scholarly journals Lifetime of Meteor Streams Associated with Comet Halley

1991 ◽  
Vol 126 ◽  
pp. 323-326
Author(s):  
M. Hajdukova ◽  
A. Hajduk
Keyword(s):  
Mass Loss ◽  
Structural Features ◽  
Critical Examination ◽  
Meteor Showers ◽  
Orbital Parameters ◽  
Loss Process ◽  
Meteor Streams ◽  
Flux Data ◽  
Large Particles ◽  
Comet Halley

AbstractCritical examination of the orbital parameters of particles ejected from comet Halley rejects the low age hypotheses for meteor showers associ- ated with the comet. The diffusion of the orbits of large particles is too slow for explaining the observed structural features of the stream. The mass-loss process as derived from space observations compared with the mass of the stream of particles deduced from flux data lead to comet lifetimes of the order of 105years.

scholarly journals The past orbit of comet Halley and its meteor stream

1985 ◽  
Vol 83 ◽  
pp. 399-403
Author(s):  
A. Hajduk
Keyword(s):  
Structural Features ◽  
Orbital Elements ◽  
Meteor Stream ◽  
Meteor Streams ◽  
The Past ◽  
Maximum Lifetime ◽  
Check Points ◽  
History Of ◽  
Comet Halley ◽  
Comet Orbit

AbstractThe present paper studies the structural features of the meteor streams associated with Comet Halley deduced from the observations of its meteor showers, as check points of orbital elements in a deeper history of the comet orbit. Libration of the argument of perihelion of the comet and the corresponding displacement of the nodes, as recognized in the distribution of condensations within the stream, allows to estimate the maximum lifetime of the comet in the inner Solar System at about 2 × 105 years.

scholarly journals Non-variable horizontal-branch stars

1997 ◽  
Vol 189 ◽  
pp. 363-368
Author(s):  
Robert T. Rood
Keyword(s):  
Mass Loss ◽  
Physical Basis ◽  
Horizontal Branch ◽  
Loss Process ◽  
Horizontal Branch Stars ◽  
Theoretical Results ◽  
Branch Morphology

For 25 years our ignorance of the physical basis of this mass loss process has been the barrier to progress in understanding horizontal branch morphology. I review some recent observational and theoretical results which may be giving us clues about the nature of the mass loss process.

scholarly journals Masers: Probing the mass loss process in PPN

1997 ◽  
Vol 180 ◽  
pp. 348-349
Author(s):  
Dieter Engels
Keyword(s):  
Mass Loss ◽  
Large Amplitude ◽  
Planetary Nebulae ◽  
Transition Process ◽  
Main Line ◽  
Agb Stars ◽  
Loss Process ◽  
Bipolar Outflow ◽  
Sky Survey ◽  
Sizeable Number

With the advent of the IRAS All-Sky Survey a sizeable number of transition objects between the AGB and the PN-phase were found - the Proto Planetary Nebulae (PPN). Oxygen-rich AGB stars often show prominent masers of SiO, H2O, and OH, which are lost during the transition process. The heavy mass loss on the AGB however does not stop abruptly and a new axisymmetric wind develops during the PPN phase. These winds both may host new masers and they can be used to study the changes of the mass loss process after that the stars have stopped their large-amplitude variations on the AGB. Several PPN are known to have OH masers, and at least in one case, HD 101584, the presence of a bipolar outflow could be proven (te Lintel Hekkert et al. 1992). Lewis (1989) found that main-line OH masers become prominent again. I will discuss here conclusions, which can be drawn from observations of H2O masers in PPN.

scholarly journals Long Dust Trails of Short Period Comets

1991 ◽  
Vol 126 ◽  
pp. 229-234
Author(s):  
H.U. Keller ◽  
K. Richter
Keyword(s):  
Radiation Pressure ◽  
Dust Cloud ◽  
Dust Particles ◽  
Pressure Force ◽  
Meteor Streams ◽  
Short Period ◽  
Orbital Periods ◽  
Comet Halley ◽  
Observational Techniques ◽  
Radiation Pressure Force

Comets constitute an important source for the zodiacal dust cloud. Mainly large particles are contributed because the smaller particles are emitted into hyperbolic orbits relative to the sun. Radiation pressure force reduces the effective solar gravitational attraction. Information about large cometary particles can be derived from a variety of sources requiring quite different observational techniques. Many distinct meteor streams are connected to orbits of short period comets. These streams contain large dust particles that are very little influenced by radiation pressure force. In some cases such as the η Aquarids and Orionids connected to comet Halley the total mass and the age of the meteors have been derived (Hughes, 1987; Hajduk, 1987). The mass of the streams is 5 to 10 times larger than the present mass of the nucleus and their lifetime corresponds to 2000 to 3000 orbital periods. Visible meteors are typically 10−2g and more of centimetre size.

