14 Herculis b or 14 Her b is an exoplanet approximately 58.5 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.[4][5] At the time of discovery it was the extrasolar planet with the longest orbital period, though longer-period planets have subsequently been discovered.

14 Herculis b

The exoplanet 14 Herculis b (min mass ~4.6 MJ) as rendered by Celestia.
Discovery[1]
Discovered by	Naef et al.
Discovery site	Switzerland
Discovery date	6 July 1998
Detection method	Doppler spectroscopy
Orbital characteristics[2]
Semi-major axis	2.845+0.038 −0.039 AU
Eccentricity	0.3686+0.0032 −0.0031
Orbital period (sidereal)	4.8277+0.0022 −0.0023 yr
Inclination	32.7+5.3 −3.2
Longitude of ascending node	236±15
Time of periastron	2456667.4+2.3 −2.2
Argument of periastron	22.78+0.53 −0.55
Semi-amplitude	90.0 ± 0.5[3]
Physical characteristics[2]
Mass	9.1+1.0 −1.1 MJ

Discovery

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.[5]

Orbit and mass

Preliminary astrometric measurements made by the Hipparcos satellite suggested 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.[6] According to a 2008 paper, its inclination was being calculated via astrometry with Hubble, with publication expected by mid-2009.[7]

The inclination and true mass of 14 Herculis b were finally measured in 2021, using data from Gaia. The inclination is 32.7°, corresponding to a true mass of 9.1 M_J.[2]

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 of the planet and host star will be large enough that the light from the planet and star might be spatially resolved. However, a search made using the adaptive optics CFHT 3.60m telescope on Mauna Kea did not make such a detection, confirming the object is not a star.[1]

References

External links

• Jean Schneider (2011). "Notes for Planet 14 Her b". Extrasolar Planets Encyclopaedia. Retrieved 30 September 2011.
• "14 Herculis". SolStation. Archived from the original on 19 July 2008. Retrieved 25 June 2008.

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[de] 14 Herculis b

[es] 14 Herculis b

[ru] 14 Геркулеса b