704 Interamnia ( , from Latin
Interamnium) is a very large
asteroidthumb|260px|right|[[253 Mathilde]], a [[C-type asteroid]] measuring about across. Photograph taken in 1997 by the [[NEAR Shoemaker]] probe.Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are...
, with an estimated
diameterIn geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
of 350 kilometres. Its mean distance from the
SunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
is 3.067 (
AUAn astronomical unit is a unit of length roughly equal to the mean distance between the Earth and the Sun. It is approximately 150 million kilometres ....
). It was discovered on October 2, 1910 by
Vincenzo CerulliVincenzo Cerulli was an Italian astronomer who owned a private observatory in Teramo, where he was born.Cerulli compiled a star catalog with Elia Millosevich...
, and named after the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...
name for
TeramoTeramo is a city in the central Italian region of Abruzzo, the capital of the province of Teramo.The city, from Rome, is situated between the highest mountains of Appenini and the Adriatic coast...
,
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
, where Cerulli worked. It is likely the sixth most massive asteroid after Ceres,
Vesta4 Vesta is the second most massive object in the asteroid belt, with a mean diameter of about 530 km and an estimated mass of 9% of the mass of the entire asteroid belt...
,
Pallas2 Pallas is one of the largest asteroids and is located in the main asteroid belt. It was the second asteroid to be discovered, by astronomer Heinrich Wilhelm Matthäus Olbers on March 28, 1802...
,
Hygiea10 Hygiea is an asteroid located in the main asteroid belt. With somewhat oblong diameters of 350–500 km, and a mass estimated to be 2.9% of the total mass of the belt, it is the fourth largest object in the region by volume and mass...
, and
511 Davida511 Davida is a large main belt C-type asteroid. It was discovered by R. S. Dugan in 1903. It is thought to be one of the ten most massive asteroids. It is approximately 270–310 km in diameter and comprises an estimated 1.5% of the total mass of the asteroid belt...
with a mass estimated to be 1.2% of the mass of the entire asteroid belt.
Although the largest asteroid apart from the "big four", Interamnia is a very little-studied body.
It is easily the largest of the
F-type asteroidF-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group.-Characteristics:Generally similar to the B-type asteroids, but...
s, but there exist very few details of its internal composition or shape and no lightcurve analysis has yet been done to determining the ecliptic coordinates of Interamnia's poles (and hence its
axial tiltIn astronomy, axial tilt is the angle between an object's rotational axis and a line perpendicular to its orbital plane. The angle is measured between the line perpendicular to object's orbital plane and object's rotational axis passing through north pole at which the planet appears to rotate...
).
704 Interamnia ( , from Latin
Interamnium) is a very large
asteroidthumb|260px|right|[[253 Mathilde]], a [[C-type asteroid]] measuring about across. Photograph taken in 1997 by the [[NEAR Shoemaker]] probe.Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are...
, with an estimated
diameterIn geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
of 350 kilometres. Its mean distance from the
SunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
is 3.067 (
AUAn astronomical unit is a unit of length roughly equal to the mean distance between the Earth and the Sun. It is approximately 150 million kilometres ....
). It was discovered on October 2, 1910 by
Vincenzo CerulliVincenzo Cerulli was an Italian astronomer who owned a private observatory in Teramo, where he was born.Cerulli compiled a star catalog with Elia Millosevich...
, and named after the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...
name for
TeramoTeramo is a city in the central Italian region of Abruzzo, the capital of the province of Teramo.The city, from Rome, is situated between the highest mountains of Appenini and the Adriatic coast...
,
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
, where Cerulli worked. It is likely the sixth most massive asteroid after Ceres,
Vesta4 Vesta is the second most massive object in the asteroid belt, with a mean diameter of about 530 km and an estimated mass of 9% of the mass of the entire asteroid belt...
,
Pallas2 Pallas is one of the largest asteroids and is located in the main asteroid belt. It was the second asteroid to be discovered, by astronomer Heinrich Wilhelm Matthäus Olbers on March 28, 1802...
,
Hygiea10 Hygiea is an asteroid located in the main asteroid belt. With somewhat oblong diameters of 350–500 km, and a mass estimated to be 2.9% of the total mass of the belt, it is the fourth largest object in the region by volume and mass...
, and
511 Davida511 Davida is a large main belt C-type asteroid. It was discovered by R. S. Dugan in 1903. It is thought to be one of the ten most massive asteroids. It is approximately 270–310 km in diameter and comprises an estimated 1.5% of the total mass of the asteroid belt...
with a mass estimated to be 1.2% of the mass of the entire asteroid belt.
