90377 Sedna, or simply Sedna, is a large planetoid in the outer reaches of the Solar System that was, , at a distance of about from the Sun, about three times as far as Neptune. Spectroscopy has revealed that Sedna's surface composition is similar to those 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 a possible dwarf planet. Sedna is approximately tied with and as the largest planetoid not known to have a moon. For most of its orbit, it is even farther from the Sun than at present, with its aphelion estimated at 937 AU (31 times Neptune's distance, or about 1.5% of a light-year), making it one of the most distant-known objects in the Solar System other than long-period comets.
Introduction
90377 Sedna
90377 Sedna | Introduction
In the outer reaches of the Solar System. In the outer reaches of the Solar System It is about three times as far as Neptune from the Sun. In the outer reaches of the Solar System.
where is sedna located in the solar system
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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. This classification has been contested because its perihelion is too large for it to have been scattered by a known planet, leading some astronomers to informally refer to it as the first known member of the inner Oort cloud.
90377 Sedna | Introduction
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.
90377 Sedna | Introduction
90377 Sedna, or simply Sedna, is a large planetoid in the outer reaches of the Solar System that was, , at a distance of about from the Sun, about three times as far as Neptune. Spectroscopy has revealed that Sedna's surface composition is similar to those 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 a possible dwarf planet. Sedna is approximately tied with and as the largest planetoid not known to have a moon. For most of its orbit, it is even farther from the Sun than at present, with its aphelion estimated at 937 AU (31 times Neptune's distance, or about 1.5% of a light-year), making it one of the most distant-known objects in the Solar System other than long-period comets.
90377 Sedna | Introduction
Fernandez and Adrian Brunini suggest that multiple close passes by young stars in such a cluster would pull many objects into Sedna-like orbits. 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.
90377 Sedna | Origin
If Sedna formed in its current location, the Sun's original protoplanetary disc must have extended as far as 75 AU into space. 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. 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 formed.
90377 Sedna | Origin
"I call Sedna a fossil record of the earliest Solar System", said 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." 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 Gonggong, it detected no new sednoid. 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).
90377 Sedna | Population
Sedna was later surpassed by Eris, which was detected by the same survey near aphelion at 97 AU. 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, 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.
90377 Sedna | Orbit and rotation
Sedna has the second longest orbital period of any known object in the Solar System of comparable size or larger, calculated at around 11,400 years. Its orbit is extremely eccentric, with an aphelion estimated at 937 AU and a perihelion at about 76 AU. This perihelion was the largest of that of any known Solar System object until the discovery of . At its aphelion, Sedna orbits the Sun at a mere 1.3% of Earth's orbital speed. When Sedna was discovered it was 89.6 AU from the Sun approaching perihelion, and was the most distant object in the Solar System observed.
90377 Sedna | Orbit and rotation
Combining those with precovery observations taken at the Samuel Oschin telescope in August 2003, and from the Near-Earth Asteroid Tracking consortium in 2001–2002, allowed accurate determination of its orbit. The calculations showed that the object was moving along a distant highly eccentric orbit, at a distance of 90.3 AU from the Sun. Precovery images have later been found in images of the Palomar Digitized Sky Survey dating back to 25 September 1990.
90377 Sedna | Discovery
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 to 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. Acquiring a larger sample of such objects would help in determining which scenario is most likely.
90377 Sedna | Population
90377 Sedna (520 AU average) is a large, reddish object with a gigantic, highly elliptical orbit that takes it from about 76 AU at perihelion to 940 AU at aphelion and takes 11,400 years to complete. Mike Brown, who discovered the object in 2003, asserts that it cannot be part of the scattered disc or the Kuiper belt because its perihelion is too distant to have been affected by Neptune's migration. He and other astronomers consider it to be the first in an entirely new population, sometimes termed "distant detached objects" (DDOs), which also may include the object , which has a perihelion of 45 AU, an aphelion of 415 AU, and an orbital period of 3,420 years.
Solar System | Detached objects
Mike Brown and his team favored the hypothesis that Sedna was lifted into its current orbit by a star from the Sun's birth cluster, arguing that Sedna's aphelion of about 1,000 AU, which is relatively close compared to those of long-period comets, is not distant enough to be affected by passing stars at their current distances from the Sun. They propose that Sedna's orbit is best explained by the Sun having formed in an open cluster of several stars that gradually disassociated over time. That hypothesis has also been advanced by both Alessandro Morbidelli and Scott Jay Kenyon. Computer simulations by Julio A.
