432 research outputs found
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 Îv can be also considered if the Rosetta interplanetary orbit insertion will cost less Îv.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 featuresâin 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)
BCâSIMâTNâ012 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 (SIMBIOâSYS) 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 ESAâESOC in XLSX format before each inâflight instrument test for final approval by the SIMBIOâSYS 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)
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