Search Publications
Rotation period estimates for 14 asteroids with the Earth MOID less than 1.1 AU
Eglitis, Ilgmars; Svincicka, Darja
In the present study, the Lomb–Scargle Scargle (L–S) method was employed for the analysis of brightness measurements from multiple observatories as published in the Minor Planet Center (MPC) circulars, as well as brightness measurements from the Baldone Observatory, to determine the periods of asteroids. The periods of fifteen asteroids were deter…
Near-mid infrared spectroscopy of carbonaceous chondrites: Insights into spectral variation due to aqueous alteration and thermal metamorphism in asteroids
Zhao, Haibin; Cloutis, Edward A.; Yu, Jinfei +2 more
Carbonaceous chondrites (CCs) are windows into the early Solar System and the histories of their parent bodies. Their infrared spectral signatures are powerful proxies for deciphering their composition and evolution history, but still present formidable challenges in relation to determining the degree of secondary processing such as aqueous altera…
Evidence of surface heterogeneity on active asteroid (3200) Phaethon
Granvik, Mikael; MacLennan, Eric; Marshall, Sean
Thermal infrared emission and thermophysical modeling techniques are powerful tools in deciphering the surface properties of asteroids. The near-Earth asteroid (3200) Phaethon is an active asteroid with a very small perihelion distance and is likely the source of the Geminid meteor shower. Using a thermophysical model with a non-convex shape of Ph…
Simulated SPHEREx spectra of asteroids and their implications for asteroid size and reflectance estimation
Doré, Olivier; Ivezić, Željko; Ivezić, Vedrana +6 more
We describe the construction and analysis of simulated SPHEREx spectra of Main Belt and Trojan asteroids. SPHEREx will deliver the first all-sky spectral survey at 96 spectral channels between 0.75 µm and 5.0 µm. We have developed a method for correcting SPHEREx asteroid spectra for intrinsic rotational variability that does not requir…
Optical observations of near isotropic comet C/2006 OF2 (Broughton) at two different heliocentric distances
Lara, L.; Afanasiev, V.; Kulyk, I. +3 more
Spectra and images of comet C/2006 OF2 (Broughton) were obtained with the 4.2-m William Herschel Telescope (La Palma, Spain) and with the 6-m Big Telescope Alt-azimuth (SAO RAN, Russia) at two observing epochs on October 15, 2007 and December 05, 2008.The comet was at heliocentric distances of 4.24 au and 2.59 au before and after the perihelion, r…
Style and intensity of hydration among C-complex asteroids: A comparison to desiccated carbonaceous chondrites
Vernazza, P.; Usui, F.; Schmitt, B. +3 more
Here we report a comparison between reflectance spectroscopy of meteorites under asteroidal environment (high vacuum and temperature) and Main Belt and Near Earth Asteroids spectra. Focusing on the -OH absorption feature around 3 µm, we show that the asteroidal environment induces a reduction of depth and width of the band, as well as a shif…
A model of the 3-µm hydration band with Exponentially Modified Gaussian (EMG) profiles: Application to hydrated chondrites and asteroids
Schmitt, B.; Beck, P.; Potin, S. +2 more
We present here a new method to model the shape of the 3-µm absorption band in the reflectance spectra of meteorites and small bodies. The band is decomposed into several OH/H2O components using Exponentially Modified Gaussian (EMG) profiles, as well as possible organic components using Gaussian profiles when present. We compare t…
Olivine-dominated A-type asteroids in the main belt: Distribution, abundance and relation to families
Hsieh, Henry H.; Moskovitz, Nicholas A.; Polishook, David +5 more
Differentiated asteroids are rare in the main asteroid belt despite evidence for ∼ 100 distinct differentiated bodies in the meteorite record. We have sought to understand why so few main-belt asteroids differentiated and where those differentiated bodies or fragments reside. Using the Sloan Digital Sky Survey (SDSS) to search for a needle in a ha…
Constraining the thermal properties of planetary surfaces using machine learning: Application to airless bodies
Furfaro, Roberto; Cambioni, Saverio; Delbo, Marco +2 more
We present a new method for the determination of the surface properties of airless bodies from measurements of the emitted infrared flux. Our approach uses machine learning techniques to train, validate, and test a neural network representation of the thermophysical behavior of the atmosphereless body given shape model, illumination and observatio…
New polarimetric and spectroscopic evidence of anomalous enrichment in spinel-bearing calcium-aluminium-rich inclusions among L-type asteroids
Surdej, J.; Tanga, P.; Carry, B. +14 more
Asteroids can be classified into several groups based on their spectral reflectance. Among these groups, the one belonging to the L-class in the taxonomic classification based on visible and near-infrared spectra exhibit several peculiar properties. First, their near-infrared spectrum is characterized by a strong absorption band interpreted as the…