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90377 Sedna
For other uses, see Sedna (disambiguation).
Observatory), and David Rabinowitz (Yale University) on
November 14, 2003. The discovery formed part of a survey begun in 2001 with the Samuel Oschin telescope at
Palomar Observatory near San Diego, California using
Yale’s 160 megapixel Palomar Quest camera. On that
day, an object was observed to move by 4.6 arcseconds
over 3.1 hours relative to stars, which indicated that its
distance was about 100 AU. Follow-up observations in
November–December 2003 with the SMARTS telescope
at Cerro Tololo Inter-American Observatory in Chile as
well as with the Tenagra IV telescope at the Keck Observatory on Mauna Kea in Hawaii revealed that the object
was moving along a distant highly eccentric orbit. Later,
the object was precovered on older images made by the
Samuel Oschin telescope as well as on images from the
Near-Earth Asteroid Tracking consortium. These previous positions expanded its known orbital arc and allowed
a more precise calculation of its orbit.[13]
90377 Sedna is a large minor planet in the outer reaches
of the Solar System that was, as of 2015, at a distance
of about 86 astronomical units (AU) from the Sun, about
three times as far as Neptune. Spectroscopy has revealed
that Sedna’s surface composition is similar to that of some
other trans-Neptunian objects, being largely a mixture of
water, methane, and nitrogen ices with tholins. Its surface
is one of the reddest among Solar System objects. It is
most likely a dwarf planet.
For most of its orbit, it is even farther from the Sun than
at present, with its aphelion estimated at 937 AU[4] (31
times Neptune’s distance), making it one of the most distant known objects in the Solar System other than longperiod comets.[lower-alpha 2][lower-alpha 3]
Sedna has an exceptionally long and elongated orbit, taking approximately 11,400 years to complete and a distant
point of closest approach to the Sun at 76 AU. These facts
have led to much speculation about its origin. The Minor
Planet Center currently places Sedna in the scattered disc,
a group of objects sent into highly elongated orbits by the
gravitational influence of Neptune. However, this classification has been contested, because Sedna never comes
close enough to Neptune to have been scattered by it,
leading some astronomers to conclude that it is in fact
the first known member of the inner Oort cloud. Others
speculate that it might have been tugged into its current
orbit by a passing star, perhaps one within the Sun’s birth
cluster (an open cluster), or even that it was captured from
another star system. Another hypothesis suggests that its
orbit may be evidence for a large planet beyond the orbit
of Neptune.
1.2 Naming
Astronomer Michael E. Brown, co-discoverer of Sedna
and the dwarf planets Eris, Haumea, and Makemake,
thinks that it is the most scientifically important transNeptunian object found to date, because understanding its unusual orbit is likely to yield valuable information about the origin and early evolution of the Solar
System.[12]
“Our newly discovered object is the coldest most distant place known in the Solar System”, said Mike Brown
on his website, “so we feel it is appropriate to name it
in honor of Sedna, the Inuit goddess of the sea, who
is thought to live at the bottom of the frigid Arctic
Ocean.”[14] Brown also suggested to the International Astronomical Union's (IAU) Minor Planet Center that any
future objects discovered in Sedna’s orbital region should
also be named after entities in arctic mythologies.[14]
The team made the name “Sedna” public before the object had been officially numbered.[15] Brian Marsden, the
head of the Minor Planet Center, said that such an action was a violation of protocol, and that some members
of the IAU might vote against it.[16] However, no objection was raised to the name, and no competing names
were suggested. The IAU’s Committee on Small Body
Nomenclature formally accepted the name in September
2004,[17] and also considered that, in similar cases of extraordinary interest, it might in the future allow names to
be announced before they were officially numbered.[15]
1
2 Orbit and rotation
1.1
History
Discovery
Sedna has the longest orbital period of any known
large object in the Solar System,[lower-alpha 3] calculated at
Sedna (provisionally designated 2003 VB12 ) was discov- around 11,400 years.[4][lower-alpha 1] Its orbit is extremely
ered by Michael Brown (Caltech), Chad Trujillo (Gemini eccentric, with an aphelion estimated at 937 AU[4] and a
1
2
3
PHYSICAL CHARACTERISTICS
Artist’s impression of Sedna
The orbit of Sedna (red) set against the orbits of outer Solar System objects (Pluto’s orbit is purple).
perihelion at about 76 AU. This perihelion was the largest
of that of any known Solar System object until the discovery of 2012 VP113.[18][19] When Sedna was discovered it was 89.6 AU[20] from the Sun approaching perihelion, and was the most distant object in the Solar System
yet observed. Eris was later detected by the same survey
at 97 AU. Only the orbits of some long-period comets
extend farther than that of Sedna; they are too dim to
be discovered except when approaching perihelion in the
inner Solar System. Even as Sedna nears its perihelion
in mid 2076,[10][lower-alpha 4] the Sun would appear merely
as an extremely bright star-like pinpoint in its sky, 100
times brighter than a full moon on Earth (for comparison, the Sun appears from Earth to be roughly 400,000
times brighter than the full Moon), and too far away to be
visible as a disc to the naked eye.[21]
Pluto in 1930. In 2004, the discoverers placed an upper limit of 1,800 km on its diameter,[26] but by 2007
this was revised downward to less than 1,600 km after
observation by the Spitzer Space Telescope.[27] In 2012,
measurements from the Herschel Space Observatory suggested that Sedna’s diameter was 995 ± 80 km, which
would make it smaller than Pluto’s moon Charon.[6] Because Sedna has no known moons, determining its mass
is currently impossible without sending a space probe.
Observations from the SMARTS telescope show that in
visible light Sedna is one of the reddest objects in the
Solar System, nearly as red as Mars.[14] Chad Trujillo
and his colleagues suggest that Sedna’s dark red colour
is caused by a surface coating of hydrocarbon sludge,
or tholin, formed from simpler organic compounds after
long exposure to ultraviolet radiation.[28] Its surface is homogeneous in colour and spectrum; this may be because
Sedna, unlike objects nearer the Sun, is rarely impacted
by other bodies, which would expose bright patches of
fresh icy material like that on 8405 Asbolus.[28] Sedna and
two other very distant objects – 2006 SQ372 and (87269)
When first discovered, Sedna was thought to have an
2000 OO67 – share their color with outer classical Kuiper
[21]
unusually long rotational period (20 to 50 days).
