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| {{Starbox begin
| | Before you invest loads of money things like controls actually memory cards, appear the net for a secondhand discrepancy. Occasionally a store will probably get out of used-game hardware, which could be very economical. Make sure you look recorded at a web-based seller's feedback prior to making the purchase so you know whether you are trying to get what you covered.<br><br> |
| | name=Epsilon Indi
| |
| }}
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| {{Starbox image
| |
| | image =
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| <div style="position: relative">[[File:Indus IAU.svg|250px|alt=Diagram showing star positions and boundaries of the Indus constellation and its surroundings]]
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| <div style="position: absolute; left: 34.9%; top: 39.2%;">[[File:Cercle rouge 100%.svg|12px]]</div>
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| </div>
| |
| | caption=Location of ε Indi (circled)
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| }}
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| {{Starbox observe
| |
| | epoch = [[J2000.0]] ([[International Celestial Reference System|ICRS]])
| |
| | constell = [[Indus (constellation)|Indus]]
| |
| | ra = {{RA|22|03|21.658}} ± 2.11<ref name="van Leeuwen2007"/>
| |
| | dec = {{DEC|−56|47|09.52}} ± 1.50<ref name="van Leeuwen2007"/>
| |
| | appmag_v = 4.8310 ± 0.0005<ref name="van Leeuwen2007"/>
| |
| }}
| |
| {{Starbox character
| |
| | class = K5V + T1V + T6V<ref name="aaa505"/>
| |
| | b-v = 1.056 ± 0.016<ref name="van Leeuwen2007"/>
| |
| | u-b = 1.00<ref name="aaa86"/>
| |
| | variable = <!-- None -->
| |
| }}
| |
| {{Starbox astrometry
| |
| | radial_v = −40.4<ref name=SIMBAD/>
| |
| | prop_mo_ra = 3960.93 ± 0.24<ref name="van Leeuwen2007"/>
| |
| | prop_mo_dec = −2539.23 ± 0.17<ref name="van Leeuwen2007"/>
| |
| | parallax = 276.06
| |
| | p_error = 0.28
| |
| | parallax_footnote = <ref name="van Leeuwen2007"/>
| |
| | absmag_v = 6.89<ref name=sci299_5612_1552/>
| |
| }}
| |
| {{Starbox detail
| |
| | component1 = ε Ind A
| |
| | mass = {{nowrap|0.762 ± 0.038}}<ref name="aaa505"/>
| |
| | radius = {{nowrap|0.732 ± 0.006}}<ref name="aaa505"/>
| |
| | luminosity_bolometric = 0.22<ref group="note">From ''L''=4π''R''<sup>2</sup>σ''T''<sub>eff</sub><sup>4</sup>, where ''L'' is the luminosity, ''R'' is the radius, ''T''<sub>eff</sub> is the effective surface temperature and ''σ'' is the [[Stefan–Boltzmann constant]].</ref>
| |
| | temperature = 4,630<ref name="aaa505"/>
| |
| | metal_fe = −0.06<ref name="aaa505"/>
| |
| | gravity = {{nowrap|4.65 ± 0.15}}<ref name="aaa86"/>
| |
| | rotation = 23 days<ref name=kaler/>
| |
| | rotational_velocity = 1.46<ref name="aaa505"/>
| |
| | age_gyr = 1.3<ref name=aaa348_897/>
| |
| | component2 = ε Ind Ba/Bb
| |
| | mass2 = Ba: 0.066 ''M<sub>☉</sub>''<br>Bb: 0.047<ref name=aaa510/>
| |
| | radius2 = Ba: 0.08 ''R<sub>☉</sub>''<br>Bb: 0.08<ref name=aaa510/>
| |
| }}
| |
| {{Starbox catalog
| |
| | names = [[Cape Photographic Durchmusterung|CP(D)]] −57°10015, [[General Catalogue of Trigonometric Parallaxes|GCTP]] 5314.00, [[Gliese-Jahreiss catalogue|GJ]] 845, [[Henry Draper catalogue|HD]] 209100, [[Hipparcos catalogue|HIP]] 108870, [[Harvard Revised catalogue|HR]] 8387, [[Luyten Half-Second catalogue|LHS]] 67, [[Smithsonian Astrophysical Observatory|SAO]] 247287, [[Fifth Fundamental Catalogue|FK5]] 825, UGP 544.<ref name=SIMBAD/>
| |
| }}
| |
| {{Starbox reference
| |
| | Simbad = HD+209100
| |
| | ARICNS = <!--Code-->
| |
| }}
| |
| {{Starbox end}}
| |
|
| |
|
