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we present hubble space telescope (hst) and keck 10 m telescope observations of active asteroid 288p/300163 (2006 vw139) taken to examine ejected dust. the nucleus is a c-type object with absolute magnitude hv = 17.0 ± 0.1 and estimated diameter ∼2.6 km (for assumed visual geometric albedo pv = 0.04). variations in the... | hubble and keck telescope observations of active asteroid 288p/300163 (2006 vw139) |
we present deep imaging observations of activated asteroid p/2016 g1 (panstarrs) using the 10.4 m gran telescopio canarias (gtc) from 2016 late april to early june. the images are best interpreted as the result of a relatively short-duration event with an onset of about {350}-30+10 days before perihelion (i.e., around ... | early evolution of disrupted asteroid p/2016 g1 (panstarrs) |
studying comets is believed to bring invaluable clues on the formation and evolution of our planetary system. in comparison to planets, they have undergone much less alteration, and should have therefore retained a relatively pristine record of the conditions prevailing during the early phases of the solar system. howe... | on the evolution of comets |
planet atmosphere and hydrosphere compositions are fundamentally set by accretion of volatiles, and therefore by the division of volatiles between gas and solids in planet-forming disks. for hyper-volatiles such as co, this division is regulated by volatile sublimation energies, and by the ability of other ice componen... | entrapment of co in co2 ice |
observations of the sungrazing comet c/2012 s1 (ison) were carried out using the atacama large millimeter/submillimeter array at a heliocentric distance of 0.58-0.54 au (pre-perihelion) on 2013 november 16-17. temporally resolved measurements of the coma distributions of hnc, ch3oh, h2co, and dust were obtained over th... | alma mapping of rapid gas and dust variations in comet c/2012 s1 (ison):new insights into the origin of cometary hnc |
we observed comet 96p/machholz 1 on a total of nine nights before and after perihelion during its 2017/2018 apparition. both its unusually small perihelion distance and the observed fragmentation during multiple apparitions make 96p an object of great interest. our observations show no evidence of a detectable dust com... | properties of the bare nucleus of comet 96p/machholz 1 |
we present tails, an open-source deep-learning framework for the identification and localization of comets in the image data of the zwicky transient facility (ztf), a robotic optical time-domain survey currently in operation at the palomar observatory in california, usa. tails employs a custom efficientdet-based archit... | tails: chasing comets with the zwicky transient facility and deep learning |
we report the detection of ch3oh emission in comet 46p/wirtanen on ut 2018 december 8 and 9 using the atacama compact array (aca), part of the atacama large millimeter/submillimeter array (alma). these interferometric measurements of ch3oh along with continuum emission from dust probed the inner coma (<2000 km from ... | rapidly varying anisotropic methanol (ch3oh) production in the inner coma of comet 46p/wirtanen as revealed by the alma atacama compact array |
las cumbres observatory (lco) has deployed a homogeneous telescope network of ten 1-m telescopes to four locations in the northern and southern hemispheres, with a planned network size of twelve 1-m telescopes at 6 locations. this network is very versatile and is designed to respond rapidly to target of opportunity eve... | neoexchange - an online portal for neo and solar system science |
context. the space environment in which planets are embedded mainly depends on the host star and impacts the evolution of the planetary atmosphere. the quiet m dwarf gj 436 hosts a close-in hot neptune which is known to feature a comet-like tail of hydrogen atoms that escaped from its atmosphere due to energetic stella... | the space weather around the exoplanet gj 436b. i. the large-scale stellar magnetic field |
compressive strength is a key to understanding the internal structure of dust aggregates in protoplanetary disks and their resultant bodies, such as comets and asteroids in the solar system. previous work has modeled the compressive strength of highly porous dust aggregates with volume filling factors lower than 0.1. h... | formulating compressive strength of dust aggregates from low to high volume filling factors with numerical simulations |
empirically, the estimated lifetime of a typical protoplanetary disk is <5-10 myr. however, the disk lifetimes required to produce a variety of observed exoplanetary systems may exceed this timescale. some hypothesize that this inconsistency is due to estimating disk fractions at the cores of clusters, where radiati... | what's behind the elephant's trunk? identifying young stellar objects on the outskirts of ic 1396 |