90377 Sedna | Origin
Sedna has a V-band absolute magnitude (H) of about 1.8, and it is estimated to have an albedo of about 0.32, thus giving it a diameter of approximately 1,000 km. At the time of its discovery it was the intrinsically brightest object found in the Solar System since Pluto in 1930. In 2004, the discoverers placed an upper limit of 1,800 km on its diameter, but by 2007 this was revised downward to less than 1,600 km after observation by the Spitzer Space Telescope. In 2012, measurements from the Herschel Space Observatory suggested that Sedna's diameter was , which would make it smaller than Pluto's moon Charon.
90377 Sedna | Physical characteristics
At 38 K, the N vapor pressure would be 14 microbar (1.4 Pa or 0.000014 atm). 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.
90377 Sedna | Physical characteristics
Sedna will come to perihelion around 2075–2076. 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, NASA is not known to be considering any type of mission at this time. 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 or 23 June 2046. Sedna would be 77.27 or 76.43 AU from the Sun when the spacecraft arrived near the end of 2057 or 2073, respectively.
90377 Sedna | Exploration
Because Sedna has no known moons, determining its mass is currently impossible without sending a space probe. Sedna is currently the largest trans-Neptunian Sun-orbiting object not known to have a satellite. Only a single attempt has been made to find a satellite, and it has been suggested that there is a chance of up to 25% that a satellite could have been missed. 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. 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.
90377 Sedna | Physical characteristics
Sedna (provisionally designated ) was discovered by Michael Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University) on 14 November 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 were made in November–December 2003 with the SMARTS telescope at Cerro Tololo Inter-American Observatory in Chile, the Tenagra IV telescope in Nogales, Arizona, and the Keck Observatory on Mauna Kea in Hawaii.
90377 Sedna | Discovery
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. Sedna and two other very distant objects – and – share their color with outer classical Kuiper belt objects and the centaur 5145 Pholus, suggesting a similar region of origin. Trujillo and colleagues have placed upper limits in Sedna's surface composition of 60% for methane ice and 70% for water ice. The presence of methane further supports the existence of tholins on Sedna's surface, because they are produced by irradiation of methane.
90377 Sedna | Physical characteristics
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. 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.
90377 Sedna | Origin
Sedna's highly elliptical orbit means that the probability of its detection was roughly 1 in 80, which suggests that, unless its discovery was a fluke, another 40–120 Sedna-sized objects would exist within the same region. Another object, , 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. 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).
90377 Sedna | Population
This question was answered under the International Astronomical Union definition of a planet, adopted on 24 August 2006, which mandated that a planet must have cleared the neighborhood around its orbit. Sedna has a Stern–Levison parameter estimated to be much less than 1, and therefore cannot be considered to have cleared the neighborhood, even though no 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, and several astronomers have called it one.
90377 Sedna | Classification
90377 Sedna, a trans-Neptunian object discovered by Michael Brown (Caltech), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale University) on November 14, 2003, is named after her.
Sedna (mythology) | In astronomy
The Minor Planet Center, which officially catalogs the objects in the Solar System, classifies Sedna as a scattered object. This grouping is heavily questioned, and many astronomers have suggested that it, together with a few other objects (e.g. ), be placed in a new category of distant objects named "extended scattered disc objects" (E-SDO), "detached objects", "distant detached objects" (DDO), or "scattered-extended" in the formal classification by the Deep Ecliptic Survey. The discovery of Sedna resurrected the question of which astronomical objects should be considered planets and which should not. On 15 March 2004, articles on Sedna in the popular press reported that a tenth planet had been discovered.
90377 Sedna | Classification
When first discovered, Sedna was thought to have an unusually long rotational period (20 to 50 days). It was initially speculated that Sedna's rotation was slowed by the gravitational pull of a large binary companion, similar to Pluto's moon Charon. A search for such a satellite by the Hubble Space Telescope in March 2004 found nothing, and subsequent measurements from the MMT telescope suggest a much shorter rotation period of about 10 hours, more typical for a body of its size.
90377 Sedna | Orbit and rotation
The former name was later used for 90377 Sedna, a distant trans-Neptunian object discovered in 2003.