It
belt objects and the centaur 5145 Pholus, suggesting a
was initially speculated that Sedna’s rotation was slowed
similar region of origin.[29]
by the gravitational pull of a large binary companion,
similar to Pluto's moon Charon.[14] A search for such a Trujillo and colleagues have placed upper limits in
satellite by the Hubble Space Telescope in March 2004 Sedna’s surface composition of 60% for methane ice and
found nothing,[22][lower-alpha 5] and subsequent measure- 70% for water ice.[28] The presence of methane further
ments from the MMT telescope suggest a much shorter supports the existence of tholins on Sedna’s surface, berotation period of about 10 hours, rather typical for a cause they are produced by irradiation of methane.[30]
Barucci and colleagues compared Sedna’s spectrum with
body of its size.[24]
that of Triton and detected weak absorption bands belonging to methane and nitrogen ices. From these observations, they suggested the following model of the
3 Physical characteristics
surface: 24% Triton-type tholins, 7% amorphous carbon, 10% nitrogen, 26% methanol, and 33% methane.[31]
Sedna has a V-band absolute magnitude (H) of about The detection of methane and water ices was confirmed
1.8, and it is estimated to have an albedo of about in 2006 by the Spitzer Space Telescope mid-infrared
0.32, thus giving it a diameter of approximately 1,000 photometry.[30] The presence of nitrogen on the surface
km.[6] At the time of its discovery it was the intrinsi- suggests the possibility that, at least for a short time,
cally brightest object found in the Solar System since Sedna may have a tenuous atmosphere. During a 200-
3
year period near perihelion, the maximum temperature
on Sedna should exceed 35.6 K (−237.6 °C), the transition temperature between alpha-phase solid N2 and the
beta phase seen on Triton. At 38 K, the N2 vapor pressure would be 14 microbar (1.4 Pa or 0.000014 atm).[31]
However, its deep red spectral slope is indicative of high
concentrations of organic material on its surface, and its
weak methane absorption bands indicate that methane on
Sedna’s surface is ancient, rather than freshly deposited.
This means that Sedna is too cold for methane to evaporate from its surface and then fall back as snow, which
happens on Triton and probably on Pluto.[30]
esis has also been advanced by both Alessandro Morbidelli and Scott Jay Kenyon.[39][40] Computer simulations by Julio A. Fernandez and Adrian Brunini suggest
that multiple close passes by young stars in such a cluster would pull many objects into Sedna-like orbits.[13] A
study by Morbidelli and Levison suggested that the most
likely explanation for Sedna’s orbit was that it had been
perturbed by a close (approximately 800 AU) pass by another star in the first 100 million years or so of the Solar
System’s existence.[39][41]
Models of internal heating via radioactive decay suggest
that Sedna might be capable of supporting a subsurface
ocean of liquid water.[32]
4
Origin
In their paper announcing the discovery of Sedna, Mike
Brown and his colleagues described it as the first observed
body belonging to the Oort cloud, the hypothetical cloud
of comets thought to exist nearly a light-year from the
Sun. They observed that, unlike scattered disc objects
such as Eris, Sedna’s perihelion (76 AU) is too distant
for it to have been scattered by the gravitational influence of Neptune.[13] Because it is a great deal closer to
the Sun than was expected for an Oort cloud object, and
has an inclination roughly in line with the planets and the
Kuiper belt, they described the planetoid as being an “inner Oort cloud object”, situated in the disc reaching from
the Kuiper belt to the spherical part of the cloud.[33][34]
Comparison of Sedna with the other largest trans-Neptunian objects and with Earth (all to scale)
The trans-Neptunian planet hypothesis has been advanced in several forms by a number of astronomers, including Rodney Gomes and Patryk Lykawka. One scenario involves perturbations of Sedna’s orbit by a hypothetical planetary-sized body in the inner Oort cloud. Recent simulations show that Sedna’s orbital traits could be
explained by perturbations by a Neptune-mass object at
2,000 AU (or less), a Jupiter-mass (MJ) at 5,000 AU,
or even an Earth-mass object at 1,000 AU.[38][42] Computer simulations by Patryk Lykawka have suggested that
Sedna’s orbit may have been caused by a body roughly the
size of Earth, ejected outward by Neptune early in the Solar System’s formation and currently in an elongated orbit
between 80 and 170 AU from the Sun.[43] Mike Brown’s
various sky surveys have not detected any Earth-sized objects out to a distance of about 100 AU. However, it is
possible that such an object may have been scattered out
of the Solar System after the formation of the inner Oort
cloud.[44]
If Sedna formed in its current location, the Sun’s original protoplanetary disc must have extended as far as 75
AU into space.[35] Also, Sedna’s initial orbit must have
been approximately circular, otherwise its formation by
the accretion of smaller bodies into a whole would not
have been possible, because the large relative velocities
between planetesimals would have been too disruptive.
