“Groombridge 1618”的意思、由来-开放百科全书

Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. It is located close to Earth, at a distance of less than 16 light years. This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass. There is a suspected planetary companion with an orbital period of 122 days.

Properties

This star was first identified as entry number 1618 in the work A Catalog of Circumpolar Stars, published posthumously by Stephen Groombridge in 1838.^[1] It has a high proper motion across the sky, which is normally taken as an indicator that the star is located nearby—making it an early candidate for parallax measurement of its distance. In 1884 the parallax angle was measured as {{nowrap|0″.322 ± 0″.023}}, which is larger than the modern value of 0″.205.^[2]

Groombridge 1618 has a stellar classification of K8 V, which means it is a K-type main sequence star that is generating energy by fusing hydrogen at its core. It has 67% of the mass of the Sun, 61% of the Sun's radius,^[16] but radiates only 15% of the Sun's energy and only 4.6% of the Sun's energy in the visible light spectrum. The effective surface temperature of the star's photosphere is about 4,000 K, giving it an orange hue.

It is a BY Draconis variable with a surface magnetic field strength of 750 G.^[7] The chromosphere is relatively inactive^[31] and possesses star spots comparable to Sun spots. However, like the star UV Ceti, it has been observed to undergo increases in luminosity as a flare star.^[8]

System

A search for an excess amount of infrared emission from this star by the Infrared Space Observatory came up

a debris disk (such as Vega).^[33] However, observations using the Herschel Space Observatory showed a small excess suggesting the presence of a low temperature debris disk. The data can be modeled by a ring of coarse, highly-reflective dust at a temperature below 22 K orbiting at least 51 AU from the host star.^[14] If this star does have a companion, astrometric measurements appear to place an upper bound of 3–12 times the mass of Jupiter on such a hypothetical object (for orbital periods in the range of 5–50 years).^[35]

According to Marcy & Benitz (1989),^[3] a possible periodicity of 122 days has been detected, implying the potential presence of a massive planetary object with minimum mass 4 times that of Jupiter. This candidate planet has not been confirmed and the signal the authors had found could have been due to intrinsic stellar activity from the star's young age.

If confirmed, the planet would be located within the star's habitable zone.{{#tag:ref|

^[22] 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

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,

,^[22] the distance of the Inner HZ - Runaway Greenhouse limit from Groombridge 1618 can be calculated as

.|group="note"|name=maximum greenhouse}}

An examination of this system in 2010 using the MMT telescope fitted with adaptive optics failed to detect a planetary companion.^[4]

The habitable zone for this star, defined as the locations where liquid water could be present on an Earth-like planet, is at a radius of 0.26–0.56 AU, where 1 AU is the average distance from the Earth to the Sun.^[41]

