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| epoch = J2000.0
| epoch = J2000.0
| constell = [[Cetus]]
| constell = [[Cetus]]
| ra = {{RA|02|32|09.42277}}<ref name=GaiaDR2/>
| ra = {{RA|02|32|09.42241}}<ref name=GaiaDR3/>
| dec = {{DEC|-01|02|05.6245}}<ref name=GaiaDR2/>
| dec = {{DEC|-01|02|05.6166}}<ref name=GaiaDR3/>
| appmag_v = +5.36<ref name=Anderson2012/>
| appmag_v = +5.36<ref name=Anderson2012/>
}}
}}
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}}
}}
{{Starbox astrometry
{{Starbox astrometry
| radial_v = {{Val|−6.21|0.13}}<ref name=GaiaDR2/>
| radial_v = {{val|−6.34|0.13}}<ref name=GaiaDR3/>
| prop_mo_ra = −23.619<ref name=GaiaDR2/>
| prop_mo_ra = −23.268
| prop_mo_dec = −30.485<ref name=GaiaDR2/>
| prop_mo_dec = −30.987
⚫
| pm_footnote = <ref name=GaiaDR3/>
| parallax = 12.0264
| p_error = 0.1044
| parallax = 12.1717
| p_error = 0.0962
⚫
| parallax_footnote = <ref name=GaiaDR2/>
| parallax_footnote = <ref name=GaiaDR3/>
| absmag_v = 0.808<ref name=Liu2007/>
| absmag_v = 0.808<ref name=Liu2007/>
}}
}}
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| gravity = {{Val|2.67|0.04}}<ref name=Gallenne2018/>
| gravity = {{Val|2.67|0.04}}<ref name=Gallenne2018/>
| temperature = {{Val|4846|163|128|fmt=commas}}<ref name=GaiaDR2/>
| temperature = {{Val|4846|163|128|fmt=commas}}<ref name=GaiaDR2/>
| radius = {{Val|10.62|0.68|0.58}}<ref name=GaiaDR2/>
| radius = {{val|10.38|0.15|0.26}}<ref name="Teng2023"/>
| luminosity = {{Val|56.1|0.6}}<ref name=GaiaDR2/>
| luminosity = {{Val|56.1|0.6}}<ref name=GaiaDR2/>
}}
}}
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{{Starbox end}}
{{Starbox end}}


'''75 Ceti''' is a single<ref name=Eggleton2008/> [[star]] in the [[celestial equator|equatorial]] [[constellation]] of [[Cetus]] with at least one planet.<ref name="Sato2012"/> It is visible to the naked eye as a dim, orange-hued star with an [[apparent visual magnitude]] of +5.36.<ref name=Anderson2012/> The star is located 271&nbsp;[[light year]]s distant from the Sun, based on [[stellar parallax|parallax]], but is drifting closer with a [[radial velocity]] of −6&nbsp;km/s.<ref name=GaiaDR2/>
'''75 Ceti''' is a single<ref name=Eggleton2008/> [[star]] in the [[celestial equator|equatorial]] [[constellation]] of [[Cetus]] with at least two planets.<ref name="Teng2023"/> It is visible to the naked eye as a dim, orange-hued star with an [[apparent visual magnitude]] of +5.36.<ref name=Anderson2012/> The star is located {{convert|268|ly|pc|lk=on|abbr=off}} distant from the Sun, based on [[stellar parallax|parallax]], but is drifting closer with a [[radial velocity]] of −6&nbsp;km/s.<ref name=GaiaDR3/>


