编辑“︁Groombridge 1618”︁

{{Sky|10|11|22.1400|+|49|27|15.2492|15.886}}
{{Starbox begin
| name     = Groombridge 1618
}}
{{Starbox image
|image={{Location map|100x100|AlternativeMap=Ursa Major_constellation_map.svg
|alt=Groombridge 1618 is located in the constellation Ursa Major.
|caption=Groombridge 1618在[[大熊座]]的位置|border=infobox|mark=Red_pog.png|width=330
|label=Groombridge&nbsp;1618
|position=bottom
|lat=42.5
|long=73.3
}}|caption=
}}
{{Starbox observe
| epoch    = J2000.0
| constell = [[大熊座]]
| ra       = {{RA|10|11|22.13995}}<ref name="GaiaDR3"/>
| dec      = {{DEC|+49|27|15.2510}}<ref name="GaiaDR3"/>
| appmag_v = +6.60<ref name=mnras133_475/>
}}
{{Starbox character
| class    = K7.5&nbsp;Ve<ref name=lepine2013/>
| b-v      = +1.34<ref name=mnras133_475/>
| u-b      = +1.27<ref name=mnras133_475/>
| variable = [[BY Draconis variable|BY Dra]],<ref name="AAA264_2_L31"/> [[Flare star]]<ref name="Andrillat_Morguleff"/>
}}
{{Starbox astrometry
| radial_v = {{val|-26.48|0.12}}<ref name="GaiaDR3"/>
| prop_mo_ra = {{val|−1363.287|0.016}}
| prop_mo_dec = {{val|−505.770|0.020}}
| pm_footnote = <ref name="GaiaDR3"/>
| parallax = 205.3148
| p_error = 0.0224
| parallax_footnote = <ref name="GaiaDR3"/>
| absmag_v = 8.11<ref name=cgssn09/>
}}
{{Starbox detail
| age_gyr = 6.6<ref name="AAA536_L4"/>
| metal_fe = –0.03<ref name="mnras356" />
| mass = {{Val|0.670|0.033}}<ref name=aaa397_L5/>
| radius = {{Val|0.605|0.02}}<ref name=aaa397_L5/>
| rotational_velocity = 2.8<ref name=apj660_1_732/>
| gravity = 4.51;<ref name="mnras356" /> 4.70<ref name=aaa397_L5/>
| luminosity_bolometric = 0.15<ref name="AAA536_L4"/>
| luminosity_visual = 0.049
| habitable_inner = 0.398<ref name=kopparapu-2013/><ref group="note" name="maximum greenhouse"/><!--Conservative, Inner HZ - Runaway Greenhouse limit, based on 15% luminosity & 3970 Kelvin--> [[Astronomical unit|au]] 
| habitable_outer = 0.755<ref name=kopparapu-2013/><!--Conservative, Outer HZ - Maximum Greenhouse limit, taking 15% luminosity & 3970 Kelvin--> [[Astronomical unit|au]]  
| temperature = 3,970<ref name="mnras356"/>
}}
{{Starbox catalog
| names = {{odlist | BD=+50°&nbsp;1725 | FK5=| HD=88230 | HIP=49908 | SAO=43223 | GCTP=2390.00 | GJ=380 | IRAS=10082+4942 | LFT=696 }}<ref name="SIMBAD"/>
}}
{{Starbox reference
|Simbad = HD+88230
}}
{{Starbox end}}

'''格龙布里奇 1618'''是位於[[大熊座]]的一顆恆星。它的[[視星等]]為+6.6，處於或低於普通觀察者肉眼可見恆星的閾值。它距離地球相對較近，距離為15.89光年（4.87光年）。這是一顆光譜類型為K7.5 Ve的主序星，質量僅為太陽的67% 。

==特性==
{{維基數據鏈接|Q1348145}}

格龙布里奇 1618的恆星分類為K8V，這意味著它是一顆[[K型主序星]]，通過在其核心聚變氫來產生能量。它的質量是太陽的67%，半徑是太陽的61%，<ref name=aaa397_L5/> 但輻射的能量只有[[太陽光度|太陽]]的15%，[[可見光]]光譜中的能量也只有太陽的 4.6% 。恆星光球層的有效表面溫度約為 4,000 K，呈現橙色。

