HD 177830 b

Planetbox begin
name=HD 177830 bPlanetbox star
star = HD 177830
constell = Lyra
RA=RA|19|05|20.7735
DEC=DEC|+25|55|14.379
dist_ly=192.54
dist_pc=59.06
class=K0Planetbox orbit
semimajor=1.227±0.071
semimajor_gigameter = 183.6
periastron = 1.110
periastron_gigameter = 166.1
apastron = 1.344
apastron_gigameter = 201.1
eccentricity=0.096±0.048
period=410.1±2.2
period_year = 1.123
period_megasecond = 35.43
speed = 32.65
ang_dist=17
long_peri=189
t_peri=2,450,254±42
semi-amp=32.64±0.98Planetbox character
mass=>1.53±0.13
radius = ~1.165
density = ~1280
gravity_earth = ~2.98
gravity = ~29.2
temperature = ~342Planetbox discovery
discovery_date=November 14, 1999
discovery_site=California, USA
discovery_method=Doppler spectroscopy
discoverers=Vogt, Marcy
Butler, Apps "et al"
discovery_status=PublishedPlanetbox catalog
names = Gliese 743.2 b, HIP 93746 b

HD 177830 b is an extrasolar planet located approximately 193 light-years away in the constellation of Lyra, orbiting the star HD 177830. It was discovered in 1999 by the California and Carnegie Planet Search team using the very successful radial velocity method. The planet has a minimum mass of 1.53 times that of Jupiter. Since the inclination of the planet's orbit is not known, its true mass is likely to be somewhat more. Although not detected directly, the planet is certainly a gas giant.

Mean distance from the star is 23% greater than Earth's distance from the Sun. The orbit is nearly circular with distance ranges from 1.110 AU (periastron) to 1.334 AU (apoastron). Because the star is 4.78 times more luminous than the Sun, the planet must be hotter than Earth, at around 342 K.

In 2000 a group of scientists proposed, based on preliminary "Hipparcos" astrometrical satellite data, that the orbital inclination is as little as 1.3°. If that was the case, the planet would have a mass of 67 times that of Jupiter making it a brown dwarf instead of a planet. However, it is very unlikely that the planet would have such orbit. Furthermore, brown dwarfs with short orbits around solar-mass stars are exceedingly rare (the so-called "brown dwarf desert") making the claim even more unlikely.

ee also

* HD 177830 c

References

*cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/308981 | author=Vogt "et al." | title=Six New Planets from the Keck Precision Velocity Survey | journal=The Astrophysical Journal | year=2000 | volume=536 | issue=2 | pages=902 – 914 | doi=10.1086/308981
*cite journal | url=http://www.journals.uchicago.edu/doi/abs/10.1086/504701 | author=Butler "et al." | title=Catalog of Nearby Exoplanets | journal=The Astrophysical Journal | volume=646 | issue=1 | pages=505 – 522 | year=2006 | doi=10.1086/504701 | format=abstract ( [http://xxx.lanl.gov/abs/astro-ph?papernum=0607493 web Preprint] )

External links

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