interstellar small bodies are unique probes into the histories of exoplanetary systems. one hypothesized class of interlopers are "jurads," exocomets released into the milky way during the post-main-sequence as the thermally pulsing asymptotic giant branch (agb) host stars lose mass. in this study, we assess the prospe... | interstellar comets from post-main-sequence systems as tracers of extrasolar oort clouds |
we here study the level of albedo variegation on the nucleus of comet 67p/churyumov-gerasimenko. this is done by fitting the parameters of a standard photometric phase function model to disc-average radiance factor data in images acquired by the rosetta/osiris narrow angle camera in the orange filter. local discrepanci... | albedo variegation on comet 67p/churyumov-gerasimenko |
comets play a dual role in understanding the formation and evolution of the solar system. first, the composition of comets provides information about the origin of the giant planets and their moons because comets formed early and their composition is not expected to have evolved significantly since formation. they, the... | constraints from comets on the formation and volatile acquisition of the planets and satellites |
the impact of a meteoroid onto an asteroid transfers linear and angular momentum to the larger body, which may affect its orbit and its rotational state. here we show that the meteoroid environment of our solar system can have an effect on small asteroids that is comparable to the yarkovsky and yarkovsky-o'keefe-radzie... | meteoroid impacts onto asteroids: a competitor for yarkovsky and yorp |
we present multiband photometric observations of nine centaurs. five of the targets are known active centaurs (167p/cineos, 174p/echeclus, p/2008 cl94, p/2011 s1, and c/2012 q1), and the other four are inactive centaurs belonging to the redder of the two known color subpopulations (83982 crantor, 121725 aphidas, 250112... | photometry of active centaurs: colors of dormant active centaur nuclei |
aims: we wish to investigate the energy conversion between particles and electromagnetic fields and determine the location where it occurs in the plasma environment of comets.methods: we used a hybrid plasma model that included photoionization, and we considered two cases of the solar extreme ultraviolet flux. other pa... | energy conversion in cometary atmospheres. hybrid modeling of 67p/churyumov-gerasimenko |
water and hydroxyl, once thought to be found only in the primitive airless bodies that formed beyond roughly 2.5-3 au, have recently been detected on the moon and vesta, which both have surfaces dominated by evolved, non-primitive compositions. in both these cases, the water/oh is thought to be exogenic, either brought... | evidence for oh or h2o on the surface of 433 eros and 1036 ganymed |
the extractable organic material (eom) from atmospheric total suspended particles (tsp) contains several organic compounds including non‑substituted polycyclic aromatic hydrocarbons (pahs), alkyl‑pahs, and nitro‑pahs. these chemicals seem to be among the key drivers of tsp genotoxicity. we have shown previously that th... | similar polycyclic aromatic hydrocarbon and genotoxicity profiles of atmospheric particulate matter from cities on three different continents |
rampino & caldeira carry out a circular spectral analysis (csa) of the terrestrial impact cratering record over the past 260 million years (ma), and suggest a ∼26 ma periodicity of impact events. for some of the impacts in that analysis, new accurate and high-precision ('robust'; 2se < 2 per cent) 40ar-39ar ages... | a tale of clusters: no resolvable periodicity in the terrestrial impact cratering record |
context. sufficiently far from the sun, all comets go through a phase of low activity. rosetta observations at large heliocentric distances of approximately 3 au showed that the plasma at a low-activity comet is affected by both steady state electric fields and low-frequency waves.aims: our goal is to provide a model f... | particle-in-cell modelling of comet 67p/churyumov-gerasimenko. spatial structures of densities and electric fields |
context. the european space agency (esa) rosetta mission was the most comprehensive study of a comet ever performed. in particular, the rosetta orbiter, which carried many instruments for monitoring the evolution of the dusty gas emitted by the cometary nucleus, returned an enormous volume of observational data collect... | the near-nucleus gas coma of comet 67p/churyumov-gerasimenko prior to the descent of the surface lander philae |
we measured the chemical composition of comet c/2021 a1 (leonard) using the long-slit echelle grating spectrograph ishell/irtf on 2021 december 20 and on 2022 january 8 and 9. we sampled 11 primary volatiles (h2o, hcn, nh3, co, c2h2, c2h6, ch4, ch3oh, h2co, ocs, and hcl) and three product species (cn, nh2, and oh) and ... | strongly depleted methanol and hypervolatiles in comet c/2021 a1 (leonard): signatures of interstellar chemistry? |
the paleocene-eocene thermal maximum (petm) is an abrupt global warming event that occurred at about 55.8 ma and is closely linked to a large carbon isotope excursion. what caused the petm is unresolved. an unusual abundance of single-domain magnetite particles in petm sediments on the atlantic coastal plain might repr... | quantified abundance of magnetofossils at the paleocene-eocene boundary from synchrotron-based transmission x-ray microscopy |
