HD 170469

From Wikipedia, the free encyclopedia

**HD 170469**
Observation data Epoch J2000.0
Constellation (pronunciation)	Ophiuchus
Right ascension	18^h 29^m 11^s
Declination	+11º 41' 44"
Apparent magnitude (V)	8.21
Distance	211.91 ly (64.97 pc)
Spectral type	G5IV
Other designations
BD +11º3479, SAO 103765, HIP 90593

HD 170469 is a yellow subgiant star in the constellation Ophiuchus. It has apparent magnitude +8.21 and it is 211.91 ly away.

In 2007, the planet was discovered by using N2K Consortium by Fischer.

[edit] HD 170469 b

**HD 170469**
Orbital elements
Extrasolar planet		List of extrasolar planets
Semimajor axis	(a)	2.07 AU
Eccentricity	(e)	0.36
Orbital period	(P)	1143 d
Angular distance	(θ)	30.783 mas
Longitude of periastron	(ω)	73 ± 19°
Time of periastron	(T₀)	2,451,826 ± 4 JD
Semi-amplitude	(K)	23.8 m/s
Physical characteristics
Mass	(m)	>0.67 M_J
Discovery information
Discovery date		April 10, 2007
Discoverer(s)		Fischer et al.
Detection method		Radial velocity
Discovery status		Published

HD 170469 b is a gas giant planet orbiting HD 170469. It is 67% the mass of Jupiter. The mass value is only minimum since if inclination is unknown.

The orbital distance is more than twice the distance from Earth to the Sun, although taking over three Earth years to orbit the star. The combined distance and period would make orbital velocity of 19.1 km/s, slower than Earth's 29.8 km/s. However, the orbit is very eccentric, meaning the orbital distance and orbital velocity can vary drastically. At periastron, the distance is 1.32 AU and velocity of 22.3 km/s. At apastron, the distance is 2.82 AU and velocity of 16.4 km/s. This type of Jupiter-like planet is called eccentric Jupiter.