它也是[[磁場]]強度為 750 G 的[[天龍座BY型變星]]<ref name="AAA264_2_L31"/>。[[色球]]相對不活躍<ref name="AAA238_1_221"/> 並產生可與[[太陽耀斑]]媲美的星斑。然而，像UV Ceti一樣，它已被觀察到作為[[耀星]]經歷了光度的增加。a<ref name="Andrillat_Morguleff"/>

==行星搜索==
紅外空間天文台對這顆恆星的過量紅外輻射的搜索結果是否定的，這意味著格龙布里奇 1618附近沒有碎片盤（例如[[織女星]]）。<ref name=AAA387_1_L285/> 然而，使用[[赫雪爾太空望遠鏡]]進行的觀測顯示存在低溫碎片盤。數據可以用溫度低於 22 K 的粗糙、高反射性塵埃環模擬，環繞主恆星至少51個[[天文單位]]。<ref name="AAA536_L4"/> 如果這顆星確實有伴星，天體測量測量結果似乎將 3-12 倍木星質量的上限置於這樣一個假設的物體上（軌道周期在 5-50 年的範圍內）。<ref name="BAAS10_630"/>

觀測結果傾向於將周期為 122天的單個顯著物體作為行星物體，其最小質量是木星的 4 倍。這顆候選行星從未得到證實，作者發現的信號可能是由於恆星年輕時的內在恆星活動。如果得到證實，這顆行星將位於恆星的宜居帶內。<ref name="Marcy & Benitz">{{cite journal | last1=Marcy | first1=Geoffrey W. | last2=Benitz | first2=Karsten J. | title=A search for substellar companions to low-mass stars| journal=Astrophysical Journal, Part 1| volume=344|issue=1|pages=441–453 |date=1989|bibcode=1989ApJ...344..441M | doi=10.1086/167812 }}</ref> {{#tag:ref|<math>\scriptstyle S_{eff_{\ast}}= S_{eff_{\odot}} + aT_{\ast} + bT_{\ast}^2 + cT_{\ast}^3  + dT_{\ast}^4</math> <ref name=kopparapu-2013/> when used to calculate the stellar flux reaching the outer atmosphere of an Earth-like planet orbiting Groombridge 1618 at the Inner Habitable Zone edge - the Runaway Greenhouse limit gives a <math>\scriptstyle S_{eff_{\ast}}</math> of 0.9397 or 93.97% the stellar flux reaching the top of Earth's atmosphere. By applying the previously calculated stellar flux and the known 15% luminosity of Groombridge 1618 into the equation, <math>\scriptstyle {d = {\left(\frac{{L_{\ast}}/{L_{\odot}}}{S_{eff_{\ast}}} \right)^{0.5} AU}}</math>,<ref name=kopparapu-2013/> the distance of the Inner HZ - Runaway Greenhouse limit from Groombridge 1618 can be calculated as <math>\scriptstyle{0.4 AU}</math>.|group="note"|name=maximum greenhouse}}

2010 年使用配備自適應光學系統的[[多鏡面望遠鏡]]對該系統進行的檢查未能檢測到行星伴星。<ref>{{cite journal
 | display-authors=1
 | title=Constraints on Long-period Planets from an L'- and M-band Survey of Nearby Sun-like Stars: Observations
 | last1=Heinze | first1=A. N. | last2=Hinz | first2=Philip M.
 | last3=Sivanandam | first3=Suresh | last4=Kenworthy | first4=Matthew
 | last5=Meyer | first5=Michael | last6=Miller | first6=Douglas
 | journal=The Astrophysical Journal | volume=714 | issue=2
 | pages=1551&ndash;1569 |date=May 2010
 | doi=10.1088/0004-637X/714/2/1551 | bibcode=2010ApJ...714.1551H |arxiv = 1003.5340 | s2cid=119199321
 }}</ref>

這顆恆星的[[宜居帶]]定義為類地行星上可能存在液態水的區域，半徑為0.26–0.56個[[天文單位]]，其中1個[[天文單位]]是地球到太陽的平均距離。<ref name="aaa555_A104"/>

