scholarly journals Analysis of the Karma asteroid family

2020 ◽  
Vol 501 (1) ◽  
pp. 356-366
Author(s):  
Debora Pavela ◽  
Bojan Novaković ◽  
Valerio Carruba ◽  
Viktor Radović
Keyword(s):  
Numerical Simulations ◽  
Family Members ◽  
Dynamical Evolution ◽  
Absolute Magnitude ◽  
Parent Body ◽  
Outer Edge ◽  
Middle Part ◽  
Near Earth Space ◽  
The Family ◽  
Original Family

ABSTRACT The Karma asteroid family is a group of primitive asteroids in the middle part of the main belt, just at the outer edge of the 3J:1A mean-motion resonance. We obtained the list of the family members with 317 asteroids, and estimated that it was formed by the catastrophic disruption of a parent body that was between 34 and 41 km in diameter. Based on the V-shape method, age of the Karma family is estimated to be about 137 Myr. A detailed dynamical map of the region combined with numerical simulations allowed us to reconstruct the long-term dynamical evolution of the family, and to identify the mechanisms responsible for this evolution. The numerical simulations successfully reproduced the main features in the orbital distribution of the family members but also showed that some regions of the Karma family could be missing. A more detailed analysis revealed that these regions likely consist of very dark objects, fainter than absolute magnitude H = 17, that have not yet been detected. Based on the obtained results, we concluded that magnitude–frequency distribution of family members up to H = 16 mag is neither affected by dynamical erosion nor observational incompleteness, and therefore represents the result of collisional grinding of the original family population. Finally, we found that the Karma family have been supplying some asteroids to the near-Earth region via the 3J:1A resonance. Currently, there should about 10 family members larger than 1 km in diameter, orbiting in the near-Earth space.

scholarly journals Dynamical evolution of Oort cloud comets to near-Earth space

2006 ◽  
Vol 2 (S236) ◽  
pp. 43-54 ◽  
Author(s):  
Olga A. Mazeeva
Keyword(s):  
Dynamical Evolution ◽  
Absolute Magnitude ◽  
Oort Cloud ◽  
Outer Solar System ◽  
Earth Space ◽  
Near Earth Space ◽  
Long Period ◽  
Order Of Magnitude ◽  
Orbital Periods ◽  
Stellar Perturbations

AbstractThe dynamical evolution of 2⋅105 hypothetical Oort cloud comets by the action of planetary, galactic and stellar perturbations during 2⋅109 years is studied numerically. The evolution of comet orbits from the outer (104 AU <a<5⋅104 AU, a is semimajor axes) and the inner Oort cloud (5⋅103 AU <a<104 AU) to near-Earth space is investigated separately. The distribution of the perihelion (q) passage frequency in the planetary region is obtained calculating the numbers of comets in every interval of Δ q per year. The flux of long-period (LP) comets (orbital periods P>200 yr) with perihelion distances q<1.5 AU brighter than visual absolute magnitude H10=7 is ∼ 1.5 comets per year, and ∼18 comets with H10<10.9. The ratio of all LP comets with q<1.5 AU to ‘new’ comets is ∼5. The frequency of passages of LP comets from the inner Oort cloud through region q<1.5 AU is ∼3.5⋅10−13 yr−1, that is roughly one order of magnitude less than frequency of passages of LP comets from the outer cloud (∼5.28⋅10−12 yr−1). We show that the flux of ‘new’ comets with 15<q<31 AU is higher than with q<15 AU, by a factor ∼1.7 for comets from the outer Oort cloud and, by a factor ∼7 for comets from the inner cloud. The perihelia of comets from the outer cloud previously passed through the planetary region are predominated in the Saturn-Uranus region. The majority of inner cloud comets come in the outer solar system (q>15 AU), and a small fraction (∼0.01) of them can reach orbits with q<1.5 AU. The frequency of transfer of comets from the inner cloud (a<104 AU) to the outer Oort cloud (a>104 AU), from where they are injected to the region q<1.5 AU, is ∼6⋅10−14 yr−1.

scholarly journals What we know about Families of Asteroids

1989 ◽  
Vol 8 ◽  
pp. 273-279
Author(s):  
V. Zappala’
Keyword(s):  
Family Members ◽  
Parent Body ◽  
Classification Methods ◽  
Hypervelocity Impacts ◽  
Mass Distributions ◽  
Proper Elements ◽  
The Family ◽  
Families Of Asteroids ◽  
Asteroid Families ◽  
Degree Of Fragmentation

