Query Results from the ADS Database
Retrieved 21 abstracts, starting with number 1. Total number selected: 13154.
TY - Journal
T1 - Predictions for the detection of Earth and Mars Trojan asteroids by the Gaia satellite
A1 - Todd, M.
A1 - Tanga, P.
A1 - Coward, D. M.
A1 - Zadnik, M. G.
JO - Monthly Notices of the Royal Astronomical Society
VL - 437
Y1 - 2014/2/1
SP - 4019
EP - 4026
KW - methods: numerical/ methods: observational/ methods: statistical/ celestial mechanics/ minor planets/ asteroids: general/ planets and satellites: general
UR - http://adsabs.harvard.edu/abs/2014MNRAS.437.4019T
N2 - The European Space Agency Gaia satellite, planned for launch in late
2013, will perform systematic astrometric observations of the whole sky
over a five year period. During this mission, many thousands of Solar
System objects down to magnitude V = 20 will be observed including
near-Earth asteroids and objects at solar elongations as low as 45°,
which are difficult to observe with ground-based telescopes. We
simulated the detection of Trojan asteroids in the orbits of Earth and
Mars by Gaia. We find that Gaia will not detect the Earth Trojan 2010
TK7 although it will detect any Earth Trojans with diameters
larger than 600 m. We also find that Gaia will detect the currently
known Mars Trojans and could discover more than 100 new Mars Trojans as
small as 400 m in diameter. The results of the Gaia mission will test
the predictions about the Mars Trojan asteroid population and lead to
greater understanding about the evolution of the Solar System.
DO - 10.1093/mnras/stt2223
C1 - eprint: arXiv:1311.3372
SN - 0035-8711
ER -
TY - Journal
T1 - Tidal end states of binary asteroid systems with a nonspherical component
A1 - Taylor, Patrick A.
A1 - Margot, Jean-Luc
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 418
EP - 422
UR - http://adsabs.harvard.edu/abs/2014Icar..229..418T
N2 - We derive the locations of the fully synchronous end states of tidal
evolution for binary asteroid systems having one spherical component and
one oblate- or prolate-spheroid component. Departures from a spherical
shape, at levels observed among binary asteroids, can result in the lack
of a stable tidal end state for particular combinations of the system
mass fraction and angular momentum, in which case the binary must
collapse to contact. We illustrate our analytical results with
near-Earth Asteroids (8567) 1996 HW1, (66391) 1999
KW4, and 69230 Hermes.
DO - 10.1016/j.icarus.2013.11.008
C1 - eprint: arXiv:1312.0537
SN - 0019-1035
ER -
TY - Journal
T1 - Unexpected D-type interlopers in the inner main belt
A1 - DeMeo, Francesca E.
A1 - Binzel, Richard P.
A1 - Carry, Benoiˆt
A1 - Polishook, David
A1 - Moskovitz, Nicholas A.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 392
EP - 399
UR - http://adsabs.harvard.edu/abs/2014Icar..229..392D
N2 - Very red featureless asteroids (spectroscopic D-types) are expected to
have formed in the outer Solar System far from the Sun. They comprise
the majority of asteroids in the Jupiter Trojan population, and are also
commonly found in the outer main belt and among Hildas. The first
evidence for D-types in the inner and middle parts of the main belt was
seen in the Sloan Digital Sky Survey (SDSS). Here we report follow-up
observations of SDSS D-type candidates in the near-infrared. Based on
follow up observations of 13 SDSS D-type candidates, we find a
˜20% positive confirmation rate. Known inner belt D-types range in
diameter from roughly 7 to 30 km. Based on these detections we estimate
there are ˜100 inner belt D-types with diameters between 2.5 and
20 km. The lower and upper limits for total mass of inner belt D-types
is 2 × 1016 kg to 2 × 1017 kg which
represents 0.01--0.1% of the mass of the inner belt. The inner belt
D-types have albedos at or above the upper end typical for D-types which
raises the question as to whether these inner belt bodies represent only
a subset of D-types, they have been altered by external factors such as
weathering processes, or if they are compositionally distinct from other
D-types. All D-types and candidates have diameters less than 30 km, yet
there is no obvious parent body in the inner belt. Dynamical models have
yet to show how D-types originating from the outer Solar System could
penetrate into the inner reaches of the main belt under current
scenarios of planet formation and subsequent Yarkovsky drift.