Siarnaq | Naming
In May 2018, astrophysicist Ethan Siegel publicly advocated for a space probe mission to study Sedna as it approaches perihelion. Siegel characterized Sedna as an attractive target due to its status as a possible inner Oort cloud object. Because of Sedna's long orbital period, "we will not get the opportunity to study it this close to the Sun for many millennia again." Such a mission could be facilitated by Dual-Stage 4-Grid ion thrusters that might cut cruise times considerably if powered, for example, by a fusion reactor.
90377 Sedna | Exploration
The trans-Neptunian object Sedna has an extra-long and unusual elliptical orbit around the Sun, ranging between 76 and 937 AU. Sedna's orbit takes about 11,400 years to complete once. Its discoverer, Michael Brown of Caltech, noted in a "Discover" magazine article that Sedna's location seemed to defy reasoning: "Sedna shouldn't be there", Brown said. "There's no way to put Sedna where it is. It never comes close enough to be affected by the Sun, but it never goes far enough away from the Sun to be affected by other stars." Brown therefore postulated that a massive unseen object may be responsible for Sedna's anomalous orbit.
Nemesis (hypothetical star) | Orbit of Sedna
The team made the name "Sedna" public before the object had been officially numbered. 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. No objection was raised to the name, and no competing names were suggested. The IAU's Committee on Small Body Nomenclature accepted the name in September 2004, 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.
90377 Sedna | Naming
It redetected Sedna but no other objects in Sedna-like orbits were identified.
Palomar Distant Solar System Survey | Introduction
When Sedna was discovered, its extreme orbit raised questions about its origin. Its perihelion is so distant (approximately 76 AU) that no currently observed mechanism can explain Sedna's eccentric distant orbit. It is too far from the planets to have been affected by the gravity of Neptune or the other giant planets and too bound to the Sun to be affected by outside forces such as the galactic tides. Hypotheses to explain its orbit include that it was affected by a passing star, that it was captured from another planetary system, or that it was tugged into its current position by a trans-Neptunian planet.
Planets beyond Neptune | Sedna's orbit
Brown terms this population the "inner Oort cloud" because it may have formed through a similar process, although it is far closer to the Sun. Sedna is very likely a dwarf planet, though its shape has yet to be determined. The second unequivocally detached object, with a perihelion farther than Sedna's at roughly 81 AU, is , discovered in 2012. Its aphelion is only half that of Sedna's, at 400–500 AU.
Solar System | Detached objects
The Minor Planet Center classifies the trans-Neptunian object 90377 Sedna as a scattered-disc object. Its discoverer Michael E. Brown has suggested instead that it should be considered an inner Oort-cloud object rather than a member of the scattered disc, because, with a perihelion distance of 76 AU, it is too remote to be affected by the gravitational attraction of the outer planets. Sedna is not the only such object: (discovered before Sedna) and have a perihelion too far away from Neptune to be influenced by it. This led to a discussion among astronomers about a new minor planet set, called the "extended scattered disc" (E-SDO).
Scattered disc | Detached objects
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 were responsible, all such objects would share roughly the same perihelion (≈80 AU). If Sedna had been 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.
Sednoid | Theoretical population
The most obvious solution to determining Sedna's peculiar orbit would be to locate a number of objects in a similar region, whose various orbital configurations would provide an indication as to their history. If Sedna had been pulled into its orbit by a trans-Neptunian planet, any other objects found in its region would have a similar perihelion to Sedna (around 80 AU).
Planets beyond Neptune | Sedna's orbit
Barucci and colleagues compared Sedna's spectrum with that of Triton and detected weak absorption bands belonging to methane and nitrogen ices. From these observations, they suggested the following model of the surface: 24% Triton-type tholins, 7% amorphous carbon, 10% nitrogen ices, 26% methanol, and 33% methane. The detection of methane and water ices was confirmed in 2006 by the Spitzer Space Telescope mid-infrared photometry. The presence of nitrogen on the surface suggests the possibility that, at least for a short time, Sedna may have a tenuous atmosphere. During a 200-year period near perihelion, the maximum temperature on Sedna should exceed , the transition temperature between alpha-phase solid N and the beta-phase seen on Triton.
90377 Sedna | Physical characteristics
The planetoid discovered at a distance of about 13 billion kilometers (90 AU) from the Sun, travels in an elliptical orbit of 11,400 years with a perihelion point of only 76 AU from the Sun during its closest approach (the next to occur in 2076), and travels out to 936 AU at its farthest point. However, Sedna is not considered a Kuiper belt object, because its orbit does not bring it into the region of the Kuiper belt at 50 AU. Sedna is a “detached object”, and thus is not in a resonance with Neptune.