See also

Notes

1. ^{{cite journal | title=New reduction of Groombridge's catalogue of circumpolar stars | author=Dyson, F. W. | author2=Thackeray, W. G. | author3=Christie, W. H. M. | journal=Proceedings of the Royal Society of Edinburgh | date=1905 | bibcode=1905Gmb...C......0D }}
2. ^{{cite journal | last = Ball | first = Robert S. | title=On the Annual Parallax of Groombridge 1618 | journal=Dunsink Observatory Publications | date=1884 | volume=5 | issue=2 | pages=187–217 | bibcode=1884DunOP...5..187B }}
3. ^¹{{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 }}
4. ^{{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=1551–1569 |date=May 2010 | doi=10.1088/0004-637X/714/2/1551 | bibcode=2010ApJ...714.1551H |arxiv = 1003.5340 }}
5. ^¹²³⁴⁵{{cite journal | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 }}
6. ^¹²³⁴{{cite journal | author=Ségransan, D. | author2=Kervella, P. | author3=Forveille, T. | author4=Queloz, D. | title=First radius measurements of very low mass stars with the VLTI | journal=Astronomy and Astrophysics | volume=397 | issue=3 | pages=L5–L8 |date=January 2003 | doi=10.1051/0004-6361:20021714 | bibcode=2003A&A...397L...5S |arxiv = astro-ph/0211647 }}
7. ^¹{{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 | journal=The Astrophysical Journal | volume=660 | issue=1 | pages=732–739 | doi=10.1086/513142 | bibcode=2007ApJ...660..732L | arxiv=astro-ph/0701702 }}
8. ^¹{{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 | accessdate=2013-08-01 }}
9. ^¹²³{{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 }} See table 3.
10. ^¹{{cite journal | last1=Holmberg | first1=J. | last2=Nordstrom | first2=B. | last3=Andersen | first3=J. | title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics | journal=Astronomy and Astrophysics | volume=501 | issue=3 |date=July 2009 | pages=941–947 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H|arxiv = 0811.3982 }}
11. ^¹²³{{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 }}
12. ^¹²³⁴{{cite journal | url=http://iopscience.iop.org/0004-637X/765/2/131/ | 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 }}
13. ^¹{{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}}
14. ^¹{{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}}
15. ^¹²{{citation | last1 = Gudel | first1 = M. | title = Radio and X-ray emission from main-sequence K stars | journal = Astronomy and Astrophysics | volume = 264 | issue = 2 | page = L31–L34 |date=October 1992 | bibcode = 1992A&A...264L..31G | postscript = .}}
16. ^¹{{citation | last1 = Byrne | first1 = P. B. | last2 = Doyle | first2 = J. G. | 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 | postscript = .}}
17. ^¹²{{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 = .}}
18. ^¹²³{{citation | last1 = Eiroa | first1 = C. | last2 = Marshall | first2 = J. P. | last3 = Mora | first3 = A. | last4 = Krivov | first4 = A. V. | last5 = Montesinos | first5 = B. | last6 = Absil | first6 = O. | last7 = Ardila | first7 = D. | last8 = Arévalo | first8 = M. | last9 = Augereau | first9 = J.-Ch. | last10 = Bayo | first10 = A. | last11 = Danchi | first11 = W. | last12 = Del Burgo | first12 = C. | last13 = Ertel | first13 = S. | last14 = Fridlund | first14 = M. | last15 = González-García | first15 = B. M. | last16 = Heras | first16 = A. M. | last17 = Lebreton | first17 = J. | last18 = Liseau | first18 = R. | last19 = Maldonado | first19 = J. | last20 = Meeus | first20 = G. | last21 = Montes | first21 = D. | last22 = Pilbratt | first22 = G. L. | last23 = Roberge | first23 = A. | last24 = Sanz-Forcada | first24 = J. | last25 = Stapelfeldt | first25 = K. | last26 = Thébault | first26 = P. | last27 = White | first27 = G. J. | last28 = Wolf | first28 = S. | display-authors = 1 | title = Herschel discovery of a new class of cold, faint debris discs | journal = Astronomy & Astrophysics | volume = 536 | page = L4 |date=December 2011 | arxiv = 1110.4826 | doi = 10.1051/0004-6361/201117797 | bibcode = 2011A&A...536L...4E | postscript = .}}
19. ^¹{{citation | display-authors=1 | last1=Cantrell | first1=Justin R. | last2=Henry | first2=Todd J. | last3=White | first3=Russel J | title=The Solar Neighborhood XXIX: The Habitable Real Estate of Our Nearest Stellar Neighbors | journal=The Astronomical Journal | volume=146 | issue=4 | page=99 | date=October 2013 | doi=10.1088/0004-6256/146/4/99 | bibcode=2013AJ....146...99C | arxiv=1307.7038 | postscript=. }}
20. ^¹{{citation | display-authors=1 | last1=Holmberg | first1=J. | last2=Nordström | first2=B. | last3=Andersen | first3=J. | title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics | journal=Astronomy and Astrophysics | volume=501 | issue=3 |date=July 2009 | pages=941–947 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H | arxiv=0811.3982 | postscript=.}}
21. ^¹{{citation | title=A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky | journal=The Astronomical Journal | display-authors=1 | last1=Lépine | first1=Sébastien | last2=Hilton | first2=Eric J. | last3=Mann | first3=Andrew W. | last4=Wilde | first4=Matthew | last5=Rojas-Ayala | first5=Bárbara | last6=Cruz | first6=Kelle L. | last7=Gaidos | first7=Eric | volume=145 | issue=4 | pages=102 | year=2013 | bibcode= 2013AJ....145..102L | doi= 10.1088/0004-6256/145/4/102 |arxiv = 1206.5991 | postscript=. }}

