Epsilon Eridani

Epsilon Eridani

Starbox begin
name=Epsilon Eridani
Starbox observe
epoch=J2000.0
constell=Eridanus
ra=RA|03|32|55.8442cite web
url=http://simbad3.u-strasbg.fr/sim-id.pl?protocol=html&Ident=HD+22049
title=HD 22049 -- Variable of BY Dra type
work=SIMBAD
publisher=Centre de Données astronomiques de Strasbourg
accessdate=2007-11-29
]
dec=DEC|−09|27|29.744
appmag_v=3.73
Starbox character
class=K2V
b-v=+0.88cite journal
last=Mendoza | first=E. E.
coauthors=Gomez, V. T.; Gonzalez, S.
title=UBVRI photometry of 225 Am stars.
journal=Astronomical Journal
year=1978
volume=83
pages=606–614
url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1978AJ.....83..606M
accessdate=2007-11-29
doi=10.1086/112242
]
u-b=+0.58
r-i=+0.42
v-r=+0.50
variable=BY Draconis
Starbox astrometry
radial_v=+15.5±0.9
prop_mo_ra=−976.36
prop_mo_dec=17.98
parallax=310.74
p_error=0.85
parallax_footnote=
absmag_v=6.19
Starbox detail
age=(0.5–1.0)Esp|9cite journal
author=Di Folco, E. "et al"
title=VLTI near-IR interferometric observations of Vega-like stars. Radius and age of α PsA, β Leo, β Pic, ε Eri and τ Cet
journal=Astronomy and Astrophysics | year=2004
volume=426 | pages=601–617
url=http://adsabs.harvard.edu/abs/2004A&A...426..601D
accessdate=2008-07-24
]
metal= [Fe/H] =−0.13±0.04cite journal
last=Santos | first=N. C.
coauthors=Israelian, G.; Mayor, M.
title=Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
journal=Astronomy & Astrophysics | year=2004 | volume=415
pages=1153–1166
url=http://arxiv.org/abs/astro-ph/0311541
accessdate=2007-11-29
doi=10.1051/0004-6361:20034469
—the percentage of iron is given by egin{smallmatrix}10^{-0.13} = 0.74end{smallmatrix}, or 74%]
mass=0.85cite web
author=Staff | date=June 8, 2007
url=http://www.chara.gsu.edu/RECONS/TOP100.posted.htm
title=The One Hundred Nearest Star Systems
publisher=Research Consortium on Nearby Stars
accessdate=2007-11-29
]
radius=0.84cite journal
last=Johnson | first=H. M. | coauthors=Wright, C. D.
title=Predicted infrared brightness of stars within 25 parsecs of the sun
journal=Astrophysical Journal Supplement Series
year=1983 | volume=53 | pages=643–711
url=http://adsbit.harvard.edu/abs/1983ApJS...53..643J
accessdate=2007-11-29
doi=10.1086/190905
—see p. 653.]
rotation=11.1 days
gravity=4.57 [cite journal
author=Zhao, G.; Chen, Y. Q.; Qiu, H. M.; Li, Z. W.
title=Chemical Abundances of 15 Extrasolar Planet Host Stars
journal=The Astronomical Journal | year=2002
volume=124 | issue=4 | pages=2224–2232
url=http://www.journals.uchicago.edu/doi/full/10.1086/342862
accessdate=2007-06-01
doi=10.1086/342862
]
luminosity=0.28
temperature=5073±42
Starbox reference
Simbad = HD+22049
Starbox catalog
names = 18 Eridani, BD -09°697, GCTP 742.00, GJ 144, HD 22049, HIP 16537, HR 1084, LHS 1557, SAO 130564, WDS 03330-0928

Epsilon Eridani (ε Eri / ε Eridani) is a main-sequence K2 class star. It is the closest star in the constellation Eridanus, as well as the third closest star visible to the naked eye. This star has an estimated age of less than a billion years. Because of its relative youth, this star has a higher level of magnetic activity than the Sun and its stellar wind is an estimated 30 times as strong. The rotation period is a relatively rapid 11.1 days, although this varies by latitude. Epsilon Eridani is both smaller and less massive than the Sun, with a lower level of metallicity, or elements with a higher atomic number than helium.