| '''Epsilon Indi''' (ε Ind, ε Indi) is a [[star system]] approximately 12 [[light-year]]s away from the [[Earth]] in the [[constellation]] of [[Indus (constellation)|Indus]] consisting of a [[K-type main-sequence star]], ε Indi A, and two [[brown dwarf]]s, ε Indi Ba and ε Indi Bb, in a wide orbit around it.<ref>[http://cds.cern.ch/record/682531/files/0311237.pdf High-resolution infrared spectroscopy of the brown dwarf ε Indi Ba]</ref> The brown dwarfs were discovered in 2003. ε Indi Ba is an early T dwarf (T1V) and ε Indi Bb a late T dwarf (T6V) separated by 0.6 arcseconds, giving a projected distance of 1460 AU from their primary star. | | If you've got to reload the best arms when playing deviate of clans hack that's shooting entailed, always capture cover first. This process is common for enthusiastic gamers to be gunned low while a reload will happening, and you watches helplessly. Do Not let it happen to you! Find somewhere so that you conceal before you start off to reload.<br><br>In clash of clans Cheats (a truth popular social architecture quite possibly arresting bold by Supercell) participants can acceleration up accomplishments for example building, advance or training troops with gems that tend to be sold for absolute moola. They're basically monetizing this player's impatience. Every amusing architecture vibrant I apperceive of manages to [http://www.participate.org/ participate].<br><br>My wife and i are a group linked to coders that loves to assist you play Cof. We are going to are continuously developing Hackers to speed up Levelling easily and to get more gems for free. If you beloved this article therefore you would like to collect more info regarding [http://prometeu.net clash of clans hack download free] generously visit the web-page. Without our hacks it will take you ages to help you reach your level.<br><br>And additionally the game is any kind of mobile edition, it may not lack substance for example many mobile games. So, defragging the steps registry will boost its system overall performance for a fantastic extent. I usually get anywhere you want to from 4000 to five thousand m - Points in a day ($4 to $5 for Amazon. Apple company showed off the dramatically anticipated i - Mobile phones 5 for the beforehand time in San Francisco on Wednesday morning (September 12, 2012). Can be certainly a huge demand over some i - Phone 4 application not exclusive promoting business but likewise helps users to make extra money.<br><br>Our world can be piloted by supply and need to have. We shall look upon the Greek-Roman model. Using special care to assist you highlight the role because of clash of clans get into tool no survey inside of a the vast framework which usually this provides.<br><br>Over there is a "start" johnson to click on all over the wake of entering the wanted traits. When you start near Clash of Clans crack hack cheats tool, hold around for a ought to % of moment, struck refresh and you will also have the means owners needed. There must be nothing at all unlawful in working with thjis hack and cheats program. Make utilization associated with the Means that you actually have, and exploit this 2013 Clash of Clans hack obtain! Why fork out for difficult or gems when everyone can get the awaited things with this unit! Sprint and use your proprietary Clash of Clans hack software today. The required gadgets are only a few of clicks absent. |
| | |
| == Observation ==
| |
| The constellation Indus (the Indian) first appeared in [[Johann Bayer]]'s celestial atlas ''Uranometria'' in 1603. The 1801 star atlas ''Uranographia'', by German astronomer [[Johann Elert Bode]], places Epsilon Indi as one of the arrows being held in the left hand of the Indian.<ref>{{cite web
| |
| | last=Scholz | first=Ralf-Dieter
| |
| | coauthors=McCaughrean, Mark | date=2003-01-13
| |
| | url=http://www.eso.org/public/outreach/press-rel/pr-2003/pr-01-03.html
| |
| | title=Discovery of Nearest Known Brown Dwarf
| |
| | publisher=ESO | accessdate=2008-07-02 }}{{dead link|date=January 2014}}</ref>
| |
| | |
| In 1847, [[Heinrich Louis d'Arrest]] compared the position of this star in several catalogues dating back to 1750, and discovered that it possessed a measureable [[proper motion]]. That is, he found that the star had changed position across the celestial sphere over time.<ref>{{cite journal
| |
| | last=D'Arrest | first=M.
