Rotational properties of the Haumea family members and candidates: Short-term variability

Haumea is one of the most interesting and intriguing transneptunian objects (TNOs). It is a large, bright, fast rotator, and its spectrum indicates nearly pure water ice on the surface. It has at least two satellites and a dynamically related family of more than ten TNOs with very similar proper orbital parameters and similar surface properties. The Haumean family is the only one currently known in the transneptunian belt. Various models have been proposed but the formation of the family remains poorly understood. In this work, we have investigated the rotational properties of the family members and unconfirmed family candidates with short-term variability studies, and report the most complete review to date. We present results based on five years of observations and report the short-term variability of five family members, and seven candidates. The mean rotational periods, from Maxwellian fits to the frequency distributions, are 6.27+/-1.19 h for the confirmed family members, 6.44+/-1.16 h for the candidates, and 7.65+/-0.54 h for other TNOs (without relation to the family). According to our study, there is a suggestion that Haumea family members rotate faster than other TNOs, however, the sample of family member is still too limited for a secure conclusion. We also highlight the fast rotation of 2002 GH32. This object has a 0.36+/-0.02 mag amplitude lightcurve and a rotational period of about 3.98 h. Assuming 2002 GH32 is a triaxial object in hydrostatic equilibrium, we derive a lower limit to the density of 2.56 g cm^-3. This density is similar to Haumea's and much more dense than other small TNO densities.Comment: Accepted for publication, A

Understanding the trans-Neptunian Solar system: Reconciling the results of serendipitous stellar occultations and the inferences from the cratering record

The most pristine remnants of the Solar system's planet formation epoch orbit the Sun beyond Neptune, the small bodies of the trans-Neptunian object populations. The bulk of the mass is in ~100 km objects, but objects at smaller sizes have undergone minimal collisional processing, with New Horizons recently revealing that ~20 km effective diameter body (486958) Arrokoth appears to be a primordial body, not a collisional fragment. This indicates bodies at these sizes (and perhaps smaller) retain a record of how they were formed, and are the most numerous record of that epoch. However, such bodies are impractical to find by optical surveys due to their very low brightnesses. Their presence can be inferred from the observed cratering record of Pluto and Charon, and directly measured by serendipitous stellar occultations. These two methods produce conflicting results, with occultations measuring roughly ten times the number of ~km bodies inferred from the cratering record. We use numerical models to explore how these observations can be reconciled with evolutionary models of the outer Solar system. We find that models where the initial size of bodies decreases with increasing semimajor axis of formation, and models where the surface density of bodies increases beyond the 2:1 mean-motion resonance with Neptune can produce both sets of observations, though comparison to various observational tests favours the former mechanism. We discuss how to evaluate the astrophysical plausibility of these solutions, and conclude extended serendipitous occultation surveys with broad sky coverage are the most practical approach.Comment: Resubmitted to Astronomy & Astrophysics with revisions after referee's comments. Likely to be the first author's last paper; it's been an honour working with all of yo

Rosetta Asteroid Candidates

AbstractThe new scenario of the Rosetta mission to comet 67/P Churyumov-Gerasimenko (launch on February 2004), includes as baseline the fly-by of one or two asteroids. Several asteroids are now possible fly-by candidates (single or double) within the available resources. Other candidates whose fly-bys require a larger Δv can be also considered if the Rosetta interplanetary orbit insertion will cost less Δv.All the up to date available information on the possible targets are discussed in this report

ESO Large Programme on Trans-Neptunian Objects and Centaurs: Spectroscopic Investigation of Centaur 2001 BL41 and TNOs (26181) 1996 GQ21 and (26375) 1999 DE9*

Observational results that are part of an ESO Large Programme dedicated to the characterization of the physical properties of trans-Neptunian objects and Centaurs are presented. We report observations related to the Centaur 2001 BL41 and two trans-Neptunian objects, (26181) 1996 GQ21 and (26375) 1999 DE9. We present results from broadband photometry (JHK filters) and low-dispersion infrared spectroscopy performed with ISAAC at the Very Large Telescope, in Chile. None of the spectra show evidence of absorption features—in particular, water ice features. We use a radiative transfer model to investigate the surface composition of these icy and primitive outer solar system bodies. We suggest models composed of geographical mixtures of organic compounds and minerals

BC-SIM-TN-003 - Reports and Note Layout and Flow - Version 2

In this document, we will describe the name convention, the format, the flow of reports, notes, and plans produced for the Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO-SYS)

BC‐SIM‐TN‐012 Simbio_stack2tcl User Manual Version 1.0.0

In this document, we will describe a software developed to convert a STACK, a list of TeleCommand and related parameters for the Spectrometer and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO‐SYS) instrument suite onboard the ESA mission BepiColombo to Mercury, in a sequence of commands that can be ingested by the instrument Electrical Model (EM) located in Orsay. The STACK is provided by the Mission Operation Center (MOC) at ESA‐ESOC in XLSX format before each in‐flight instrument test for final approval by the SIMBIO‐SYS Team. This document reports the software features, functionalities, and syntax. The software is a MATLAB script. It could be used as a standalone or integrated into a pipeline

BC-SIM-TR-029 SIMBIO-SYS ICO#03 Test Report

This document will briefly report the results of the tests performed during the Instrument Checkout (ICO) # 03 for the Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO-SYS)

BC-SIM-TR-025 HRIC ICO3 REPORT

The present document has been issued to describe the Instrument Check Out Phase (ICO#3) Tests of HRIC, channel of the Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO-SYS)