Hills cloud | Sedna, the first candidate
This line of inquiry eventually led to the hypothesis of Planet Nine. Brown has stated that it is more likely that one or more non-companion stars, passing near the Sun billions of years ago, could have pulled Sedna out into its current orbit. In 2004, Kenyon forwarded this explanation after analysis of Sedna's orbital data and computer modeling of possible ancient non-companion star passes.
Nemesis (hypothetical star) | Orbit of Sedna
His work is considered similar to more recent Planet Nine theories in that the planets would be responsible for a clustering of the orbits of several objects, in this case the aphelion distances of periodic comets similar to that of the Jupiter-family comets. The discovery of Sedna's peculiar orbit in 2004 led to speculation that it had encountered a massive body other than one of the known planets. Sedna's orbit is detached, with a perihelion distance of 76 AU that is too large to be due to gravitational interactions with Neptune. Several authors proposed that Sedna entered this orbit after encountering an unknown planet on a distant orbit, a member of the open cluster that formed with the Sun, or another star that later passed near the Solar System.
Planet Nine | History
With an aphelion over 2100 AU, it brings the object further out than Sedna.
Sednoid | Known members
Sedna is a minor planet discovered by Michael E. Brown, Chad Trujillo and David L. Rabinowitz on 14 November 2003. Spectroscopic measures show that its surface composition is similar to that of other trans-Neptunian objects: It is mainly composed of a mixture of water ices, methane, and nitrogen with tholins. Its surface is one of the reddest in the Solar System. This may be the first detection of a Hills cloud object, depending on the definition used. The area of the Hills cloud is defined as any objects with orbits measuring between 2,000 and 15,000 AU. Sedna is, however, much closer than the supposed distance of the Hills cloud.
Hills cloud | Sedna, the first candidate
However, Sedna is much closer to the Sun than expected for objects in the Hills cloud and its inclination is close to that of the planets and the Kuiper belt. Considerable mystery surrounds , with its retrograde orbit that could make it originate from the Hills cloud or perhaps the Oort cloud. The same goes for damocloids, whose origins are doubtful, such as the namesake for this category, 5335 Damocles.
Hills cloud | Possible Hills cloud objects
Sedna Planitia is a large lowland area of Venus, south of Ishtar Terra. It is thought to be lava-covered and similar to a lunar mare. Its name is derived from the Inuit sea goddess.
Sedna Planitia | Introduction
One particularly distant body is 90377 Sedna, which was discovered in November 2003. Although it takes over 10,000 years to orbit, during the next 50 years it will slowly move closer to the Sun as it comes to perihelion at a distance of 76 AU from the Sun. Sedna is the largest known sednoid, a class of objects that play an important role in the Planet Nine hypothesis. Pluto (30–49 AU, about 34 AU in 2015) was the first Kuiper belt object to be discovered (1930) and is the largest known dwarf planet.
List of Solar System objects most distant from the Sun | Noted objects
Although Sedna is officially considered a scattered-disc object by the MPC, its discoverer Michael E. Brown has suggested that because its perihelion distance of 76 AU is too distant to be affected by the gravitational attraction of the outer planets it should be considered an inner-Oort-cloud object rather than a member of the scattered disc. This classification of Sedna as a detached object is accepted in recent publications.
Detached object | Classification
Among the extreme trans-Neptunian objects are three high-perihelion objects classified as sednoids: 90377 Sedna, , and 541132 Leleākūhonua. They are distant detached objects with perihelia greater than 70 AU. Their high perihelia keep them at a sufficient distance to avoid significant gravitational perturbations from Neptune. Previous explanations for the high perihelion of Sedna include a close encounter with an unknown planet on a distant orbit and a distant encounter with a random star or a member of the Sun's birth cluster that passed near the Solar System.
Trans-Neptunian object | Extreme trans-Neptunian objects
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). Following the discovery of Leleākūhonua, Sheppard et al. concluded that it implies a population of about 2 million Inner Oort Cloud objects larger than 40 km, with a total mass in the range of (several times the mass of the asteroid belt and 80% the mass of Pluto).
