.. _p16-properties-comet:

P16: Properties of a Comet
==========================

Observing Goals:
^^^^^^^^^^^^^^^^

Your goal is to find and observe a comet over the course of a night, using multiple filters to attempt to determine properties of the comet that you observe.
Useful Background and References:

    * List of comets in the sky: https://in-the-sky.org/data/comets.php
    * Make finder charts: https://theskylive.com/ (The search here is quite bad -- but if you use google for the name of the comet, you can find the skylive link that way)

Observation Planning:
^^^^^^^^^^^^^^^^^^^^^

    * Observation Time

        * You will be observing HALF a night.

    * Target Selection

        * You should select a comet that is bright enough to observe, is high enough in the sky and far from the sun that you can observe it for a good portion of the night.

    * Observations

        * You should take multiple images that you can later stack in multiple different bands, use a finder chart to make sure that you are observing the comet.
        * You should use all broad band filters available to obtain as much data as possible from the comet (that means take flats in each filter!). The outer parts of the comet are the most interesting, so you need multiple images that you can stack to obtain the highetst signal to noise.

Data Analysis:
^^^^^^^^^^^^^^^


    * Data Reduction Basic Steps

        *  Visit the page :ref:`data-reduction`
        * Reduce your data to remove observational artefacts

    * Further for this project

        * You should make stacked images in each filter to obtain the highest signal to noise that you can of the comet
        * You should also try to do photometry and make a time sequence through the set of images you have

    * Further Analysis for this project

        * Make careful determinations of the point spread function of stars that you see in your images, and of the comet -- compare these and determine if you can prove that the comet is not just a point source
        * Create as deep images as possible, and remove a central point spread profile to see if you can find any extended parts of the comet structure
        * Analyse the changes in brightness over time. Does the comet show any signs of variablility? Does this seem periodic? or sporadic?

Results: 
^^^^^^^^^

Can you answer these questions with your work?

    * Q1: Can you prove that the comet is not just a point source but actually a comet?
    * Q2: Do you see any teltale signs of the object being a comet? Where and what are these?
    * Q3: Did you observe any variability over time? 
    * Q4: Is the comet only reflecting sunlight or is any portion of sunlight also being absorbed?

Presenting your results:
^^^^^^^^^^^^^^^^^^^^^^^^

   - :ref:`a1-poster`
   - :ref:`a2-talk`