Skip to main content Accessibility help
×
Home
Hostname: page-component-55597f9d44-xbgml Total loading time: 0.315 Render date: 2022-08-13T00:33:02.071Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

Observational constraints on dust disk lifetimes: Implications for planet formation

Published online by Cambridge University Press:  22 October 2009

Lynne A. Hillenbrand
Affiliation:
California Institute of Technology, MS 105-24, Pasadena, CA 91105, USA
Mario Livio
Affiliation:
Space Telescope Science Institute, Baltimore
Kailash Sahu
Affiliation:
Space Telescope Science Institute, Baltimore
Jeff Valenti
Affiliation:
Space Telescope Science Institute, Baltimore
Get access

Summary

Thus far, our impressions regarding the evolutionary timescales for young circumstellar disks have been based on small number statistics. Over the past decade, however, in addition to precision study of individual star/disk systems, substantial observational effort has been invested in obtaining less detailed data on large numbers of objects in young star clusters. This has resulted in a plethora of information now enabling statistical studies of disk evolutionary diagnostics. Along an ordinate, one can measure disk presence or strength through indicators such as ultraviolet/blue excess or spectroscopic emission lines tracing accretion, infrared-excess tracing dust, or millimeter flux-measuring mass. Along an abscissa, one can track stellar age. While bulk trends in disk indicators versus age are evident, observational errors affecting both axes, combined with systematic errors in our understanding of stellar ages, both cloud and bias any such trends. Thus, detailed understanding of the physical processes involved in disk dissipation and of the relevant timescales remains elusive. Nevertheless, a clear effect in current data that is unlikely to be altered by data analysis improvements is the dispersion in disk lifetimes. Inner accretion disks are traced by near-infrared emission. Moderating a generally declining trend in near-infrared continuum excess and excess frequency with age over <1 to 8 ± 4 Myr, is the fact that a substantial fraction of rather young (<1 Myr old) stars apparently have already lost their inner accretion disks, while a significant number of rather old (8–16 Myr) stars apparently still retain them. By the age of 3–8 Myr, evidence for inner accretion disks for the vast majority of stars (~90%) ceases to be apparent. Terrestrial zone dust is traced by mid-infrared emission where sufficient sensitivity and uniform data collection are only now being realized with data return from the Spitzer Space Telescope. Constraints on mid-disk dissipation and disk-clearing trends with radius are forthcoming.

Type
Chapter
Information
A Decade of Extrasolar Planets around Normal Stars
Proceedings of the Space Telescope Science Institute Symposium, held in Baltimore, Maryland May 2–5, 2005
, pp. 84 - 105
Publisher: Cambridge University Press
Print publication year: 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)
4
Cited by

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×