词条	Groombridge 1618
释义	Properties System See also Notes References Notes External links {{Starbox begin \| name = Groombridge 1618 }}{{Starbox observe \| epoch = J2000.0 \| constell = Ursa Major \| ra = {{RA\|10\|11\|22.14051}}^[1] \| dec = {{DEC\|+49\|27\|15.2567}}^[1] \| appmag_v = +6.60^[3] }}{{Starbox character \| class = K7.5 Ve^[4] \| b-v = +1.34^[3] \| u-b = +1.27^[3] \| variable = BY Dra,^[7] Flare star^[8] }}{{Starbox astrometry \| radial_v = –26.8^[9] \| prop_mo_ra = –1362.32^[1] \| prop_mo_dec = –504.52^[1] \| parallax = 205.21 \| p_error = 0.54 \| parallax_footnote = ^[1] \| absmag_v = 8.11^[13] }}{{Starbox detail \| age_gyr = 6.6^[14] \| metal_fe = –0.03^[15] \| mass = {{Val\|0.670\|0.033}}^[16] \| radius = {{Val\|0.605\|0.02}}^[16] \| rotational_velocity = 2.8^[18] \| gravity = 4.51;^[15] 4.70^[16] \| luminosity_bolometric = 0.15^[14] \| luminosity_visual = 0.046 \| habitable_inner = 0.398^[22] au \| habitable_outer = 0.755^[22] au \| temperature = 3,970^[15] }}{{Starbox catalog \| names = {{odlist \| BD=+50° 1725 \| FK5=\| HD=88230 \| HIP=49908 \| SAO=43223 \| GCTP=2390.00 \| GJ=380 \| IRAS=10082+4942 \| LFT=696 }}^[26] }}{{Starbox reference \|Simbad=HD+88230 }}{{Starbox end}} Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. It is located close to Earth, at a distance of less than 16 light years. This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass. There is a suspected planetary companion with an orbital period of 122 days. Properties This star was first identified as entry number 1618 in the work A Catalog of Circumpolar Stars, published posthumously by Stephen Groombridge in 1838.^[1] It has a high proper motion across the sky, which is normally taken as an indicator that the star is located nearby—making it an early candidate for parallax measurement of its distance. In 1884 the parallax angle was measured as {{nowrap\|0″.322 ± 0″.023}}, which is larger than the modern value of 0″.205.^[2] Groombridge 1618 has a stellar classification of K8 V, which means it is a K-type main sequence star that is generating energy by fusing hydrogen at its core. It has 67% of the mass of the Sun, 61% of the Sun's radius,^[16] but radiates only 15% of the Sun's energy and only 4.6% of the Sun's energy in the visible light spectrum. The effective surface temperature of the star's photosphere is about 4,000 K, giving it an orange hue. It is a BY Draconis variable with a surface magnetic field strength of 750 G.^[7] The chromosphere is relatively inactive^[31] and possesses star spots comparable to Sun spots. However, like the star UV Ceti, it has been observed to undergo increases in luminosity as a flare star.^[8] System A search for an excess amount of infrared emission from this star by the Infrared Space Observatory came up negative, implying that Groombridge 1618 does not possess a debris disk (such as Vega).^[33] However, observations using the Herschel Space Observatory showed a small excess suggesting the presence of a low temperature debris disk. The data can be modeled by a ring of coarse, highly-reflective dust at a temperature below 22 K orbiting at least 51 AU from the host star.^[14] If this star does have a companion, astrometric measurements appear to place an upper bound of 3–12 times the mass of Jupiter on such a hypothetical object (for orbital periods in the range of 5–50 years).