male wistar rats were exposed to herbicide, pendimethalin (pnd) at varying oral doses of 62.5, 125 and 250 mg/kg b.w. for 14 days. toxiological effects were assessed in terms of oxidative stress, dna damage, histopathological alterations and induction of anti-inflammatory and apoptotic responses linked bax, bcl-2, ifn-... | pendimethalin-induced oxidative stress, dna damage and activation of anti-inflammatory and apoptotic markers in male rats |
the giant planets are believed to experience dynamic instability, delivering numerous impactors (asteroids, comets and leftover planetesimals) to the moon. dynamic simulations show that the impacts of leftover planetesimals decay much quicker than those from the main belt. due to the relatively slow decay of early luna... | a new chronology from debiased crater densities: implications for the origin and evolution of lunar impactors |
the detailed features of molecular photochemistry are key to understanding chemical processes enabled by non-adiabatic transitions between potential energy surfaces. but even in a small molecule like hydrogen sulphide (h2s), the influence of non-adiabatic transitions is not yet well understood. here we report high reso... | rotational and nuclear-spin level dependent photodissociation dynamics of h2s |
we investigate the recent and future orbital evolution of the solar system small body 2019 ld2 (hereafter "ld2"), which was recently found to show cometary activity. while ld2's orbit initially looks similar to that of a jupiter trojan, numerical integrations show that it is only co-orbital with jupiter for approximate... | an extremely temporary co-orbital: the dynamical state of active centaur 2019 ld2 |
we present the current status and first results from a monte carlo-type simulation toolbox for solar system small body dynamics. we also present fundamental methods for evaluating the results of this type of simulations using convergence criteria. the calculations consider a body in the solar system with a mass loss me... | a monte carlo-type simulation toolbox for solar system small body dynamics: application to the october draconids |
considering the importance and lack of data of toxicogenomic approaches on occupational exposure to anesthetics, we evaluated possible associations between waste anesthetic gases (wags) exposure and biological effects including oxidative stress, dna damage, inflammation, and transcriptional modulation. the exposed grou... | oxidative stress, dna damage, inflammation and gene expression in occupationally exposed university hospital anesthesia providers |
comet 73p/schwassmann-wachmann 3, a member of the jupiter family of comets, broke into several fragments in the autumn of 1995. a dramatic increase in the comet's intrinsic brightness was then seen, suggestive of a massive expulsion of dust. orbiting the sun about every 5.4 years, the comet has continued to disintegrat... | will comet 73p/schwassman-wachmann 3 produce a meteor outburst in 2022? |
after the final landing of philae at the abydos site on comet 67/p churyumov-gerasimenko, the mupus (multipurpose sensors for surface and sub-surface science) device started hammering itself into the cometary ground on 14th november 2014, and continued hammering for more than 3 h. during this period, the casse (comet a... | the sesame/casse instrument listening to the mupus pen insertion phase on comet 67p/churyumov-gerasimenko |
context. sulfur (s) is of prime interest in the context of (astro)chemical evolution and habitability. however, the origin of s-bearing organic compounds in the solar system is still not well constrained.aims: we carried out laboratory experiments to test whether complex organosulfur compounds can be formed when surfac... | sulfur ion irradiation experiments simulating space weathering of solar system body surfaces. organosulfur compound formation |
in this paper, we develop previous studies that considered a free molecular gas flow through a dust porous mantle of a cometary nucleus. before, we considered various types of both homogeneous and heterogeneous layers built of nonintersecting spheres, including the layers containing microscopic cracks and inner cavitie... | transport characteristics of a hierarchical near-surface layer of the nucleus of comet 67p/churyumov-gerasimenko |
we present revised results for the main molecular species in five oort cloud comets observed with near-infrared echelle grating spectrometer (nirspec) at the keck observatory between 1999 and 2012 (c/1999 s4 (linear), c/2001 a2 (linear), c/2007 w1 (boattini), c/2012 f6 (lemmon), and c/2012 s1 (ison)). the re-evaluation... | new insights into the chemical composition of five oort cloud comets after re-analysis of their infrared spectra |
in general, small bodies of the solar system, e.g. asteroids and comets, have a very irregular shape. this feature affects significantly the gravitational potential around these irregular bodies, which hinders dynamical studies. the poincaré surface of section technique is often used to look for stable and chaotic regi... | poincaré surfaces of section around a 3d irregular body: the case of asteroid 4179 toutatis |