Therefore, it must have been tugged into its current eccentric orbit by a gravitational interaction with another
body.[36] In their initial paper, Brown, Rabinowitz and
colleagues suggested three possible candidates for the
perturbing body: an unseen planet beyond the Kuiper
belt, a single passing star, or one of the young stars embedded with the Sun in the stellar cluster in which it It has been suggested that Sedna’s orbit is the result of
formed.[13]
influence by a large binary companion to the Sun, thouMike Brown and his team favored the hypothesis that sands of AU distant. One such hypothetical companion
Sedna was lifted into its current orbit by a star from the is Nemesis, a dim companion to the Sun that has been
Sun’s birth cluster, arguing that Sedna’s aphelion of about proposed to be responsible for the supposed periodicity
1,000 AU, which is relatively close compared to those of of mass extinctions on Earth from cometary impacts, the
long-period comets, is not distant enough to be affected lunar impact record, and the common orbital elements of
by passing stars at their current distances from the Sun. a number of long-period comets.[42][45] However, to date
They propose that Sedna’s orbit is best explained by the no direct evidence of Nemesis has been found, and many
Sun having formed in an open cluster of several stars that lines of evidence (such as crater counts), have thrown its
gradually disassociated over time.[13][37][38] That hypoth- existence into doubt.[46][47] John J. Matese and Daniel
4
6
P. Whitmire, longtime proponents of the possibility of
a wide binary companion to the Sun, have suggested that
an object of 5 MJ lying at roughly 7,850 AU from the Sun
could produce a body in Sedna’s orbit.[48]
Morbidelli and Kenyon have also suggested that Sedna
did not originate in the Solar System, but was captured
by the Sun from a passing extrasolar planetary system,
specifically that of a brown dwarf about 1/20th the mass
of the Sun (M☉).[39][40][49][50]
5
Population
CLASSIFICATION
Brown in 2006. “Eventually, when other fossil records
are found, Sedna will help tell us how the Sun formed
and the number of stars that were close to the Sun when it
formed.”[12] A 2007–2008 survey by Brown, Rabinowitz
and Megan Schwamb attempted to locate another member of Sedna’s hypothetical population. Although the survey was sensitive to movement out to 1,000 AU and discovered the likely dwarf planet 2007 OR10 , it detected
no new sednoid.[51] Subsequent simulations incorporating the new data suggested about 40 Sedna-sized objects
probably exist in this region, with the brightest being
about Eris’s magnitude (−1.0).[51]
In 2014, astronomers announced the discovery of 2012
VP113,[19] an object half the size of Sedna in a 4200-year
Main article: Sednoid
orbit similar to Sedna’s and a perihelion within Sedna’s
Sedna’s highly elliptical orbit means that the probability
range of roughly 80 AU,[52] which led some to speculate
that it offered evidence of a trans-Neptunian planet.[53]
6 Classification
Artist’s conception of the surface of Sedna, with the Milky Way,
Antares, the Sun and Spica above
of its detection was roughly 1 in 80, which suggests that,
unless its discovery was a fluke, another 40–120 Sednasized objects would exist within the same region.[13][23]
Another object, 2000 CR105, has a similar but less extreme orbit: it has a perihelion of 44.3 AU, an aphelion
of 394 AU, and an orbital period of 3,240 years. It may
have been affected by the same processes as Sedna.[39]
Each of the proposed mechanisms for Sedna’s extreme
orbit would leave a distinct mark on the structure and dynamics of any wider population. If a trans-Neptunian
planet was responsible, all such objects would share
roughly the same perihelion (about 80 AU). If Sedna were
captured from another planetary system that rotated in
the same direction as the Solar System, then all of its
population would have orbits on relatively low inclinations and have semi-major axes ranging from 100–500
AU. If it rotated in the opposite direction, then two populations would form, one with low and one with high inclinations. The perturbations from passing stars would produce a wide variety of perihelia and inclinations, each dependent on the number and angle of such encounters.[44]
Sedna compared to some other very distant orbiting bodies
The Minor Planet Center, which officially catalogs the
objects in the Solar System, classifies Sedna as a scattered
object.[54] However, this grouping is heavily questioned,
and many astronomers have suggested that it, together
with a few other objects (e.g. 2000 CR105), be placed
in a new category of distant objects named extended scattered disc objects (E-SDO),[55] detached objects,[56] distant detached objects (DDO),[42] or scattered-extended in
the formal classification by the Deep Ecliptic Survey.[57]
The discovery of Sedna resurrected the question of which
astronomical objects should be considered planets and
which should not. On March 15, 2004, articles on Sedna
in the popular press reported that a tenth planet had
been discovered. This question was answered under the
International Astronomical Union definition of a planet,
adopted on August 24, 2006, which mandated that a
planet must have cleared the neighborhood around its orAcquiring a larger sample of such objects would help bit. Sedna has a Stern–Levison parameter estimated to be
in determining which scenario is most likely.[51] “I call much less than 1,[lower-alpha 6] and therefore cannot be conSedna a fossil record of the earliest Solar System”, said sidered to have cleared the neighborhood, even though no
5
other objects have yet been discovered in its vicinity. To
be a dwarf planet, Sedna must be in hydrostatic equilibrium. It is bright enough, and therefore large enough, that
this is expected to be the case,[59] and several astronomers
have called it one.[60][61][62][63][64]
[4] Different programs using different epochs and/or data sets
will produce slightly different dates for Sedna’s perihelion.
Using a 2014 epoch, the JPL Small-Body Database has a
perihelion date of 2076.[3] Using a 1990 epoch the Lowell
DES has perihelion on 2479282.9591 (2075-12-11) As
of 2010, the JPL Horizons (using numerical integration)
indicated a perihelion date of 2076-Jul-18.[10]
7
[5] The HST search found no satellite candidates to a limit
of about 500 times fainter than Sedna (Brown and Suer
2007).[23]
Exploration
Sedna will come to perihelion around 2075–
2076.[lower-alpha 4] This close approach to the Sun
provides an opportunity for study that will not occur
again for 12,000 years. Although Sedna is listed on
NASA’s Solar System exploration website,[65] NASA is
not known to be considering any type of mission at this
time.[66] It was calculated that a flyby mission to Sedna
could take 24.48 years using a Jupiter gravity assist,
based on launch dates of 6 May 2033 and 23 June 2046.
Sedna would be 77.27 or 76.43 AU from the Sun when
the spacecraft arrives.[67]
8
See also
• List of Solar System objects most distant from the
Sun in 2015
9
[6] The Stern–Levison parameter (Λ) as defined by Alan
Stern and Harold F. Levison in 2002 determines if an
object will eventually clear its orbital neighbourhood of
small bodies. It is defined as the object’s fraction of solar
mass (i.e., the object’s mass divided by the Sun’s mass)
squared, divided by its semi-major axis to the 3/2 power,
times a constant 1.7×1016 .[58](see equation 4) If an object’s Λ
is greater than 1, then that object will eventually clear its
neighbourhood, and it can be considered for planethood.