^[35] According to Marcy & Benitz (1989),^[3] a possible periodicity of 122 days has been detected, implying the potential presence of a massive planetary object with minimum mass 4 times that of Jupiter. This candidate planet has not been confirmed and the signal the authors had found could have been due to intrinsic stellar activity from the star's young age. If confirmed, the planet would be located within the star's habitable zone.{{#tag:ref\| ^[22] 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 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, ,^[22] the distance of the Inner HZ - Runaway Greenhouse limit from Groombridge 1618 can be calculated as .\|group="note"\|name=maximum greenhouse}} {{OrbitboxPlanet begin \| name=unconfirmed Groombridge 1618 \| table_ref=^[3] \| period_unit=day }}{{OrbitboxPlanet hypothetical \| exoplanet = b \| mass = ≳4 \| period = 122.5 \| semimajor = 0.41 \| eccentricity = 0 }}{{Orbitbox end}} An examination of this system in 2010 using the MMT telescope fitted with adaptive optics failed to detect a planetary companion.^[4] The habitable zone for this star, defined as the locations where liquid water could be present on an Earth-like planet, is at a radius of 0.26–0.56 AU, where 1 AU is the average distance from the Earth to the Sun.^[41] See also Stephen Groombridge List of nearest stars Groombridge 1618 in fiction Notes 1. ^{{cite journal \| title=New reduction of Groombridge's catalogue of circumpolar stars \| author=Dyson, F. W. \| author2=Thackeray, W. G. \| author3=Christie, W. H. M. \| journal=Proceedings of the Royal Society of Edinburgh \| date=1905 \| bibcode=1905Gmb...C......0D }} 2. ^{{cite journal \| last = Ball \| first = Robert S. \| title=On the Annual Parallax of Groombridge 1618 \| journal=Dunsink Observatory Publications \| date=1884 \| volume=5 \| issue=2 \| pages=187–217 \| bibcode=1884DunOP...5..187B }} 3. ^¹{{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 }} 4. ^{{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=1551–1569 \|date=May 2010 \| doi=10.1088/0004-637X/714/2/1551 \| bibcode=2010ApJ...714.1551H \|arxiv = 1003.5340 }} 5. ^¹²³⁴⁵{{cite journal \| first=F. \| last=van Leeuwen \|date=November 2007 \| title=Validation of the new Hipparcos reduction \| journal=Astronomy and Astrophysics \| volume=474 \| issue=2 \| pages=653–664 \| bibcode=2007A&A...474..653V \| doi=10.1051/0004-6361:20078357 \|arxiv = 0708.1752 }} 6. ^¹²³⁴{{cite journal \| author=Ségransan, D. \| author2=Kervella, P. \| author3=Forveille, T. \| author4=Queloz, D. \| title=First radius measurements of very low mass stars with the VLTI \| journal=Astronomy and Astrophysics \| volume=397 \| issue=3 \| pages=L5–L8 \|date=January 2003 \| doi=10.1051/0004-6361:20021714 \| bibcode=2003A&A...397L...5S \|arxiv = astro-ph/0211647 }} 7. ^¹{{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 \| journal=The Astrophysical Journal \| volume=660 \| issue=1 \| pages=732–739 \| doi=10.1086/513142 \| bibcode=2007ApJ...660..732L \| arxiv=astro-ph/0701702 }} 8. ^¹{{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 \| accessdate=2013-08-01 }} 9. ^¹²³{{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 }} See table 3. 