Debris from comet Halley, comet's mass loss and age

1987 ◽  
Vol 10 (5) ◽  
pp. 587-591 ◽  
Author(s):  
G. Cevolani ◽  
G. Bortolotti ◽  
A. Hajduk
Keyword(s):  
Mass Loss ◽  
Comet Halley

scholarly journals Origin and Evolution of Recent Leonid Meteor Showers

1971 ◽  
Vol 13 ◽  
pp. 193-198 ◽  
Author(s):  
Bruce A. McIntosh
Keyword(s):  
Radiation Pressure ◽  
Ejection Velocity ◽  
Meteor Showers ◽  
Small Particles ◽  
Origin And Evolution ◽  
The Past ◽  
Long Duration ◽  
Large Particles ◽  
Particle Orbits ◽  
Perihelion Passage

The four most prominent returns of the Leonid shoiver in the past decade fall into two broad classes. The 1966 and 1969 showers were of short duration, had a high proportion of small particles, and occurred with the longest apparent delay after the perihelion passage of the parent comet Temple-Tuttle. By contrast, the 1961 and 1965 returns were of long duration, and had more large particles. The 1961 return preceded the comet.There are three major influences on particle orbits: ejection velocity, radiation pressure, and close encounters with planets. The observations are explainable in a qualitative way on the basis of the first two. But some speculation concerning the results of planetary perturbations must be invoked.

scholarly journals 48. Existence of meteor showers associated by short-period comets anomalous in motion

1968 ◽  
Vol 33 ◽  
pp. 504-508
Author(s):  
Z. Sekanina
Keyword(s):  
Mass Loss ◽  
Meteor Showers ◽  
Gravitational Effects ◽  
Short Period ◽  
Cometary Activity

The observed properties of non-gravitational effects in the motion of the short-period comets are described in connection with the possible mass-loss processes in their nuclei. The impulses on the nuclei have been found to be about 1 cm/sec to 3 m/sec per revolution. The contributions to the observed dynamic anomalies of gas- and dust-matter ejections from the nucleus into the comet's atmosphere are estimated. The existence of meteor showers is related to the characteristics of cometary activity. Methods of further investigations are suggested.

Theoretical Cometary Radiants and the Structure of Meteor Streams

1972 ◽  
Vol 45 ◽  
pp. 472-477
Author(s):  
E. N. Kramer
Keyword(s):  
Observational Data ◽  
Meteor Showers ◽  
Cometary Nuclei ◽  
Meteor Streams ◽  
Source Of Information ◽  
Indirect Source

Observational data on radiants of meteor showers and the structure of meteor streams may be used as an indirect source of information about the evolution of cometary and meteor orbits. Investigation of the structure of some meteor streams provides evidence for comparatively high velocities of ejection of meteoroids from cometary nuclei. Further evolution of the streams is determined by planetary perturbations and other factors, the influence of which depends on the size and composition of the meteoroids.

The structure of meteor streams associated with Comet Halley: Eta Aquarids and Orionids

1974 ◽  
Vol 22 ◽  
pp. 309-311
Author(s):  
Anton Hajduk
Keyword(s):  
Density Distribution ◽  
Meteor Shower ◽  
Point Of View ◽  
Orbital Elements ◽  
Statistical Point ◽  
Radar Observations ◽  
Meteor Streams ◽  
Stream Structure ◽  
Comet Halley ◽  
Radar Meteor

The association of Comet Halley with the Orionid and Eta Aquarid meteor streams is not commonly accepted at present. Southworth (1961) has determined the differences in the orbital elements of the Orionid stream and Comet Halley on the basis of 19 photographic meteors and found them to be rather large.Extensive observational material obtained since the beginning of this century, including a homogeneous series of the radar observations, carried out at the Springhill Meteor Observatory during the periods of the Orionid meteor shower activity in 1957–1967 has been used by the author (Hajduk 1971) to study the stream structure and its association with Comet Halley from a statistical point of view.The present analysis is an extension of the paper mentioned, based mainly on the radar observations of the Eta Aquarid meteor shower carried out at the Springhill Observatory during the period 1958–67. The total number of 240,000 radar meteor echoes observed in 670 hours between May 1 and May 10 during each of the years previously cited was used in this investigation. The observed variations in the hourly rates of echoes of different duration enable us to study the density distribution and size distribution of meteoric particles along and across the stream.

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