根據美國宇航局戈達德太空飛行中心的分析，這顆恆星是附近五顆K型恆星之一，屬於類太陽恆星和M型恆星之間演化生命可能性的“最佳點”。<ref name=Nasa2019-03-07/>

==參見==
* [[鄰近恆星列表]]

== 注釋 ==
{{Reflist|group=note|refs=}}

==參考資料==
{{Reflist|refs=
<ref name=Nasa2019-03-07>{{cite news
 |url          = https://www.nasa.gov/feature/goddard/2019/k-star-advantage
 |title        = "Goldilocks" Stars May Be "Just Right" for Finding Habitable Worlds
 |work         = [[NASA]]
 |author       = Bill Steigerwald
 |date         = 2019-03-07
 |access-date  = 2020-05-12
 |quote        = {{'}}I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,{{'}} said Arney.
 |archive-date = 2019-06-17
 |archive-url  = https://web.archive.org/web/20190617062905/https://www.nasa.gov/feature/goddard/2019/k-star-advantage/
 |dead-url     = no
}}</ref>

<ref name=aaa397_L5>{{cite journal |doi=10.1051/0004-6361:20021714 |last1=Ségransan |first1=Damien |last2=Kervella |first2=Pierre |last3=Forveille |first3=Thierry |last4=Queloz |first4=Didier |title=First radius measurements of very low mass stars with the VLTI |journal=Astronomy and Astrophysics |date=2003 |volume=397 |issue=3 |pages=L5–L8 |bibcode=2003A&A...397L...5S |arxiv=astro-ph/0211647 |s2cid=10748478 }}</ref>

<ref name=apj660_1_732>{{cite journal | last=López-Morales | first=Mercedes |date=May 2007 | title=On the Correlation between the Magnetic Activity Levels, Metallicities, and Radii of Low-Mass Stars | url=https://archive.org/details/sim_astrophysical-journal_2007-05-01_660_1/page/732 | journal=The Astrophysical Journal | volume=660 | issue=1 | pages=732&ndash;739 | doi=10.1086/513142 | bibcode=2007ApJ...660..732L | arxiv=astro-ph/0701702 | s2cid=119530297 }}</ref>

<ref name="SIMBAD">{{cite web | url=http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=Groombridge+1618 | title=NSV 4765 -- Flare Star | work=SIMBAD | publisher=[[Centre de Données astronomiques de Strasbourg]] | access-date=2013-08-01 | archive-date=2022-12-05 | archive-url=https://web.archive.org/web/20221205053108/http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=Groombridge+1618 | dead-url=no }}</ref>

<ref name="mnras356">{{cite journal | last1=Woolf | first1=Vincent M. | last2=Wallerstein | first2=George | title=Metallicity measurements using atomic lines in M and K dwarf stars | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=356 | issue=3 | pages=963–968 |date=January 2005 | doi=10.1111/j.1365-2966.2004.08515.x | bibcode=2005MNRAS.356..963W | arxiv=astro-ph/0410452 | s2cid=15664454 }} See table 3.</ref>

<ref name=mnras133_475>{{citation | last1=Argue | first1=A. N. | title=UBV photometry of 550 F, G and K type stars | journal=Monthly Notices of the Royal Astronomical Society | volume=133 | issue=4 | pages=475–493 | date=1966 | bibcode=1966MNRAS.133..475A | doi = 10.1093/mnras/133.4.475 | doi-access=free }}</ref>

<ref name=kopparapu-2013>{{cite journal | title=Habitable Zones around Main-sequence Stars: New Estimates| last1=Kopparapu| first1= R. K.| last2=Ramirez | first2= R. | last3=Kasting | first3= J.F. | last4=Eymet| first4=V. | last5=Robinson | first5= T. D. | last6=Mahadevan | first6= S. | last7=Terrien | first7=R.C. | last8=Domagal-Goldman | first8=S. | last9=Meadows| first10= V. | last10=Deshpande | first9= R. | journal=The Astrophysical Journal |date=March 2013| volume=765 | issue=2 | doi=10.1088/0004-637X/765/2/131 | arxiv=1301.6674 | pages=16 |bibcode = 2013ApJ...765..131K | s2cid=76651902}}</ref>