DO - 10.1016/j.icarus.2013.11.026
C1 - eprint: arXiv:1312.2962
SN - 0019-1035
ER -
TY - Journal
T1 - The preliminary analysis of the 4179 Toutatis snapshots of the Chang'E-2 flyby
A1 - Zou, Xiaoduan
A1 - Li, Chunlai
A1 - Liu, Jianjun
A1 - Wang, Wenrui
A1 - Li, Han
A1 - Ping, Jinsong
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 348
EP - 354
UR - http://adsabs.harvard.edu/abs/2014Icar..229..348Z
N2 - On 2012 December, 13, 08:30 (UTC), Chang'E-2 flew by Asteroid 4179
Toutatis in deep space 7 million kilometers away from Earth. The flyby
mission returned clear optical images of Toutatis for the first time.
The flyby distance and image pixel scale were calculated from the image
size of the asteroid compared to a predicted view of an earlier radar
shape model. We compared the similarities and differences in both the
radar model and the CE-2 photo mosaic, and measured the craters and
lumps on the surface of Toutatis. We preliminarily analyzed the
topography of the Toutatis surface. We found that the density of craters
on the small lobe is less than that on the big lobe.
DO - 10.1016/j.icarus.2013.11.002
SN - 0019-1035
ER -
TY - Journal
T1 - Assessment of the 2880 impact threat from Asteroid (29075) 1950 DA
A1 - Farnocchia, D.
A1 - Chesley, S. R.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 321
EP - 327
UR - http://adsabs.harvard.edu/abs/2014Icar..229..321F
N2 - In this paper we perform an assessment of the 2880 Earth impact risk for
Asteroid (29075) 1950 DA. To obtain reliable predictions we analyze the
contribution of the observational dataset and the astrometric treatment,
the numerical error in the long-term integration, and the different
accelerations acting on the asteroid. The main source of uncertainty is
the Yarkovsky effect, which we statistically model starting from 1950
DA's available physical characterization, astrometry, and dynamical
properties. Before the release of 2012 radar data, this modeling
suggests that 1950 DA has 99% likelihood of being a retrograde rotator.
By using a 7-dimensional Monte Carlo sampling we map 1950 DA's
uncertainty region to the 2880 close approach b-plane and find a
5×10-4 impact probability. With the recently released
2012 radar observations, the direct rotation is definitely ruled out and
the impact probability decreases to 2.5×10-4.
DO - 10.1016/j.icarus.2013.09.022
C1 - eprint: arXiv:1310.0861
SN - 0019-1035
ER -
TY - Journal
T1 - Stability of rubble-pile satellites
A1 - Sharma, Ishan
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 278
EP - 294
UR - http://adsabs.harvard.edu/abs/2014Icar..229..278S
N2 - We consider the stability of rubble-pile satellites that are held
together by their own gravity. A satellite is said to be stable whenever
it is both orbitally and structurally stable to both orbital and
structural perturbations. We restrict attention to satellites whose
dimensions are small compared to their respective orbital radii and
their associated planets' sizes. In this case, we show that a satellite
is stable whenever it is orbitally stable to orbital perturbations and
structurally stable to structural perturbations. Orbital stability is
investigated by a spectral analysis, while structural stability is
probed by appropriately extending the work of Sharma [Sharma, I., 2012.
Stability of rotating non-smooth complex fluids. J. Fluid Mech. 708,
71--99; Sharma, I., 2013. Structural stability of rubble-pile
asteroids. Icarus 223, 367--382]. The stability test is then
applied to planetary satellites of the Solar System that are suspected
to be granular aggregates, including many of the recently discovered
smaller moons of the giant planets.
DO - 10.1016/j.icarus.2013.09.023
SN - 0019-1035
ER -
TY - Journal
T1 - Transmission infrared spectra (2--25 mum) of carbonaceous chondrites (CI, CM, CV--CK, CR, C2 ungrouped): Mineralogy, water, and asteroidal processes
A1 - Beck, P.
A1 - Garenne, A.
A1 - Quirico, E.
A1 - Bonal, L.
A1 - Montes-Hernandez, G.
A1 - Moynier, F.
A1 - Schmitt, B.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 263
EP - 277
UR - http://adsabs.harvard.edu/abs/2014Icar..229..263B
N2 - In this work, infrared transmission spectra (2--25 mum range,
5000--400 cm-1) of 40 carbonaceous chondrites were
analyzed (21 CMs, 5 CVs, 6 CRs, 3 CKs, 3 C2s and 2 CIs). All these
meteorite groups are known to have experienced significant aqueous
alteration (except the CKs). These IR measurements provide information
about the parent body processes experienced, as well as spectra for
comparison with observations of Solar System small bodies and possibly
with astronomical observations of accretion and debris disks.
DO - 10.1016/j.icarus.2013.10.019
SN - 0019-1035
ER -
TY - Journal
T1 - Hypervelocity impacts on asteroids and momentum transfer I. Numerical simulations using porous targets
A1 - Jutzi, Martin
A1 - Michel, Patrick
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 247
EP - 253
UR - http://adsabs.harvard.edu/abs/2014Icar..229..247J
N2 - In this paper, we investigate numerically the momentum transferred by
impacts of small (artificial) projectiles on asteroids. The study of the
momentum transfer efficiency as a function of impact conditions and of
the internal structure of an asteroid is crucial for performance
assessment of the kinetic impactor concept of deflecting an asteroid
from its trajectory. The momentum transfer is characterized by the
so-called momentum multiplication factor beta, which has been
introduced to define the momentum imparted to an asteroid in terms of
the momentum of the impactor. Here we present results of code
calculations of the beta factor for porous targets, in which porosity
takes the form of microporosity and/or macroporosity. The results of our
study using a large range of impact conditions indicate that the
momentum multiplication factor beta is small for porous targets even
for very high impact velocities (beta<2 for
vimp<=15km/s), which is consistent with published scaling
laws and results of laboratory experiments (Holsapple, K.A., Housen,
K.R. [2012]. Icarus 221, 875--887; Holsapple, K.A., Housen, K.R.
[2013]. Proceedings of the IAA Planetary Defense Conference 2013,
Flagstaff, USA). It is found that both porosity and strength can have a
large effect on the amount of transferred momentum and on the scaling of
beta with impact velocity. On the other hand, the macroporous
inhomogeneities considered here do not have a significant effect on
beta.
DO - 10.1016/j.icarus.2013.11.020
SN - 0019-1035
ER -
TY - Journal
T1 - On the non-uniform distribution of the angular elements of near-Earth objects
A1 - JeongAhn, Youngmin
A1 - Malhotra, Renu
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 236
EP - 246
UR - http://adsabs.harvard.edu/abs/2014Icar..229..236J
N2 - We examine the angular distributions of near-Earth objects (NEOs) which
are often regarded as uniform. The apparent distribution of the
longitude of ascending node, Omega, is strongly affected by well-known
seasonal effects in the discovery rate of NEOs. The deviation from the
expected pi-periodicity in the apparent distribution of Omega
indicates that its intrinsic distribution is slightly enhanced along a
mean direction, Omega‾=111°; approximately 53% of NEOs have
Omega values within ±90° of Omega‾. We also find
that each subgroup of NEOs (Amors, Apollos and Atens) has different
observational selection effects which cause different non-uniformities
in the apparent distributions of their arguments of perihelion omega,
and longitudes of perihelion varpi. For their intrinsic distributions,
our analysis reveals that the Apollo asteroids have non-uniform omega
due to secular dynamics associated with inclination-eccentricity-omega
coupling, and the Amors' varpi distribution is peaked towards the
secularly forced eccentricity vector. The Apollos' omega distribution
is axial, favoring values near 0° and 180°; the two quadrants
centered at 0° and 180° account for 55% of the Apollos' omega
values. The Amors' varpi distribution peaks near varpi‾=4°;
61% of Amors have varpi within ±90° of this peak. We show
that these modest but statistically significant deviations from uniform
random distributions of angular elements are owed to planetary
perturbations, primarily Jupiter's. It is remarkable that this strongly
chaotic population of minor planets reveals the presence of Jupiter in
its angular distributions.
