Spitzer Space Telescope - Directors Discretionary Time Proposal #478


Spitzer Observations of the Naked Eye GRB080319B

Principal Investigator: Shrinivas Kulkarni
           Institution: Caltech

     Technical Contact: Arne Rau, Caltech

Co-Investigators:
Stephen Cenko, Caltech
Arne Rau, Caltech
Eran Ofek, Caltech
Derek Fox, Penn State
Edo Berger, Princeton
Michael Werner, JPL

Science Category: GRBs
Observing Modes: IrsPeakupImage
Hours Approved: 1.6

Abstract:
We request a single epoch of IRS blue peak-up imaging of GRB080319B,
the brightest optical counterpart to a gamma-ray burst ever detected.
The peak optical magnitude observed from GRB080319B, R ~ 6 mag, implies
the event was (briefly) visible to the naked eye and almost 3 magnitudes
brighter than the previous record holder, GRB990123.  Like GRB990123,
GRB080319B shows a dramatic rise and fall at early times indicative that
we are probing the shocked ejecta of the outflow via reverse shock emission.
Spitzer infrared imaging, when coupled with our broadband optical, X-ray,
and radio campaign, should help unravel what underlying properties
distinguish events like GRB080319B and GRB990123 from the majority of
GRB afterglows.