In [[Chinese language|Chinese]], {{lang|zh|天囷}} ({{lang|zh-Latn|Tiān Qūn}}), meaning ''[[Stomach (Chinese constellation)|Circular Celestial Granary]]'', refers to an asterism consisting of [[Alpha Ceti|α Ceti]], [[Kappa1 Ceti|κ<sup>1</sup> Ceti]], [[Lambda Ceti|λ Ceti]], [[Mu Ceti|μ Ceti]], [[Xi1 Ceti|ξ<sup>1</sup> Ceti]], [[Xi2 Ceti|ξ<sup>2</sup> Ceti]], [[Nu Ceti|ν Ceti]], [[Gamma Ceti|γ Ceti]], [[Delta Ceti|δ Ceti]], 75 Ceti, [[70 Ceti]], [[63 Ceti]] and [[66 Ceti]]. Consequently, 75 Ceti itself is known as the Tenth Star of Circular Celestial Granary.<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060711.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日]</ref>
In [[Chinese language|Chinese]], {{lang|zh|天囷}} ({{lang|zh-Latn|Tiān Qūn}}), meaning ''[[Stomach (Chinese constellation)|Circular Celestial Granary]]'', refers to an asterism consisting of [[Alpha Ceti|α Ceti]], [[Kappa1 Ceti|κ<sup>1</sup> Ceti]], [[Lambda Ceti|λ Ceti]], [[Mu Ceti|μ Ceti]], [[Xi1 Ceti|ξ<sup>1</sup> Ceti]], [[Xi2 Ceti|ξ<sup>2</sup> Ceti]], [[Nu Ceti|ν Ceti]], [[Gamma Ceti|γ Ceti]], [[Delta Ceti|δ Ceti]], 75 Ceti, [[70 Ceti]], [[63 Ceti]] and [[66 Ceti]]. Consequently, 75 Ceti itself is known as the Tenth Star of Circular Celestial Granary.<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060711.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日]</ref>
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This is an aging [[giant star]] with a [[stellar classification]] of K1&nbsp;III,<ref name=Houk1999/> having exhausted the supply of hydrogen at its [[stellar core|core]] and expanded to 10.6<ref name=GaiaDR2/> times the [[Sun's radius]], or {{Convert|10.6|solar radius|AU|2|disp=out|lk=on}}. It is a [[red clump]] giant,<ref name=Gallenne2018/> which indicates it is on the [[horizontal branch]] and is generating energy through [[helium fusion]] at the core. The star is 1.4<ref name=Gallenne2018/>&nbsp;billion years old with 1.9<ref name=Gallenne2018/> times the [[Sun's mass]]. It is radiating 56<ref name=GaiaDR2/> times the [[luminosity of the Sun]] from its swollen [[photosphere]] at an [[effective temperature]] of 4,846&nbsp;K.<ref name=GaiaDR2/>
This is an aging [[giant star]] with a [[stellar classification]] of K1&nbsp;III,<ref name=Houk1999/> having exhausted the supply of hydrogen at its [[stellar core|core]] and expanded to 10.6<ref name=GaiaDR2/> times the [[Sun's radius]], or {{Convert|10.6|solar radius|AU|2|disp=out|lk=on}}. It is a [[red clump]] giant,<ref name=Gallenne2018/> which indicates it is on the [[horizontal branch]] and is generating energy through [[helium fusion]] at the core. The star is 1.4<ref name=Gallenne2018/>&nbsp;billion years old with 1.9<ref name=Gallenne2018/> times the [[Sun's mass]]. It is radiating 56<ref name=GaiaDR2/> times the [[luminosity of the Sun]] from its swollen [[photosphere]] at an [[effective temperature]] of 4,846&nbsp;K.<ref name=GaiaDR2/>


==Planetary system==
The planetary companion was discovered by [[Doppler spectroscopy|Doppler measurements]] at the [[Okayama Planet Search Program|Okayama Astrophysical Observatory]], and announced in 2012. The planet's discoverers consider the planet, designated '''75 Ceti b''', to be "typical" of [[gas giant]]s.<ref name="Sato2012"/> Note that (like many recorded planets) b takes in much more [[insolation]] than does Jupiter and, indeed, Earth.<ref>Square root of luminosity means that an Earth like planet would have to be >7 AU from the star.</ref>
A planetary companion was discovered by [[Doppler spectroscopy|Doppler measurements]] at the [[Okayama Planet Search Program|Okayama Astrophysical Observatory]], and announced in 2012. The planet's discoverers consider the planet, designated 75 Ceti b, to be "typical" of [[gas giant]]s.<ref name="Sato2012"/> Note that (like many recorded planets) b takes in much more [[insolation]] than does Jupiter and, indeed, Earth.<ref>Square root of luminosity means that an Earth like planet would have to be >7 AU from the star.</ref>

There may be additional periodic factors in the data, corresponding to ''m'' sin ''i'' of around {{Jupiter mass|0.4}} and {{Jupiter mass|1}}, at distances of ~0.9 AU and ~4 AU, where ''i'' is the [[orbital inclination]] and ''m'' is the planet's actual mass.<ref name="Sato2012"/> In 2023, the presence of a second, Jupiter-mass planet orbiting at 4 AU (75 Ceti c) was confirmed, which is more irradiated than Earth as well. The shorter period signal corresponding to a possible planet at 0.9 AU was found to be an alias of the true period of planet c.<ref name="Teng2023"/>