In 2006, a planet was confirmed in orbit around this star. This planet completes an orbit every 2502 days at a mean distance of 3.4 Astronomical Units (505 million kilometers) from the star. As of 2008, Epsilon Eridani is the nearest star to the Sun that is known to have a planet. The star also has an orbiting disk of dust, and perturbations in this material may be caused by an unconfirmed second planet.

Due to it being a relatively close and Sun-like star, Epsilon Eridani regularly appears in science fiction. Its closest neighbor is Luyten 726-8 (UV Ceti and BL Ceti) at 5.22 light-years away.Fact|date=July 2008

Observation

This star is located in the northern part of the constellation Eridanus, about 3° east of the slightly brighter star Delta Eridani. With a declination of −9.45°, Epsilon Eridani can be viewed from much of the Earth's surface. Only to the north of latitude 80° N is it permanently hidden below the horizon. [cite book
first=William Wallace | last=Campbell | year=1899
title=The Elements of Practical Astronomy
publisher=The MacMillan Company
location=New York
] The apparent magnitude of 3.73 can make this star difficult to observe from an urban area with the unaided eye, as the night skies over cities are illuminated by light pollution. [cite book
first=Kohei | last=Narisada
coauthors=Schreuder, Duco | year=2004
title=Light Pollution Handbook
publisher=Springer
isbn=140202665X
]

The Bayer designation for this star was established in 1603 as part of the "Uranometria", a star catalog produced by Johann Bayer. Epsilon is the fifth letter in the Greek alphabet, and it was assigned to the fifth brightest star in the constellation of Eridanus. [cite book
first=Nick | last=Kanas | year=2007
title=Star Maps: History, Artistry, and Cartography
publisher=Springer
isbn=0387716688
] The preliminary version of the star catalog by John Flamsteed, published in 1712, gave this star the Flamsteed designation 18 Eridani. In 1918 this star appeared in the "Henry Draper Catalogue" with the designation HD 22049 and a preliminary spectral classification of K0. [cite journal
last=Cannon | first=Annie J.
coauthors=Pickering, Edward C.
title=The Henry Draper catalogue 0h, 1h, 2h, and 3h
journal=Annals of Harvard College Observatory
year=1918 | volume=91 | pages=1–290
url=http://adsabs.harvard.edu/abs/1918AnHar..91....1C
accessdate=2008-07-21
—see p. 236
]

Based on observations between 1800 and 1880, Epsilon Eridani was found to have a large proper motion, which at the time was estimated at three arcseconds annually. This implied a relatively close proximity to the Sun, [cite book
first=Leila | last=Belkora | year=2002
title=Minding the Heavens: The Story of Our Discovery of the Milky Way
publisher=CRC Press | isbn=0750307307
] making it a star of interest for the purpose of trigonometric parallax measurements. [cite journal
last=Gill | first=David | coauthors=Elkin, W. L.
title=Heliometer Determinations of Stellar Parallaxes in the Southern Hemisphere
journal=Memoirs of the Royal Astronomical Society
year=1884 | volume=48 | pages=77–115
url=http://books.google.com/books?id=F60RAAAAYAAJ
accessdate=2008-07-21
—see pp. 174–80
] From 1881–3, William L. Elkin made a series of heliometric measurements from the Royal Observatory at the Cape of Good Hope, South Africa. As a result of these observations, a preliminary parallax of 0.14 ± 0.02 arcseconds was computed for Epsilon Eridani. [cite book
first=David | last=Gill | year=1893
title=Heliometer Observations for Determination of Stellar Parallax
publisher=Eyre and Spottiswoode | location=London
] [cite journal
last=Gill | first=David | title=The Fixed Stars
journal=Nature | year=1884 | volume=30
pages=156–159
] By 1917, observers had refined their parallax estimate to 0.317 arcseconds, [cite journal
last=Adams | first=W. S. | coauthors=Joy, A. H.
title=The luminosities and parallaxes of five hundred stars.
journal=Astrophysical Journal | year=1917
volume=46 | pages=313–339
url=http://adsabs.harvard.edu/abs/1917ApJ....46..313A
accessdate=2008-07-19
] which is quite close to the modern value of 0.3107 arcseconds. This parallax is equivalent to a distance of about 10.5 light years, making Epsilon Eridani the 13th nearest known star (and ninth nearest stellar system) to the Sun.

The OZMA Project, headed by Dr. Frank Drake, was intended to search for signals from an
extraterrestrial intelligence using a radio telescopeat Green Bank, West Virginia. The target stars chosen for this project were the two nearest solitary Sun-like stars, Epsilon Eridani and Tau Ceti. However, no signal of extraterrestrial origin was detected. (A false signal was detected on April 8, 1960 that originated from a high-flying aircraft.) [cite book
first=Jean | last=Heidmann | coauthors=Dunlop, Storm
year=1995 | title=Extraterrestrial intelligence
publisher=Cambridge University Press
isbn=0521585635
] In 1995, based on its location within 7.2 pc, Epsilon Eridani was among the target stars of Project Phoenix, a microwave survey for signals from extraterrestrial intelligence. [cite conference
author=Henry, T. "et al"
title=The Current State of Target Selection for NASA's High Resolution Microwave Survey
booktitle=Progress in the Search for Extraterrestrial Life
pages=207–218
publisher=Astronomical Society of the Pacific
date=August 16-20,1993 | location=Santa Cruz, California
url=http://adsabs.harvard.edu/abs/1995ASPC...74..207H
accessdate=2008-07-22
] By 2004 Project Phoenix had checked about 800 stars, but had not yet detected an unimpeachable signal. [cite news
last=Whitehouse | first=David | date=2004-03-25
title=NASA's Hubble Space Telescope Finds "Blue Straggler" Stars in the Core of a Globular Cluster
publisher=BBC News
url=http://news.bbc.co.uk/1/hi/sci/tech/3567729.stm
accessdate=2008-07-22
]

Based on perturbations in the position of Epsilon Eridani between 1938 and 1972, it was suspected that the star had an unseen companion with an orbital period of 25 years. [cite journal
last=van de Kamp | first=P.
title=Parallax and orbital motion of Epsilon Eridani.
journal=Astronomical Journal | year=1974
volume=79 | pages=491–492
url=http://adsabs.harvard.edu/abs/1974AJ.....79..491V
accessdate=2008-07-28
] However, this claimwas refuted in 1993. Radial velocity observations between 1980 and 2000 then provided convincing evidence of a planetary companion orbiting the star with a period of about seven years. [cite journal
author=Hatzes, Artie P. "et al"
title=Evidence for a Long-period Planet Orbiting Epsilon Eridani
journal=The Astrophysical Journal | year=2000
volume=544 | issue=2 | pages=L145–L148
doi=10.1086/317319
] The evidence for a planetary system was further strengthened by the discovery of a ring of dust orbiting the star in 1998. This dust showed concentrations that could be explained by interaction with a nearby planet. [cite news
last=Greaves | first=Jane | date=1998-07-08
title=Astronomers discover a nearby star system just like our own Solar System
url=http://www.jach.hawaii.edu/~jsg/kbelt.html
publisher=JAC/UCLA | accessdate=2008-07-28
] In 2006, the existence of a planet with a 6.9 year orbit was confirmed using the Hubble Space Telescope. [cite journal
author=Benedict, G. Fritz; McArthur, Barbara E. "et al"
title=The Extrasolar Planet ε Eridani b: Orbit and Mass
journal=The Astronomical Journal | year=2006
volume=132 | issue=5 | pages=2206–2218
url=http://adsabs.harvard.edu/abs/2006AJ....132.2206B
accessdate=2008-07-28
]

Properties

Epsilon Eridani has an estimated 85% of the Sun's mass and 84% of the Sun's radius, but has only 28% of its luminosity. It is the second nearest spectral class K star after α Centauri B. Compared to the Sun, this star is considered slightly low in the abundance of elements with atomic numbers higher than helium. Epsilon Eridani has only about 74% of the Sun's abundance of iron in its chromosphere.