AbstractAsteroid families are considered for the most to represent fragments of collisional breakup of precursor bodies. If true, this offers the unique possibility to examine the interiors of large bodies and to study the processes of collision on a scale much larger than can be done in laboratory. Indeed, the general features of the mass distributions and of the ejection velocities of the family members can be interpreted in terms of collisional disruption of a parent body followed by self-gravitational reaccumulation on the largest remnant. However, several problems remain open: a) the degree of fragmentation in real families is generally lower than that observed for experimental targets; b) the relative velocities computed including also proper eccentricity and inclination differences are higher by about a factor 4 than those derived from semiaxes differences only; c) only very few of the presently proposed families have distributions of inferred mineralogies consistent with cosmochemistry. Further studies are needed, including better proper elements computation, classification methods, and new investigations on the physics of hypervelocity impacts.

scholarly journals Physical and dynamical characterization of the Euphrosyne asteroid family

2020 ◽  
Vol 643 ◽  
pp. A38
Author(s):  
B. Yang ◽  
J. Hanuš ◽  
M. Brož ◽  
O. Chrenko ◽  
M. Willman ◽  
...  
Keyword(s):  
Family Members ◽  
Orbital Evolution ◽  
Parent Body ◽  
Element Space ◽  
Infrared Telescope ◽  
The Family ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Telescope Facility ◽  
Homogeneous Composition

Aims. The Euphrosyne asteroid family occupies a unique zone in orbital element space around 3.15 au and may be an important source of the low-albedo near-Earth objects. The parent body of this family may have been one of the planetesimals that delivered water and organic materials onto the growing terrestrial planets. We aim to characterize the compositional properties as well as the dynamical properties of the family. Methods. We performed a systematic study to characterize the physical properties of the Euphrosyne family members via low-resolution spectroscopy using the NASA Infrared Telescope Facility. In addition, we performed smoothed-particle hydrodynamics (SPH) simulations and N-body simulations to investigate the collisional origin, determine a realistic velocity field, study the orbital evolution, and constrain the age of the Euphrosyne family. Results. Our spectroscopy survey shows that the family members exhibit a tight taxonomic distribution, suggesting a homogeneous composition of the parent body. Our SPH simulations are consistent with the Euphrosyne family having formed via a reaccumulation process instead of a cratering event. Finally, our N-body simulations indicate that the age of the family is 280−80+180 Myr, which is younger than previous estimates.

scholarly journals Asteroid cratering families: recognition and collisional interpretation

2019 ◽  
Vol 622 ◽  
pp. A47 ◽  
Author(s):  
A. Milani ◽  
Z. Knežević ◽  
F. Spoto ◽  
P. Paolicchi
Keyword(s):  
Dynamical Evolution ◽  
Parent Body ◽  
Element Space ◽  
Secular Resonance ◽  
Proper Elements ◽  
The Family ◽  
New Interpretation ◽  
Fragmentation Type ◽  
Definition Of ◽  
Quantitative Definition

Aims. We continue our investigation of the bulk properties of asteroid dynamical families identified using only asteroid proper elements to provide plausible collisional interpretations. We focus on cratering families consisting of a substantial parent body and many small fragments. Methods. We propose a quantitative definition of cratering families based on the fraction in volume of the fragments with respect to the parent body; fragmentation families are above this empirical boundary. We assess the compositional homogeneity of the families and their shape in proper element space by computing the differences of the proper elements of the fragments with respect to the ones of the major body, looking for anomalous asymmetries produced either by post-formation dynamical evolution, or by multiple collisional/cratering events, or by a failure of the hierarchical clustering method (HCM) for family identification. Results. We identified a total of 25 dynamical families with more than 100 members ranging from moderate to heavy cratering. For three families (4, 15 and 283) we confirm the occurrence of two separate cratering events, while family (569) Misa is a mixed case, with one cratering event and one fragmentation event. The case of family 3 remains dubious, in that there could be either one or two collisions. For family 20, we propose a double collision origin, not previously identified. In four cases (31, 480, 163 and 179) we performed a dedicated search for dynamical resonant transport mechanisms that could have substantially changed the shape of the family. By using a new synthetic method for computation of secular frequencies, we found possible solutions for families 31, 480, and 163, but not for family 179, for which we propose a new interpretation, based on a secular resonance contaminating this family: the family of 179 should be split into two separate clusters, one containing (179) itself and the other, family (9506) Telramund, of fragmentation type, for which we have computed an age.