<ref name=AAA387_1_L285>{{cite journal | display-authors=1 | last1=Laureijs | first1=R. J. | last2=Jourdain de Muizon | first2=M. | last3=Leech | first3=K. | last4=Siebenmorgen | first4=R. | last5=Dominik | first5=C. | last6=Habing | first6=H. J. | last7=Trams | first7=N. | last8=Kessler | first8=M. F. | title=A 25 micron search for Vega-like disks around main-sequence stars with ISO | journal=Astronomy & Astrophysics | date=2002 | volume=387 | issue=1 | pages=L285–L293 | doi=10.1051/0004-6361:20020366 | bibcode=2002A&A...387..285L | hdl=1887/7333 | url=https://openaccess.leidenuniv.nl/bitstream/handle/1887/7333/A%26A_387_285_293.pdf?sequence=1 | doi-access=free | access-date=2023-03-20 | archive-date=2017-08-09 | archive-url=https://web.archive.org/web/20170809071043/https://openaccess.leidenuniv.nl/bitstream/handle/1887/7333/a%26a_387_285_293.pdf?sequence=1 | dead-url=no }}</ref>

<ref name="BAAS10_630">{{cite journal
 | last1 = Hershey | first1 = J. L. | last2 = Borgman | first2 = E. R.
 | title=Upper Limits on the Mass of a Dark Companion of Groombridge 1618 from the 40-year Sproul Plate Series
 | journal=Bulletin of the American Astronomical Society
 | date=1978
 | volume=10
 | pages=630
 | bibcode=1978BAAS...10..630H
}}</ref>

<ref name="AAA264_2_L31">{{citation
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 | title     = Radio and X-ray emission from main-sequence K stars
 | journal   = Astronomy and Astrophysics
 | volume    = 264
 | issue     = 2
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 |date=October 1992
 | bibcode   = 1992A&A...264L..31G
 | postscript = .
}}</ref>

<ref name="AAA238_1_221">{{citation
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 | title     = Activity in late-type stars. VII - Chromospheric and transition region line fluxes in 2 dM and 1 dM(e) stars
 | journal   = Astronomy and Astrophysics
 | volume    = 238
 | issue     = 1–2
 | pages      = 221–226
 |date=November 1990
 | bibcode   = 1990A&A...238..221B
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}}</ref>

<ref name="Andrillat_Morguleff">{{citation
 | last1     = Andrillat
 | first1    = Y.
 | last2     = Morguleff
 | first2    = N.
 | title     = Three potassium-flare stars
 | pages = 160
 | work      = Proceedings of the Colloquium, held in Trieste, June 13–17, 1966, Trieste
 | editor1-last = Hack
 | editor1-first = Margherita
 | date      = 1967
 | bibcode   = 1967lts..conf..160A
 | postscript = .
}}</ref>

<ref name="AAA536_L4">{{citation
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<ref name="aaa555_A104">{{citation | display-authors=1
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<ref name=cgssn09>{{citation
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<ref name="GaiaDR3">{{Cite Gaia DR3|823773494718931968}}</ref>

<ref name=lepine2013>{{citation
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 | postscript=. }}</ref>

}}

==註釋==
{{Reflist|group=nb}}

==外部連結==
*{{cite web
 | url=http://www.solstation.com/stars/groo1618.htm
 | title=Groombridge 1618
 | publisher=Sol Company
 | access-date=2007-06-24
 | archive-date=2012-05-11
 | archive-url=https://web.archive.org/web/20120511143450/http://solstation.com/stars/groo1618.htm
 | dead-url=no
 }}
*{{cite web
 | url=http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00785.htm
 | title=ARICNS 4C00785
 | publisher=Astronomisches Rechen-Institut 
 | access-date=2007-06-24 |archive-url = https://web.archive.org/web/20070610061931/http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00785.htm <!-- Bot retrieved archive --> |archive-date = 2007-06-10}}

{{nearest systems|4}}
{{Stars of Ursa Major}}

[[Category:K型主序星]]
[[Category:本地泡]]
[[Category:大熊座]]
[[Category:耀星]]
[[Category:假想行星系]]
[[Category:HD和HDE天體|088230]]
[[Category:HIP天體|049908]]
[[Category:格利泽和GJ天体|0380]]
[[Category:BD、CD和CP天体|BD+50 1725]]