Sednoid | Theoretical population
Brown initially nicknamed Sedna "The Flying Dutchman", or "Dutch", after a legendary ghost ship, because its slow movement had initially masked its presence from his team. For an official name for the object, Brown settled on "Sedna", a name from Inuit mythology, which Brown chose partly because the Inuit were the closest polar culture to his home in Pasadena, and partly because the name, unlike Quaoar, would be easily pronounceable. On his website, he wrote: 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.
90377 Sedna | Naming
Other people also confuse Nibiru with Sedna (90377 Sedna) or Eris (136199 Eris), trans-Neptunian objects discovered by Mike Brown in 2003 and 2005 respectively. However, despite having been described as a "tenth planet" in an early NASA press release, Eris (then known only as 2003 UB) is now classified as a dwarf planet. Only slightly more massive than Pluto, Eris has a well-determined orbit that never takes it closer to the Earth than . Sedna is slightly smaller than Pluto, and never comes closer to Earth than . Mike Brown believes the confusion results from both the real Sedna and the imaginary Nibiru having extremely elliptical orbits.
Nibiru cataclysm | Sedna or Eris
Its elongated orbit (eccentricity = 0.977) has a perihelion of 36.19 AU, an aphelion of ~3,060 AU and a barycentric orbital period of ~60,900 years. The latter values are the largest known for any Solar System body that is not a long-period comet. Based on the barycentric orbital period, takes roughly 5 times longer than Sedna to orbit the Sun.
2014 FE72 | Orbit
came to perihelion 8.3 AU from the Sun on 27 October 2012, when it reached an apparent magnitude of about 20. In 1927, when it was 100 AU from the Sun, it had an apparent magnitude of about 30.8. For comparison dwarf planet 90377 Sedna had an apparent magnitude of 21.7 when it was 100 AU from the Sun. It comes to opposition at the start of September. It will not be 50 AU from the Sun until 2045. After leaving the planetary region of the Solar System, will have a barycentric aphelion of 1920 AU with an orbital period of 29900 years.
2013 BL76 | Orbit
, is an extreme trans-Neptunian object of the extended scattered disc in the outermost region of the Solar System, approximately 180 kilometers in diameter. It was discovered by astronomers at the Mauna Kea Observatory on 26 April 2003.
(506479) 2003 HB57 | Introduction
Acquiring a larger sample of such objects would therefore help in determining which scenario is most likely. "I call Sedna a fossil record of the earliest Solar System", said 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." A 2007–2008 survey by Brown, Rabinowitz and 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 Gonggong, it detected no new sednoids.
Sednoid | Theoretical population
Sedna is an open-source database management system that provides native storage for XML data. The distinctive design decisions employed in Sedna are (i) schema-based clustering storage strategy for XML data and (ii) memory management based on layered address space.
Sedna (database) | Introduction
, also known by its OSSOS survey designation uo3L91, is a trans-Neptunian object discovered on September 29, 2013 by the Outer Solar System Origins Survey using the Canada–France–Hawaii Telescope at Mauna Kea Observatory. This object orbits the Sun between , and has a barycentric orbital period of nearly 20,000 years. It has the second largest semi-major axis yet detected for an orbit with a perihelion beyond the zone of strong influence of Neptune , second only to 541132 Leleākūhonua, but exceeding the semi-major axes of , and . has one of highest perihelion of any known extreme trans-Neptunian object, behind sednoids including Sedna (76 AU), (80 AU), and Leleākūhonua (65 AU).
2013 SY99 | Introduction
HD 30963 is close to the orbit that the solar system is traversing in the Milky Way. The sun will be close to the current location of HD 30963 in about 18.5 million years. Interstellar absorption lines for Na I are present for velocities lower than 10 km/s.
HD 30963 | Introduction
For comparison, Sedna has a barycentric semi-major axis of 506 AU and a period of 11,400 years. Both and take longer than Sedna and " to orbit the Sun using barycentric coordinates.
(523622) 2007 TG422 | Unstable heliocentric solutions
DENIS-P J082303.1-491201 (also known as DENIS J082303.1-491201, DE0823-49), is a binary system of two brown dwarfs, located away from the Earth. The system is located in the constellation Vela. The primary has a spectral class of L1.5, a mass of and a temperature of . The secondary is also a brown dwarf but with a spectral type of L5.5, a mass of , and a temperature of . The mass ratio is around 0.64 to 0.74. The system has an orbital period of 248 days. The age of the system is estimated to be around 80 to 500 million years old, a relatively young object in the solar neighbourhood, however it does not seem to belong to have any association with any moving groups.