comets, comet-like objects and their fragments are the most plausible source for the dust in both the inner heliosphere and planetary debris discs around other stars. the smallest size of dust particles in debris discs is not known and recent observational results suggest that the size distribution of the dust extends ... | comets as a possible source of nanodust in the solar system cloud and in planetary debris discs |
next to water, methanol is one of the most abundant molecules in astrophysical ices. a new experimental approach is presented here for the direct monitoring via gas chromatography coupled to mass spectrometry (gc-ms) of a sublimating photoprocessed pure methanol ice. unprecedentedly, in a same analysis, compelling evid... | methanol ice vuv photoprocessing: gc-ms analysis of volatile organic compounds |
remote observations of the light scattered by dust particles in comet 67p/churyumov-gerasimenko (67p/c-g) (photometry and imaging polarimetry) allow us to compare the deduced physical properties of these particles with in situ measurements provided by the rosetta mission. onboard experiments on the dust confirm propert... | properties of dust particles in comets from photometric and polarimetric observations of 67p |
water and ammonia have long been seen as the main species of extraterrestrial space, especially on solar giants, moons, comets, and numerous extrasolar planets. the phases formed by their admixtures under temperature and pressure conditions of the giant planets are important for understanding many observable properties... | ionic and superionic phases in ammonia dihydrate n h3.2 h2o under high pressure |
context. since its arrival at the comet 67p/churyumov-gerasimenko in august 2014, the rosetta spacecraft followed the comet as it went past the perihelion and beyond until september 2016. during this time there were many scientific instruments operating on board rosetta to study the comet and its evolution in unprecede... | exposed bright features on the comet 67p/churyumov-gerasimenko: distribution and evolution |
aims: we aim to characterize the circular depressions of comet 67p/churyumov-gerasimenko and investigate whether such surface morphology of a comet nucleus is related to the cumulative sublimation effect since becoming a jupiter family comet (jfc).methods: the images from the rosetta/osiris science camera experiment ar... | physical properties and dynamical relation of the circular depressions on comet 67p/churyumov-gerasimenko |
we carried out numerical modeling of impacts of asteroids and icy bodies with a diameter from 30 m to 100 m and calculated radiation fluxes on the ground, luminous efficiencies and areas of potential fire. the integral luminous efficiency of impactors with a diameter of 30 m entering the atmosphere at acute angles can ... | thermal radiation and luminous efficiency of superbolides |
in this paper, we report the first in situ detection of the ammonium ion nh_4+ at 67p/churyumov-gerasimenko (67p/c-g) in a cometary coma, using the rosetta orbiter spectrometer for ion and neutral analysis (rosina)/double focusing mass spectrometer (dfms). unlike neutral and ion spectrometers onboard previous cometary ... | first in-situ detection of the cometary ammonium ion nh_4+ (protonated ammonia nh3) in the coma of 67p/c-g near perihelion |
aims: prior to 2019, the june epsilon ophiuchids (jeo) were known as a minor unconfirmed meteor shower with activity that was considered typically moderate for bright fireballs. an unexpected bout of enhanced activity was observed in june 2019, which even raised the possibility that it was linked to the impact of the s... | characterization of the june epsilon ophiuchids meteoroid stream and the comet 300p/catalina |
we report the possible disintegration of comet c/2019 y4 (atlas), revealed by the public monitoring program carried out by the 0.6-m ningbo education xinjiang telescope (next). | possible disintegration of comet c/2019 y4 (atlas) |
we present analyses of spitzer observations of 29p/schwassmann-wachmann 1 using 16 μm irs "blue" peak-up (pu) and 24 and 70 μm mips images obtained on ut 2003 november 23 and 24 that characterize the centaur's large-grain (10-100 μm) dust coma during a time of non-outbursting "quiescent" activity. estimates of ϵfρ for ... | characterization of thermal-infrared dust emission and refinements to the nucleus properties of centaur 29p/schwassmann-wachmann 1 |
because of the high fraction of refractory material present in comets, the heat produced by the radiogenic decay of elements such as aluminum and iron can be high enough to induce the loss of ultravolatile species such as nitrogen, argon, or carbon monoxide during their accretion phase in the protosolar nebula (psn). h... | impact of radiogenic heating on the formation conditions of comet 67p/churyumov-gerasimenko |