Using the unlikely highest estimated mass for Sedna of
2×1021 kg, Sedna’s Λ is (2×1021 /1.9891×1030 )2 / 5193/2 ×
1.7×1016 = 1.44×10−6 . This is much less than 1, so Sedna
is not a planet by this criterion.
Notes
[1] Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the orbital period. Using a 1950 epoch, Sedna has a 12,100-year
period,[2] but using a 2010 epoch Sedna has an 11,800year period.[3] For objects at such high eccentricity, the
Sun’s barycentric coordinates are more stable than heliocentric coordinates.[5] Using JPL Horizons, the barycentric orbital period is approximately 11,400 years.[4]
[2] As of 2014, Sedna was about 86.3 AU from the Sun;[9]
Eris, the most massive known dwarf planet, and 2007
OR10 , the largest object in the Solar System without a
name, are currently farther from the Sun than Sedna at
96.4 AU and 87.0 AU, respectively.[11] Eris is near its
aphelion (furthest distance from the Sun), whereas Sedna
is nearing its 2076 perihelion (closest approach to the
Sun).[10] Sedna will overtake Eris as the farthest known
large object in the Solar System in 2114, but the probable
dwarf planet 2007 OR10 has recently overtaken Sedna and
will overtake Eris by 2045.[10]
[3] Small Solar System bodies such as (308933) 2006 SQ372,
2005 VX3, (87269) 2000 OO67, 2002 RN109, 2007
TG422, and several comets (such as the Great Comet of
1577) have larger heliocentric orbits. But only (308933)
2006 SQ372 , (87269) 2000 OO67 , and 2007 TG422 have a
perihelion point further than Jupiter’s orbit, so it is debatable whether or not most of these objects are misclassified
comets.
10 References
[1] “Discovery Circumstances: Numbered Minor Planets
(90001)–(95000)". IAU: Minor Planet Center. Retrieved
2008-07-23.
[2] Marc W. Buie (2009-11-22). “Orbit Fit and Astrometric record for 90377”. Deep Ecliptic Survey. Retrieved
2006-01-17.
[3] “JPL Small-Body Database Browser: 90377 Sedna (2003
VB12)" (2012-10-16 last obs). Retrieved 2014-03-30.
[4] Horizons output. “Barycentric Osculating Orbital Elements for 90377 Sedna (2003 VB12)". Retrieved 201104-30. (Solution using the Solar System Barycenter
and barycentric coordinates. Select Ephemeris Type:
Elements and Center:@0) (saved Horizons output file
2011-Feb-04). In the second pane “PR=" can be found,
which gives the orbital period in days (4.15E+06, which
is ~11400 Julian years).
[5] Kaib, Nathan A.; Becker, Andrew C.; Jones, R.
Lynne; Puckett, Andrew W.; Bizyaev, Dmitry; Dilday, Benjamin; Frieman, Joshua A.; Oravetz, Daniel
J.; Pan, Kaike; Quinn, Thomas; Schneider, Donald P.; Watters, Shannon (2009).
“2006 SQ372:
A Likely Long-Period Comet from the Inner Oort
Cloud”. The Astrophysical Journal 695 (1): 268–
275. arXiv:0901.1690. Bibcode:2009ApJ...695..268K.
doi:10.1088/0004-637X/695/1/268.
[6] Pál, A.; Kiss, C.; Müller, T. G.; Santos-Sanz, P.; Vilenius,
E.; Szalai, N.; Mommert, M.; Lellouch, E.; Rengel, M.;
Hartogh, P.; Protopapa, S.; Stansberry, J.; Ortiz, J. -L.;
Duffard, R.; Thirouin, A.; Henry, F.; Delsanti, A. (2012).
""TNOs are Cool": A survey of the trans-Neptunian region. VII. Size and surface characteristics of (90377)
6
10
Sedna and 2010 EK139 ". Astronomy & Astrophysics 541:
L6. arXiv:1204.0899. Bibcode:2012A&A...541L...6P.
doi:10.1051/0004-6361/201218874.
[7] “Case of Sedna’s Missing Moon Solved”. HarvardSmithsonian Center for Astrophysics. 2005-04-05. Retrieved 2005-04-07.
[8] Stephen C. Tegler (2006-01-26). “Kuiper Belt Object
Magnitudes and Surface Colors”. Northern Arizona University. Retrieved 2006-11-05.
[9] “AstDys (90377) Sedna Ephemerides”. Department of
Mathematics, University of Pisa, Italy. Retrieved 201105-05.
[10] JPL Horizons On-Line Ephemeris System (2010-07-18).
“Horizons Output for Sedna 2076/2114”. Retrieved
2010-07-18. Horizons
[11] “AstDys (136199) Eris Ephemerides”. Department of
Mathematics, University of Pisa, Italy. Archived from the
original on 4 June 2011. Retrieved 2011-05-05.
[12] Cal Fussman (2006). “The Man Who Finds Planets”. Discover. Archived from the original on 16 June 2010. Retrieved 2010-05-22.
[13] Mike Brown, David Rabinowitz, Chad Trujillo (2004).
“Discovery of a Candidate Inner Oort Cloud Planetoid”.
Astrophysical Journal 617 (1): 645–649.
arXiv:astro-ph/0404456. Bibcode:2004ApJ...617..645B.
doi:10.1086/422095.
[14] Brown, Mike. “Sedna”. Caltech. Archived from the original on 25 July 2010. Retrieved 2010-07-20.
[15] “MPEC 2004-S73 : Editorial Notice”. IAU Minor Planet
Center. 2004. Retrieved 2010-07-18.
[16] Walker, Duncan (2004-03-16). “How do planets get their
names?". BBC News. Retrieved 2010-05-22.
[17] “MPC 52733” (PDF). Minor Planet Center. 2004. Retrieved 2010-08-30.
[18] Chadwick A. Trujillo, M. E. Brown, D. L. Rabinowitz;
Brown; Rabinowitz (2007). “The Surface of Sedna in the
Near-infrared”. Bulletin of the American Astronomical Society 39: 510. Bibcode:2007DPS....39.4906T.
[19] Trujillo, Chadwick A.; S. S. Sheppard (2014). “A Sednalike body with a perihelion of 80 astronomical units”.