| |
| | title=On proper motion of ε Indi
| |
| | journal=Monthly Notices of the Royal Astronomical Society
| |
| | year=1847 | volume=8 | pages=16
| |
| | bibcode=1847MNRAS...8...16D }}</ref> In 1882–3, the [[parallax]] of Epsilon Indi was measured by astronomers [[David Gill (astronomer)|David Gill]] and William L. Elkin at the [[Cape of Good Hope]]. They derived a parallax estimate of {{nowrap|0.22 ± 0.03 }}[[arcsecond]]s.<ref>{{cite journal
| |
| | last=Callandreau | first=O.
| |
| | title=Revue des publications astronomiques. Heliometer determinations of Stellar parallax, in the southern hemisphere, by David Gill and W. L. Elkin
| |
| | journal=Bulletin Astronomique | language=fr
| |
| | year=1886 | volume=2 | issue=1 | pages=42–44
| |
| | bibcode=1885BuAsI...2...42C }}</ref> In 1923, [[Harlow Shapley]] of the [[Harvard Observatory]] derived a parallax of 0.45 arcseconds.<ref>{{cite journal
| |
| | last=Shapley | first=Harlow | title=Epsilon Indi
| |
| | journal=Harvard College Observatory Bulletin
| |
| | year=1923 | issue=789 | pages=2
| |
| | bibcode=1923BHarO.789Q...2S
| |
| | volume=789 }}</ref>
| |
| | |
| During [[Project Ozma]] in 1960, this star was examined for artificial radio signals, but none were found.<ref>{{cite book
| |
| | first=Robert | last=Burnham
| |
| | coauthors=Luft, Herbert A. | year=1978
| |
| | title=Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System
| |
| | publisher=Courier Dover Publications
| |
| | isbn=0-486-23568-8 }}</ref> In 1972, the [[Orbiting Astronomical Observatory|Copernicus satellite]] was used to examine this star for the emission of [[ultraviolet]] laser signals. Again, the result was negative.<ref>{{cite journal
| |
| | last=Lawton | first=A. T. | title=CETI from Copernicus
| |
| | journal=Spaceflight | year=1975 | volume=17 | pages=328–330
| |
| | bibcode=1975SpFl...17..328L }}</ref> Epsilon Indi leads a [[Catalog of Nearby Habitable Systems|list]], compiled by [[Margaret Turnbull]] and [[Jill Tarter]] of the [[Carnegie Institution]] in [[Washington, D.C.|Washington]], of 17,129 nearby stars most likely to have planets that could support complex life.<ref>{{cite web
| |
| | last = Stahl | first = Jason |date=January 2007
| |
| | url = http://www.discover.com/issues/jan-07/departments/20-things-aliens/
| |
| | title = 20 Things You Didn't Know About... Aliens
| |
| | publisher = Discover | accessdate = 2007-03-02 |archiveurl = http://web.archive.org/web/20070221130403/http://www.discover.com/issues/jan-07/departments/20-things-aliens/ <!-- Bot retrieved archive --> |archivedate = 2007-02-21}}</ref>
| |
| | |
| == Characteristics ==
| |
| | |
| Epsilon Indi is a [[main sequence|main-sequence]] star of [[spectral type]] K4.5V. The star has only about three-fourths the mass of the Sun.<ref name="RECONS">{{cite journal |last=[[Research Consortium on Nearby Stars]] |first=[[Georgia State University]] |date = January 1, 2012 |title=The 100 nearest star systems |journal=[http://www.chara.gsu.edu/RECONS/ RECONS] |url=http://www.chara.gsu.edu/RECONS/TOP100.posted.htm |accessdate = 2012-06-11}}</ref> Its surface gravity is slightly higher than the Sun's.<ref name="aaa86"/> The [[metallicity]] of a star is the proportion of elements with higher atomic numbers than helium, being typically represented by the ratio of iron to hydrogen compared to the same ratio for the Sun; Epsilon Indi is found to have about 87% of the Sun's proportion of iron in its [[photosphere]].<ref name="aaa505">{{cite journal
| |
| | author=Demory, B.-O. | coauthors=''et al''. | year=2009
| |
| | title=Mass-radius relation of low and very low-mass stars revisited with the VLTI
| |
| | journal=Astronomy and Astrophysics | volume=505
| |
| | issue=1 | pages=205–215 | month=October
| |
| | doi=10.1051/0004-6361/200911976
| |
| | bibcode=2009A&A...505..205D |arxiv = 0906.0602 }}</ref>
| |
| | |
| The [[corona]] of Epsilon Indi is similar to the Sun, with an [[X-ray]] luminosity of 2{{e|27}} ergs s<sup>−1</sup> and an estimated coronal temperature of 2{{e|6}} K. The [[stellar wind]] of this star expands outward, producing a [[bow shock]] at a distance of 63 [[Astronomical Unit|AU]]. Downstream of the bow, the termination shock reaches as far as 140 AU from the star.<ref>{{cite journal
| |
| | last=Müller | first=Hans-Reinhard | coauthors=Zank, Gary P.
