1087 Arabis

Lightcurve-based 3D-model of Arabis
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	2 September 1927
Designations
MPC designation	(1087) Arabis
Pronunciation	/ˈærəbɪs/[2]
Named after	Arabis (flowering plant)[3]
Alternative designations	1927 RD · 1973 LB A917 UE
Minor planet category	main-belt · (outer) Eos[4][5]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	89.40 yr (32,655 days)
Aphelion	3.2984 AU
Perihelion	2.7300 AU
Semi-major axis	3.0142 AU
Eccentricity	0.0943
Orbital period (sidereal)	5.23 yr (1,911 days)
Mean anomaly	12.959°
Mean motion	0° 11m 17.88s / day
Inclination	10.061°
Longitude of ascending node	30.425°
Argument of perihelion	25.793°
Physical characteristics
Dimensions	31.67 km (derived)[4] 31.75±2.5 km[6] 36.97±0.50 km[7] 37.498±0.493 km[8] 45.625±0.588 km[9] 47.98±0.80 km[10]
Synodic rotation period	5.794 h[11] 5.794995±0.000002 h[a] 5.79500±0.00001 h[b] 5.79501±0.00005 h[12] 5.797±0.001 h[13]
Geometric albedo	0.098±0.015[10] 0.1031±0.0150[9] 0.171±0.006[7] 0.2137 (derived)[4] 0.2248±0.040[6]
Spectral type	Tholen = S[1][4] B–V = 0.823[1] U–B = 0.370[1]
Absolute magnitude (H)	9.73[1][6][7][10] · 9.75±0.26[14] · 9.79[4][9][11]

1087 Arabis /ˈærəbɪs/ is a stony Eoan asteroid from the outer regions of the asteroid belt, approximately 35 kilometers in diameter. It was discovered by Karl Reinmuth at the Heidelberg Observatory in 1927 and assigned the provisional designation 1927 RD. The asteroid was named after the flowering plant Arabis (rockcress).^[15]

Arabis was officially discovered on 2 September 1927, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany.^[15] On the same night, it was independently discovered by Soviet-Russian astronomers Sergey Belyavsky and Nikolaj Ivanov at the Simeiz Observatory on the Crimean peninsula.^[3] The Minor Planet Center does not acknowledge these independent discoverers.^[15]

The asteroid was first identified as A917 UE at the Simeiz Observatory in October 1917, almost 10 years prior to its official discovery observation at Heidelberg.^[15]

Arabis is a member the Eos family (606),^[4][5] the largest asteroid family in the outer main belt consisting of nearly 10,000 known asteroids.^[16]: 23 It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 3 months (1,911 days). Its orbit has an eccentricity of 0.09 and an inclination of 10° with respect to the ecliptic.^[1] The body's observation arc begins with its official discovery observation at Heidelberg.^[15]

In the Tholen classification, Arabis is a common S-type asteroid.^[1][4]

During the early 1990s, a rotational lightcurve was obtained in a photometric survey of small asteroids by European astronomers at the Chilean La Silla Observatory using the ESO 1-metre telescope. In November 2006, another lightcurve of Arabis was obtained by astronomers at the Oakley Observatory in Indiana, United States. Lightcurve analysis gave two well-defined rotation periods of 5.794 and 5.797 hours with a brightness variation of 0.14 and 0.40 magnitude, respectively (U=3/3).^[11][13]

Between 2011 and 2017, an international collaboration modeled three lightcurves with a period of 5.794995, 5.79500 and 5.79501 hours, respectively.^[12][a][b] The more recent studies also determined two spin axis of (155.0°, 25.0°) and (331.0°, 5.0°) in ecliptic coordinates (λ, β).^[a][b]

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, Arabis measures between 31.75 and 47.98 kilometers in diameter and its surface has an albedo between 0.098 and 0.2248.^{[6][7][8][9][10]}

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2137 and a diameter of 31.67 kilometers based on an absolute magnitude of 9.79.^[4]

This minor planet was named after the flowering plant Arabis (rockcress), a genus of herbs of the brassicaceae (known as the mustards, the crucifers, or the cabbage family). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 102).^[3]

Due to his many discoveries, Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between (1009) and (1200). This list also contained a sequence of 28 asteroids, starting with 1054 Forsytia, that were all named after plants, in particular flowering plants (also see list of minor planets named after animals and plants).^[17]

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1087 Arabis at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1087 Arabis at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters