= > in this proposal, more time is being requested for svwb.sbdsk4 = we propose to test the hypothesis that stellar angular momentum is regulated during the pre-main sequence phase via coupling of the star to its circumstellar disk. previous work has shown that classical t tauri stars with massive circumstellar disks (0.01 msun) rotate more slowly than their weak-emission counterparts which lack such disks. these observations found a natural explanation in models where the evolution of stellar angular momentum is regulated through magnetic coupling with a circumstellar disk. a sample of 10 rapidly rotating (p < 1 day) and 10 slowly rotating (p > 1 day) solar-mass stars has been selected in the young open cluster alpha per. we will survey these stars with the isophot instrument in order to detect the presence of optically-thin remnant circumstellar disks. recent models suggest that solar-type stars with rotation periods much greater than 1 day should have remained coupled to their disks for greater than 10 myr. remnant disks around the slowest rotating (p virgul 6 days) stars in alpha per cluster (age 50 myr) should have just begun to dissipate after the termination of the disk-locking phase. with these carefully designed iso measurements we should be able to; i) examine the connection between stellar rotation and the presence of disk material; and ii) determine the overall frequency of optically-thin circumstellar material around low-mass stars in alpha per. this proposal is a key component of a two-part follow-up to the program evolution of circumstellar disks by beckwith et al. awarded gto time in the first iso call for proposals.
Instrument
PHT17 , PHT18 , PHT19 , PHT37 , PHT38 , PHT39
Temporal Coverage
1998-03-16T10:59:35Z/1998-03-20T00:16:02Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, 1999, Evolution Of Circumstellar Disks: A Test Of Disk-Regulated Angular Momentum Evolution, 1.0, European Space Agency, https://doi.org/10.5270/esa-fkrd0is
