Science Goals

These are the major goals for the IOTA occultation campaign for the Pluto occultation; they are virtually the same as those that the PHOT/Southwest Research Inst.-Wellesley-Lowell-UVA collaboration, and the Lucky Star Project, propose:

1) Measure overall seasonal changes to Pluto's lower atmosphere
    a.  A good spread of observers over the entire shadow
    b.  Timing is less critical--really only need a few well-timed chords, others can have ~1 second time accuracy and their data will be mapped back to the well-timed chords. But timing <0.1 sec is better, and necessary in case either the ingress or egress is lost due to clouds or other problems.
    c.  Desired cadence is 2 Hz or faster, dead-time less than 10%
    d.  "High" SNR; linearity of sensors is critical
    e.  Primarily fixed telescopes will be used (i.e., at observatories)

2) Map central flash (this probes deeper layers of Pluto’s atmosphere); the central flash should be detectable ~ ±100 km around centrality, but the real action, i.e. flash larger than ~10% of the unocculted stellar flux, should occur ~ ± 50 km around centrality, and becomes really spectacular inside ~ ± 20 km, with values larger than the unocculted stellar flux at a few km from centrality.
    a.  A concentration of chords within about 150km of the central line is needed, number TBD; starting in early July, this will be coordinated with Occult Watcher and other tools to ensure good coverage
    b.  Timing is critical, need accuracy <<0.1 sec
    c.  Desired cadence is 10 Hz or faster, near zero dead-time
    d.  "High" SNR, linearity of sensors is critical
    e.  A mix of fixed and mobile telescopes will be needed
    f.  Observation in two or more wavelength bands (such as B, V, I) are desired, to measure haze in the lower atmosphere. This would be most practical at observatories with two or more telescopes.

We’ll concentrate our efforts for lining up observatories in the zone (within 150 km of the predicted central line), but of course we will also encourage observations throughout the occultation zone, to the outside detectable limit. This is important, as a general fit of our model to observations requires largely distributed chords, across the whole occultation zone.