DO - 10.1016/j.icarus.2013.10.030
C1 - eprint: arXiv:1310.5457
SN - 0019-1035
ER -
TY - Journal
T1 - Scheila's scar: Direct evidence of impact surface alteration on a primitive asteroid
A1 - Bodewits, D.
A1 - Vincent, J.-B.
A1 - Kelley, M. S. P.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 190
EP - 195
UR - http://adsabs.harvard.edu/abs/2014Icar..229..190B
N2 - Asteroid (596) Scheila was the first object for which the immediate
aftermath of an inter-asteroidal collision was observed. In December
2010, the 113 km-sized asteroid was impacted by a smaller asteroid of
less than 100 m in diameter. The scale of the impactor was established
by observations of fading ejecta plumes. Comparison of the lightcurves
obtained before and after the impact allowed us to assess how much of
Scheila's surface was altered. Cratering physics based on the impactor
size suggests that the size of the affected area is larger than
expected, (effective radii of 3.5--10 km depending on the change in
the albedo of the surface). Similar but more localized albedo changes
have been observed on Vesta and the martian moons, but are not
understood. Empirical laws describing ejecta blankets however indicate
that at distances between 3.5 and 10 km from the crater, Scheila's
surface would be covered by a thin layer 2 mm to 2 cm thick. This
dusting, possibly mixed with bright impactor material may be enough to
explain to observed brightness increase. Our results show that
sub-critical impacts may play a significant role in processing the
surfaces of asteroids. The large effect of small impacts on asteroidal
lightcurves complicate shape modeling.
DO - 10.1016/j.icarus.2013.11.003
C1 - eprint: arXiv:1310.8515
SN - 0019-1035
ER -
TY - Journal
T1 - Block distributions on Itokawa
A1 - Mazrouei, S.
A1 - Daly, M. G.
A1 - Barnouin, O. S.
A1 - Ernst, C. M.
A1 - DeSouza, I.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 181
EP - 189
UR - http://adsabs.harvard.edu/abs/2014Icar..229..181M
N2 - Asteroid 25143 Itokawa is a small elongated asteroid with two distinct
parts. The evolution of this two-part body has been the source of
speculation. The scenarios for the formation of this asteroid include:
two-body capture, catastrophic disruption and rapid reaccretion, YORP
spin-up and mass shedding, and disruption (or partial disruption) with
two-body reaccretion. In this paper we use the global and regional
analyses of block populations and size--frequency distributions as
evidence of the probable evolutionary history of Itokawa. The block
sample used in this study is believed to be complete for blocks of size
>6 m and consists of a sample more than twice as large as previous
known studies.
DO - 10.1016/j.icarus.2013.11.010
SN - 0019-1035
ER -
TY - Journal
T1 - Near-infrared spectroscopy of 3:1 Kirkwood Gap asteroids II: Probable and plausible parent bodies; primitive and differentiated
A1 - Fieber-Beyer, Sherry K.
A1 - Gaffey, Michael J.
JO - Icarus
VL - 229
Y1 - 2014/2/1
SP - 99
EP - 108
UR - http://adsabs.harvard.edu/abs/2014Icar..229...99F
N2 - The 3:1 Kirkwood Gap asteroids are a mineralogically diverse set of
asteroids located in a region that delivers meteoroids into
Earth-crossing orbits. Mineralogical characterizations of asteroids
in/near the 3:1 Kirkwood Gap can be used as a tool to "map" conditions
and processes in the early Solar System. The chronological studies of
the meteorite types provide a "clock" for the relative timing of those
events and processes. By identifying the source asteroids of particular
meteorite types, the "map" and "clock" can be combined to provide a much
more sophisticated understanding of the history and evolution of the
late solar nebula and the early Solar System.
