Evidence of the complex structure of asteroid 21 Lutetia

Prokof’eva-Mikhailovskaya, V. V.; Batrakov, Yu. V.; Bochkov, V. V.; Busarev, V. V.; Karachkina, L. G.

doi:10.1134/s003809460704003x

Cited by 2 publications

(1 citation statement)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To constrain the interior composition, we need to estimate the mass and density of the asteroid. Although Prokof'eva-Mikhailovskaya et al (2007) concluded about a complex satellite system of Lutetia, no satellites have yet been detected around the asteroid (Busch et al 2009). The only available mass estimations of Lutetia come from the astrometric method and infer a density comparable to those of iron meteorites (Baer et al 2009).…”

Section: Discussionmentioning

confidence: 99%

Puzzling asteroid 21 Lutetia: our knowledge prior to the Rosetta fly-by

Belskaya

Fornasier

Krugly

et al. 2010

A&A

View full text Add to dashboard Cite

Aims. A wide observational campaign was carried out in [2004][2005][2006][2007][2008][2009] that aimed to complete the ground-based investigation of Lutetia prior to the Rosetta fly-by in July 2010. Methods. We obtained BVRI photometric and V-band polarimetric measurements over a wide range of phase angles, and visible and infrared spectra in the 0.4-2.4 μm range. We analyze them with previously published data to retrieve information about Lutetia's surface properties.Results. Values of lightcurve amplitudes, absolute magnitude, opposition effect, phase coefficient, and BVRI colors of Lutetia surface seen at near pole-on aspect are determined. We define more precisely parameters of polarization phase curve and show their distinct deviation from any other moderate-albedo asteroid. An indication of possible variations in both polarization and spectral data across the asteroid surface are found. To explain features found by different techniques, we propose that (i) Lutetia has a non-convex shape, probably due to a large crater, and heterogeneous surface properties probably related to surface morphology; (ii) at least part of the surface is covered by a fine-grained regolith of particle size smaller than 20 μm; (iii) the closest meteorite analogues of Lutetia's surface composition are particular types of carbonaceous chondrites, or Lutetia has specific surface composition that is not representative among studied meteorites.

show abstract

Section: Discussionmentioning

confidence: 99%

Puzzling asteroid 21 Lutetia: our knowledge prior to the Rosetta fly-by

Belskaya

Fornasier

Krugly

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

Multi-color, rotationally resolved photometry of asteroid 21 Lutetia from OSIRIS/Rosetta observations

Lamy¹,

Faury²,

Jordá³

et al. 2010

A&A

View full text Add to dashboard Cite

Context. Asteroid 21 Lutetia is the second target of the Rosetta space mission. Extensive pre-encounter, space-, and ground-based observations are being performed to prepare for the flyby in July 2010. Aims. The aim of this article is to accurately characterize the photometric properties of this asteroid over a broad spectral range from the ultraviolet to the near-infrared and to search for evidence of surface inhomogeneities. Methods. The asteroid was imaged on 2 and 3 January 2007 with the Narrow Angle Camera (NAC) of the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) during the cruise phase of the Rosetta spacecraft. The geometric conditions were such that the aspect angle was 44 • (i.e., mid-northern latitudes) and the phase angle 22.4 • . Lutetia was continuously monitored over 14.3 h, thus exceeding one rotational period and a half, with twelve filters whose spectral coverage extended from 271 to 986 nm. An accurate photometric calibration was obtained from the observations of a solar analog star, 16 Cyg B. Results. High-quality light curves in the U, B, V, R and I photometric bands were obtained. Once they were merged with previous light curves from over some 45 years, the sidereal period is accurately determined: P rot = 8.168271 ± 0.000002 h. Color variations with rotational phase are marginally detected with the ultraviolet filter centered at 368 nm but are absent in the other visible and near-infrared filters. The albedo is directly determined from the observed maximum cross-section obtained from an elaborated shape model that results from a combination of adaptive-optics imaging and light curve inversion. Using current solutions for the phase function, we find geometric albedos p V = 0.130 ± 0.014 when using the linear phase function and p V (H − G) = 0.180 ± 0.018 when using the (H − G) phase function, which incorporates the opposition effect. The spectral variation of the reflectance indicates a steady decrease with decreasing wavelength rather than a sharp fall-off.

show abstract

Evidence of the complex structure of asteroid 21 Lutetia

Cited by 2 publications

References 10 publications

Puzzling asteroid 21 Lutetia: our knowledge prior to the Rosetta fly-by

Puzzling asteroid 21 Lutetia: our knowledge prior to the Rosetta fly-by

Multi-color, rotationally resolved photometry of asteroid 21 Lutetia from OSIRIS/Rosetta observations

Contact Info

Product

Resources

About