Characteristics
Although the largest asteroid apart from the "big four", Interamnia is a very little-studied body.
It is easily the largest of the
F-type asteroidF-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group.-Characteristics:Generally similar to the B-type asteroids, but...
s, but there exist very few details of its internal composition or shape and no lightcurve analysis has yet been done to determining the ecliptic coordinates of Interamnia's poles (and hence its
axial tiltIn astronomy, axial tilt is the angle between an object's rotational axis and a line perpendicular to its orbital plane. The angle is measured between the line perpendicular to object's orbital plane and object's rotational axis passing through north pole at which the planet appears to rotate...
). Its apparently high bulk density (though subject to much error) suggests an extremely solid body entirely without internal porosity or traces of
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
. This also strongly suggests that Interamnia is large enough to have fully withstood all the collisions that have occurred in the asteroid belt since the
Solar SystemThe Solar System consists of the Sun and those celestial objects bound to it by gravity, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago...
was formed.
Its very dark surface and relatively large distance from the Sun means Interamnia can never be seen with 10x50
binocularsBinoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes with binocular vision when viewing distant objects. Most are sized to be held...
. At most oppositions its
magnitudeThe apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere...
is around +11.0, which is less than the
minimum brightness of Vesta, Ceres or Pallas. Even at a
perihelicIn celestial mechanics, an apsis, plural apsides is the point of greatest or least distance of the elliptical orbit of an object from its center of attraction, which is generally the center of mass of the system....
opposition its magnitude is only +9.9, which is over four magnitudes lower than Vesta.
Its orbit is slightly more eccentric that that of Hygiea (15% versus 12%) but differs from Hygiea's in its much greater
inclinationInclination in general is the angle between a reference plane and another plane or axis of direction.- Orbits :The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
and slightly shorter period. Another difference is that Interamnia's perihelion is located on the opposite side from the perihelia of the "big four", so that at Interamnia at perihelion is actually closer to the Sun than Ceres and Pallas are at the same longitude. It is unlikely to collide with Pallas because their nodes are located too far apart, whilst although its nodes are located on the opposite side from those of Ceres, it is generally clear of Ceres when both cross the same orbital plane and a collision is again unlikely.
Size
Observations of a favorable
occultationAn occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy and can also be used in a general sense to describe when an object in the foreground occults objects in the background...
of a bright 6.6
magnitudeThe apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere...
star on March 23, 2003, produced thirty-five
chordsA chord of a curve is a geometric line segment whose endpoints both lie on the curve.A secant or a secant line is the line extension of a chord.- Chords of a circle :Among properties of chords of a circle are the following:...
indicating an ellipsoid of 350×304km.
Mass
In 2001, Michalak estimated Interamnia to have a mass of 6.9
kgThe kilogram is the base unit of mass in the International System of Units .[The spelling kilogram is the modern spelling used by the International Bureau of Weights and Measures , the U.S...]
. Though Michalak's estimate depends on the masses of
19 Fortuna19 Fortuna is one of the largest main belt asteroids. It has a composition similar to 1 Ceres: a darkly colored surface that is heavily space weathered with the composition of primitive organic compounds, including tholins....
,
29 Amphitrite29 Amphitrite is one of the largest S-type asteroids, probably third in diameter after Eunomia and Juno, although Iris and Herculina are similar in size....
, and
16 Psyche16 Psyche is one of the ten most massive Main belt asteroids. It is over 200 kilometers in diameter and contains a little less than 1% of the mass of the entire main asteroid belt. It is the most massive of the metallic M-type asteroids....
, thus this mass was obtained assuming an incomplete dynamical
model. In 2007, Baer and Chesley estimated Interamnia to have a mass of (7.12±0.84)
kgThe kilogram is the base unit of mass in the International System of Units .[The spelling kilogram is the modern spelling used by the International Bureau of Weights and Measures , the U.S...]
. Though a more recent estimate by Baer suggests it has a mass of only 3.70 kg. This would make it less massive than
511 Davida511 Davida is a large main belt C-type asteroid. It was discovered by R. S. Dugan in 1903. It is thought to be one of the ten most massive asteroids. It is approximately 270–310 km in diameter and comprises an estimated 1.5% of the total mass of the asteroid belt...
.
External links
Wiki links
- List of Solar System objects by size