Data Set Overview : NASA's International Halley Watch (IHW) has created a Comet Halley Archive. The collection of data spans the full wavelength range as submitted by scientists to the IHW. The observations belong to one of the following Disciplines: Amateur, Astrometry, Infrared Studies, Large-Scale Phenomena, Meteor Studies, Near-Nucleus Studies, Photometry and Polarimetry, Radio Studies, and Spectroscopy and Spectrophotometry. The data collected by these nine disciplines were augmented by Spacecraft measurements. The data were submitted to IHW, but the evaluation and selection for the Archive has been the primary responsibility of the Discipline Specialist Teams for each network in cooperation with the Lead Center. The Photometry and Polarimetry Network collected 3318 magnitudes for the Broadband Photometry Subnetwork. These data span the dates from 1981 December 02 to 1988 May 19.   Processing Level Id : 3 Software Flag : N   Parameters : Data Set Parameter Name : MAGNITUDE Data Set Parameter Unit : MAGNITUDE   Description ----------- A logarithmic unit often used by astronomers for expressing either the flux from a given source or the intrinsic luminosity of a source. The defining equation is mag : mag(0) - 2.5 log(flux); thus larger number refer to fainter sources. The zero-point, m(0), of the logarithmic scale is arbitrary. For apparent brightnesses, the zero point is normally defined by a set of standard sources, usually stars. The brightness can be in any spectral bandpass desired although well-defined zero points exist only for certain bandpasses.   Source Instrument Parameters : Instrument Host ID : PPN Data Set Parameter Name : MAGNITUD Instrument Parameter Name : N/A Important Instrument Parameters : 0   Measurement Information :  Atmospheric Conditions ---------------------- N/A   Source ------ N/A   Calibration Standard -------------------- N/A   Wavelength Calibration ---------------------- N/A   Processing : N/A

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