3.0V
U-B color index	? / ?
B-V color index	0.773 / 0.46
Variable type	none / ?
Astrometry
Radial velocity (R_v)	28.9 km/s
Proper motion (μ)	RA: -80.05 mas/yr Dec.: -141.79 mas/yr
Parallax (π)	23.57 ± 0.92 mas
Distance	138 ± 5 ly (42 ± 2 pc)
Absolute magnitude (M_V)	+2.81 / ?
Details
Mass	1.39 / ? M_☉
Radius	2.82 / ? R_☉
Luminosity	? / ? L_☉
Temperature	5370 / ? K
Metallicity	0.29 ± 0.05 [Fe/H]
Rotation	34.5 / ?
Age	~3700 million years
Other designations
HR 1988, BD+01°1126, HIP 27253

HD 38529 (also known as HR 1988) is a binary star located about 138 light-years away in the constellation Orion.

1 HD 38529 A
- 1.1 HD 38529 Ab
- 1.2 HD 38529 Ac
2 HD 38529 B
3 See also
4 References
5 External links

[edit] HD 38529 A

HD 38529 A is a yellow subgiant star, which has also been classified as a main sequence dwarf of spectral type G4V. It is about 40% more massive than our Sun. Two substellar companions are known in orbit around this star, including one brown dwarf.

[edit] HD 38529 Ab

**HD 38529 Ab**
Orbital elements

Semi-major axis a:	0.129 AU
Eccentricity e:	0.29 (± 0.02)
Orbital period P:	14.309 (± 0.05) d
Inclination i:	?°
Longitude of periastron ω:	87.7 (± 4)°
Time of periastron τ:	2,450,005.8 (± 1.5) JD
Physical characteristics
Mass:	>0.78 M_J
Radius:	? R_J
Density:	? kg/m³
Temperature:	? K
Discovery
Discovery date:	2000
Detection method(s):	Doppler Spectroscopy
Discoverer(s):	Marcy et al.

HD 38529 Ab is an extrasolar planet discovered in 2000. Because of its mass, it is likely that it is a gas giant.

[edit] HD 38529 Ac

**HD 38529 Ac**
Orbital elements

Semi-major axis a:	3.68 AU
Eccentricity e:	0.36 ± 0.05
Orbital period P:	2174.3 ± 30 d
Inclination i:	160°
Longitude of periastron ω:	14.7 ± 10°
Time of periastron τ:	2,450,073.8 ± 35 JD
Physical characteristics
Mass:	37⁺³⁶_-19 M_J
Radius:	? R_J
Density:	? kg/m³
Temperature:	? K
Discovery
Discovery date:	2002
Detection method(s):	Doppler Spectroscopy
Discoverer(s):	Marcy et al.

HD 38529 Ac is a brown dwarf companion to HD 38529 A. Radial velocity measurements give a minimum mass of 12.7 times that of Jupiter, close to the brown dwarf limit at 13 Jupiter masses. Astrometric measurements from the Hipparcos mission give a best fit inclination of 160° and a mass 37 times that of Jupiter.

[edit] HD 38529 B

HD 38529 B is a common proper motion stellar companion to HD 38529 A at a projected distance of about 12042 AU. The star is a red dwarf of spectral type M3.0V.

[edit] See also

[edit] References

Fischer, D., Marcy, G., Butler, R., Vogt, S., Frink, S., Apps, K. (2001). "Planetary Companions to HD 12661, HD 92788, and HD 38529 and Variations in Keplerian Residuals of Extrasolar Planets". The Astrophysical Journal 551: 1107 – 1118.
Fischer et al. (2003). "A Planetary Companion to HD 40979 and Additional Planets Orbiting HD 12661 and HD 38529". The Astrophysical Journal 586: 1394-1408.
Reffert, S., Quirrenbach, A. (2006). "Hipparcos astrometric orbits for two brown dwarf companions: HD 38529 and HD 168443". Astronomy and Astrophysics 449: 699 – 702.
Raghavan, D. et al. (2006). "Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems" (preprint)

[edit] External links

HD 38529. SIMBAD. Retrieved on April 14, 2007.
Notes for star HD 38529. The Extrasolar Planets Encyclopaedia. Retrieved on April 14, 2007.
John Whatmough. HD 38529. Extrasolar Visions. Retrieved on April 14, 2007.