Nature 507: 471–474. Bibcode:2014Natur.507..471T.
doi:10.1038/nature13156.
[20] “AstDys (90377) Sedna Ephemerides 2003-11-14”. Department of Mathematics, University of Pisa, Italy. Retrieved 2008-05-05.
[21] “Hubble Observes Planetoid Sedna, Mystery Deepens;
Long View from a Lonely Planet”. Hubblesite, STScI2004-14. 2004. Retrieved 2010-07-21.
[22] “Hubble Observes Planetoid Sedna, Mystery Deepens”.
Hubblesite, STScI-2004-14. 2004. Retrieved 2010-0830.
REFERENCES
[23] Michael E. Brown. “The largest Kuiper belt objects”.
In M. Antonietta Barucci, Hermann Boehnhardt, Dale
P. Cruikshank. The Solar System Beyond Neptune (pdf).
University of Arizona Press. pp. 335–345. ISBN 0-81652755-5.
[24] B. Scott Gaudi, Krzysztof Z. Stanek, Joel D. Hartman,
Matthew J. Holman, Brian A. McLeod (CfA) (2005).
“On the Rotation Period of (90377) Sedna”. The
Astrophysical Journal 629 (1): L49–L52. arXiv:astroph/0503673.
Bibcode:2005ApJ...629L..49G.
doi:10.1086/444355.
[25] AstDyS, Objects at least two Neptune distances from Sun
[26] W. M. Grundy, K. S. Noll, D. C. Stephens (2005).
“Diverse Albedos of Small Trans-Neptunian
Objects”.
Icarus (Lowell Observatory, Space
Telescope Science Institute) 176 (1):
184–191.
arXiv:astro-ph/0502229. Bibcode:2005Icar..176..184G.
doi:10.1016/j.icarus.2005.01.007.
[27] John Stansberry, Will Grundy, Mike Brown, Dale Cruikshank, John Spencer, David Trilling, Jean-Luc Margot
(2008). “Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope”.
In M. Antonietta Barucci, Hermann Boehnhardt, Dale
P. Cruikshank. The Solar System Beyond Neptune (pdf).
University of Arizona Press. pp. 161–179. arXiv:astroph/0702538v2. ISBN 0-8165-2755-5.
[28] Trujillo, Chadwick A.; Brown, Michael E.; Rabinowitz,
David L.; Geballe, Thomas R. (2005). “Near‐Infrared
Surface Properties of the Two Intrinsically Brightest
Minor Planets: (90377) Sedna and (90482) Orcus”. The
Astrophysical Journal 627 (2): 1057–1065. arXiv:astroph/0504280.
Bibcode:2005ApJ...627.1057T.
doi:10.1086/430337.
[29] Sheppard, Scott S. (2010). “The
outer Solar System objects”.
Journal 139 (4): 1394–1405.
Bibcode:2010AJ....139.1394S.
6256/139/4/1394.
colors of extreme
The Astronomical
arXiv:1001.3674.
doi:10.1088/0004-
[30] J. P. Emery; C. M. Dalle Ore; D. P. Cruikshank; Fernández, Y. R.; Trilling, D. E.; Stansberry, J. A. (2007).
“Ices on 90377 Sedna: Conformation and compositional constraints” (pdf). Astronomy and Astrophysics
406 (1): 395–398. Bibcode:2007A&A...466..395E.
doi:10.1051/0004-6361:20067021.
[31] M. A. Barucci; D. P. Cruikshank; E. Dotto; Merlin, F.;
Poulet, F.; Dalle Ore, C.; Fornasier, S.; De Bergh, C.
(2005). “Is Sedna another Triton?". Astronomy & Astrophysics 439 (2): L1–L4. Bibcode:2005A&A...439L...1B.
doi:10.1051/0004-6361:200500144.
[32] Hussmann, Hauke; Sohl, Frank; Spohn, Tilman
“Subsurface oceans and deep
(November 2006).
interiors of medium-sized outer planet satellites
and large trans-neptunian objects” (PDF). Icarus
185 (1): 258–273.
Bibcode:2006Icar..185..258H.
doi:10.1016/j.icarus.2006.06.005.
7
[33] Jewitt, David; Morbidelli, Alessandro; Rauer, Heike
(2007). Trans-Neptunian Objects and Comets: Saas-Fee
Advanced Course 35. Swiss Society for Astrophysics and
Astronomy. Berlin: Springer. p. 86. arXiv:astroph/0512256v1. ISBN 3-540-71957-1.
[34] Lykawka, Patryk Sofia; Mukai, Tadashi (2007). “Dynamical classification of trans-neptunian objects: Probing their origin, evolution, and interrelation”. Icarus
Bibcode:2007Icar..189..213L.
189 (1): 213–232.
doi:10.1016/j.icarus.2007.01.001.
[35] S. Alan Stern (2005). “Regarding the accretion of
2003 VB12 (Sedna) and like bodies in distant heliocentric orbits”. The Astronomical Journal (Astronomical Journal) 129 (1): 526–529. arXiv:astro-ph/0404525.
Bibcode:2005AJ....129..526S. doi:10.1086/426558. Retrieved 2010-08-05.
[36] Sheppard, Scott S.; Jewitt, David C. (2005). “Small Bodies in the Outer Solar System” (PDF). Frank N. Bash Symposium. The University of Texas at Austin. Retrieved
2008-03-25.
[37] Brown, Michael E. (2004). “Sedna and the birth of the
solar system”. Bulletin of the American Astronomical Society (American Astronomical Society Meeting 205) 36
(127.04): 1553. Bibcode:2004AAS...20512704B.
[38] “Transneptunian Object 90377 Sedna (formerly known as
2003 VB12)". The Planetary Society. Archived from the
original on 25 November 2009. Retrieved 2010-01-03.
[39] Morbidelli, Alessandro; Levison, Harold F. (2004). “Scenarios for the Origin of the Orbits of the Trans-Neptunian
Objects 2000 CR105 and 2003 VB12 (Sedna)". The
Astronomical Journal 128 (5): 2564–2576. arXiv:astroph/0403358.
