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HD 28185 b

2007 Schools Wikipedia Selection. Related subjects: Space (Astronomy)

   CAPTION: HD 28185 b

     Extrasolar planet    Lists of extrasolar planets
                      Parent star
   Star                   HD 28185
   Constellation          Eridanus
   Right ascension    (α) 04^h 26^m 26.3205^s
   Declination        (δ) −10° 33′ 02.955″
   Spectral type          G5V
                   Orbital elements
   Semimajor axis     (a) 1.031 ± 0.060 AU
   Eccentricity       (e) 0.070 ± 0.040
   Orbital period     (P) 383.0 ± 2.0 d
   Inclination        (i)  ?°
   Longitude of
   periastron         (ω) 351 ± 25°
   Time of periastron (τ) 2,451,863 ± 26 JD
               Physical characteristics
   Mass               (m) >5.72 ± 0.93 M[J]
   Radius             (r)  ? R[J]
   Density            (ρ)  ? kg/ m^3
   Temperature        (T)  ? K
                 Discovery information
   Discovery date         2001
   Discoverer(s)          Santos et al.
   Detection method       Radial velocity
   Discovery status       Confirmed

   HD 28185 b is an extrasolar planet orbiting the Sun-like star HD 28185.
   The planet is located in a near-circular orbit in its star's habitable
   zone. HD 28185 b was discovered in 2001 as a part of the CORALIE survey
   for southern extrasolar planets.

Discovery

   Like the majority of known extrasolar planets, HD 28185 b was
   discovered by detecting small periodic variations in the radial
   velocity of its parent star caused by the gravitational attraction of
   the planet. This was achieved by measuring the Doppler shift of the
   star's spectrum. In 2001 it was announced that HD 28185 exhibited a
   wobble along the line of sight with a period of 383 days, with an
   amplitude indicating a mass 5.72 times that of Jupiter.

Orbit and mass

   HD 28185 b takes 1.04 years to orbit its parent star. Unlike most known
   long- period planets, the orbit of HD 28185 b has a low eccentricity,
   comparable to that of Mars in our solar system. The orbit lies entirely
   within its star's habitable zone.

   The amplitude of the radial velocity oscillations means that the planet
   has a mass at least 5.7 times that of Jupiter in our solar system.
   However, the radial velocity method only yields a minimum value on the
   planet's mass, depending on the orbital inclination to our line of
   sight. Therefore the true mass of the planet may be much greater than
   this lower limit.

Characteristics

   Given the planet's high mass, it is most likely to be a gas giant with
   no solid surface. Since the planet has only been detected indirectly
   through observations of the star, properties such as its radius,
   composition and temperature are unknown.

   Since HD 28185 b orbits in its star's habitable zone, some have
   speculated on the possibility of life on worlds in the HD 28185 system.
   While it is unknown whether gas giants can support life, simulations of
   tidal interactions suggest that HD 28185 b could harbour Earth-mass
   satellites in orbit around it for many billions of years. Such moons,
   if they exist, may be able to provide a habitable environment, though
   it is unclear whether such satellites would form in the first place.
   Additionally, a small planet in one of the gas giant's Trojan points
   could survive in a habitable orbit for long periods.

   Retrieved from " http://en.wikipedia.org/wiki/HD_28185_b"
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   with only minor checks and changes (see www.wikipedia.org for details
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