10. ^¹{{cite journal \| last1=Holmberg \| first1=J. \| last2=Nordstrom \| first2=B. \| last3=Andersen \| first3=J. \| title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics \| journal=Astronomy and Astrophysics \| volume=501 \| issue=3 \|date=July 2009 \| pages=941–947 \| doi=10.1051/0004-6361/200811191 \| bibcode=2009A&A...501..941H\|arxiv = 0811.3982 }} 11. ^¹²³{{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 }} 12. ^¹²³⁴{{cite journal \| url=http://iopscience.iop.org/0004-637X/765/2/131/ \| 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 }} 13. ^¹{{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}} 14. ^¹{{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}} 15. ^¹²{{citation \| last1 = Gudel \| first1 = M. \| title = Radio and X-ray emission from main-sequence K stars \| journal = Astronomy and Astrophysics \| volume = 264 \| issue = 2 \| page = L31–L34 \|date=October 1992 \| bibcode = 1992A&A...264L..31G \| postscript = .}} 16. ^¹{{citation \| last1 = Byrne \| first1 = P. B. \| last2 = Doyle \| first2 = J. G. \| 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 \| postscript = .}} 17. ^¹²{{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 = .}} 18. ^¹²³{{citation \| last1 = Eiroa \| first1 = C. \| last2 = Marshall \| first2 = J. P. \| last3 = Mora \| first3 = A. \| last4 = Krivov \| first4 = A. V. \| last5 = Montesinos \| first5 = B. \| last6 = Absil \| first6 = O. \| last7 = Ardila \| first7 = D. \| last8 = Arévalo \| first8 = M. \| last9 = Augereau \| first9 = J.-Ch. \| last10 = Bayo \| first10 = A. \| last11 = Danchi \| first11 = W. \| last12 = Del Burgo \| first12 = C. \| last13 = Ertel \| first13 = S. \| last14 = Fridlund \| first14 = M. \| last15 = González-García \| first15 = B. M. \| last16 = Heras \| first16 = A. M. \| last17 = Lebreton \| first17 = J. \| last18 = Liseau \| first18 = R. \| last19 = Maldonado \| first19 = J. \| last20 = Meeus \| first20 = G. \| last21 = Montes \| first21 = D. \| last22 = Pilbratt \| first22 = G. L. \| last23 = Roberge \| first23 = A. \| last24 = Sanz-Forcada \| first24 = J. \| last25 = Stapelfeldt \| first25 = K. \| last26 = Thébault \| first26 = P. \| last27 = White \| first27 = G. 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Improved distances, ages, and kinematics \| journal=Astronomy and Astrophysics \| volume=501 \| issue=3 \|date=July 2009 \| pages=941–947 \| doi=10.1051/0004-6361/200811191 \| bibcode=2009A&A...501..941H \| arxiv=0811.3982 \| postscript=.}} 21. ^¹{{citation \| title=A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky \| journal=The Astronomical Journal \| display-authors=1 \| last1=Lépine \| first1=Sébastien \| last2=Hilton \| first2=Eric J. \| last3=Mann \| first3=Andrew W. \| last4=Wilde \| first4=Matthew \| last5=Rojas-Ayala \| first5=Bárbara \| last6=Cruz \| first6=Kelle L. \| last7=Gaidos \| first7=Eric \| volume=145 \| issue=4 \| pages=102 \| year=2013 \| bibcode= 2013AJ....145..102L \| doi= 10.1088/0004-6256/145/4/102 \|arxiv = 1206.5991 \| postscript=. }} References {{Reflist\|30em\|refs=^[5]^[6]^[7]^[8]^[9]^[10]^[11]^[12]^[13]^[14]^[15]^[16]^[17]^[18]^[19]^[20]^[21] }} Notes {{Reflist\|group=nb}} External links {{cite web \| url=http://www.solstation.com/stars/groo1618.htm \| title=Groombridge 1618 \| publisher=Sol Company \| accessdate=2007-06-24 }} {{cite web \| url=http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00785.htm \| title=ARICNS 4C00785 \| publisher=Astronomisches Rechen-Institut \| accessdate=2007-06-24 \|archiveurl = https://web.archive.org/web/20070610061931/http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00785.htm \|archivedate = 2007-06-10}}{{nearest systems\|4}}{{Stars of Ursa Major}} 10 : K-type main-sequence stars\|Local Bubble\|Ursa Major (constellation)\|Flare stars\|Hypothetical planetary systems\|Henry Draper Catalogue objects\|Hipparcos objects\|Gliese and GJ objects\|Groombridge objects\|Durchmusterung objects
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