Spin clusters inside four young asteroid groups

2020 ◽  
Vol 493 (2) ◽  
pp. 2556-2567
Author(s):  
V Carruba ◽  
L G M Ramos ◽  
F Spoto
Keyword(s):  
Numerical Simulations ◽  
Transition Region ◽  
Semimajor Axis ◽  
Family Members ◽  
Proper Elements ◽  
The Family ◽  
Induced Fission ◽  
Spin Clusters ◽  
Spin Pairs ◽  
Asteroid Families

ABSTRACT Asteroid groups may either form because of collisions or because of spin induced fission. Recently it has been shown that young spin clusters tend to form more frequently in young collisional families than in older groups. Here, we study the occurrence of spin clusters inside four very recently identified asteroid groups: the (525) Adelaide, (2258) Viipuri, (6142) Tantawi, and (18429) (1994 AO1) groups. Using combinations of techniques based on backward numerical simulations, we identify four spin pairs among the family members. All groups have fractions of observed spin clusters well above 5 per cent, so confirming an observed trend for other young asteroid groups. The (2258) Viipuri and (18429) (1994 AO1) groups are compatible with an origin as a spin clusters themselves, and could be other occurrences of cascade spin clusters, as recently detected in other asteroid groups. Finally, the separation between collisional asteroid families and spin clusters in domains of dispersion of proper semimajor axis, σa, versus age seems to be more complex than previously thought. While spin clusters tend to be much more compact in proper elements than collisional families, there appears to be a transition region in σa where both the groups be found.

Recent Investigations of the First Bleeder Family in Åland (Finland) Described by von Willebrand

1981 ◽  
Vol 45 (01) ◽  
pp. 073-076 ◽  
Author(s):  
D Nyman ◽  
A W Eriksson ◽  
M Blombäck ◽  
R R Frants ◽  
P Wahlberg
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Family Members ◽  
Disease Type ◽  
Type I ◽  
Low Level ◽  
Laboratory Techniques ◽  
The Family ◽  
Original Family ◽  
Von Willebrand

SummaryThe still living members of the original bleeder family on the Åland Islands described by von Willebrand in 1926 have been reinvestigated by using modem laboratory techniques for the measurement of the Factor VIII complex and with regard to platelet aggregation. The low level of F VIII: C activity demonstrated in 1957 could be confirmed in some of the family members, who however all had only mild bleeding symptoms. More consistently, in 6 out of 10, a low F VIIIR: Ag was found; all of those also had a low F VIII: RCoF. In none of the members were excessively low values for any of the parameters found. However, the spectrum of the whole F VIII complex indicates that the original family described by von Willebrand belongs to von Willebrand’s disease, type I.

POLA PENDIDIKAN AGAMA DALAM KELUARGA JAMA’AH TABLIGH DI DESA BOLANG KECAMATAN DAYEUHLUHUR KABUPATEN CILACAP

2019 ◽  
Vol 20 (2) ◽  
pp. 283-298
Author(s):  
Kholid Mawardi ◽  
Cucu Nurzakiyah
Keyword(s):  
Religious Education ◽  
Adult Children ◽  
Daily Activity ◽  
Family Members ◽  
Special Study ◽  
Children's Education ◽  
The Family ◽  
Children’S Education ◽  
The Village

The results of the study found that the responsibility of religious education of children in the family of Tablighi Jama'ah differed in terms of several conditions, namely first, when parents were not going to khuruj where both parents were responsible for children's education; secondly, when the father goes khuruj, then the mother is responsible for everything including children's education; third, when both parents go khuruj, then the responsibility of the child is left to other family members such as grandparents or their first adult children; and fourth, when the child goes to khuruj, where parents are responsible for children's religious education both mother and father. The pattern of the religious education in the Tablighi Jama'ah family in the village of Bolang is formed from several similarities held in the implementation of religious education, one of which is the daily activity that is carried out by the Tablighi Jama'at family. Al-Qur'an becomes one of the material given to children in the ta'lim. Children are taught how to read the Qur'an and memorize short letters such as Surat al-Falaq, al-Ikhlas, and so on. In addition to al-Qur'an, in this ta'lim there is a special study in the Tablighi Jama'ah, which is reading the book of fadhilah ‘amal, and the last is mudzakarah six characteristics.

