81 Ceti b

Last updated
81 Ceti b
Discovery
Discovered by Sato et al.
Discovery dateJuly 2, 2008
Doppler Spectroscopy
Orbital characteristics
2.5 AU (370,000,000 km)
Eccentricity 0.206 ± 0.029
952.7 ± 8.8 d
2486 ± 26
175 ± 69
Star 81 Ceti
Physical characteristics
Mean radius
1.14 RJ Estimate
Mass 5.30 MJ [1] [2]

    81 Ceti b (abbreviated 81 Cet b) is an extrasolar planet approximately 331 light years away in the constellation of Cetus. It is estimated to be 5.3 times the mass of Jupiter which also makes it a gas giant. [1] [2] It orbits the G-type giant star 81 Ceti at an average distance of 2.5 AU, taking about 2.6 years to revolve with an eccentricity of 20.6. [3]

    Contents

    Discovery

    The preprint announcing this planet was submitted to the arXiv electronic repository on July 2, 2008, by Bun'ei Sato and collaborators, who discovered it using the Doppler Spectroscopy method, during the Okayama Planet Search radial velocity survey of G and K giants at Okayama Astrophysical Observatory. [3]

    See also

    Related Research Articles

    <span class="mw-page-title-main">Lynx (constellation)</span> Constellation in the northern celestial hemisphere

    Lynx is a constellation named after the animal, usually observed in the Northern Celestial Hemisphere. The constellation was introduced in the late 17th century by Johannes Hevelius. It is a faint constellation, with its brightest stars forming a zigzag line. The orange giant Alpha Lyncis is the brightest star in the constellation, and the semiregular variable star Y Lyncis is a target for amateur astronomers. Six star systems have been found to contain planets. Those of 6 Lyncis and HD 75898 were discovered by the Doppler method; those of XO-2, XO-4, XO-5 and WASP-13 were observed as they passed in front of the host star.

    14 Andromedae, abbreviated 14 And, also named Veritate, is a single, orange-hued giant star situated approximately 247 light-years away in the northern constellation of Andromeda. It is dimly visible to the naked eye with an apparent visual magnitude of 5.22. The star is moving closer to the Earth with a heliocentric radial velocity of −60 km/s. In 2008 an extrasolar planet was discovered to be orbiting the star.

    <span class="mw-page-title-main">Upsilon Andromedae b</span> Extrasolar planet in the Andromeda constellation

    Upsilon Andromedae b, formally named Saffar, is an extrasolar planet approximately 44 light-years away from the Sun in the constellation of Andromeda. The planet orbits the solar analog star, Upsilon Andromedae A, approximately every five days. Discovered in June 1996 by Geoffrey Marcy and R. Paul Butler, it was one of the first hot Jupiters to be discovered. It is also one of the first non-resolved planets to be detected directly. Upsilon Andromedae b is the innermost-known planet in its planetary system.

    <span class="mw-page-title-main">Upsilon Ceti</span> Star in the constellation Cetus.

    Upsilon Ceti, Latinized from υ Ceti, is a solitary star in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 3.95. Based upon an annual parallax shift of 11.14 mas, it is located about 293 light years from the Sun.

    HD 167042 is a 6th magnitude K-type subgiant star located approximately 164 light-years away in Draco constellation. It has mass of 1.88 times that of the Sun and the age is only 1.8 billion years old. When this star was a main sequence, it was white mid to late A-type star based on its mass.

    HD 104985, formally named Tonatiuh, is a solitary star with a exoplanetary companion in the northern constellation of Camelopardalis. The companion is designated HD 104985 b and named Meztli. This star has an apparent visual magnitude of 5.78 and thus is dimly visible to the naked eye under favorable seeing conditions. It is located at a distance of approximately 329 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −20 km/s.

    Xi Aquilae b, formally named Fortitudo, is an extrasolar planet approximately 184 light-years from the Sun in the constellation of Aquila. The planet was discovered orbiting the yellow giant star Xi Aquilae in 2008. The planet has a minimum mass of 2.8 Jupiter and a period of 137 days.

    41 Lyncis b, also designated HD 81688 b and named Arkas, is an extrasolar planet approximately 280 light-years from Earth in the constellation of Ursa Major.

    <span class="mw-page-title-main">18 Delphini b</span> Extrasolar planet in the constellation Delphinus

    18 Delphini b, formally named Arion, is an extrasolar planet approximately 249 light-years away in the constellation of Delphinus.

    HD 104985 b, also named Meztli, is an extrasolar planet approximately 97 parsecs (317 lys) from the SunThe 198-day period planet orbits the yellow giant star HD 104985 (Tonatiuh) at a distance of 0.78 AU. With a mass 61/3 times Jupiter it is a gas giant.

    41 Lyncis, also designated HD 81688 and named Intercrus, is a fifth-magnitude star located in the northern constellation of Ursa Major. An extrasolar planet is thought to be orbiting the star.

    18 Delphini, also named Musica, is a single star in the constellation of Delphinus of the low northern hemisphere. It has a Sun-like golden hue and is faintly visible to the naked eye with an apparent visual magnitude of 5.506. The star is located at a distance of approximately 249 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +4 km/s. An object believed to be an extrasolar planet orbits the star.

    <span class="mw-page-title-main">14 Andromedae b</span> Extrasolar planet in Andromeda constellation

    14 Andromedae b, formally named Spe, is an exoplanet approximately 249 light years away in the constellation of Andromeda.

    81 Ceti is a star located approximately 331 light years away from the Sun in the equatorial constellation of Cetus. 81 Ceti is the Flamsteed designation for this object. It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.65. The star is drifting further away from the Earth with a heliocentric radial velocity of +9 km/s.

    6 Lyncis is a star in the northern constellation of Lynx, located approximately 179 light years from Earth. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.86. This object is moving away from the Earth with a heliocentric radial velocity of +40 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.341 arc seconds per annum.

    <span class="mw-page-title-main">6 Lyncis b</span> Exoplanet orbiting the star 6 Lyncis

    6 Lyncis b is an extrasolar planet orbiting the K-type subgiant star 6 Lyncis which is approximately 182 light years away in the Lynx constellation. The planet has a minimum mass 2.4 MJ. The orbital period for this planet is 899 days, or 2.46 years. The orbital radius for this planet is 2.2 AU, periastron 1.9 AU, and apastron 2.5 AU, corresponding to the orbital eccentricity of 0.134. This planet was discovered on July 3, 2008 by Sato et al., who used Doppler spectroscopy to find variations of the line of sight motion of the star caused by the planet’s gravity during its orbit.

    The Okayama Planet Search Program (OPSP) was started in 2001 with the goal of spectroscopically searching for planetary systems around stars. It reported on the detection of 3 new extrasolar planets:, around intermediate-mass G and K giants 18 Delphini, Xi Aquilae, and HD 81688. Also, it updated the orbital parameters of HD 104985 b, the first planet discovered around the G giants from the survey, by using the data collected during the past six years. Since 2001, it has been conducting a precise Doppler survey of about 300 G and K giants using a 1.88m telescope, the High Dispersion Echelle Spectrograph (HIDES), and an iodine absorption cell I2 cell at the Okayama Astrophysical Observatory (OAO).

    <span class="mw-page-title-main">Chi Piscium</span> Yellow-hued giant star in the constellation Pisces

    Chi Piscium (χ Piscium) is a solitary, orange-hued star in the zodiac constellation of Pisces. It can be seen with the naked eye, having an apparent visual magnitude of +4.64. Based upon an annual parallax shift of 8.50 mas as seen from Earth, it is located about 384 light years from the Sun.

    75 Ceti is a single star in the equatorial constellation of Cetus with at least two planets. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.36. The star is located 268 light-years distant from the Sun, based on parallax, but is drifting closer with a radial velocity of −6 km/s.

    HD 5608 is an orange-hued star in the northern constellation of Andromeda with one known planet, HD 5608 b. It is a dim star near the lower limit of visibility to the naked eye, having an apparent visual magnitude of +5.98. The distance to HD 5608, as estimated from an annual parallax shift of 17.07 mas, is 191 light-years. It is moving closer to the Earth with a heliocentric radial velocity of −23 km/s, and is expected to make its closest approach in 1.285 million years when it comes to within 124 light-years.

    References

    1. 1 2 NASA 7012
    2. 1 2 81 Ceti b
    3. 1 2 Sato, Bun'ei; et al. (2008). "Planetary Companions to Evolved Intermediate-Mass Stars: 14 Andromedae, 81 Ceti, 6 Lyncis, and HD167042". Publications of the Astronomical Society of Japan. 60 (6): 1317–1326. arXiv: 0807.0268 . Bibcode:2008PASJ...60.1317S. doi:10.1093/pasj/60.6.1317.