NDLI: Observational studies of the clearing phase in proto-planetary disks surrounding intermediate mass stars

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Observational studies of the clearing phase in proto-planetary disks surrounding intermediate mass stars

Content Provider	NASA Technical Reports Server (NTRS)
Author	Grady, Carol A.
Copyright Year	1999
Description	A detailed study of circumstellar gas associated with young, intermediate-mass stars has demonstrated that, far from being unique or an infrequently occurring phenomenon, beta Pic-like infall activity is routinely observed in stars younger than 10-50 Myr when the observer's line of sight lies within 15 degrees of the disk mid-plane. Detailed studies of 2 Herbig Ae/Be stars, AB Aur and HD 163296 demonstrate that enhanced infall episodes last 20-60 hours, comparable to the duration of similar episodes in beta Pictoris. The infall activity is consistent with detection of the comae of swarms of star-grazing bodies of asteroidal to cometary composition. Episodic fluctuations in the infall activity are clearly present by approximately 6 Myr, and may indicate the presence of massive planets within the disk. This study has therefore, directly contributed to NASA's Origins of Planetary Systems theme by identifying under what conditions extra-solar planetesimals can be remotely sensed, indicating that such bodies appear to be routinely detectable among young stars in the 1-10 Myr range, and suggesting that temporal studies of spectroscopic variability may provide a means of identifying those systems harboring massive planets. This study has resulted in 2 refereed review papers, 13 other refereed papers, and 17 conference papers.
File Size	318439
Page Count	7
File Format	PDF
Alternate Webpage(s)	http://archive.org/details/NASA_NTRS_Archive_19990063636
Archival Resource Key	ark:/13960/t09w5ct0r
Language	English
Publisher Date	1999-03-15
Access Restriction	Open
Subject Keyword	Astrophysics Stellar Envelopes B Stars Protoplanets Stellar Mass Asteroids A Stars Herbig-haro Objects Remote Sensing Line of Sight Planetary Systems Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science
Content Type	Text
Resource Type	Technical Report

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