Bibcode:2004AJ....128.2564M.
doi:10.1086/424617.
[40] Kenyon, Scott J.; Bromley, Benjamin C. (2 December 2004).
“Stellar encounters as the origin
of distant Solar System objects in highly eccentric
orbits”. Nature 432 (7017): 598–602. arXiv:astroph/0412030.
Bibcode:2004Natur.432..598K.
doi:10.1038/nature03136. PMID 15577903.
[41] “The Challenge of Sedna”. Harvard-Smithsonian Center
for Astrophysics. Retrieved 2009-03-26.
[42] Gomes, Rodney S.; Matese, John J.; and Lissauer,
Jack J. (2006). “A distant planetary-mass solar companion may have produced distant detached objects”.
Icarus 184 (2): 589–601. Bibcode:2006Icar..184..589G.
doi:10.1016/j.icarus.2006.05.026.
[43] Lykawka, P. S.; Mukai, T. (2008). “An Outer Planet
Beyond Pluto and the Origin of the Trans-Neptunian
Belt Architecture”.
Astronomical Journal 135 (4):
1161. arXiv:0712.2198. Bibcode:2008AJ....135.1161L.
doi:10.1088/0004-6256/135/4/1161.
[44] Schwamb, Megan E. (2007). “Searching for Sedna’s Sisters: Exploring the inner Oort cloud” (PDF). Cal Tech.
Retrieved 2010-08-06.
[45] Staff (April 25, 2006). “Evidence Mounts For Companion Star To Our Sun”. SpaceDaily. Archived from the
original on 7 January 2010. Retrieved November 27,
2009.
[46] Hills, J. G. (1984). “Dynamical constraints on the
mass and perihelion distance of Nemesis and the stability of its orbit”. Nature 311 (5987): 636–638.
Bibcode:1984Natur.311..636H. doi:10.1038/311636a0.
[47] “Nemesis is a myth”. Max Planck Institute. 2011. Retrieved 2011-08-11.
[48] Matese, John J.; Whitmire, Daniel P.; and Lissauer, Jack
J. (2006). “A Widebinary Solar Companion as a Possible
Origin of Sedna-like Objects”. Earth, Moon, and Planets 97 (3–4): 459–470. Bibcode:2005EM&P...97..459M.
doi:10.1007/s11038-006-9078-6. Retrieved 2010-08-17.
[49] Ken Croswell. “Sun Accused of Stealing Planetary Objects from Another Star”. Scientific American.
[50] Govert Schilling. “Grand Theft Sedna: how the sun might
have stolen a mini-planet”. New Scientist.
[51] Schwamb, Megan E.; Brown, Michael E.; Rabinowitz, David L. (2009).
“A Search for Distant Solar System Bodies in the Region of Sedna”.
The Astrophysical Journal Letters 694 (1): L45–
L48. arXiv:0901.4173. Bibcode:2009ApJ...694L..45S.
doi:10.1088/0004-637X/694/1/L45.
[52] “JPL Small-Body Database Browser: (2012 VP113)"
(2013-10-30 last obs). Jet Propulsion Laboratory. Retrieved 2014-03-26.
[53] “A new object at the edge of our Solar System discovered”. Physorg.com. 26 March 2014.
[54] IAU: Minor Planet Center (2008-07-02). “List of Centaurs and Scattered-Disk Objects”. Central Bureau for
Astronomical Telegrams, Harvard-Smithsonian Center
for Astrophysics. Retrieved 2008-07-02.
[55] Gladman, Brett J. (2001). “Evidence for an Extended
Scattered Disk?". Observatoire de la Cote d'Azur. Retrieved 2010-07-22.
[56] “The Solar System Beyond The Planets”. Solar System
Update : Topical and Timely Reviews in Solar System Sciences. Springer-Praxis Ed. 2006. ISBN 3-540-26056-0.
[57] Elliot, J. L.; Kern, S. D.; Clancy, K. B.; Gulbis, A.
A. S.; Millis, R. L.; Buie, M. W.; Wasserman, L. H.;
Chiang, E. I.; Jordan, A. B.; et al. (2006). “The
Deep Ecliptic Survey: A Search for Kuiper Belt Objects
and Centaurs. II. Dynamical Classification, the Kuiper
Belt Plane, and the Core Population”. The Astronomical
Journal 129 (2): 1117. Bibcode:2005AJ....129.1117E.
doi:10.1086/427395.
[58] Stern, S. Alan; and Levison, Harold F.; Levison (2002).
“Regarding the criteria for planethood and proposed planetary classification schemes” (PDF). Highlights of Astronomy 12: 205–213, as presented at the XXIVth General
Assembly of the IAU–2000 [Manchester, UK, 7–18 August 2000]. Bibcode:2002HiA....12..205S.
8
11
[59] Brown, Michael E. “The Dwarf Planets”. California Institute of Technology, Department of Geological Sciences.
Archived from the original on 29 February 2008. Retrieved 2008-02-16.
[60] Barucci, M.; Morea Dalle Ore, C.; Alvarez-Candal, A.;
De Bergh, C.; Merlin, F.; Dumas, C.; Cruikshank, D.
(2010). "(90377) Sedna: Investigation of surface compositional variation”. The Astronomical Journal 140 (6):
6. Bibcode:2010AJ....140.2095B. doi:10.1088/00046256/140/6/2095.
[61] Rabinowitz, Schaefer, Tourtellotte, 2011. “SMARTS
Studies of the Composition and Structure of Dwarf Planets”. Bulletin of the American Astronomical Society, Vol.
43
[62] Malhotra, 2010. “On the Importance of a Few Dwarf
Planets”. Bulletin of the American Astronomical Society,
Vol. 41
[63] Tancredi, G.; Favre, S. (2008). “Which are the dwarfs
in the solar system?" (PDF). Asteroids, Comets, Meteors.
Retrieved 2011-01-05.
[64] Michael E. Brown (Sep 23, 2011). “How many dwarf
planets are there in the outer solar system? (updates
daily)". California Institute of Technology. Retrieved
2011-09-23.