theoretical work on the meteoroid stream ejected by comet 15p/finlay predicts multiple outbursts in 2021 in agreement with previous authors. this work predicts the first outburst to happen around 2021-09-29t08:35 ut, for a radiant located at alpha=260.8 degrees, delta=-57.4 degrees and will be best visible from new-zea... | meteor shower outburst caused by comet 15p/finlay |
we present a photometric and astrometric study of the split active asteroid p/2016 j1 (panstarrs). the two components (hereafter j1-a and j1-b) separated either ∼1500 days (2012 may to june) or 2300 days (2010 april) prior to the current epoch, with a separation speed v sep = 0.70 ± 0.02 m s-1 for the former scenario a... | split active asteroid p/2016 j1 (panstarrs) |
the paleocene-eocene thermal maximum is marked by a prominent negative carbon-isotope excursion, reflecting the injection of thousands of gigatons of isotopically light carbon into the atmosphere. the sources of the isotopically light carbon remain poorly constrained. utilizing a multiproxy geochemical analysis (osmium... | assessing the contributions of comet impact and volcanism toward the climate perturbations of the paleocene-eocene thermal maximum |
the biomolecular homochirality in living organisms has been investigated for decades, but its origin remains poorly understood. it has been shown that circular polarized light (cpl) and other energy sources are capable of inducing small enantiomeric excesses (ees) in some primary biomolecules, such as amino acids or su... | the astrophysical formation of asymmetric molecules and the emergence of a chiral bias |
the alice ultraviolet spectrograph on the european space agency rosetta spacecraft observed comet 67p/churyumov-gerasimenko in its orbit around the sun for just over two years. alice observations taken in 2015 october, two months after perihelion, show large increases in the comet’s lyβ, o i 1304, o i 1356, and c i 165... | ultraviolet observations of coronal mass ejection impact on comet 67p/churyumov-gerasimenko by rosetta alice |
in addition to the manufacture of complex organic molecules from impacting cometary and icy planet surface analogs, which is well-established, dust grain-grain collisions driven by turbulence in interstellar or circumstellar regions may represent a parallel chemical route toward the shock synthesis of prebiotically rel... | dust motions in magnetized turbulence: source of chemical complexity |
predictions of the 2018 draconid activity at the earth and the sun-earth l1 and l2 lagrange points are presented. numerical simulations of the meteoroids’ ejection and evolution from comet 21p/giacobini-zinner are performed with a careful implementation of the results analysis and weighting. model meteoroid fluxes at e... | the draconid meteoroid stream 2018: prospects for satellite impact detection |
the under-abundance of asteroids on orbits with small perihelion distances suggests that thermally driven disruption may be an important process in the removal of rocky bodies in the solar system. here we report our study of how the debris streams arise from possible thermally driven disruptions in the near-sun region.... | debris of asteroid disruptions close to the sun |
the international rosetta mission of the european space agency (esa) was launched on 2nd march 2004 on its 10 year journey to comet churyumov-gerasimenko and has reached it early august 2014. the main mission objectives were to perform close observations of the comet nucleus throughout its orbit around the sun and deli... | rosetta mission operations for landing |
it has been suggested that centaurs may lose their red surfaces and become bluer due to the onset of cometary activity, but the way in which cometary outbursts affect the surface composition and albedo of active centaurs is poorly understood. we obtained consistent visual-near-infrared (vnir) reflectance spectra of the... | 174p/echeclus and its blue coma observed post-outburst |
we observed the dynamically new sungrazing comet ison (c/2012 s1) extensively at lowell observatory throughout 2013 in order to characterize its behavior prior to perihelion. ison had “typical” abundances for an oort cloud comet. its dust production, as measured by afρ , remained nearly constant during the apparition b... | observations of comet ison (c/2012 s1) from lowell observatory |
we observed comet 322p/soho 1 (p/1999 r1) from the ground and with the spitzer space telescope when it was between 2.2 and 1.2 au from the sun. these are the first observations of any solar and heliospheric observatory (soho)-discovered periodic comet by a non-solar observatory and allow us to investigate its behavior ... | comet 322p/soho 1: an asteroid with the smallest perihelion distance? |
remote and in situ observations of cometary gases have revealed the presence of a wealth of complex organic molecules, including carbon chains, alcohols, imines, and the amino acid glycine. such chemical complexity in cometary material implies that impacts by comets could have supplied reagents for prebiotic chemistry ... | neutral-neutral synthesis of organic molecules in cometary comae |
