Spitzer Space Telescope - General Observer Proposal #30563


Very Low Luminosity Objects:  Investigating the Lowest Luminosity,
Embedded Protostars with Spectra from 5-100  microns

Principal Investigator: Michael Dunham
           Institution: University of Texas at Austin

Co-Investigators: 
Neal Evans, University of Texas at Austin                             
Philip Myers, Harvard-Smithsonian Center for Astrophysics             
Tyler Bourke, Harvard-Smithsonian Center for Astrophysics             
Tracy Huard, Harvard-Smithsonian Center for Astrophysics              
Jes Jorgensen, Harvard-Smithsonian Center for Astrophysics            
Subhanjoy Mohanty, Harvard-Smithsonian Center for Astrophysics        

Science Category: star formation 
 Observing Modes: IrsStare MipsSed 
  Hours Approved: 15.2 

Abstract:
One of the most surprising results from the Spitzer Space Telescope
Legacy Project "From Molecular Cores to Planet Forming Disks" has been
the discovery of a very low luminosity protostar (L ~ 0.1 Lsun) in
L1014, a dense core previously believed to be starless.  Other,
similar objects have now been discovered in other cores as well,
leading to the definition of a new class of Very Low Luminosity
Objects.  These objects are difficult to understand in the standard
model of star formation, they either feature mass accretion rates much
lower than predicted, masses far below the stellar/substellar
boundary, or some combination of the two.  Understanding these objects
is essential for the development of a complete picture of low-mass
star and brown dwarf formation.  We propose a project to obtain
low-resolution IRS and MIPS SED mode spectra of 17 of these Very Low
Luminosity Objects at wavelengths ranging from 5 to 100  microns.
These observations will allow us to place constraints on the
luminosities of these sources not possible with existing data.  This
will allow us to confirm the current results suggesting these sources
all have luminosities less than or equal to 0.1 Lsun.  We will also
use the observations to probe the properties of the dust in the
regions surrounding these heavily embedded objects.  Finally, they
will allow us to investigate the presence and properties of
circumstellar disks around these objects, and through this, a possible
explanation for their very low luminosities.