Colors of Minor Bodies in the Outer Solar System

Abstract

Abstract. We present a compilation of all available colors for 104 Minor Bodies in the Outer Solar System (MBOSSes); for each object, the original references are listed. The measurements were combined in a way that does not introduce rotational color artifacts. We then derive the slope, or reddening gradient, of the low resolution reflectance spectra obtained from the broad-band color for each object. A set of color-color diagrams, histograms and cumulative probability functions are presented as a reference for further studies, and are discussed. In the color-color diagrams, most of the objects are located very close to the "reddening line" (corresponding to linear reflectivity spectra). A small but systematic deviation is observed toward the I band indicating a flattening of the reflectivity at longer wavelengths, as expected from laboratory spectra. A deviation from linear spectra is noticed toward the B for the bluer objects; this is not matched by laboratory spectra of fresh ices, possibly suggesting that these objects could be covered with extremely evolved/irradiated ices. Five objects (1995 SM55, 1996 TL66, 1999 OY3, 1996 TO66 and (2060 Chiron) have almost perfectly solar colors; as two of these are known or suspected to harbour cometary activity, the others should be searched for activity or fresh ice signatures. In the color-color diagrams, 1994 ES2, 1994 EV3, 1995 DA2 and 1998 HK151 are located very far from the main group of objects; it is suspected that this corresponds to inaccurate measurements and not intrinsically strange objects. The color distributions were analyzed as functions of the orbital parameters of the objects and of their absolute magnitude. No significant correlation is observed, with the following exceptions: Cubewanos with low orbital excitation (low i, e and/or E = e 2 + sin 2 i), and therefore experiencing on average fewer and less violent collisions have significantly redder colors; Cubewanos with faint absolute magnitude M (1, 1) tend to be redder than the others, while Plutinos present the opposite trend. The color distribution of the various MBOSS classes are analyzed and compared using generic statistic tools. The comets were found to be significantly bluer than the other MBOSSes. Finally, we compare the various 1D and 2D color distributions to simple models, in order to throw some light on the question of the bimodality of MBOSS color distributions. It is found that with the current data set, all color distributions are compatible with simple, continuous distribution models, while some color distributions are not compatible with simple bimodal distribution models. Table 1 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/389/641, and the tables and complete set of figures corresponding the up-to-date database are available on the web at http://www.sc.eso.org/~ohainaut/MBOSS.

“TNOs are Cool”: A survey of the trans-Neptunian region

“…We assume (V − R) obj = 0.55 ± 0.11, the mean value from Hainaut & Delsanti (2002) for 66 SDOs/Detached objects, except for 2007 OR 10 (see discussion for this object in Sect. 5.3).…”

Observations, compositional, and physical characterization of near-Earth and Mars-crosser asteroids from a spectroscopic survey

“…We can also see in Table 1 the values for the solar analogue star P330E, as well as an average value for Hardorp's class 1 solar analogues, compiled by Campins et al (1985). Values for the Sun were compiled from different papers (Hardorp 1980;Campins et al 1985;Colina et al 1996;Hainaut & Delsanti 2002). As can be seen from Table 1, all the stars used as SAs have colours that are similar to those of the Sun, from visible to near-infrared wavelengths.…”

Color Patterns in the Kuiper Belt: A Possible Primordial Origin

“…Every group, except our R p 1.03 group, finds the entire KBO population and the individual dynamical classes exhibit a relatively uniform distribution of colors, i.e., a continuum of colors (Luu & Jewitt 1996;Jewitt & Luu 1998Barucci et al 1999Barucci et al , 2000Boehnhardt et al 2001;Delsanti et al 2001;Doressoundiram et al 2001Doressoundiram et al , 2002Hainaut & Delsanti 2002;Trujillo & Brown 2002). An explanation put forth to explain the continuum of colors is that solar ultraviolet photons and solar wind particles steadily redden KBO surfaces while occasional impacts by kilometer-sized KBOs puncture the red crusts and expose interior gray icy material in the form of craters and ejecta blankets (Luu & Jewitt 1996;Stern 2002).…”