DO - 10.1016/j.icarus.2013.11.001
SN - 0019-1035
ER -
TY - Journal
T1 - Finding Very Small Near-Earth Asteroids using Synthetic Tracking
A1 - Shao, Michael
A1 - Nemati, Bijan
A1 - Zhai, Chengxing
A1 - Turyshev, Slava G.
A1 - Sandhu, Jagmit
A1 - Hallinan, Gregg
A1 - Harding, Leon K.
JO - The Astrophysical Journal
VL - 782
Y1 - 2014/2/1
SP - 1
KW - astrometry/ instrumentation: detectors/ minor planets/ asteroids: general/ techniques: image processing
UR - http://adsabs.harvard.edu/abs/2014ApJ...782....1S
N2 - We present an approach that significantly increases the sensitivity for
finding and tracking small and fast near-Earth asteroids (NEAs). This
approach relies on a combined use of a new generation of high-speed
cameras which allow short, high frame-rate exposures of moving objects,
effectively "freezing" their motion, and a computationally enhanced
implementation of the "shift-and-add" data processing technique that
helps to improve the signal-to-noise ratio (SNR) for detection of NEAs.
The SNR of a single short exposure of a dim NEA is insufficient to
detect it in one frame, but by computationally searching for an
appropriate velocity vector, shifting successive frames relative to each
other and then co-adding the shifted frames in post-processing, we
synthetically create a long-exposure image as if the telescope were
tracking the object. This approach, which we call "synthetic tracking,"
enhances the familiar shift-and-add technique with the ability to do a
wide blind search, detect, and track dim and fast-moving NEAs in near
real time. We discuss also how synthetic tracking improves the
astrometry of fast-moving NEAs. We apply this technique to observations
of two known asteroids conducted on the Palomar 200 inch telescope and
demonstrate improved SNR and 10 fold improvement of astrometric
precision over the traditional long-exposure approach. In the past 5 yr,
about 150 NEAs with absolute magnitudes H = 28 (~10 m in size) or
fainter have been discovered. With an upgraded version of our camera and
a field of view of (28 arcmin)2 on the Palomar 200 inch
telescope, synthetic tracking could allow detecting up to 180 such
objects per night, including very small NEAs with sizes down to 7 m.
DO - 10.1088/0004-637X/782/1/1
C1 - eprint: arXiv:1309.3248
SN - 0004-637X
ER -
TY - Journal
T1 - Intermittent Dust Mass Loss from Activated Asteroid P/2013 P5 (PANSTARRS)
A1 - Moreno, F.
A1 - Licandro, J.
A1 - Álvarez-Iglesias, C.
A1 - Cabrera-Lavers, A.
A1 - Pozuelos, F.
JO - The Astrophysical Journal
VL - 781
Y1 - 2014/2/1
SP - 118
KW - methods: numerical/ minor planets/ asteroids: individual: P/2013 P5 (PANSTARRS)
UR - http://adsabs.harvard.edu/abs/2014ApJ...781..118M
N2 - We present observations and models of the dust environment of activated
asteroid P/2013 P5 (PANSTARRS). The object displayed a complex
morphology during the observations, with the presence of multiple tails.
We combined our own observations, all made with instrumentation attached
to the 10.4 m Gran Telescopio Canarias on La Palma, with previously
published Hubble Space Telescope images to build a model aimed at
fitting all the observations. Altogether, the data cover a full three
month period of observations which can be explained by intermittent dust
loss. The most plausible scenario is that of an asteroid rotating with
the spinning axis oriented perpendicular to the orbit plane and losing
mass from the equatorial region, consistent with rotational break-up.
Assuming that the ejection velocity of the particles (v ~ 0.02-0.05 m
s--1) corresponds to the escape velocity, the object
diameter is constrained to ~30-130 m for bulk densities 3000-1000 kg
m--3.
DO - 10.1088/0004-637X/781/2/118
C1 - eprint: arXiv:1312.5895
SN - 0004-637X
ER -