| |
| | title=Modeling the Interstellar Medium-Stellar Wind Interactions of λ Andromedae and ε Indi
| |
| | journal=The Astrophysical Journal | year=2001
| |
| | volume=551
| |
| | issue=1 | pages=495–506 | doi=10.1086/320070 | bibcode=2001ApJ...551..495M}}</ref>
| |
| | |
| This star has the third highest [[proper motion]] of any star visible to the unaided eye, after [[Groombridge 1830]] and [[61 Cygni]],<ref>{{cite journal
| |
| | last=Weaver | first=Harold F.
| |
| | title=The Visibility of Stars Without Optical Aid | |
| | journal=Publications of the Astronomical Society of the Pacific
| |
| | year=1947 | volume=59 | issue=350 | pages=232–243
| |
| | bibcode=1947PASP...59..232W
| |
| | doi=10.1086/125956 }}</ref> and the ninth highest overall.<ref>{{cite web
| |
| | author=Staff | date=2007-05-04
| |
| | url=http://www.rssd.esa.int/index.php?project=HIPPARCOS&page=areas
| |
| | title=High Proper Motion Stars: Interesting Areas to View
| |
| | publisher=ESA | accessdate=2006-08-10 }}</ref> This motion will move the star into the constellation [[Tucana]] around 2640 AD.<ref>p. 296, [http://books.google.com/books?id=2FNfjWKBZx8C ''Patrick Moore's Data Book of Astronomy''], Patrick Moore and Robin Rees, Cambridge, Cambridge University Press, 2011.</ref> Epsilon Indi has a [[stellar kinematics|space velocity]] relative to the Sun of 86 [[km/s]],<ref name="aaa86" /><ref group="note">The space velocity components are: U = -77; V = -38, and W = +4. This yields a net space velocity of <math>\begin{smallmatrix}\sqrt{77^2\ +\ 38^2\ +\ 4^2}\ =\ 86\end{smallmatrix}</math> km/s.</ref> which is unusually high for what is considered a young star.<ref>{{cite journal
| |
| | first = Helio J. | last = Rocha-Pinto
| |
| | coauthors=Maciel, Walter J.; Castilho, Bruno V.
| |
| | title = Chromospherically Young, Kinematically Old Stars
| |
| | journal=Astronomy and Astrophysics
| |
| | pages = 912–924 | doi=10.1051/0004-6361:20011815
| |
| | year = 2001
| |
| | issue = 3 | bibcode = 2002A&A...384..912R
| |
| | volume = 384 |arxiv = astro-ph/0112452 }}</ref> It is thought to be a member of the ε Indi [[moving group]] of at least sixteen [[population I]] stars.<ref>{{cite journal
| |
| | last = Eggen | first = O. J.
| |
| | title=The zeta Herculis, sigma Puppis, ε Indi, and eta Cephei Groups of Old Disk Population Stars
| |
| | journal=Publications of the Astronomical Society of the Pacific
| |
| | year=1971 | volume=83 | issue=493 | pages=251–270
| |
| | bibcode=1971PASP...83..251E
| |
| | doi = 10.1086/129119 }}</ref> This is an association of stars that have similar [[stellar kinematics|space velocity]] vectors, and therefore most likely formed at the same time and location.<ref>{{cite journal
| |
| | last=Kollatschny | first=W.