The chromosphere of Epsilon Eridani is more magnetically active than the Sun. Approximately 9% of the deep photosphere is found to have a magnetic field with a strength about 0.14 Tesla. [cite journal
last=Valenti | first=Jeff A.
coauthors=Marcy, Geoffrey W.; Basri, Gibor
title=Infrared Zeeman analysis of epsilon Eridani
journal=The Astrophysical Journal, Part 1
year=1995 | volume=439 | issue=2 | pages=939-956
url=http://adsabs.harvard.edu/abs/1995ApJ...439..939V
accessdate=2008-07-19
] The overall magnetic activity level of this star is irregular but it may vary with a five year period. Assuming that the radius of the star does not change over this interval, then the variation in activity level appears to produce a temperature variation of 15 K, which corresponds to a magnitude variation of 0.014.cite journal
last=Gray | first=David F.
coauthors=Baliunas, Sallie L.
title=Magnetic activity variations of epsilon Eridani
journal=Astrophysical Journal, Part 1 | year=1995
volume=441 | issue=1 | pages=436–442
url=http://adsabs.harvard.edu/abs/1995ApJ...441..436G
accessdate=2008-07-19
]

Rotational modulation of the magnetic activity shows that the equator of the star rotates with a 11.10 ± 0.03 day period, or more than double the rotation period of the Sun. Stars that vary in magnitude because of magnetic activity coupled with rotation are classified as BY Draconis variables. Photometry has also shown that the surface of Epsilon Eridani, like the Sun, is undergoing differential rotation. That is, the rotation period at the surface varies by latitude, with the measured periods ranging from 10.8 to 12.3 days. The axial tilt of this star remains uncertain, with estimates ranging from a low of 24° up to 72°. [cite journal
last=Froehlich | first=H.-E.
title=The differential rotation of epsilon Eri from MOST data
journal=Astronomische Nachrichten
year=2007 | volume=328 | pages=1037
url=http://arxiv.org/abs/0711.0806
accessdate=2008-07-25
]

The high level of chromospheric activity, strong magnetic field and the relatively high rotation rate indicate that this is a young star. [cite journal
last=Drake | first=Jeremy J. | coauthors=Smith, Geoffrey
title=The fundamental parameters of the chromospherically active K2 dwarf Epsilon Eridani
journal=Astrophysical Journal, Part 1 | year=1993
volume=412 | issue=2 | pages=797–809
url=http://adsabs.harvard.edu/abs/1993ApJ...412..797D
accessdate=2008-07-24
] Computer models give anestimated age of 700–850 million years, although the actual age may be a low as 500 million or as high as a billion years. However, the somewhat low abundance of heavy elements is characteristic of a much older star. This anomaly might be caused by a diffusion process that has transported some of the helium and heavier elements out of the photosphere to a region below the star's outer convection zone. [cite web
last=Gai | first=Ning
coauthors=Bi, Shao-Lan; Tang, Yan-Ke | year=2008
url=http://adsabs.harvard.edu/abs/2008arXiv0806.1811G
title=Modeling ε Eridani and asteroseismic tests of element diffusion
publisher=SAO/NASA ADS | accessdate=2008-07-24
]

Relative to the Sun, the outer atmosphere of Epsilon Eridani appears both larger and hotter. This is caused by a 30-fold higher mass loss rate from the star's stellar wind. The wind is generating an astrosphere that spans about 8,000 AU and a bow shock that lies 1,600 AU from the star. At the star's estimated distance from the Earth, this astrosphere would span an angle of 42 arcminutes, which is wider than the appearance of a full Moon. [cite journal
last=Wood | first=Brian E.
coauthors=Müller, Hans-Reinhard; Zank, Gary P.; Linsky, Jeffrey L.
title=Measured Mass-loss Rates of Solar-like Stars as a Function of Age and Activity
journal=The Astsophysical Journal | year=2002
volume=574 | pages=1–2
doi=10.1086/340797
]