DENIS J082303.1−491201 | Introduction
Even without gravitational evidence, Mike Brown, the discoverer of Sedna, has argued that Sedna's 12,000-year orbit means that probability alone suggests that an Earth-sized object exists beyond Neptune. Sedna's orbit is so eccentric that it spends only a small fraction of its orbital period near the Sun, where it can be easily observed. This means that unless its discovery was a freak accident, there is probably a substantial population of objects roughly Sedna's diameter yet to be observed in its orbital region. Mike Brown noted that "Sedna is about three-quarters the size of Pluto. If there are sixty objects three-quarters the size of Pluto [out there] then there are probably forty objects the size of Pluto ...
Planets beyond Neptune | Probability
Vadna is a village in Borsod-Abaúj-Zemplén county, Hungary.
Vadna | Introduction
Among the extreme trans-Neptunian objects are the sednoids, three objects with an outstandingly high perihelion: Sedna, , and Leleākūhonua. Sedna and are distant detached objects with perihelia greater than 70 AU. Their high perihelia keep them at a sufficient distance to avoid significant gravitational perturbations from Neptune. Previous explanations for the high perihelion of Sedna include a close encounter with an unknown planet on a distant orbit and a distant encounter with a random star or a member of the Sun's birth cluster that passed near the Solar System.
Extreme trans-Neptunian object | Sednoids
HD 145377 b is an extrasolar planet located approximately 180 light-years awayThis planet was discovered on October 26, 2008 by Moutou "et al." using the HARPS spectrograph on ESO's 3.6 meter telescope installed at La Silla Observatory in Atacama desert, Chile.
HD 145377 b | Introduction
SNED1 is located on the plus strand of chromosome 2 at locus 2q37.3. The Refseq identification number is NM_001080437.1 The genomic DNA sequence of SNED1 contains 96,729bp and the longest spliced mRNA as predicted by AceView is 7048bp and contains 31 exons. There are 9 splice variants of SNED1 that exhibited protein structure matches using the Phyre 2 database which is discussed under "Tertiary and Quaternary Structure".
SNED1 | Locus
Radna () is a settlement in the Municipality of Sevnica in east-central Slovenia. It lies at the confluence of the Mirna River and the Sava River in the historical region of Lower Carniola. The municipality is now included in the Lower Sava Statistical Region. The village was historically named "Tariška vas". There is a large 17th-century mansion in the settlement.
Radna, Sevnica | Introduction
Most of the SeqA in the cell is found bound to new DNA, at the replication fork.
SeqA protein | Localisation
It was located 1'.6 west and 0'.7 north of the nucleus.
IC 5201 | Introduction
When Sedna was discovered in 2003, it was moving at 1.75 arcsec/h, and in light of that the team reanalyzed their old data with a lower limit on the angular motion, sorting through the previously excluded images by eye. In January 2005, the re-analysis revealed Eris's slow motion against the background stars. Follow-up observations were then carried out to make a preliminary determination of Eris's orbit, which allowed the object's distance to be estimated. The team had planned to delay announcing their discoveries of the bright objects Eris and until further observations and calculations were complete, but announced them both on July 29 when the discovery of another large TNO they had been tracking, , was controversially announced on July 27 by a different team in Spain.
Eris (dwarf planet) | Discovery
Niesadna is a village in the administrative district of Gmina Pilawa, within Garwolin County, Masovian Voivodeship, in east-central Poland. It lies approximately north-east of Pilawa, north of Garwolin, and south-east of Warsaw.
Niesadna | Introduction
It is currently at 35.8 AU from the Sun, near its perihelion.
(230965) 2004 XA192 | Introduction
It is expected to be about half the size of Sedna and similar in size to Huya. Its surface is thought to have a pink tinge, resulting from chemical changes produced by the effect of radiation on frozen water, methane, and carbon dioxide. This optical color is consistent with formation in the gas-giant region and not the classical Kuiper belt, which is dominated by ultra-red colored objects.
2012 VP113 | Classification and physical characteristics
"Sequoia" is a bright member of the Hungaria family (), a large family within the larger dynamical Hungaria group that forms the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.8–2.1 AU once every 2 years and 8 months (982 days; semi-major axis of 1.93 AU). Its orbit has an eccentricity of 0.09 and an inclination of 18° with respect to the ecliptic. The body's observation arc begins at the North African Algiers Observatory in December 1928, about 7 weeks after its official discovery observation at Bergedorf.