Information Practices of Baby Boomers as Caregivers

2013 ◽  
Author(s):  
Khuan Seow ◽  
Nadia Caidi
Keyword(s):  
Social Policy ◽  
Baby Boomers ◽  
Information Needs ◽  
Family Members ◽  
Age Groups ◽  
Maladie D’Alzheimer ◽  
Policy Makers ◽  
Age Related ◽  
The Family ◽  
Growing Age

Canada has an aging population with the fastest growing age groups (80 and 45-64 years old) vulnerable to age-related diseases such as Alzheimer’s disease. Caregiving responsibilities often fall to the family members of the afflicted without much attention and consideration being placed on the information needs of these caregivers. We call for a better understanding of these caregivers' information needs and uses by social policy makers as well as information providers.La population du Canada a tendance à vieillir considérablement, avec la hausse la plus rapide dans les groupes d’âge (80 et 45 à 64 ans). Les personnes âges sont très vulnérables à toute sorte de maladies, telles que la maladie d’Alzheimer. La responsabilité revient souvent aux membres de la famille qui doivent prendre soin des personnes atteintes de cette maladie. Or, nous ne connaissons que peu de chose sur les besoins en information des personnes qui prennent soin de ces malades de l’Alzheimer : qui sont-ils ? Quelles sont leurs sources... 

Pengaruh Penyuluhan Terhadap Respon Psikososial Keluarga Pasien Yang Dirawat Di Ruang Icu Rsud Dr.Sosodoro Djatikoesumo Bojonegoro

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Maslichah Maslichah ◽  
Bayu Akbar Khayudin ◽  
Ikha Ardianti
Keyword(s):  
Health Workers ◽  
Family Members ◽  
T Test ◽  
Family Counseling ◽  
Test Design ◽  
Significance Level ◽  
Paired Sample ◽  
The Family ◽  
Post Test ◽  
Psychosocial Responses

ABSTRAK Pasien yang dirawat di ICU pada umumnya mengalami sakit kritis biasanya hal ini akan menimbulkan bebagai  respons psikososial  dari anggota keluarganya. Respons ini dapat berupa respons positif maupun respons negatif. Salah satu cara agar respons psikososial menjadi positif yaitu memberikan penyuluhan kepada keluarga pasien agar ada peningkatan kognisi dan emosi. Desain penelitian ini menggunakan metode “Pre-Experiment”, dengan rancangan “One group pra-post test design”. Dengan populasi semua keluarga yang anggota keluarganya dirawat di Ruang ICU RSUD.dr.Sosodoro Djatikoesumo. Sampel diambil dengan proses Total Sampling. Variabel independen  yaitupenyuluhan keluarga pasien ICU, dan variabel dependen adalah respon psikososial keluarga pasien. Pengumpulan data menggunakan kuesioner. hasil penelitian yang dilakukan dengan uji statistik paired sample t-test, pada tingkat signifikansi diperoleh nilai 0,027 0,05 maka Ho ditolak dan H1 diterimaPerawat sebagai tenaga kesehatan yang harus selalu mengembangkan profesionalisme, perlu mengupayakan agar respons psikososial keluarga yang negatif dapat ditekan. Salah satu upayanya yaitu adalah memberikan penyuluhan kepada keluarga. Dalam penyuluhan akan diberikan: komunikasi, informasi, edukasi dan support. Kata Kunci : Penyuluhan, Respon Psikososial Keluarga  ABSTRACT Patients admitted to the ICU in general suffer from a critical illness usually this will lead to the kinds of psychosocial responses of family members. This response can be either a positive response or a negative response. One way to be positive psychosocial responses that provide counseling to the patient's family that there was an increase in cognition and emotion.This study design using the "Pre-Experiment", the draft "One group pre-post test design". With a population of all the families who have family members admitted to the ICU RSUD.dr.Sosodoro Djatikoesumo. Samples were taken with total sampling process. Independent variables, family counseling ICU patients, and the dependent variable is the family of the patient's psychosocial response. Collecting data using questionnaires. results of research conducted by the statistical test paired sample t-test, at a significance level obtained value 0,027 0,05 hence Ho refused and H1 accepted.Nurses as health workers must always develop professionalism, needs to strive for psychosocial response can be suppressed negative family. One of the efforts that are giving counseling to the family. In the extension will be granted: communication, information, education and support. Keywords: Counseling, Family Psychosocial Response

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