1275 Cimbria

1275 Cimbria (prov. designation: 1932 WG) is a Eunomia asteroid from the central regions of the asteroid belt, approximately 27 kilometers (17 miles) in diameter. It was discovered on 30 November 1932, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southern Germany.^[16] The asteroid was named after the Cimbri, an ancient Germanic tribe.^[3]

1275 Cimbria

Modelled shape of Cimbria from its lightcurve
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	30 November 1932
Designations
MPC designation	(1275) Cimbria
Pronunciation	/ˈsɪmbriə/[2]
Named after	Cimbri[3] (ancient Germanic tribe)
Alternative designations	1932 WG · 1949 QL2 A914 TG
Minor planet category	main-belt · (middle) Eunomia[4][5]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	84.42 yr (30,833 days)
Aphelion	3.1314 AU
Perihelion	2.2301 AU
Semi-major axis	2.6807 AU
Eccentricity	0.1681
Orbital period (sidereal)	4.39 yr (1,603 days)
Mean anomaly	143.95°
Mean motion	0° 13m 28.56s / day
Inclination	12.877°
Longitude of ascending node	188.56°
Argument of perihelion	196.98°
Physical characteristics
Dimensions	18.70±4.19 km[6] 26.31±0.30 km[7] 27.622±0.500 km[8] 28.65±4.4 km[4][9] 30.94±4.26 km[10] 33.599±0.594 km[11]
Synodic rotation period	5.65±0.05 h[12] 5.65454±0.00001 h[13] 5.655±0.0023 h[14]
Geometric albedo	0.0807±0.0106[11] 0.095±0.039[10] 0.1109±0.044[4][9] 0.135±0.004[7] 0.141±0.007[8] 0.25±0.13[6]
Spectral type	Tholen = X[1] · X[15] · M[4] B–V = 0.698[1] U–B = 0.304[1]
Absolute magnitude (H)	10.426±0.001 (R)[14] · 10.72[1][4][7][9][10][11] · 10.78[6] · 11.07±1.21[15]

Orbit and classification

Cimbria is a member of the Eunomia family (502),^[4][5] a prominent family of typically stony asteroids and the largest one in the intermediate main belt with more than 5,000 members.^[17]

The asteroid orbits the Sun in the central main-belt at a distance of 2.2–3.1 AU once every 4 years and 5 months (1,603 days). Its orbit has an eccentricity of 0.17 and an inclination of 13° with respect to the ecliptic.^[1] It was first identified as A914 TG at Simeiz Observatory in October 1914. The body's observation arc begins with its official discovery observation at Heidelberg in 1932.^[16]

Naming

This minor planet was named after the Cimbri, an ancient Proto-Germanic tribe that fought the Romans together with the Teutons and the Ambrones. At first victorious, they were destroyed by Gaius Marius in the Cimbrian War (113–101 BC). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 117).^[3]

Physical characteristics

In the Tholen classification, Cimbria is an X-type asteroid, rather than a stony S-type asteroid, which is the overall spectral type for members of the Eunomia family.^[17]: 23

Rotation period

In November and December 2002, two rotational lightcurves of Cimbria were obtained from photometric observations by Italian amateur astronomers Silvano Casulli, Antonio Vagnozzi, Marco Cristofanelli and Marco Paiella. Lightcurve analysis gave a well-defined rotation period of 5.65 hours with a brightness variation of 0.40 and 0.57 magnitude, respectively (U=3/3-).^[12] In December 2012, astronomers at the Palomar Transient Factory in California measured a period of 5.655 hours and an amplitude of 0.26 magnitude (U=2).^[14]

Poles

The asteroid's lightcurve has also been modeled using photometric data from the Lowell Photometric Database. It gave a concurring period of 5.65454 hours and determined two spin axis of (85.0°, −61.0°) and (271.0°, −31.0°) in ecliptic coordinates (λ, β).^[13]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Cimbria measures between 18.70 and 33.599 kilometers in diameter and its surface has an albedo between 0.0807 and 0.25.^{[6][7][8][9][10][11]}

The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is an albedo of 0.1109 and a diameter of 28.65 kilometers based on an absolute magnitude of 10.72.^[4][9]