1103 Sequoia | Orbit and classification
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Doriprismatica sedna | References
A sednoid is a trans-Neptunian object with a perihelion well beyond the Kuiper cliff at . Only three objects are known from this population: 90377 Sedna, , and 541132 Leleākūhonua (), but it is suspected that there are many more. All three have perihelia greater than . These objects lie outside an apparently nearly empty gap in the Solar System and have no significant interaction with the planets. They are usually grouped with the detached objects. Some astronomers, such as Scott Sheppard, consider the sednoids to be inner Oort cloud objects (OCOs), though the inner Oort cloud, or Hills cloud, was originally predicted to lie beyond 2,000 AU, beyond the aphelia of the three known sednoids.
Sednoid | Introduction
The three published sednoids, like all of the more extreme detached objects (objects with semi-major axes > 150 AU and perihelia > 30 AU; the orbit of Neptune), have a similar orientation (argument of perihelion) of ≈ 0° (). This is not due to an observational bias and is unexpected, because interaction with the giant planets should have randomized their arguments of perihelion (ω), with precession periods between 40 Myr and 650 Myr and 1.5 Gyr for Sedna. This suggests that one or more undiscovered massive perturbers may exist in the outer Solar System. A super-Earth at 250 AU would cause these objects to librate around ω = for billions of years.
Sednoid | Known members
Along with the similar orbits of other distant trans-Neptunian objects, the orbit of "Leleākūhonua" suggests, but does not prove, the existence of a hypothetical Planet Nine in the outer Solar System. , the object is inbound 78 AU from the Sun; about two-and-a-half times farther out than Pluto's current location. It will come to perihelion (closest approach to the Sun) in 2078. As with Sedna, it would not have been found had it not been on the inner leg of its long orbit. This suggests that there may be many similar objects, most too distant to be detected by contemporary technological methods.
541132 Leleākūhonua | Implications of orbit
HD 212301 b is an extrasolar planet located approximately 172 light-years (53 parsecs) away in the constellation of Octans, orbiting the star HD 212301. It has an orbital period of 2.25 Earth days. The orbital distance is 0.0341 astronomical units or 5.10 gigameters. On August 22, 2005, taking place in ESO La Silla Observatory in Chile, the planet was discovered by Lo Curto who used the HARPS spectrometer.
HD 212301 b | Introduction
, also written as is a resonant trans-Neptunian object from the Kuiper belt, located in the outermost region of the Solar System. It measures approximately 134 kilometers in diameter. It was discovered by astronomers at the Mauna Kea Observatory on 28 April 1998.
(91133) 1998 HK151 | Introduction
HD 90156 b is an extrasolar planet which orbits the G-type main sequence star HD 90156, located approximately 73 light years away.
HD 90156 b | Introduction
2121 Sevastopol, provisional designation , is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 27 June 1971, by Russian astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. Its minor-planet moon was discovered in 2010.
2121 Sevastopol | Introduction
The Hodna () is a natural region of Algeria located between the Tell and Saharan Atlas ranges at the eastern end of the "Hautes Plaines". It is a vast depression lying in the northeastern section of M'Sila Province and the western end of Batna Province.
Hodna | Introduction
Sodna Vas (; , ) is a small settlement in the Municipality of Podčetrtek in eastern Slovenia. The area was traditionally part of the Styria region. It is now included in the Savinja Statistical Region.
Sodna Vas | Introduction
At aphelion it is over 1,000 AU from the Sun and, with a perihelion of 21 AU, almost crosses the orbit of Uranus at closest approach. Astronomers with the Deep Ecliptic Survey classify it as a centaur rather than a trans-Neptunian object. came to perihelion in April 2005. Both and take longer than Sedna to orbit the Sun using either heliocentric coordinates or barycentric coordinates.
(87269) 2000 OO67 | Description
Such clustering could be explained if they were disturbed by an unseen object at least as large as Jupiter, possibly a brown dwarf, located in the outer part of the Oort cloud. They also suggested that such an object might explain the trans-Neptunian object Sedna's peculiar orbit. However, the sample size of Oort comets was small and the results were inconclusive.
Tyche (hypothetical planet) | History
Organellar DNA (oDNA) is DNA contained in organelles (such as mitochondria and choloroplasts), outside the nucleus of Eukaryotic cells.