comets have been invoked in numerous studies as a potentially important source of dust and gas around stars, but none has studied the thermo-physical evolution, out-gassing rate, and dust ejection of these objects in such stellar systems. in this paper we investigate the thermo-physical evolution of comets in exo-plane... | extrasolar comets: the origin of dust in exozodiacal disks? |
we describe a new iteration method to estimate asteroid coordinates, based on a subpixel gaussian model of the discrete object image. the method operates by continuous parameters (asteroid coordinates) in a discrete observational space (the set of pixel potentials) of the ccd frame. in this model, the kind of coordinat... | a new method based on the subpixel gaussian model for accurate estimation of asteroid coordinates |
we report a new active asteroid in the main belt of asteroids between mars and jupiter. object (62412) 2000 sy178 exhibited a tail in images collected during our survey for objects beyond the kuiper belt using the dark energy camera on the ctio 4 m telescope. we obtained broadband colors of 62412 at the magellan telesc... | discovery and characteristics of the rapidly rotating active asteroid (62412) 2000 sy178 in the main belt |
the discovery of the first two macroscopic interstellar objects (isos) passing through the solar system has opened entirely new perspectives in planetary science. the exploration of these objects offers a qualitatively new insight into the processes related to the origin, structure and evolution of planetary systems th... | synthetic population of interstellar objects in the solar system |
the zodiacal light is a nightglow mostly visible along the plane of the ecliptic. it represents the background radiation associated with solar light scattered by the tenuous flattened interplanetary cloud of dust particles surrounding the sun and the planets. it is an interesting subject of study, as the source of the ... | zodiacal light observations and its link with cosmic dust: a review |
the cyano radical (cn) is a key molecule across many different factions of astronomy and chemistry. accurate, empirical rovibronic energy levels with uncertainties are determined for eight doublet states of cn using the marvel (measured active rotational-vibrational energy levels) algorithm. 40 333 transitions were val... | experimental energy levels of 12c14n through marvel analysis |
refractory organic compounds formed in molecular clouds are among the building blocks of the solar system objects and could be the precursors of organic matter found in primitive meteorites and cometary materials. however, little is known about the evolutionary pathways of molecular cloud organics from dense molecular ... | evolution of morphological and physical properties of laboratory interstellar organic residues with ultraviolet irradiation |
comets hold the key to the understanding of our solar system, its formation and its evolution, and to the fundamental plasma processes at work both in it and beyond it. a comet nucleus emits gas as it is heated by the sunlight. the gas forms the coma, where it is ionised, becomes a plasma and eventually interacts with ... | cometary plasma science -- a white paper in response to the voyage 2050 call by the european space agency |
asteroid 1i/'oumuamua is the first observed interstellar object. its light-curve amplitude indicates that the object is highly elongated with an axial ratio of at least 5:1. the absence of such elongated asteroids in the solar system and the apparent lack of observed interstellar objects are intriguing problems. here w... | dust bombardment can explain the extremely elongated shape of 1i/'oumuamua and the lack of interstellar objects |
we review the state of knowledge on the origin of earth's water. empirical constraints come from chemical and isotopic measurements of solar system bodies and of earth itself. dynamical models have revealed pathways for water delivery to earth during its formation; most are anchored to specific models for terrestrial p... | origin of earth's water: sources and constraints |
this brief review will discuss the current knowledge on the origin and evolution of the nitrogen atmospheres of the icy bodies in the solar system, particularly of titan, triton and pluto. an important tool to analyse and understand the origin and evolution of these atmospheres can be found in the different isotopic si... | nitrogen atmospheres of the icy bodies in the solar system |
the great comet c/1995 o1 (hale-bopp) presented a remarkable opportunity to study its long-term brightness over four years. we used 2240 observations published in the international comet quarterly from 17 observers during 1995 july to 1999 september to create a secular lightcurve. in order to account for observer diffe... | the visual lightcurve of comet c/1995 o1 (hale-bopp) from 1995 to 1999 |
the surface granularity of small solar system bodies is diverse through the different types of planetary bodies and even for specific objects it is often not known in detail. one of the physical properties that strongly depends on the surface structure is the surface temperature. in highly porous media with large voids... | a method to distinguish between micro- and macro-granular surfaces of small solar system bodies |