{{OrbitboxPlanet begin
{{OrbitboxPlanet begin
| table_ref = <ref name="Sato2012"/>
| table_ref = <ref name="Teng2023"/>
| period_unit = day
| period_unit = day
}}
}}
{{OrbitboxPlanet
{{OrbitboxPlanet
| exoplanet = b
| exoplanet = b
| semimajor = 2.1
| semimajor = {{val|1.912|0.002|0.003}}
| eccentricity = {{Val|0.117|0.048}}
| eccentricity = {{val|0.093|0.026|0.042}}
| period = {{Val|691.9|3.6}}
| period = {{val|696.62|1.33|1.69}}
| mass = >3
| mass = {{val|2.479|0.074|0.090|p=≥}}
}}
}}
{{OrbitboxPlanet
| exoplanet = c
| semimajor = {{val|3.929|0.058|0.052}}
| eccentricity = {{val|0.023|0.191|0.003}}
| period = {{val|2051.62|45.98|40.47}}
| mass = {{val|0.912|0.088|0.143|p=≥}}
}}
{{Orbitbox end}}
{{Orbitbox end}}

There may be additional periodic factors in the data, corresponding to ''m'' sin ''i'' of around
{{Jupiter mass|0.4}} and {{Jupiter mass|1}}, at distances of ~0.9 AU and ~4 AU, where ''i'' is the [[orbital inclination]] and ''m'' is the planet's actual mass. If these additional companions are confirmed, they are more irradiated than Earth as well.


==References==
==References==
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<ref name=GaiaDR2>{{Cite Gaia DR2|2500064286492779264}}</ref>
<ref name=GaiaDR2>{{Cite Gaia DR2|2500064286492779264}}</ref>
<ref name=GaiaDR3>{{Cite Gaia DR3|2500064286492779264}}</ref>


<ref name=Gallenne2018>{{cite journal
<ref name=Gallenne2018>{{cite journal
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| volume=64 | issue=6 | at=135 | year=2012
| volume=64 | issue=6 | at=135 | year=2012
| arxiv=1207.3141 | bibcode=2012PASJ...64..135S | doi=10.1093/pasj/64.6.135 | s2cid=119197073 }}</ref>
| arxiv=1207.3141 | bibcode=2012PASJ...64..135S | doi=10.1093/pasj/64.6.135 | s2cid=119197073 }}</ref>

<ref name="Teng2023">{{cite journal |last1=Teng |first1=Huan-Yu |last2=Sato |first2=Bun'ei |display-authors=etal |date=August 2023 |title=Revisiting Planetary Systems in Okayama Planet Search Program: A new long-period planet, RV astrometry joint analysis, and multiplicity-metallicity trend around evolved stars |journal=[[Publications of the Astronomical Society of Japan]] |volume= |issue= |pages= |doi= |arxiv=2308.05343}}</ref>


}}
}}
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[[Category:K-type giants]]
[[Category:K-type giants]]
[[Category:Horizontal-branch stars]]
[[Category:Horizontal-branch stars]]
[[Category:Planetary systems with one confirmed planet]]
[[Category:Planetary systems with two confirmed planets]]
<!-- Catalogues -->
<!-- Catalogues -->
[[Category:Bayer objects|Ceti, 75]]
[[Category:Bayer objects|Ceti, 75]]
[[Category:Cetus]]
[[Category:Cetus]]
[[Category:Durchmusterung objects]]
[[Category:Durchmusterung objects|BD-01 0353]]
[[Category:Flamsteed objects|Ceti, 75]]
[[Category:Flamsteed objects|Ceti, 75]]
[[Category:Hipparcos objects|011791]]
[[Category:Hipparcos objects|011791]]
[[Category:Henry Draper Catalogue objects|015779]]
[[Category:Henry Draper Catalogue objects|015779]]
[[Category:Bright Star Catalogue objects|0739]]
[[Category:Bright Star Catalogue objects|0739]]
[[Category:TIC objects]]
[[Category:TIC objects|251095345]]

Revision as of 17:42, 11 August 2023

75 Ceti
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension 02h 32m 09.42241s[1]
Declination −01° 02′ 05.6166″[1]
Apparent magnitude (V) +5.36[2]
Characteristics
Spectral type K1 III[3]
B−V color index +1.004±0.002[2]
Astrometry
Radial velocity (Rv)−6.34±0.13[1] km/s
Proper motion (μ) RA: −23.268 mas/yr[1]
Dec.: −30.987 mas/yr[1]
Parallax (π)12.1717 ± 0.0962 mas[1]
Distance268 ± 2 ly
(82.2 ± 0.6 pc)
Absolute magnitude (MV)0.808[4]
Details
Mass1.85±0.05[5] M☉
Radius10.38+0.15
−0.26[6] R☉
Luminosity56.1±0.6[7] L☉
Surface gravity (log g)2.67±0.04[5] cgs
Temperature4,846+163
−128[7] K
Metallicity [Fe/H]0.00±0.06[5] dex
Age1.41±0.01[5] Gyr
Other designations
75 Cet, BD–01°353, GC 3043, HD 15779, HIP 11791, HR 739, SAO 129959[8]
Database references
SIMBADdata
Exoplanet Archivedata

75 Ceti is a single[9] star in the equatorial constellation of Cetus with at least two planets.[6] It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.36.[2] The star is located 268 light-years (82 parsecs) distant from the Sun, based on parallax, but is drifting closer with a radial velocity of −6 km/s.[1]

In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, 75 Ceti itself is known as the Tenth Star of Circular Celestial Granary.[10]

This is an aging giant star with a stellar classification of K1 III,[3] having exhausted the supply of hydrogen at its core and expanded to 10.6[7] times the Sun's radius, or 0.05 AU. It is a red clump giant,[5] which indicates it is on the horizontal branch and is generating energy through helium fusion at the core. The star is 1.4[5] billion years old with 1.9[5] times the Sun's mass. It is radiating 56[7] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,846 K.[7]

Planetary system

A planetary companion was discovered by Doppler measurements at the Okayama Astrophysical Observatory, and announced in 2012. The planet's discoverers consider the planet, designated 75 Ceti b, to be "typical" of gas giants.[11] Note that (like many recorded planets) b takes in much more insolation than does Jupiter and, indeed, Earth.[12]

There may be additional periodic factors in the data, corresponding to m sin i of around 0.4 MJ and 1 MJ, at distances of ~0.9 AU and ~4 AU, where i is the orbital inclination and m is the planet's actual mass.[11] In 2023, the presence of a second, Jupiter-mass planet orbiting at 4 AU (75 Ceti c) was confirmed, which is more irradiated than Earth as well. The shorter period signal corresponding to a possible planet at 0.9 AU was found to be an alias of the true period of planet c.[6]

The 75 Ceti planetary system[6]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥2.479+0.074
−0.090 MJ 		1.912+0.002
−0.003 		696.62+1.33
−1.69 		0.093+0.026
−0.042 		— —
c ≥0.912+0.088
−0.143 MJ 		3.929+0.058
−0.052 		2051.62+45.98
−40.47 		0.023+0.191
−0.003 		— —

References

  1. ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  3. ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
  4. ^ Liu, Y. J.; et al. (2007). "The abundances of nearby red clump giants". Monthly Notices of the Royal Astronomical Society. 382 (2): 553–66. Bibcode:2007MNRAS.382..553L. doi:10.1111/j.1365-2966.2007.11852.x.
  5. ^ a b c d e f g Gallenne, A.; et al. (August 2018). "Fundamental properties of red-clump stars from long-baseline H-band interferometry". Astronomy & Astrophysics. 616: 12. arXiv:1806.09572. Bibcode:2018A&A...616A..68G. doi:10.1051/0004-6361/201833341. S2CID 119331707. A68.
  6. ^ a b c d Teng, Huan-Yu; Sato, Bun'ei; et al. (August 2023). "Revisiting Planetary Systems in Okayama Planet Search Program: A new long-period planet, RV astrometry joint analysis, and multiplicity-metallicity trend around evolved stars". Publications of the Astronomical Society of Japan. arXiv:2308.05343.
  7. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  8. ^ "75 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-01.
  9. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  10. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
  11. ^ a b Sato, Bun'ei; et al. (2012). "Substellar Companions to Seven Evolved Intermediate-Mass Stars". Publications of the Astronomical Society of Japan. 64 (6). 135. arXiv:1207.3141. Bibcode:2012PASJ...64..135S. doi:10.1093/pasj/64.6.135. S2CID 119197073.
  12. ^ Square root of luminosity means that an Earth like planet would have to be >7 AU from the star.
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