Organellar DNA | Introduction
, provisional designation , is a resonant trans-Neptunian object and possible dwarf planet from the circumstellar disc of the Kuiper belt in the outer Solar System, approximately 440 kilometers in diameter. It was discovered on 10 February 1999, by astronomers Jane Luu, David Jewitt and Chad Trujillo at Mauna Kea Observatories on the Big Island of Hawaii, United States.
(469306) 1999 CD158 | Introduction
903 Nealley is a minor planet orbiting the Sun. The semi-major axis of the orbit of 903 Nealley lies just inside the Hecuba gap, located at 3.27 AU.
903 Nealley | Introduction
, is a trans-Neptunian- and scattered disc object from the outermost region of the Solar System, approximately 117 kilometers in diameter. It was first observed by astronomers during the Outer Solar System Origins Survey at the Mauna Kea Observatories on 24 May 2015.
2015 KH163 | Introduction
"C16orf82" is located in humans at locus 16p12.1 on the positive strand.
C16orf82 | Locus
, provisional designation , is a 1:6 resonant trans-Neptunian object and dwarf planet candidate located in the outermost region of the Solar System that takes almost a thousand years to complete an orbit around the Sun. It was discovered on 24 September 2008 by American astronomers Megan Schwamb, Michael Brown and David Rabinowitz at the Palomar Observatory in California, with no known earlier precovery images.
(528381) 2008 ST291 | Introduction
, provisional designation , is a trans-Neptunian object from the classical Kuiper belt, located in the outermost region of the Solar System. The cubewano belongs to the cold population. It has a perihelion (closest approach to the Sun) at 40.297 AU and an aphelion (farthest approach from the Sun) of 48.306 AU. It is about 146 km in diameter. It was discovered on 28 April 1998, at the Mauna Kea Observatory, Hawaii.
(85627) 1998 HP151 | Introduction
The star has a mass of 1.6 solar masses making it a late A type star. It is located approximately 90 parsecs away in the constellation of Carina.
HD 95086 b | Introduction
, provisional designation , is a trans-Neptunian object and member of the Haumea family that resides in the Kuiper belt, located in the outermost region of the Solar System. It was discovered on 19 September 1995, by American astronomer Nichole Danzl of the Spacewatch program at Kitt Peak National Observatory near Tucson, Arizona, in the United States. It measures approximately 600–700 kilometers in diameter and was the second-brightest known object in the Kuiper belt, after Pluto, until was discovered.
(24835) 1995 SM55 | Introduction
In humans, SKIDA1 is located on the reverse strand of chromosome 10 at locus 10p12.31. It contains five exons.
SKIDA1 | Structure
In Spain, Setiawan discovered this planet in 2003, using the radial velocity method. However, a follow-up study by Soto et al. (2015) failed to detect a signal via the radial velocity method, so it remains unconfirmed.
HD 122430 b | Introduction
"For places in the Czech Republic and Slovakia, see Rudná (disambiguation)." Rudna may refer to:
Rudna | Introduction
S5 0014+81 is a distant, compact, hyperluminous, broad-absorption-line quasar, or blazar, located near the high declination region of the constellation Cepheus, near the North Equatorial Pole.
S5 0014+81 | Introduction
Originally described from the Eastern Pacific, records from the Caribbean are considered the result of a recent introduction, presumably human-introduced. The indigenous distribution of "Doriprismatica sedna" includes Eastern Pacific: from the Gulf of California to the Galapagos Islands and non-indigenous in Western Atlantic: Florida, Belize, Bahamas and Panama.
Doriprismatica sedna | Distribution
As of 2017 its current position is at 46.7 AU from the Sun.
(469306) 1999 CD158 | Orbit and classification
HD 73267 b is an extrasolar planet located approximately 177 light-years away. This planet was discovered on October 26, 2008 by Moutou "et al." using the HARPS spectrograph on ESO's 3.6 meter telescope installed at La Silla Observatory in Atacama desert, Chile.
HD 73267 b | Introduction
HD 199442 is a giant star situated in the Aquarius constellation. It is located about 310 light years from the solar system.
HD 199442 | Introduction
C7orf61 is located on the reverse (or negative) DNA strand and is situated in chromosome 7 (7q22.1) from base pairs 100,456,615-100,464,271 - roughly 7,656 bp. It has a total of 3 exons and lacks isoforms.
C7orf61 | Locus