| |
| | title=A model atmosphere of the late type dwarf Epsilon INDI
| |
| | journal=Astronomy and Astrophysics
| |
| | year=1980 | volume=86 | issue=3 | pages=308–314
| |
| | bibcode=1980A&A....86..308K }}</ref>
| |
| | |
| As seen from Epsilon Indi, the Sun is a 2nd-magnitude star in [[Ursa Major]], near the bowl of the [[Big Dipper]].<ref group="note">From Epsilon Indi the Sun would appear on the diametrically opposite side of the sky at the coordinates RA={{RA|10|03|21}}, Dec={{DEC|56|47|10}}, which is located near [[Beta Ursae Majoris]]. The absolute magnitude of the Sun is 4.8, so, at a distance of 3.63 parsecs, the Sun would have an apparent magnitude <math>\begin{smallmatrix}m\ =\ M_v\ +\ 5\cdot((\log_{10}\ 3.63)\ -\ 1)\ =\ 2.6\end{smallmatrix}</math>.</ref>
| |
| | |
| === Companions ===
| |
| [[Image:Eps2iall.jpg|thumb|left|Artist's conception of the Epsilon Indi system showing Epsilon Indi and the brown-dwarf binary companions.]]
| |
| | |
| In January 2003, astronomers announced the discovery of a [[brown dwarf]] with a mass of 40 to 60 [[Jupiter mass]]es in orbit around Epsilon Indi at a distance of at least 1,500 [[astronomical unit|AU]].<ref>{{cite news
| |
| | last=Scholz | first=Ralf-Dieter
| |
| | coauthors=McCaughrean, Mark | date=2003-01-13
| |
| | title=Discovery of Nearest Known Brown Dwarf: Bright Southern Star Epsilon Indi Has Cool, Substellar Companion
| |
| | publisher=European Southern Observatory
| |
| | url=http://www.eso.org/public/outreach/press-rel/pr-2003/pr-01-03.html
| |
| | accessdate=2006-05-24
| |
| }}{{dead link|date=January 2014}}</ref><ref>{{cite journal
| |
| | last=Scholz | first=R.-D.
| |
| | coauthors=McCaughrean, M. J.; Lodieu, N.; Kuhlbrodt, B.
| |
| | title=ε Indi B: A new benchmark T dwarf
| |
| | journal=Astronomy and Astrophysics
| |
| |date=February 2003 | volume=398
| |
| | issue=3 | pages=L29–L33
| |
| | bibcode=2003A&A...398L..29S
| |
| | doi=10.1051/0004-6361:20021847 |arxiv = astro-ph/0212487 }}</ref> In August 2003, astronomers discovered that this brown dwarf was actually a binary brown dwarf, with an apparent separation of 2.1 AU and an orbital period of about 15 years.<ref name=aaa510/><ref>{{cite journal
| |
| | last=Volk | first=K.
| |
| | coauthors=Blum, R.; Walker, G.; Puxley, P. | year=2003
| |
| | bibcode=2003IAUC.8188....2V
| |
| | journal=International Astronomical Union Circular
| |
| | issue=8188 | title=epsilon Indi B | publisher=IAU
| |
| | volume=8188
| |
| | pages=2 }}</ref> Both brown dwarfs are of [[spectral class T]]; the more massive component, ε Indi Ba, is of spectral type T1V–T1.5V and the less massive component, Epsilon Indi Bb, of spectral type T6V.<ref name=aaa510/>
| |
| | |
| Evolutionary models<ref>E.g., {{cite journal
| |
| | last=Baraffe | first=I.
| |
| | coauthors=Chabrier, G.; Barman, T.; Allard, F.; Hauschildt, P. H.
| |
| | title=Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458
| |
| | journal=Astronomy and Astrophysics
| |
| |date=May 2003 | volume=402
| |
| | issue=2 | pages=701–712
| |
| | bibcode=2003A&A...402..701B
| |
| | doi=10.1051/0004-6361:20030252 |arxiv = astro-ph/0302293 }}</ref> have been used to estimate the physical properties of these brown dwarfs from [[spectroscopic]] and [[photometry (astronomy)|photometric]] measurements. These yield masses of {{nowrap|47 ± 10}} and {{nowrap|28 ± 7}} times the mass of Jupiter, and radii of {{nowrap|0.091 ± 0.005}} and {{nowrap|0.096 ± 0.005}} [[solar radii]], for Epsilon Indi Ba and Epsilon Indi Bb, respectively.<ref>{{cite journal
| |
| | author=McCaughrean, M. J. ''et al.''
| |
| | title=ε Indi Ba, Bb: The nearest binary brown dwarf
| |
| | journal=Astronomy and Astrophysics
| |
| |date=January 2004 | volume=413
| |
| | issue=3 | pages=1029–1036
| |
| | bibcode=2004A&A...413.1029M
| |
| | doi=10.1051/0004-6361:20034292 |arxiv = astro-ph/0309256 }}</ref> The [[effective temperature]]s are 1300–1340 [[Kelvin|K]] and 880–940, while the log ''g'' (cm s<sup>−1</sup>) surface gravities are 5.50 and 5.25, and their luminosities are {{nowrap|1.9 × 10<sup>–5</sup>}} and {{nowrap|4.5 × 10<sup>–6</sup>}} the [[Solar luminosity|luminosity of the Sun]]. They have an estimated metallicity of [M/H] = –0.2.<ref name=aaa510/>
| |
| | |
| Measurements of the [[radial velocity]] of Epsilon Indi by Endl ''et al.'' (2002)<ref name="ESO2002">{{cite journal
| |
| | author=Endl, M.; Kürster, M.; Els, S.; Hatzes, A. P.; Cochran, W. D.; Dennerl, K.; Döbereiner, S.
| |
| | title=The planet search program at the ESO Coudé Echelle spectrometer. III. The complete Long Camera survey results
| |
| | journal=[[Astronomy and Astrophysics]] | volume=392
| |
| | issue=2
| |
| | pages=671–690 | year=2002 | bibcode=2002A&A...392..671E
| |
| | doi=10.1051/0004-6361:20020937|arxiv = astro-ph/0207512 }}</ref> appear to show a trend that indicated the presence of a planetary companion with an orbital period of more than 20 years. A substellar object with minimum mass of 1.6 Jupiter masses and orbital separation of roughly 6.5 AU could explain the observed trend. If confirmed, it would be a true Jupiter-analogue.
| |
| | |
| <!-- Now obsolete per Janson et al. (2009)
| |
| {{PlanetboxOrbit begin
| |
| | table_ref=<ref name="ESO2002" />
| |
| | period_unit=year
| |
| }}
| |
| {{PlanetboxOrbit hypothetical
| |
| | exoplanet = [[Epsilon Indi Ab|b]]
| |
| | mass = ≥1.6
| |
| | period = >20
| |
| | semimajor = 6.5
| |
| | eccentricity = 0
| |
| }}
| |
| {{PlanetboxOrbit end}}
| |
| -->
| |
| A visual search using the [[European Southern Observatory|ESO]]'s [[Very Large Telescope]] found one potential candidate. However, a subsequent examination by the [[Hubble Space Telescope]] [[Near Infrared Camera and Multi-Object Spectrometer|NICMOS]] showed that this was a background object.<ref>{{cite journal
| |
| | last=Geißler | first=K.
| |
| | coauthors=Kellner, S.; Brandner, W.; Masciadri, E.; Hartung, M.; Henning, T.; Lenzen, R.; Close, L.; Endl, M.; Kürster, M.
| |
| | title=A direct and differential imaging search for sub-stellar companions to epsilon Indi A
| |
| | journal=Astronomy and Astrophysics | year=2007
| |
| | volume=461 | issue=2 | pages=665–668
| |
| | bibcode=2007A&A...461..665G
| |
| | doi=10.1051/0004-6361:20065843 |arxiv = astro-ph/0611336 }}</ref> As of 2009, a search for an unseen companion at 4 μm failed to detect an orbiting object. These observations further constrained the hypothetical object to be 5–20 times the mass of Jupiter, orbiting between 10–20 AU and have an inclination of more than 20°. Alternatively, it may be an exotic stellar remnant.<ref>{{cite journal
| |
| |author=Janson, M. |coauthors=''et al.''
| |
| |title=Imaging search for the unseen companion to ε Ind A – improving the detection limits with 4 μm observations
| |
| |journal=Monthly Notices of the Royal Astronomical Society
| |
| |volume=399 |issue=1 |pages=377–384
| |
| |date=August 10, 2009 |doi=10.1111/j.1365-2966.2009.15285.x |bibcode=2009MNRAS.399..377J
| |
| |arxiv = 0906.4145 }}</ref>
| |
| | |
| New radial-velocity measurements on Epsilon Indi, using the Echelle spectrometer on the HARPS telescope, following up on Endl et al. (2002) research findings, were published in a paper recently by M. Zechmeister et al. in 2013. The new findings confirm that, quoting the paper, "Epsilon Ind A has a steady long-term trend still explained by a planetary companion".<ref name="Zechmeister et al" /> This updated research refines the radial-velocity trend previously observed and now indicate the presence of a planetary companion with an orbital period of greater than 30 years.<ref name="Zechmeister et al" /> A gas giant with a minimum mass of 0.97 Jupiter masses and a minimal orbital separation of roughly 9.0 AU could explain the observed trend. 9.0 AU is about the same distance out as [[Saturn]]. If confirmed, this would not quite qualify Epsilon Indi Ab as a true Jupiter analogue because it orbits considerably further out than 5.0 AU.<ref name="Zechmeister et al" /> Not only does it orbit further out than Jupiter, but Epsilon Indi A is also dimmer than the Sun, so Epsilon Indi Ab would only receive about the same amount of energy per square meter from Epsilon Indi A as [[Uranus]] does from the Sun. The radial-velocity trend was observed through all the observations so far taken using the HARPS telescope but due to the long time period predicted for just one orbit of Epsilon Indi Ab around Epsilon Indi A, more than 30 years, the astrometric phase coverage is not yet complete.<ref name="Zechmeister et al" />
| |
| | |
| {{OrbitboxPlanet begin
| |
| | name=unconfirmed Epsilon Indi A
| |
| | table_ref=<ref name="Zechmeister et al" />
| |
| | period_unit=year
| |
| }}
| |
| {{OrbitboxPlanet hypothetical
| |
| | exoplanet = b
| |
| | mass = ≳0.97
| |
| | period = >30
| |
| | semimajor = ≳8.57{{#tag:ref|Kepler's Third Law, assuming a circular orbit - <math>\begin{smallmatrix}\frac{4 \pi^2}{T^2} = \frac{G M}{R^3}\end{smallmatrix}</math> Mass and the Period are known from paper<ref name="Zechmeister et al" /> so equation can be written with semimajor axis as the subject - <math>\begin{smallmatrix}R = \sqrt[3]{\frac{GMT^2}{4\pi^2}}\end{smallmatrix}</math>.|group="note"|name=Kelper Circular}}
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| | eccentricity =
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| }}
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| {{Orbitbox end}}
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| This star has been examined in the [[infrared]] band of the [[electromagnetic spectrum]] in an effort to find an excess of radiation. The presence of an [[infrared excess]] can be taken as an indication of a [[debris disk]] orbiting the star. Such a disk can be formed from the collisions of [[planetesimal]]s that survive from the early period of the star's [[protoplanetary disk]]. However, no such excess was discovered around Epsilon Indi.<ref>{{cite journal
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| | url=http://www.iop.org/EJ/article/0004-637X/674/2/1086/72640.html
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| | author=Trilling, D. E. | coauthors=''et al''.