a key feature of the galilean satellite system is its monotonic decrease in bulk density with growing distance from jupiter, indicating an ice mass fraction that is zero in the innermost moon io and about half in the outer moons ganymede and callisto. jupiter-formation models, and perhaps the juno spacecraft water meas... | early stages of galilean moon formation in a water-depleted environment |
the supersolar abundances of volatiles observed in giant planets suggest that a compositional gradient was present at the time of their formation in the protosolar nebula. to explain this gradient, several studies have investigated the radial transport of trace species and the effect of icelines on the abundance profil... | evolution of the reservoirs of volatiles in the protosolar nebula |
aims: understanding the activity is vital for deciphering the structure, formation, and evolution of comets. we investigate models of cometary activity by comparing them to the dynamics of 67p/churyumov-gerasimenko.methods: we matched simple thermal models of water activity to the combined rosetta datasets by fitting t... | activity distribution of comet 67p/churyumov-gerasimenko from combined measurements of non-gravitational forces and torques |
context. meteoroids are pieces of asteroids and comets. they serve as unique probes to the physical and chemical properties of their parent bodies. we can derive some of these properties when meteoroids collide with the atmosphere of earth and become a meteor or a bolide. even more information can be obtained when mete... | semi-automatic meteoroid fragmentation modeling using genetic algorithms |
the asteroid (3200) phaethon is known to be the parent body of the geminids, although meteor showers are commonly associated with the activity of periodic comets. what is most peculiar to the asteroid is its comet-like activity in the ejection of micrometer-sized dust particles at every perihelion passage, while the ac... | electrostatic dust ejection from asteroid (3200) phaethon with the aid of mobile alkali ions at perihelion |
aims: the main objective of our study is to obtain new observational results for the active long-period comet c/2011 kp36 (spacewatch). this comet has unusual orbital properties and moves at distances larger than 5 au from the sun.methods: we carried out extensive observations of comet c/2011 kp36 (spacewatch) at the 6... | observations of distant comet c/2011 kp36 (spacewatch): photometry, spectroscopy, and polarimetry |
here we report on the results of observations of comet 29p/schwassmann-wachmann 1 obtained using four telescopes, in three different countries, from 2019 september 25 to 2020 january 19. during the last four months of 2019, comet 29p/schwassmann-wachmann 1 exhibited new outburst behavior indicative of small or mini out... | dust production from mini outbursts of comet 29p/schwassmann-wachmann 1 |
concentration of fine particulate matter (pm2.5) is one of the most important environmental parameters to estimate health impacts attributable to air pollution. despite the fact there are many studies regarding pm2.5 effects on human health, most of them were performed under conditions that do not simulate the natural ... | histological changes in lung tissues related with sub-chronic exposure to ambient urban levels of pm2.5 in córdoba, argentina |
comets contain primitive material leftover from the formation of the solar system, making studies of their composition important for understanding the formation of volatile material in the early solar system. this includes organic molecules, which, for the purpose of this review, we define as compounds with c–h and/or ... | organic matter in cometary environments |
covering both homemade and commercial products, this book provides the reader with simple and straightforward information about the modeling, building, and use of binoscopes. binoscopes can be thought of as binoculars enlarged to the size of telescopes - essentially, a combination of the two. constructing a binoscope i... | building and using binoscopes, second edition |
polarimetric studies are an important source of information about the physical properties of celestial bodies. in 2018, we put into operation the new two-channel polarimeters in the crimean astrophysical observatory and the peak terskol observatory. with the help of these instruments, in the period from 2018 to 2020, w... | aperture polarimetry of selected comets in 2018-2020: observations and computer simulation |
we present initial observations of the newly discovered active asteroid 313p/gibbs (formerly p/2014 s4), taken to characterize its nucleus and comet-like activity. the central object has a radius ∼0.5 km (geometric albedo 0.05 assumed). we find no evidence for secondary nuclei and set (with qualifications) an upper lim... | a new active asteroid 313p/gibbs |