[65] “Solar System Exploration: Multimedia:
NASA. Retrieved 2010-01-03.
Gallery”.
[66] “Solar System Exploration: Missions to Dwarf Planets”.
NASA. Retrieved 11 November 2010.
[67] McGranaghan, R.; Sagan, B.; Dove, G.; Tullos, A.;
Lyne, J. E.; Emery, J. P. (2011). “A Survey of Mission Opportunities to Trans-Neptunian Objects”. Journal of the British Interplanetary Society 64: 296–303.
Bibcode:2011JBIS...64..296M.
11
External links
• Media related to Sedna at Wikimedia Commons
• How Sedna and family were captured in a close encounter with a solar sibling (9 Jun 2015)
• NASA’s Sedna page (Discovery Photos)
• Mike Brown’s Sedna page
EXTERNAL LINKS
9
12
12.1
Text and image sources, contributors, and licenses
Text
• 90377 Sedna Source: https://en.wikipedia.org/wiki/90377_Sedna?oldid=700312557 Contributors: Eloquence, Vicki Rosenzweig, Bryan
Derksen, The Anome, Tarquin, Wayne Hardman, Danny, Chrislintott, Rmhermen, Imran, Zimriel, Bdesham, Nealmcb, Ken Arromdee,
Michael Hardy, Stormwriter, Gabbe, Ixfd64, Dori, Minesweeper, ArnoLagrange, Ahoerstemeier, Docu, Jniemenmaa, Den fjättrade
ankan~enwiki, Kingturtle, Glenn, Whkoh, Nikai, Kwekubo, Jeandré du Toit, Evercat, Schneelocke, Hike395, M0mms, The Tom, Ec5618,
David Newton, Dcoetzee, Doradus, Tpbradbury, Jeffrey Smith, Morwen, VeryVerily, Paul-L~enwiki, Bevo, Xaven, Nickshanks, PuzzletChung, Robbot, ChrisO~enwiki, Fredrik, Zandperl, Naddy, Gandalf61, Chris Roy, Merovingian, Sverdrup, Jxg, Texture, KellyCoinGuy, Meelar, Auric, Joelwest, Gnomon Kelemen, Davodd, Rebrane, Robinh, Chris-gore, Ilya (usurped), Vikingstad, Anthony, Jor, Seth
Ilys, Cyrius, Sushi~enwiki, DarkHorizon, FTW, Kevin Saff, Matthew Stannard, Giftlite, Dbenbenn, Jyril, Meursault2004, Curps, Henry
Flower, Wikibob, Chinasaur, Zaphod Beeblebrox, Dmmaus, Sietse, Python eggs, Mckaysalisbury, Bobblewik, John Abbe, Mooquackwooftweetmeow, Joseph Dwayne, Sedna~enwiki, The Singing Badger, HorsePunchKid, Ctachme, Martin Wisse, Satori, Icairns, Urhixidur, CoyneT, Joyous!, Rich Farmbrough, Vsmith, Wk muriithi, Roybb95~enwiki, Bender235, Zaslav, Jnestorius, RJHall, CanisRufus, El
C, Bluap, Kwamikagami, Susvolans, Art LaPella, Iridia, Bobo192, 23skidoo, DaveGorman, UnHoly, Aranae, Skatebiker, Gene Nygaard,
Drbreznjev, Adrian.benko, DavidK93, Georgia guy, LOL, PoccilScript, Ganeshk, BillC, Jacobolus, Pol098, WadeSimMiser, Eleassar777,
GregorB, JamesH, Smartech~enwiki, Marudubshinki, DePiep, Vanderdecken, Rjwilmsi, Mike Peel, R.e.b., Ucucha, Ian Pitchford, Margosbot~enwiki, Rynogertie, Chobot, Sherool, Bgwhite, Cactus.man, YurikBot, Laurentius, Jimp, RussBot, Rapomon, Eleassar, Theelf29,
Bruguiea, Lexicon, Peter Delmonte, Whatdoitypehere, Ospalh, Gadget850, Bota47, 21655, Lt-wiki-bot, Chesnok, Arthur Rubin, Nentuaby, Reyk, De Administrando Imperio, Fluent aphasia, GrinBot~enwiki, MateoP, Serendipodous, Deuar, Sardanaphalus, Attilios, Yakudza,
SmackBot, WooperJeff, Renegadeviking, DCGeist, Unyoyega, Kilo-Lima, Jrockley, Athaler, Richard B, Mirokado, Saros136, Hibernian,
Modest Genius, John Hyams, Kelvin Case, Chlewbot, SpacemanAfrica, Danielklein, J P, Kukini, Sanbuster, John, J 1982, JamesFox,
JorisvS, IronGargoyle, Ckatz, RandomCritic, JHunterJ, Eurocommuter, SandyGeorgia, Dalstadt, Novangelis, Sasata, JohnnyBGood, JDAWiseman, Michaelbusch, Metre01, Newone, Galaad2, GregFox, Courcelles, Acom, Lahiru k, CRGreathouse, Memetics, Tuvas, The ed17,
Vyznev Xnebara, Ruslik0, Aquirata, CuriousEric, MathewDill, Meodipt, Simeon, Icek~enwiki, Cydebot, Derek Balsam, ST47, Gimmetrow, Casliber, Epbr123, Headbomb, Massimo Macconi, RobotG, Maynard2k, JAnDbot, Deflective, Abyssoft, Something14, Rongou, DanPMK, Rothorpe, Acroterion, WolfmanSF, Murgh, VoABot II, Steve Hosgood, Ling.Nut, Sethhater123, Hekerui, ArthurWeasley,
Hamiltonstone, Kheider, Adriaan, RP88, Poeloq, CommonsDelinker, Fconaway, LedgendGamer, J.delanoy, DrKay, Numbo3, Javawizard, IdLoveOne, Rwessel, Richard Wolf VI, TreasuryTag, Larryisgood, AlnoktaBOT, Philip Trueman, GimmeBot, Sagittarian Milky
Way, Guillaume2303, Anonymous Dissident, Zenswashbuckler, UnitedStatesian, CO, AlleborgoBot, Hughey, SieBot, Gerakibot, Jerryobject, Interchange88, RadicalOne, Elcobbola, GaryColemanFan, Steven Crossin, Lightmouse, OKBot, Jimtpat, Rosiestep, Kortaggio,
Nergaal, ClueBot, LAX, CounterVandalismBot, Jusdafax, Njardarlogar, HumphreyW, Sethrasmussen121, RexxS, InternetMeme, Mr.
