The evolution of comets and the detectability of Extra-Solar Oort Clouds

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6257767

Stern, S A

According the standard theory, comets are natural products of solar system formation, ejected to the Oort Cloud by gravitational scattering events during the epoch of giant planet formation. Stored far from the Sun for billions of years, comets almost certainly contain a record of the events which occurred during (and perhaps even before) the epoch of planetary formation. Two themes are examined of the evolutionary processes that affect comets in the Oort Cloud, and a search for evidence of Extra-Solar Oort Clouds (ESOCs). With regard to cometary evolution in the Oort Cloud, it was found that luminous O stars and supernovae have heated the surface layers of all comets on numerous occasions to 20 to 30 K and perhaps once to 50 K. Interstellar medium (ISM) interactions blow small grains out of the Oort Clouds, and erode the upper few hundred g/cu cm of material from cometary surfaces. The findings presented contradict the standard view that comets do not undergo physical change in the Oort Cloud. A logical consequence of the intimate connection between the Oort Cloud and our planetary system is that the detection of comet clouds around other stars would strongly indicate the sites of extant extra-solar planetary systems. A search was conducted for infrared IR emission from debris in ESOCs. After examining 17 stars using the Infrared Astronomical Satellite data base, only upper limits on ESOC emission could be set.

• Research Organization: Colorado Univ., Boulder, CO (USA). Cooperative Inst. for Research in Environmental Sciences
• OSTI ID: 6257767
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMETS
COSMIC DUST
COSMIC GASES
DATA
DUSTS
ELECTROMAGNETIC RADIATION
ERUPTIVE VARIABLE STARS
FLUIDS
GASES
INFORMATION
INFRARED RADIATION
NUMERICAL DATA
PLANETARY EVOLUTION
RADIATIONS
SCATTERING
SOLAR SYSTEM
SOLAR SYSTEM EVOLUTION
STAR EVOLUTION
STARS
SUPERNOVAE
THEORETICAL DATA
VARIABLE STARS