View Single Post
  #10  
Old 24-05-2010, 01:40 PM
DaveGee's Avatar
DaveGee (Dave Gault)
Occultation Observer

DaveGee is offline
 
Join Date: Aug 2006
Location: Blue Mountains, Australia
Posts: 232
Pluto Occultations - Why?

I thought I'd give a few details of why the observation of this event, and others like it, are important.

Well, apert from the "gee wizz" factor, the observation of these events gives us (mankind) a perfect opportunity to investigate enviromental conditions at Pluto, by using the light of the target star to code into the shadow of Pluto, details of Pluto's atmosphere that otherwise can not be obtained.

The fact that Pluto had an atmosphere was discovered during a 1988 occultation that was observed across Australia and New Zealand as well as by the Kuiper Airborne Observatory, by virtue of the slow or gradual disappearance and reappearance events. It is the rate of change in the light that can lead to measurements of pressure and temperature of the atmosphere. It was during subsiquent stellar occultations, that an inversion layer was discovered, and this is shown by a "knee" in the light curve, signifying a change in density. The image below shows a typical example.

So, believe it or not, an amateur astronomer using modest equipment can produce data that can lead to further understanding of Pluto's atmosphere. Of course, I have no idea how to take it to the level of "atmospherics", and here is where the "professional" astronomer takes over. Typically the light curve data is given to the Principal Investigator, in previous cases Bruno Sicardy of Paris Observatory takes the combined observations and in the end, produces a paper of "our" results. The reward of providing data that is used in the paper is to be mentioned as a co-author.

Why is this all important? Well apart from the pure knowledge of the dynamics of Pluto's atmosphere, The New Horizons spacecraft is enroute to Pluto and is due 2015 and it would be nice to know what the atmosphere will be like before it gets there, so the various planned experiments can be optimised.

I hope this helps...
Attached Thumbnails
Click for full-size image (PlutoOccCurve.jpg)
16.9 KB27 views

Last edited by DaveGee; 24-05-2010 at 02:04 PM.
Reply With Quote