we study the motion and equilibria of the grains on the surface of the irregular celestial body (hereafter called irregular bodies). motions for the grains on the smooth and unsmooth surfaces are discussed, respectively. the linearized equations of motion relative to a surface equilibrium point and its characteristic e... | surface motion relative to the irregular celestial bodies |
the ejection of cometary grains from comets is examined. it is assumed that cometary grains are chunks of ice-dust material. we focus on cometary nuclei in the shape of prolate ellipsoids. two mechanisms are considered. the first one is the drag acting on the motionless grains lying on the surface of a comet's nucleus.... | ejection of large particles from cometary nuclei in the shape of prolate ellipsoids |
the recent discovery of an enriched metallicity for the smith high-velocity h i cloud (sc) lends support to a galactic origin for this system. we use a dynamical model of the galactic fountain to reproduce the observed properties of the sc. in our model, fountain clouds are ejected from the region of the disc spiral ar... | the galactic fountain as an origin for the smith cloud |
we report the detection of two consecutive outbursts of interstellar comet 2i/borisov in i-band images taken with the optical gravitational lensing experiment (ogle) 1.3-m telescope in las campanas. | multiple outbursts of interstellar comet 2i/borisov |
we report two observations of magnetic waves due to he+ pickup ions observed by the voyager 2 spacecraft in mid-1989 to demonstrate that such waves occur as far out as ∼30 au from the sun. the observations are sufficiently far from planets, interplanetary shocks, and other possible sources of energetic particles to mak... | observation of magnetic waves excited by newborn interstellar pickup he+ observed by the voyager 2 spacecraft at 30 au |
bennu (101195), target of the origins, spectral interpretation, resource identification, security, regolith explorer (osiris-rex) mission, is a type-b asteroid with abundant spectral evidence for hydrated silicates, low thermal inertia "boulders" and frequent bursts of particle emission. we suggest that bennu's parent ... | volatile-rich asteroids in the inner solar system |
the hayabusa2 mission successfully collected samples from the asteroid ryugu last year and will return these to earth in december 2020. it is anticipated that the samples will enable the analysis of terrestrially uncontaminated organic matter and minerals. such analyses are in turn expected to elucidate the evolution o... | the albedo of ryugu: evidence for a high organic abundance, as inferred from the hayabusa2 touchdown maneuver |
meteoritic evidence suggests that oxygen isotopic exchange between 16o-rich amorphous silicate dust and 16o-poor water vapor occurred in the early solar system. in this study, we experimentally investigated the kinetics of oxygen isotopic exchange between submicron-sized amorphous forsterite grains and water vapor at p... | oxygen isotopic exchange between amorphous silicate and water vapor and its implications for oxygen isotopic evolution in the early solar system |
magnetohydrodynamics simulations have been carried out in studying the solar wind and cometary plasma interactions for decades. various plasma boundaries have been simulated and compared well with observations for comet 1p/halley. the rosetta mission, which studies comet 67p/churyumov-gerasimenko, challenges our unders... | hall effect in the coma of 67p/churyumov-gerasimenko |
seismic nests (or clusters) are typically defined as regions of high seismic activity at intermediate depths that do not move over time and are not associated with volcanic activity at the surface (e.g. zarifi and havskov, 2003; zarifi et al., 2007; prieto et al., 2012). in this study, we focus on a seismic nest locate... | the pucallpa nest and its constraints on the geometry of the peruvian flat slab |
the new horizons encounter with the cold classical kuiper belt object 2014 mu69 (informally named "ultima thule," hereafter ultima) on 1 january 2019 will be the first time a spacecraft has ever closely observed one of the free-orbiting small denizens of the kuiper belt. related to but not thought to have formed in the... | great expectations: plans and predictions for new horizons encounter with kuiper belt object 2014 mu69 ("ultima thule") |
context. the comet c/2017 k2 panstarrs drew attention to its activity at the time of its discovery in may 2017 when it was about 16 au from the sun. this oort spike comet will approach its perihelion in december 2022, and the question about its dynamical past is an important issue to explore.aims: in order to answer th... | dynamical evolution of c/2017 k2 panstarrs |
nine recently discovered long-period comets were observed by the solar wind anisotropies (swan) lyman-alpha all-sky camera on board the solar and heliosphere observatory (soho) satellite during the period of 2013 to 2016. these were c/2012 k1 (panstarrs), c/2013 us10 (catalina), c/2013 v5 (oukaimeden), c/2013 r1 (lovej... | water production activity of nine long-period comets from soho/swan observations of hydrogen lyman-alpha: 2013-2016 |
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