Comet Halley: A carrier of interstellar dust chemical evolution

The Comet Halley campaigns resulted in an enormously better understanding of the composition of comets. Silicates, organic compounds, and volatile ices comprised of H2O, CO, CO2, S2, CN, and possibly CH4 and OCS occur in comet grains. These are all known or suspected constituents of interstellar dust. We review the chemical, elemental, and isotopic compositions of comet dust and compare this with interstellar matter. The many intriguing parallels suggest, but do not yet establish, a direct connection between comet dust and interstellar dust.

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6. From Dust to Comets

International Astronomical Union Colloquium ◽

10.1017/s0252921100070457 ◽

1977 ◽

Vol 39 ◽

pp. 491-497 ◽

Cited By ~ 1

Author(s):

J. M. Greenberg

Keyword(s):

Chemical Evolution ◽

Interstellar Dust ◽

Organic Molecules ◽

Bulk Material ◽

The Other ◽

Contraction Phase ◽

Dense Cloud ◽

Small Grains ◽

Dust Grain ◽

Complex Organic

The growth and chemical evolution of a typical interstellar dust grain are followed starting from average interstellar conditions to the dense cloud and contraction phase. Based on the theory of cometary accretion directly from cold interstellar dust it is shown that the bulk material of a primordial comet would consist mostly of an icy conglomerate of complex organic molecules and frozen radicals in which are imbedded approximately equal volumes (10% each) of small grains in two different sizes - one variety being the order of 0.05 μ and the other ~0.005 μ in size - consisting mostly of silicates

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Comet Halley as an aggregate of interstellar dust and further evidence for the photochemical formation of organics in the interstellar medium

Origins of Life and Evolution of Biospheres ◽

10.1007/bf01810858 ◽

1992 ◽

Vol 22 (5) ◽

pp. 287-307 ◽

Cited By ~ 170

Author(s):

R. Briggs ◽

G. Ertem ◽

J. P. Ferris ◽

J. M. Greenberg ◽

P. J. McCain ◽

...

Keyword(s):

Interstellar Medium ◽

Interstellar Dust ◽

Photochemical Formation ◽

Comet Halley

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The Dust in the Coma of Comet Halley

International Astronomical Union Colloquium ◽

10.1017/s0252921100066914 ◽

1991 ◽

Vol 126 ◽

pp. 261-264

Author(s):

Joniek I. Hage ◽

J. Mayo Greenberg

Keyword(s):

Mass Distribution ◽

Linear Polarization ◽

Interstellar Dust ◽

Organic Materials ◽

Observational Constraints ◽

Comet Halley

AbstractThe interstellar dust model of comets is numerically worked out to satisfy several basic constraints provided by observations of comet Halley and to derive the porosity of coma dust. The observational constraints are: (1) the strengths of the 3.4 μm and 9.7 μm emission bands; (2) the relative amount of silicates to organic materials; (3) the mass distribution of the dust. The results indicate that coma dust has a porosity in the range 0.93 < P < 0.975. Preliminary calculations concerning the observed linear polarization of comet Halley are presented.

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The evolution of massive stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900116833 ◽

1997 ◽

Vol 189 ◽

pp. 313-322 ◽

Cited By ~ 2

Author(s):

A. Maeder

Keyword(s):

Star Formation ◽

Uv Radiation ◽

Chemical Evolution ◽

Interstellar Dust ◽

Galactic Center ◽

Massive Stars ◽

Galactic Nuclei ◽

Proper Understanding ◽

Evolution Of Galaxies ◽

Distant Galaxies

Massive stars are the crossroads of many important astrophysical problems and thus a proper understanding of their evolution is very needed. They are the main sources of UV radiation, by heating the interstellar dust they produce the far-IR luminosities of galaxies. They are the precursors of Supernovae and also the main sources of nucleosynthesis. They are visible in distant galaxies and the recent observations of starbursts have shown their major role in the spectral and chemical evolution of galaxies. They begin to be observed in the galactic center and in regions of star formation around galactic nuclei.

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