The space velocity components of Epsilon Eridani are U = −3, V = +7 and W = −20 km/s. It is orbiting within the Milky Way at a mean galactocentric distance of 8.8 kpc and an orbital eccentricity of 0.09. [cite journal
last=de Mello | first=G. F. Porto
coauthors=del Peloso, E. F.; Ghezzi, L.
title=Astrobiologically Interesting Stars within 10 parsecs of the Sun
journal=Astrobiology | year=2005
volume=6 | issue=2 | pages=308–331
url=http://arxiv.org/abs/astro-ph/0511180
accessdate=2008-07-27
] During the past million years, three stars are believed to have come within two parsecs of Epsilon Eridani. The most recent encounter was with Kapteyn's Star, which approached within about a parsec about 12,500 years ago. None of these encounters are thought to have affected the circumstellar disk. [cite conference
last=Deltorn | first=J.-M. | coauthors=Kalas, P.
editors=Jayawardhana, Ray; Greene, Thoas
title=Search for Nemesis Encounters with Vega, epsilon Eridani, and Fomalhaut
booktitle=Young Stars Near Earth: Progress and Prospects
pages=227-232 | year=2001
publisher=Astronomical Society of the Pacific
location =San Francisco, CA
url=http://arxiv.org/abs/astro-ph/0105284
accessdate=2008-07-22 | isbn=1-58381-082-X
] Epsilon Eridani made its closest approach to the Solar System about 105,000 years ago, when the two stars were separated by seven light years.cite journal
last=García-Sánchez | first=J.
coauthors=Weissman, P. R.; Preston, R. A.; Jones, D. L.; Lestrade, J.-F.; Latham, D. W.; Stefanik, R. P.; Paredes, J. M.
title=Stellar encounters with the solar system
journal=Astronomy and Astrophysics
year=2001 | volume=379 | pages=634–659
url=http://adsabs.harvard.edu/abs/2001A&A...379..634G
accessdate=2008-06-12
doi=10.1051/0004-6361:20011330
]

Planetary system

PlanetboxOrbit
exoplanet = b
mass = 1.55 ± 0.24
period = 2502 ± 10
semimajor = 3.39 ± 0.36
eccentricity = 0.702 ± 0.039
OrbitboxPlanet disk
disk = Dust disk
periapsis = 30
apoapsis =
PlanetboxOrbit speculation
exoplanet = c
mass = 0.1
period = 102200
semimajor = 40
eccentricity = 0.3

Planets

As Epsilon Eridani is one of the nearest solar-type stars to our Sun, many attempts to search for orbiting planets have been made. However, the star's high activity and variability means that finding planets with the radial velocity method is difficult, and stellar activity may mimic the presence of planets.Fact|date=July 2008

There is one confirmed planet in the system, and one unconfirmed. A 2500 day-period Jupiter-like planet Epsilon Eridani b orbits at 3.39 AU in one of the most eccentric orbit of any extrasolar planets — 0.7. A possible 280 year-period low-mass planet Epsilon Eridani c orbits at 40 AU in a less eccentric orbit — 0.3.

No bodies of 3 or more Jupiter masses exist in this system. [cite arXiv | title=A comprehensive examination of the e Eri system |author=Markus Janson "et al." | class=astro-ph |year=2008 | eprint=0807.0301v1]

