47171 Lempo, or as a binary (47171) Lempo–Hiisi (also known as ), is a
trans-Neptunian object
A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has a semi-major axis of 30.1 astronomical units (au).
Typically, ...
and
trinary system from the
Kuiper belt
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
, located in the outermost regions of the
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
. It was discovered on 1 October 1999, by American astronomers
Eric Rubenstein and
Louis-Gregory Strolger during an observing run at
Kitt Peak National Observatory
The Kitt Peak National Observatory (KPNO) is a United States astronomy, astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With ...
in
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
, United States.
Rubenstein was searching images taken by Strolger as part of their Nearby Galaxies Supernova Search project. It is classified as a
plutino
In astronomy, the plutinos are a dynamical group of trans-Neptunian objects that orbit in 2:3 mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the lar ...
with a 2:3
mean-motion resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationsh ...
with
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
and is among the brighter TNOs. It reached
perihelion
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion.
General description
There are two apsides in any ellip ...
in July 2015. This minor planet was named after
Lempo
Lempo () is a sort of fiend from Finnish folklore and mythology. Lempo is the god of love and fertility in Finnish mythology.
After Christianity came to Finland, the reputation of Lempo worsened: it is portrayed in the folklore usually as an er ...
from Finnish mythology.
The trinary system's other two components, Paha and Hiisi , were discovered in 2001 and 2007, respectively, and later named after Lempo's two demon cohorts, Paha and
Hiisi
Hiisi (; plural ''hiidet'' ) is a term in Finnic mythologies, originally denoting sacred localities and later on various types of mythological entities.
In later, Christian-influenced folklore, they are depicted as demonic or trickster-like entit ...
.
History
Discovery
![Baboquivari&KittPeakNatObs](https://upload.wikimedia.org/wikipedia/commons/4/4f/Baboquivari%26KittPeakNatObs.jpg)
The Lempo system was discovered on 1 October 1999 by American astronomers
Eric Rubenstein and
Louis-Gregory Strolger during an observing run for their Nearby Galaxies Supernova Search (NGSS) project at the
Kitt Peak National Observatory
The Kitt Peak National Observatory (KPNO) is a United States astronomy, astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With ...
in
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
. Initiated in 1998 as part of Strolger's
doctoral thesis
A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144: ...
, the NGSS project was a three-year-long
CCD-based survey of
galaxies
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...
along the
celestial equator
The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. This plane of reference bases the equatorial coordinate system. In other words, the celestial equator is an abstract projectio ...
to search for nearby, low-
redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...
supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...
e. The Kitt Peak Observatory's WIYN 0.9-meter telescope was used for wide-field imaging of this region, which coincided with the
ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...
plane where
Kuiper belt object
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
s (KBOs) including Lempo were likely to appear.
Rubenstein identified Lempo as a relatively bright, slow-moving object in the
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
Cetus
Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus (mythology), Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water- ...
on images taken by Strolger on 1 October 1999.
At an
apparent magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
of 20, its exceptional brightness for a suspected KBO warranted follow-up observations to confirm the object.
Lempo was observed by Rubenstein and Strolger for three consecutive days after its discovery. The object was also found in images taken by Strolger on 30 September 1999, one day prior to its discovery. The discovery was then announced by the
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
on 21 December 1999 and the object was given the
provisional designation
Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...
.
The provisional designation indicates that Lempo was the 903rd
minor planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...
discovered in the first half of October 1999. By 2002, additional observations have extended Lempo's
observation arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...
to over two years, sufficient to determine an accurate orbit.
Lempo was consequently given the permanent
minor planet number
A formal minor-planet designation is, in its final form, a number–name combination given to a minor planet (asteroid, centaur, trans-Neptunian object and dwarf planet but not comet). Such designation always features a leading number (catalog or ...
47171 by the Minor Planet Center on 21 September 2002.
, more than 500 total observations of Lempo over an observation arc of over 46 years have been documented.
The earliest known
precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of an object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This happens mos ...
observations of Lempo have been found in
photographic plate
Photographic plates preceded photographic film as a capture medium in photography, and were still used in some communities up until the late 20th century. The light-sensitive emulsion of silver salts was coated on a glass plate, typically thinn ...
s of the
Siding Spring Observatory
Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...
's
Digitized Sky Survey
The Digitized Sky Survey (DSS) is a digitized version of several photographic astronomical surveys of the night sky, produced by the Space Telescope Science Institute between 1983 and 2006.
Versions and source material
The term Digitized Sky S ...
from June 1974 and May and September 1976.
Name
The largest primary component of the triple system is named after
Lempo
Lempo () is a sort of fiend from Finnish folklore and mythology. Lempo is the god of love and fertility in Finnish mythology.
After Christianity came to Finland, the reputation of Lempo worsened: it is portrayed in the folklore usually as an er ...
from
Finnish mythology
Finnish mythology is a commonly applied description of the folklore of Finnish paganism, of which a modern revival is practiced by a small percentage of the Finnish people. It has many features shared with Estonian and other Finnic mythologies, ...
. Originally worshiped as the god of love and fertility, he was later depicted as a
devil
A devil is the personification of evil as it is conceived in various cultures and religious traditions. It is seen as the objectification of a hostile and destructive force. Jeffrey Burton Russell states that the different conceptions of t ...
, after
Christianity
Christianity is an Abrahamic monotheistic religion based on the life and teachings of Jesus of Nazareth. It is the world's largest and most widespread religion with roughly 2.38 billion followers representing one-third of the global pop ...
came to Finland. Lempo brought down the hero
Väinämöinen
Väinämöinen () is a demigod, hero and the central character in Finnish folklore and the main character in the national epic ''Kalevala'' by Elias Lönnrot. Väinämöinen was described as an old and wise man, and he possessed a potent, mag ...
with the help of his two demon cohorts
Hiisi
Hiisi (; plural ''hiidet'' ) is a term in Finnic mythologies, originally denoting sacred localities and later on various types of mythological entities.
In later, Christian-influenced folklore, they are depicted as demonic or trickster-like entit ...
and Paha, whose names denominate the smaller inner and outer components, respectively.
The names were chosen on behalf of astronomer Bryan J. Holler.
The official naming citation was published by the Minor Planet Center on 5 October 2017.
Trinary system
Lempo
Lempo is a hierarchical
triple (or trinary) system consisting of a central primary, which is itself a
binary system
A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter ''(also see animated examples)''. More restrictive definitions require that th ...
of two similarly-sized components (Lempo and Hiisi), and a small
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
on a wide and
eccentric
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-center, in geometry
* Eccentricity (graph theory) of a v ...
circumbinary orbit (Paha). The structure of the hierarchy is discerned by denoting the apparent Lempo–Hiisi primary with the letter ''A'' and the smaller, outer companion Paha with the letter ''B''; the individual primary components Lempo and Hiisi are distinguished as ''A1'' and ''A2'', respectively.
The three components ordered from largest to smallest are Lempo, Hiisi, and Paha.
Assuming spherical shapes with a uniform
bulk density Bulk density, also called apparent density or volumetric density, is a property of powders, granules, and other "divided" solids, especially used in reference to mineral components (soil, gravel), chemical substances, (pharmaceutical) ingredients ...
for all components, the system mass estimated based on the motion of Paha is .
The orbital motion of the Lempo–Hiisi components gives somewhat a higher estimated mass of . This discrepancy is probably related to unaccounted gravitational interactions of the components in a complex triple system.
Lempo is one of the only three trans-Neptunian multiple systems with more than two components; the other two are the
dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to p ...
s
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
and
Haumea
Haumea (minor-planet designation 136108 Haumea) is a dwarf planet located trans-Neptunian object, beyond Neptune's orbit. It was discovered in 2004 by a team headed by Michael E. Brown, Mike Brown of Caltech at the Palomar Observatory in the United ...
.
The binary
Kuiper belt object
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
385446 Manwë
385446 Manwë , or (385446) Manwë–Thorondor , is a binary resonant Kuiper belt object in a 4:7 mean-motion resonance with Neptune. It was discovered on 25 August 2003, by American astronomer Marc Buie at Cerro Tololo Observatory in northern ...
is suspected to have once been a hierarchical triple system similar to Lempo, but the orbit of its inner binary evolved by tides and became a
contact binary
In astronomy, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes. A binary system whose stars share an envelope may also be called an overconta ...
.
Hiisi
![TNO close binaries comparison](https://upload.wikimedia.org/wikipedia/commons/b/b8/TNO_close_binaries_comparison.svg)
Hiisi, officially designated (47171) Lempo II Hiisi,
is the inner, second-largest component of the Lempo triple system, discovered last among the three. Together with the primary component Lempo, it forms the central binary Lempo–Hiisi which the outer component Paha revolves around. The existence of a third, inner component (or second companion) in the Lempo system was first hypothesized in 2006 by John Stansberry and collaborators, who noted that the primary seemed to have an unusually low density.
Further evidence to the existence of an inner component was posited by Seth Jacobson and
Jean-Luc Margot
Jean-Luc Margot (born 1969) is a Belgian-born astronomer and a UCLA professor who specializes in planetary sciences.
Career
Margot has discovered and studied several binary asteroids with radar and optical telescopes. His discoveries include ( ...
in October 2007, who noticed a distinct elongation of the primary in Hubble images.
The binarity of the Lempo primary was eventually confirmed in a more extensive analysis of Hubble images by Susan Benecchi, Keith Noll, Will Grundy and Hal Levison in 2009.
Due to complex discovery circumstances involving different independent groups of researchers,
Hiisi did not have a formal provisional designation signifying the year of its first observation or discovery.
Instead, it was unofficially designated "component A2" in scientific literature for being the smaller component of the central Lempo–Hiisi binary.
It eventually received its permanent
satellite designation and name while the larger, first component A1 maintained the name Lempo on 5 October 2017.
The separation between the two components is only about half the
diffraction limit
The resolution of an optical imaging system a microscope, telescope, or camera can be limited by factors such as imperfections in the lenses or misalignment. However, there is a principal limit to the resolution of any optical system, due to th ...
of Hubble, making it impossible to fully resolve the system. Instead, it appears elongated in Hubble images, revealing its binary nature.
This central pair has a semi-major axis of around 867 km and a period of about 1.9 days.
Assuming equal
albedos of about 0.079, ''Lempo'' and ''Hiisi'' are approximately and in diameter, respectively.
Assuming a uniform density for all components, the mass of Hiisi itself .
Paha
![47171-Lempo-Hubble](https://upload.wikimedia.org/wikipedia/commons/1/1f/47171-Lempo-Hubble.gif)
Paha, officially designated (47171) Lempo I Paha,
is the smaller, outer component of the Lempo triple system. It was discovered on 8 December 2001 by astronomers
Chadwick Trujillo
Chadwick A. Trujillo (born November 22, 1973) is an American astronomer, discoverer of minor planets and the co-discoverer of Eris, the most massive dwarf planet known in the Solar System.
Trujillo works with computer software and has examined ...
and
Michael Brown using the
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...
's
Space Telescope Imaging Spectrograph
The Space Telescope Imaging Spectrograph (STIS) is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. Aerospace engineer Bruce Woodgate of the Goddard Space Flight Center was the principal investigator and creat ...
to survey for binary trans-Neptunian objects.
The discovery was reported in an ''
IAU Circular
The International Astronomical Union Circulars (IAUCs) are notices that give information about astronomical phenomena. IAUCs are issued by the International Astronomical Union's Central Bureau for Astronomical Telegrams (CBAT) at irregular interval ...
'' notice published by the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
10 January 2002.
The confirmation of Paha in archival 4 October 2001 observations from the
Lick Observatory
The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The observatory is managed by th ...
's
Shane telescope
The C. Donald Shane telescope is a 120-inch (3.05-meter) reflecting telescope located at the Lick Observatory in San Jose, California, San Jose, California. It was named after astronomer C. Donald Shane in 1978, who led the effort to acquire the ne ...
adaptive optics
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical tele ...
system was reported in a follow-up ''IAU Circular'' published on 24 January 2002.
Paha previously had the temporary
provisional designation
Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...
before it was changed to S/2001 (47171) 1 after Lempo was numbered.
Being the smaller, outer component on a circumbinary orbit around the central Lempo–Hiisi binary, it was sometimes designated "component B" in scientific literature.
It received its permanent
satellite designation and name alongside Lempo and Hiisi on 5 October 2017.
In unfiltered visual wavelengths, Paha appears 2.2 magnitudes dimmer than the primary on average, corresponding to an individual
apparent magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
of 22.6.
The satellite has an estimated diameter of
and a
semi-major axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...
of , orbiting its primary in .
It is estimated to only have a mass of about .
System dynamics
The orbital dynamics of the Lempo system are highly complex and could not be modelled with solely
Keplerian dynamics.
Many crucial parameters such as initial spin states and shapes of the individual components are unknown and thus could not adequately model the dynamics of the Lempo system as a
three-body problem
In physics and classical mechanics, the three-body problem is the problem of taking the initial positions and velocities (or momenta) of three point masses and solving for their subsequent motion according to Newton's laws of motion and Newton's ...
without leading to significantly
chaotic behavior
Chaos theory is an interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to have c ...
. In a 2018 dynamical study, Alexandre Correia found that simulated models using realistically assumed spin states and shapes failed to explain the presently eccentric mutual orbit of the inner Lempo–Hiisi binary, even with the inclusion of eccentricity-damping
tidal force
The tidal force is a gravitational effect that stretches a body along the line towards the center of mass of another body due to a gradient (difference in strength) in gravitational field from the other body; it is responsible for diverse phenomen ...
s. Correia concluded that the present orbits, spin states and shapes of all components of the Lempo system needed to be remeasured to a greater precision before a more sophisticated model could be developed.
Origin
There exist two main
hypotheses
A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obser ...
on how this triple system formed. The first one is a giant collision and subsequent reaccretion in the
disc. The second one is gravitational capture of a third object by a preexisting binary. The similar sizes of Lempo and Hiisi favor the latter hypothesis.
Physical characteristics
The combined observations by the infrared
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...
,
Herschel Space Telescope
The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Teles ...
and the
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...
(HST) make it possible to estimate the sizes of the system's components and consequently provide the range of possible values for the objects' bulk
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
.
The single-body diameter (effective system size) of ''Lempo'' is currently estimated at .
The very low estimated density of 0.3–0.8 g/cm
3 obtained in 2006 (when the system was thought to be a binary) would require an unusually high
porosity
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...
of 50–75%, assuming an equal mixture of rock and ice.
The direct measurement of visible fluxes of all three components of the system in 2009 by the HST has resulted in an improved average density of confirming the earlier conclusion that the object is probably a
rubble pile
In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the ...
.
The density was revised up to in 2012 when new information from the Herschel became available. For a bulk density in the range 1–2 g/cm
3 the porosity is in the range 36–68%, again confirming that the object is a rubble pile.
Lempo has a very red
spectral slope In astrophysics and planetary science, spectral slope, also called spectral gradient, is a measure of dependence of the reflectance on the wavelength.
In digital signal processing, it is a measure of how quickly the spectrum of an audio sound tails ...
in
visible light
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...
and a flat spectrum in
near infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
. There is also a weak absorption feature near the wavelength of 2
μm, probably caused by water
ice
Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...
. The best model reproducing the near infrared spectrum includes
tholin
Tholins (after the Greek (') "hazy" or "muddy"; from the ancient Greek word meaning "sepia ink") are a wide variety of organic compounds formed by solar ultraviolet or cosmic ray irradiation of simple carbon-containing compounds such as carbon ...
s, crystalline water ice, and
serpentine as surface materials. These results are for the integrated spectrum of all three components of the system.
Exploration
The Lempo system has been considered for future exploration due to its unusual configuration.
Lempo was suggested as a target for ''
New Horizons 2
''New Horizons 2'' (also ''New Horizons II'', NHII, or NH2) was a proposed mission to the trans-Neptunian objects by NASA. It was conceived as a planetary flyby mission in 2002, based on the ''New Horizons'' spacecraft, which was in development ...
'', a proposed twin of its namesake that would fly by Jupiter, Uranus, and up to four KBOs.
See also
*
*
List of trans-Neptunian objects
This is a list of trans-Neptunian objects (TNOs), which are minor planets in the Solar System that orbit the Sun at a greater distance on average than Neptune, that is, their orbit has a semi-major axis greater than 30.1 astronomical units (AU) ...
Notes
References
External links
Beyond Jupiter: 47471 Lempo Oliver Klös, ''Journal for Occultation Astronomy'', October 2020
Andrew Lowe
Chad Trujillo
Chadwick A. Trujillo (born November 22, 1973) is an American astronomer, discoverer of minor planets and the co-discoverer of Eris, the most massive dwarf planet known in the Solar System.
Trujillo works with computer software and has examined ...
,
Northern Arizona University
Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona. It was founded in 1899 as the final public university established in the Arizona Territory, 13 years before Arizona was admitted as the 48th state.
...
*
*
{{DEFAULTSORT:47171
Trans-Neptunian objects
Lempo
Lempo () is a sort of fiend from Finnish folklore and mythology. Lempo is the god of love and fertility in Finnish mythology.
After Christianity came to Finland, the reputation of Lempo worsened: it is portrayed in the folklore usually as an er ...
Plutinos
Trinary minor planets
19991001
Trans-Neptunian satellites