(22) Calliope

Asteroid (22) Calliope
Properties of the orbit ( animation ) Epoch: 4th September 2017 ( JD 2,458,000.5)
Orbit type	Outer main belt
Major semi-axis	2.91 AU
eccentricity	0.099
Perihelion - aphelion	2.621 AU - 3.198 AU
Inclination of the orbit plane	13.7 °
Length of the ascending node	66.1 °
Argument of the periapsis	354.9 °
Time of passage of the perihelion	3rd August 2016
Sidereal period of rotation	4 a 352 d
Mean orbital velocity	17.42 km / s
Physical Properties
Medium diameter	167.5 ± 3.1 km
Dimensions	231.4 km × 175.3 km × 146.1 km
Dimensions	(8.16 ± 0.26) 10 ¹⁸ kg
Albedo	0.166
Medium density	3.35 ± 0.33 g / cm³
Rotation period	4.1483 h
Absolute brightness	6.5 mag
Spectral class (according to Tholen)	M.
Spectral class (according to SMASSII)	X
history
Explorer	John R. Hind
Date of discovery	November 16, 1852
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(22) Calliope is an asteroid found in the main outer asteroid belt . With a diameter of 167 km, it is one of the larger asteroids of the main belt and it has a moon named Linus .

Discovery and naming

Calliope was discovered on November 16, 1852 by the British astronomer John Russell Hind on a 7-inch telescope at George Bishop 's private observatory in Regent's Park , London .

The celestial body was named after Calliope , the muse of epic poetry, science, philosophy and string playing as well as the epic and elegy.

In total, the asteroid was observed through several earth-based telescopes, a total of 2588 times within 163 years. (As of Sept. 2017)

Track properties

Orbit

Calliope orbits the sun in a prograde , elliptical orbit between 392,100,000 km (2.62 AU ) and 478,400,000 km (3.19 AU) from its center. The orbital eccentricity is 0.099, the web is about 13,72 ° to the ecliptic inclined . Its orbit is therefore in the outer asteroid belt .

The orbital period of Calliope is 4.98 years.

rotation

Calliope rotates once around its axis in 4 hours and 8.9 minutes. From this it follows that the asteroid performs 10,487.9 self- rotations ("days") in a Calliope year .

Observations of the light curve show an alignment of Calliope's pole in the direction of the ecliptic coordinates with 10 ° uncertainty; this results in an axis inclination of 103 °; Calliope's rotation would therefore be slightly retrograde . ${\ displaystyle (\ beta, \ lambda) = (- 23 ^ {\ circ}, 20 ^ {\ circ})}$

Physical Properties

size

The previous observations by Kalliope indicate an asymmetrical, irregularly shaped, elongated body; the most precise determination of the diameter ( geometric mean ) is 167.536 km. With regard to the exact dimensions, the most precise value is 231.4 × 175.3 × 146.1 km.

Based on an average diameter of 167.5 km, the surface area is around 88,000 km ² , which is slightly more than the area of Austria .

Determinations of the diameter for calliope

year	Dimensions km	source
2001	181 ± 4.6	Tedesco ( IRAS ) u. a.
2002	215 × 180 × 150	Kaasalainen et al. a.
2008	166.2 ± 2.8	Descamps et al. a.
2008	235 × 144 × 124	Descamps et al. a.
2014	167.536 ± 3.053	Masiero et al. a.
2014	231.4 x 175.3 x 146.1	Johnson

The most precise determination is marked in bold .

internal structure

Calliope is one of the M-type asteroids, which indicates that their surface is partly made up of iron and nickel. The mean density is 3.35 g / cm ³ . The asteroid is likely a rubble pile ; an assumed porosity of 20 to 40% leads to a density of 4.2 to 5.8 g / cm ³ , which means that it is possibly composed of a mixture of metal and silicates. Spectroscopic studies, however, showed evidence of hydrated minerals and silicates, which indicates a rather stony surface. Kalliope also has a deep radar albedo, which does not match a purely metallic surface.

The mass of Kalliope has so far been calculated to be 8.16 ∙ 10 ¹⁸ . The absolute brightness is given as 6.45 mag.

The mean surface temperature is around 161 K (−112 ° C) and can rise to a maximum of 240 K (−32 ° C) at noon.

moon

On August 29, 2001, the discovery of a moon around Calliope was announced, which was named Linus . The moon is one of the largest asteroid moons in the main belt. Linus has a diameter of 28 kilometers and orbits Calliope in a circular orbit in its equatorial plane at a mean distance of 1109 km in 3.6 days.

The Kalliope system at a glance:

Components	Physical parameters			Path parameters				discovery
Surname	Throughput diameter (km)	Relative size %	Mass (kg)	Major semi-axis (km)	Orbital time (d)	eccentricity	Inclination to Calliope's equator	Date of discovery Date of publication
(22) Calliope	167.5	100.00	8.2 10 ¹⁸	-	-	-	-	November 16, 1852 48520000 ♠1852
Linus (Calliope I)	28.0	16.7	5.0 x 10 ¹⁶	1109	3,596	0.016	9 °	August 29, 2001 September 3, 2001 50010903 ♠0

Web links

Wm. Robert Johnston: (22) Kalliope and Linus (English)
Asteroid 22 Kalliope Interactive Locator Map of Kalliope
Asteroid (22) Kalliope Rotatable 3D-Model by Kalliope (English)

Individual evidence

↑ (22) Kalliope in the Small-Body Database of the Jet Propulsion Laboratory (English).
↑ IRAS (2001): The Supplemental IRAS Minor Planet Survey. Retrieved September 13, 2017 .
↑ Kaasalainen et al. a .: Models of Twenty Asteroids from Photometric Data . October 2002, bibcode : 2002Icar..159..369K .
↑ ^a ^b Pascal Descamps u. a .: New determination of the size and bulk density of the binary asteroid 22 Kalliope from observations of mutual eclipses . August 2008, bibcode : 2008Icar..196..578D .
↑ Joseph R. Masiero et al. a .: Main-belt Asteroids with WISE / NEOWISE: Near-infrared Albedos . August 2014, bibcode : 2014ApJ ... 791..121M .
^ Wm. Robert Johnston: (22) Kalliope and Linus (September 2014). Retrieved September 12, 2017 .
↑ Iraida Sokova: The binary asteroid 22 Kalliope: Linus orbit determination on the basis of speckle interferometric observations (2014). Retrieved September 12, 2017 .

[JPL-1] (22) Kalliope in the Small-Body Database of the Jet Propulsion Laboratory (English).

[iras-2] IRAS (2001): The Supplemental IRAS Minor Planet Survey. Retrieved September 13, 2017 .

[kaasalainen-3] Kaasalainen et al. a .: Models of Twenty Asteroids from Photometric Data . October 2002, bibcode : 2002Icar..159..369K .

[Descamps-4] Pascal Descamps u. a .: New determination of the size and bulk density of the binary asteroid 22 Kalliope from observations of mutual eclipses . August 2008, bibcode : 2008Icar..196..578D .

[Masiero-5] Joseph R. Masiero et al. a .: Main-belt Asteroids with WISE / NEOWISE: Near-infrared Albedos . August 2014, bibcode : 2014ApJ ... 791..121M .

[Johnson-6] Wm. Robert Johnston: (22) Kalliope and Linus (September 2014). Retrieved September 12, 2017 .

[sokova-7] Iraida Sokova: The binary asteroid 22 Kalliope: Linus orbit determination on the basis of speckle interferometric observations (2014). Retrieved September 12, 2017 .