In the 1964 RAND Corporation study, "Habitable Planets for Man" by Stephen R. Dole, the odds of a habitable planet in orbit around Epsilon Eridani were estimated as 3.3%. Among the known stars within 22 light years, it was listed with the 14 stars that were thought most likely to have a habitable planet. [cite book
first=Stephen H. | last=Dole
year=1964 | title=Habitable Planets for Man
publisher=Blaisdell Publishing Company
location=New York | edition=First edition
url=http://www.rand.org/pubs/commercial_books/CB179-1/
accessdate=2008-07-22
] The maximum habitable zone for Epsilon Eridani currently stretches from about 0.5–1.0 Astronomical Units (A.U.), where an A.U. is equal to the average distance between Earth and the Sun. As the star ages over a period of 20 billion years, this zone will slowly expand outward to about 0.6–1.4 A.U. [cite journal
last=Underwood | first=David R.
coauthors=Jones, Barrie W.; Sleep, P. Nick
title=The evolution of habitable zones during stellar lifetimes and its implications on the search for extraterrestrial life
journal=International Journal of Astrobiology
year=2003 | volume=2 | pages=289-299
doi=10.1017/S1473550404001715
url=http://arxiv.org/abs/astro-ph/0312522
accessdate=2008-07-22
] However, the presence of a large planet with a highly elliptical orbit in proximity to the habitable zone of the star reduces the likelihood of a terrestrial planet having a stable orbit within the habitable zone. [cite conference
first=Barrie W. | last=Jones
coauthors=Underwood, David R.; Sleep, P. Nick
title=The Stability of the Orbits of Earth-mass Planets in and near the Habitable Zones of Known Exoplanetary Systems
booktitle=Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets
pages=625–630 | publisher=Dordrecht, D. Reidel Publishing Co.
date=April 22-25, 2003 | location=Heidelberg, Germany
url=http://arxiv.org/abs/astro-ph/0305500
accessdate=2008-07-22 | isbn=92-9092-849-2
]

The presence of an outer planet in orbit around Epsilon Eridani would have a perturbing effect on cometary bodies within the dust ring. Some of these bodies would fall toward the inner part of the system, and could cross any planetary orbits within 1 AU of the star. Thus, a terrestrial planet would be subject to bombardment similar to what happened to the Earth during its first 600 million years with the Late Heavy Bombardment.cite journal
author=Greaves, J. S. "et al"
title=Structure in the ε Eridani Debris Disk
journal=The Astrophysical Journal
year=2005 | volume=619 | issue=2 | pages=L187-L190
url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005ApJ...619L.187G
accessdate=2008-07-30
]

Epsilon Eridani is a target for planet finding programs because it has the properties to allow an Earthlike planet to form. Although this system was not chosen as a primary candidate for the now-cancelled Terrestrial Planet Finder, it is a target star for NASA's proposed Space Interferometry Mission that will search for Earth-sized planets. [cite web
last=McCarthy | first=Chris | year=2008
url=http://tauceti.sfsu.edu/~chris/SIM/
title=Space Interferometery Mission: Key Science Project
publisher=Exoplanets Group, San Francisco State University
accessdate=2008-07-22
]

Dust disk

Observations with the James Clerk Maxwell Telescope showed a extended flux of radiation with sub-millimetre wavelengths at a radius of 35 arcseconds around the star. The peak emission occurs at an angular radius of 18 arcseconds, which at the distance of the star corresponds to a distance of about 60 AU. A lower level of emission is also seen at 30 AU. This emission was interpreted as coming from an analog of the Kuiper Belt in the Solar System; a compact dusty disk structure surrounding the star. The belt is being viewed at an inclination of roughly 25° to the line of sight. [cite journal
last=Greaves | first=J. S.
coauthors=Holland, W. S.; Moriarty-Schieven, G.; Jenness, T.; Dent, W. R. F.; Zuckerman, B.; McCarthy, C.; Webb, R. A.; Butner, H. M.; Gear, W. K.; Walker, H. J.
title=A Dust Ring around epsilon Eridani: Analog to the Young Solar System
journal=The Astrophysical Journal | year=1998
volume=506 | issue=2 | pages=L133–L137
url=http://adsabs.harvard.edu/abs/1998ApJ...506L.133G
accessdate=2008-07-29
]