Gerbear, Bearsona, Defwrecker, XLinkBot, Asrghasrhiojadrhr, Addbot, Roentgenium111, DOI bot, Proxima Centauri, LinkFA-Bot,
Tassedethe, Lightbot, Krenakarore, Care, Wwannsda, Luckas-bot, Ptbotgourou, Catiline63, Tbayboy, AnomieBOT, Galoubet, Masursky,
Citation bot, Astor14, James500, DynamoDegsy, ArthurBot, Xqbot, FaleBot, Gap9551, Almabot, GrouchoBot, Fotaun, Io Herodotus,
BenzolBot, Robo37, Nonexyst, Citation bot 1, DrilBot, HRoestBot, Tom.Reding, Savemaxim, IVAN3MAN, Double sharp, Trappist the
monk, DixonDBot, Tbhotch, RjwilmsiBot, TjBot, DASHBot, Steve03Mills, EmausBot, John of Reading, Jolielegal, Qurq, Bleakside,
AbbaIkea2010, Racerx11, Black Yoshi, Andromedabluesphere440, Solomonfromfinland, A2soup, Asephei, Mogzmaniac, Hevron1998,
Wayne Slam, Brandmeister, L Kensington, Aceboy2007, Alcazar84, Fjörgynn, ClueBot NG, Coverman6, The Ohioan B.S. Detector (TM),
Wingtipvortex, Sedna,dwarfplanet?, Bibcode Bot, BG19bot, Tycho Magnetic Anomaly-1, Almaak, Szczureq, BattyBot, StarryGrandma,
Nimesh Mistry, YFdyh-bot, Dexbot, Blobbie244, Pluto and Beyond, Lalji.maheshwari, Hillbillyholiday, Reatlas, Seriouscallersonly, Rfassbind, Tentinator, Baconfry, Kennethaw88, User23m, Sam Sailor, Exoplanetaryscience, Readington, Sonicwave32, Callumiscool1235, DNboards1, Treyra, Deepanshu1707 and Anonymous: 218
12.2
Images
• File:Artist’{}s_concept_of_the_Solar_System_as_viewed_from_Sedna.jpg Source:
https://upload.wikimedia.org/wikipedia/
commons/b/bc/Artist%27s_concept_of_the_Solar_System_as_viewed_from_Sedna.jpg License: Public domain Contributors: Hubble
Observes Planetoid Sedna, Mystery Deepens: http://hubblesite.org/newscenter/archive/releases/2004/14/image/e/
Original artist: NASA, ESA and Adolf Schaller
• File:Artist’{}s_conception_of_Sedna.jpg Source: https://upload.wikimedia.org/wikipedia/commons/6/68/Artist%27s_conception_of_
Sedna.jpg License: Public domain Contributors: http://www.spitzer.caltech.edu/images/1144-ssc2004-05b-Artist-s-Conception-of-Sedna
http://www.spitzer.caltech.edu/Media/releases/ssc2004-05/ssc2004-05b.shtml (OLD) Original artist: NASA/JPL-Caltech/R. Hurt (SSCCaltech)
• File:Celestia_distant_object_orbits.png Source:
https://upload.wikimedia.org/wikipedia/commons/9/94/Celestia_distant_object_
orbits.png License: CC BY 4.0 Contributors: Own work Original artist: Exoplanetaryscience
• File:EightTNOs.png Source: https://upload.wikimedia.org/wikipedia/commons/9/91/EightTNOs.png License: CC-BY-SA-3.0 Contributors: Based on the public domain Nasa images: Image:2006-16-d-print.jpg, Image:Orcus art.png. Original artist: Lexicon
• File:En-90377_Sedna-article.ogg Source:
cense: CC BY-SA 3.0 Contributors:
https://upload.wikimedia.org/wikipedia/commons/8/80/En-90377_Sedna-article.ogg Li-
• Derivative of 90377 Sedna Original artist: Speaker: Readington
Authors of the article
• File:Nh-pluto-in-true-color_2x_JPEG-edit.jpg
Source:
https://upload.wikimedia.org/wikipedia/commons/c/cd/
Nh-pluto-in-true-color_2x_JPEG-edit.jpg License: Public domain Contributors: http://pluto.jhuapl.edu/Multimedia/Science-Photos/
image.php?gallery_id=2&image_id=243 Original artist: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest
Research Institute
• File:PIA19562-Ceres-DwarfPlanet-Dawn-RC3-image19-20150506.jpg Source: https://upload.wikimedia.org/wikipedia/commons/
d/d3/PIA19562-Ceres-DwarfPlanet-Dawn-RC3-image19-20150506.jpg License: Public domain Contributors: http://photojournal.jpl.
nasa.gov/jpeg/PIA19562.jpg Original artist: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
10
12
TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES
• File:Portal-puzzle.svg Source: https://upload.wikimedia.org/wikipedia/en/f/fd/Portal-puzzle.svg License: Public domain Contributors: ?
Original artist: ?
• File:Sedna_PRC2004-14d.jpg Source: https://upload.wikimedia.org/wikipedia/commons/0/02/Sedna_PRC2004-14d.jpg License: Public domain Contributors: http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/14/image/d Original artist: NASA
• File:Sedna_orbit.svg Source: https://upload.wikimedia.org/wikipedia/commons/e/e3/Sedna_orbit.svg License: CC0 Contributors: Own
work Original artist: Szczureq/kheider/NASA
• File:Sound-icon.svg Source: https://upload.wikimedia.org/wikipedia/commons/4/47/Sound-icon.svg License:
Derivative work from Silsor's versio Original artist: Crystal SVG icon set
12.3
Content license
• Creative Commons Attribution-Share Alike 3.0
LGPL Contributors: