Elsa (;

minor planet designation 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 o ...

: 182 Elsa) is a Massalia or background

asteroid An asteroid is a minor planet of the Solar System#Inner solar system, inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic o ...

from the inner regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

, approximately in diameter. It was discovered on 7 February 1878, by Austrian astronomer

Johann Palisa Johann Palisa (6 December 1848 – 2 May 1925) was an Austrian astronomer, born in Troppau, Austrian Silesia, now Czech Republic. He was a prolific discoverer of asteroids, discovering 122 in all, from 136 Austria in 1874 to 1073 Ge ...

at the

Austrian Naval Observatory This is a list of observatory codes (IAU codes or MPC codes) published by the Minor Planet Center. For a detailed description, ''see observations of small Solar System bodies Observations of minor planets as well as comets and natural satellites ...

in today's Croatia. The

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...

has a very long

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 80 hours and likely an elongated shape. The origin of its name is uncertain.

Orbit and classification

''Elsa'' is a member of the

Massalia family The Massalia family (adj. ''Massalian''; FIN: 404) is a family of asteroids in the inner asteroid belt, named after its parent body, 20 Massalia. It consists of S-type asteroids with very low inclinations, straddling the 1:2 resonances with ...

(), a very large inner belt

asteroid family An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. A ...

consisting of stony asteroids. In a different HCM-study, however, it has been found to be a non-

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

asteroid from the main belt's background population. It orbits the Sun in the inner main-belt at a distance of 2.0–2.9 AU once every 3 years and 9 months (1,371 days;

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 lo ...

of 2.42 AU). Its orbit has an

eccentricity 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 ...

of 0.19 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 2 ° with respect to 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 agai ...

Naming

The origin of this

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 '' ...

's name is uncertain. Originally, the asteroid was named "Elsbeth" – the Austrian variant of "Elisabeth" – and only later changed into a more lyrical "Elsa" with the consent of the discoverer,

. It may have been named after the character in the legend of

Lohengrin Lohengrin () is a character in German Arthurian literature. The son of Parzival (Percival), he is a knight of the Holy Grail sent in a boat pulled by swans to rescue a maiden who can never ask his identity. His story, which first appears in Wolf ...

perpetuated by

Richard Wagner Wilhelm Richard Wagner ( ; ; 22 May 181313 February 1883) was a German composer, theatre director, polemicist, and conductor who is chiefly known for his operas (or, as some of his mature works were later known, "music dramas"). Unlike most o ...

's opera of the same name. It may also refer to the

Empress Elisabeth of Austria Duchess Elisabeth Amalie Eugenie in Bavaria (24 December 1837 – 10 September 1898) was Empress of Austria and Queen of Hungary from her marriage to Emperor Franz Joseph I on 24 April 1854 until her assassination in 1898. Elisabeth wa ...

(1854–1898), or to a relative of Admiral Bourgignon, who requested the naming, as he was the military superior of the discoverer at the Naval Observatory at Pola. Finally, the name "Elsbeth" just might have been chosen generically as it is one of the most common feminine Christian names.

Physical characteristics

''Elsa'' has been characterized as a common, stony

in both the

Tholen Tholen () is a 25,000 people Municipalities of the Netherlands, municipality in the southwest of the Netherlands. The municipality of Tholen takes its name from the town of Tholen, which is the largest population center in the municipality. The m ...

and

SMASS classification An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiat ...

Rotation period

The asteroid is a relatively slow rotator. In 1980, its

was estimated to be about 3.3 Earth days. In 2008, a collaborative effort from three different sites under the lead of Frederick Pilcher was used to build a complete

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

for the asteroid, which showed a period of hours with a brightness variation of in

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

. A possible

companion Companion may refer to: Relationships Currently * Any of several interpersonal relationships such as friend or acquaintance * A domestic partner, akin to a spouse * Sober companion, an addiction treatment coach * Companion (caregiving), a caregive ...

has been proposed to explain the slow rotation. Other period determinations gave similar results between 80.166 and 80.23 hours with an outlier by the

Palomar Transient Factory The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...

. Elsa has very amplified lightcurve indicating an elongated or irregular body. It was one of five minor planets included in the 1993 study,

Transition Comets -- UV Search for OH Emissions in Asteroids Hubble search for transition comets (Transition Comets—UV Search for OH Emissions in Asteroids) was a study involving amateur astronomers and the use of the Hubble Space Telescope, one of only six studies involving amateur astronomers approved b ...

, which was research involving amateur astronomers who were permitted to make use of the Hubble Space Telescope.

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite

IRAS The Infrared Astronomical Satellite ( Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mo ...

, the Japanese Akari satellite and the

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 20 ...

mission of NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2 ...

, ''Elsa'' measures between 36 and 45.72 kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

between 0.196 and 0.2106. During 2002, ''Elsa'' was also observed by radar from the

Arecibo Observatory The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science ...

. The return signal matched an effective diameter of .

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Minor Planet Center * * {{DEFAULTSORT:Elsa 000182 Discoveries by Johann Palisa Named minor planets 000182 000182 18780207