The asymmetrical structure of the dust belt may be explained as the gravitational perturbation by a planet. The clumps in the dust occur at orbits that have an integer resonance with the orbit of the suspected planet. Thus, for example, the region of the disk that completes two orbits for every three orbits of a planet are in 3:2 resonance. [cite journal
last=Ozernoy | first=Leonid M.
coauthors=Gorkavyi, Nick N.; Mather, John C.; Taidakova, Tanya A.
title=Signatures of exosolar planets in dust debris disks
journal=The Astrophysical Journal Letters
year=2000 | volume=537 | pages=L147–L151
doi=10.1086/312779
] With computer simulations,the ring morphology can be reproduced by the capture of dust particles in 5:3 and 3:2 orbital resonances with a planet that has an orbital eccentricity of about 0.3. [cite journal
first=A. C. | last=Quillen | coauthors=Thorndike, Stephen
title=Structure in the ε Eridani Dusty Disk Caused by Mean Motion Resonances with a 0.3 Eccentricity Planet at Periastron
journal=Astrophysical Journal | volume=578
issue=2 | year=2002 | pages=L149–L142
url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2002ApJ...578L.149Q
accessdate=2008-07-30 | doi=10.1086/344708
]

The dust disk contains approximately 1000 times more dust than is present in the inner system around our Sun, which may mean it has about 1000 times as much cometary material as our solar system.Fact|date=July 2008 The dust has an estimated mass equal to a sixth of mass of the Moon. This dust is being generated by the collision of comets, which range up to 10 to 30 km in diameter and have a combined mass of 5 to 9 times the mass of the Earth. This is similar to the estimated 10 Earth masses in the Kuiper Belt.

Within 35 AU of the star the dust is depleted, which may mean that the system has formed planets which have cleared out the dust in this region. This is consistent with currently accepted models of the inner solar system, and so there may be terrestrial planets around the star.

See also

* Epsilon Eridani in fiction
* List of nearest stars

Footnotes and references

External links

*cite web| url=http://www.jach.hawaii.edu/~jsg/kbelt.html | title=Astronomers discover a nearby star system just like our own Solar System | work=JAC/UCLA |accessmonthday=24 March | accessyear=2005
*cite journal | url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1988ApJ...331..902C&db_key=AST&high=38e0b7728702919 | author=Bruce Campbell, G.A.H. Walker, S. Yang | title=A search for substellar companions to solar-type stars | journal=Astrophysical Journal | volume=331 | issue=Part 1|year=1988|pages=902 – 921 | doi=10.1086/166608
*cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/422796 | author=Sean Moran, Marc Kuchner, and Matthew Holman | title=The Dynamical Influence of a Planet at Semimajor Axis 3.4 AU on the Dust around ε Eridani | journal=The Astrophysical Journal | volume=612 | year=2004 | pages=1163 – 1170 | doi=10.1086/422796
*
*


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  • Épsilon Eridani — Epsilon Eridani es una estrella que está situada a unos 10,5 millones de años luz de la Tierra,tiene un planeta que orbita a su alrededor. Esta novedad fue descubierta por los astrónomos del Telescopio Hubble. La Epsilon Eridani es una estrella… …   Enciclopedia Universal

  • Epsilon Eridani — Datenbanklinks zu Epsilon Eridani Stern ε Eridani …   Deutsch Wikipedia

  • Epsilon Eridani — Pour les articles homonymes, voir Epsilon (homonymie). ε (Epsilon) Eridani …   Wikipédia en Français

  • Epsilon Eridani c — Planetbox begin name = Epsilon Eridani cPlanetbox image caption = An artist s impression of Epsilon Eridani c outside the debris disc.Planetbox star star = Epsilon Eridani constell = Eridanus RA = RA|03|32|55.8442 DEC = DEC|−09|27|29.744 dist ly …   Wikipedia

  • Epsilon Eridani b — Pour les articles homonymes, voir Epsilon (homonymie). Epsilon Eridani b …   Wikipédia en Français

  • Epsilon Eridani b — Planetbox begin name = Epsilon Eridani bPlanetbox image caption = An artist s Epsilon Eridiani b staring at its parent sun.Planetbox star star = Epsilon Eridani constell = Eridanus RA = RA|03|32|55.8442 DEC = DEC|−09|27|29.744 dist ly = 10.5 ±… …   Wikipedia

  • Epsilon Eridani in fiction — As a Sun like star relatively close to the Solar System, Epsilon Eridani regularly appears in science fiction:Literature* In Kathy Tyers novel Shivering World , Goddard orbits Epsilon Eridani. * In Gordon Dickson s Childe Cycle (1959 1988) the… …   Wikipedia

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