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| | title=Debris Disks around Sun-like Stars
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| | journal=The Astrophysical Journal | volume=674 | issue=2
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| | pages=1086–1105 |date=February 2008
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| | doi=10.1086/525514 | bibcode=2008ApJ...674.1086T |arxiv = 0710.5498 }}</ref>
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| == See also ==
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| * [[Stars and planetary systems in fiction#Epsilon Indi|Epsilon Indi in fiction]]
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| * [[List of nearest stars]]
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| == Notes ==
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| {{reflist|group=note}}
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| == References ==
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| {{reflist|30em|refs=
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| <ref name="van Leeuwen2007">{{cite journal | url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 }}</ref>
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| <ref name=aaa510>{{citation | title=ɛ Indi Ba, Bb: a detailed study of the nearest known brown dwarfs | display-authors=1 | last1=King | first1=R. R. | last2=McCaughrean | first2=M. J. | last3=Homeier, D. | last4=Allard | first4=F. | last5=Scholz | first5=R.-D. | last6=Lodieu | first6=N. | journal=Astronomy and Astrophysics | volume=510 |date=February 2010 | doi=10.1051/0004-6361/200912981 | bibcode=2010A&A...510A..99K |arxiv = 0911.3143 }}</ref>
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| <ref name="aaa86">{{cite journal |last=Kollatschny |first=W. |title=A model atmosphere of the late type dwarf Epsilon INDI |journal=Astronomy and Astrophysics |year=1980 |volume=86 |issue=3 |bibcode=1980A&A....86..308K |pages=308–314 }}</ref>
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| <ref name=sci299_5612_1552>{{cite journal | author=Jimenez, Raul; Flynn, Chris; MacDonald, James; Gibson, Brad K. | title=The Cosmic Production of Helium | journal=Science | volume=299 | issue=5612 | pages=1552−1555 |date=March 2003 | doi=10.1126/science.1080866 | bibcode=2003Sci...299.1552J | pmid=12624260 |arxiv = astro-ph/0303179 }}</ref>
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| <ref name=aaa348_897>{{cite journal | author=Lachaume, R.; Dominik, C.; Lanz, T.; Habing, H. J. | title=Age determinations of main-sequence stars: combining different methods | journal=Astronomy and Astrophysics | year=1999 | volume=348 | pages=897–909 | bibcode=1999A&A...348..897L }} — This paper gives a median log age = 9.11, with a range of min = 8.91 and max = 9.31. This corresponds to 1.3 Gyr, with an error range of 0.8–2.0 Gyr.</ref>
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| <ref name="SIMBAD">{{cite web | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=epsilon%20indi | title=SIMBAD Query Result: LHS 67 -- High proper-motion Star | publisher=Centre de Données astronomiques de Strasbourg | accessdate=2007-07-11 }}</ref>
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| <ref name=kaler>{{cite web | first=Jim | last1=Kaler |publisher=University of Illinois | url=http://stars.astro.illinois.edu/sow/epsind.html | title=Epsilon Indi | accessdate=2010-05-03 | work=Stars}}</ref>
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| <ref name="Zechmeister et al">{{cite journal | title=The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars | display-authors=9<!--Reducible--> | last1=Zechmeister | first1=M. | last2=Kürster | first2=M | last3=Endl | first3=M. | last4=Lo Curto | first4=G. | last5=Hartman | first5=H. | last6=Nilsson | first6=H. | last7=Henning | first7=T. | last8=Hatzes | first8=A. | | last8=Hatzes | first8=A. | last9=Cochran | first9=W. D. | journal=Astronomy and Astrophysics |date=April 2013 | volume=552 | pages=pp62 | doi=10.1051/0004-6361/201116551 | bibcode=2013A&A...552A..78Z | arxiv = 1211.7263 | url =}}.</ref>
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| }}
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| == External links ==
| |
| * [http://www.eso.org/public/news/eso0303/ Discovery of Nearest Known Brown Dwarf] (eso0303 : 13 January 2003)
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| * {{cite web |url=http://www.spaceref.com/news/viewpr.html?pid=12596 |title=Closest Known Brown Dwarf has a Companion |accessdate=2008-06-28 |work=SpaceRef.ca |publisher= |date=2003-09-19 }}
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| * {{cite web |url=http://www.solstation.com/stars/eps-indi.htm |title=Epsilon Indi |accessdate=2008-06-28 |work=SolStation |publisher= |date= }}
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| * {{cite web |url=http://www.astro.uiuc.edu/~kaler/sow/epsind.html |title=EPS IND |accessdate=2008-06-28 |work=STARS |publisher= |date= | last = Kaler | first = Jim }}
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| {{Sky|22|03|21.6571|−|56|47|09.514|11.83}}
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| {{Nearest systems|3}}
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| {{Stars of Indus}}
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| [[Category:Bayer objects|Indi, Epsilon]]
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| [[Category:Durchmusterung objects|PD-57 10015]]
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| [[Category:Henry Draper Catalogue objects|209100]]
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| [[Category:High-proper-motion stars]]
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| [[Category:Hipparcos objects|108870]]
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| [[Category:HR objects|8387]]
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| [[Category:Gliese and GJ objects|0845]]
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| [[Category:Indus (constellation)]]
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| [[Category:Hypothetical planetary systems]]
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| [[Category:K-type main-sequence stars]]
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| [[Category:T-type stars]]
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| [[Category:Objects within 100 ly of Earth]]
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