14 Herculis b

Planetbox begin
name = 14 Herculis bPlanetbox image


caption = An artist's impression of 14 Herculis bPlanetbox star
star = 14 Herculis
constell = Hercules
RA = RA|16|10|23.59
DEC = DEC|+43|49|18.2
dist_ly = 59.0
dist_pc = 18.1
class = K0VPlanetbox orbit
semimajor = 2.77 ± 0.05cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2007ApJ...654..625W&db_key=AST&nosetcookie=1 |author=Wittenmyer, R. A., Endl, M., Cochran, W. D.|title=Long-Period Objects in the Extrasolar Planetary Systems 47 Ursae Majoris and 14 Herculis|journal=The Astrophysical Journal|volume=654|issue=1|pages=625 – 632|year=2007|doi=10.1086/509110]
eccentricity = 0.369 ± 0.005
period = 1773.4 ± 2.5
ang_dist = 153
long_peri = 22.6 ± 0.9
t_peri = 2,451,372.7 ± 3.6
semi-amp = 90.0 ± 0.5 Planetbox character
mass = >4.64 ± 0.19 Planetbox discovery
discovery_date = 6 July 1998
discoverers = Naef et al.
discovery_method = Doppler spectroscopy
discovery_site = flag|Switzerland
discovery_status = Published

14 Herculis b is an extrasolar planet approximately 59 light-years away in the constellation of Hercules. The planet was found orbiting the star 14 Herculis, with a mass that would likely make the planet a Jovian planet roughly the same size as Jupiter but much more massive. It was discovered in July 1998 by the Geneva Extrasolar Planet Search team. [cite conference|author=Mayor, M. et al.|title=Searching for giant planets at the Haute-Provence Observatory|conference=IAU Colloqu. 170|booktitle=Precise Stellar Radial Velocities|editor=(ed. Hearnshaw, J. B. and Scarfe, C. D.)|date=1998|publisher=ASP|location=San Francisco] cite web | url=http://obswww.unige.ch/Preprints/Preprints/naef_cs11.ps.gz | author=Dominique Naef, Michel Mayor, Jean-Luc Beuzit, Christian Perrier, Didier Queloz, Jean-Pierre Sivan, and Stephane Udry | title=Extrasolar Planetary Systems or Spectroscopic Binaries? Discrimination using Spectral Line Properties | | accessdate=2007-09-10] At the time of discovery was the extrasolar planet with the longest orbital period, though longer-period planets have subsequently been discovered.

Discovery

Like the majority of known extrasolar planets, 14 Herculis b was detected by measuring variations in its star's radial velocity as a result of the planet's gravity. This was done by making precise measurements of the Doppler shift of the spectrum of 14 Herculis. Prior to this analysis, another possible explanation of previous Doppler shift analysis included face-on spectroscopic binaries.

Orbit and mass

Preliminary astrometric measurements made by the Hipparcos satellite suggest that this planet has an orbital inclination of 155.3° with respect to plane of the sky, which would imply a true mass of 11.1 times that of Jupiter, close to the deuterium-burning threshold that some astronomers use to define the distinction between a planet and a brown dwarf. However subsequent analysis suggests that the Hipparcos measurements were not precise enough to accurately determine the orbits, so the actual inclination and true mass of the planet remains unknown. [cite journal|url=http://adsabs.harvard.edu/abs/2001A%26A...372..935P|title=Screening the Hipparcos-based astrometric orbits of sub-stellar objects|author=Pourbaix, D. and Arenou, F.|journal=Astronomy and Astrophysics|volume=372|pages=935 – 944|year=2001|doi=10.1051/0004-6361:20010597] Its inclination is being calculated via astrometry with Hubble. The astrometricians expect publication by mid 2009. [cite arXiv | title=HST FGS astrometry - the value of fractional millisecond of arc precision | author=G. Fritz Benedict, Barbara E. McArthur, and Jacob L. Bean |class=astro-ph |eprint=0803.0296v1 |year=2008, for "HD 145675 b"] It may also be targeted by future astrometric missions such as Gaia and the Space Interferometry Mission.

Direct imaging

Because of the wide separation between this planet and its host star, and the proximity of the 14 Herculis system to the Sun, it is a promising candidate for direct imaging of the planet, as the angular separation is predicted to be large. However, a search made using the adaptive optics CFHT 3.60m telescope on Mauna Kea did not make such a detection, suggesting the object is not a star or a brown dwarf, but of planetary mass (more massive objects would be more luminous and hence easier to detect). [cite web|url=http://www.obs-hp.fr/www/nouvelles/14her.html|title=14 Herculis: A new extrasolar planet discovered at the Haute Provence Observatory|accessdate=2007-07-28] Future space missions such as New Worlds Mission can directly image this planet and determine its radius, mass, orbit, and atmospheric characteristics.

See also

* 14 Herculis c

References

External links

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