Spitzer Space Telescope - Archive Research Proposal #20044


Archival Study of Hyades Debris Disks

Principal Investigator: William Cochran
           Institution: University of Texas at Austin

Co-Investigators: 
Diane Paulson, NASA Goddard Space Flight Center                       
Michael Endl, University of Texas at Austin                           
Lucas Cieza, University of Texas at Austin                            

Science Category: circumstellar/debris disks 
Dollars Approved: 57620.0 

Abstract:
We propose to use the Spitzer Space Telescope archival IRS, IRAC and
MIPS observations of 17 stars in the Hyades star cluster to augment
the data that we are obtaining in our Cycle 1 GO program 3371, in
order to search for remnant debris disks in a homogeneous sample of
stars of 625My age.  The dominant independent variable in the sample
is the stellar mass.  The age of the Hyades corresponds to the era of
the late heavy bombardment in our solar system about 3.9Gy ago.  Thus,
it is reasonable to believe that these Hyades dwarfs might also have
rapidly evolving debris disks at this age.  Our combined sample stars
range from F8V to M2V.  We have measured the effective temperature,
surface gravity, micro- and macro-turbulence, the abundance of Fe, Si,
Ti, Na, Mg, Ca, and Zn, the projected rotational velocity (v sin i),
as well as the stellar chromospheric activity index for most of the
stars in the sample.  Any remnant debris disks around these Hyades
stars would have escaped detection by IRAS, and would have been near
the sensitivity limit of ISO if they are similar in properties to a
solar-type zodiacal disk.