Comet for Windows Tutorial

Japanese version
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Updated on June 16, 2007

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    Comparing Light Curves    

o Compare two bright comets in 2004.

Comet for Windows can draw multiple light curves of comets in one graph.

For example, here let's compare the light curves of Comet NEAT (C/2001 Q4) and Comet LINEAR (C/2002 T7). These two comets became bright in 2004 spring, and attracted attention as "two bright comets at one time".

Please launch Comet for Windows, and select "Menu" - "Light Curve (Multiple)" menu.

Please select "Setting" - "Select Comets" menu, and select Comet NEAT (C/2001 Q4) and Comet LINEAR (C/2002 T7).

Please select "View" - "Setting" menu, and select different colors for each comet. Please input the title as "Comet NEAT and LINEAR in 2004 Spring".

Then the following graph will be displayed.

This graph shows that these two comets brightened and faded very similarly, worthy of being called "two bright comets in one time".

o Compare brightness of a periodic comet among returns.

Comet for Windows can draw multiple light curves in several returns of a periodic comet in one graph.

For example, here let's compare the light curves of Comet 121P/Shoemaker-Holt 2. Here let's see that the orbital elements and the magnitude data of Comet 121P/Shoemaker-Holt 2 in 1988, 1996, 2004 and 2013 have been already registered in the database.

Please launch Comet for Windows, and select "Menu" - "Light Curve (Multiple)" menu.

Please select "Setting" - "Select Comets" menu, and select Comet 121P/Shoemaker-Holt 2 in four returns.

When comparing the light curves of a periodic comet among returns, you have to see the light curves against the perihelion passage date. And, you have to avoid the influence of distance from the earth to compare the actual brightness of the comet. Therefore, please select "View" - "Format" menu, and select "Days from T" for the horizontal axis, "Heliocentric Magnitude" for the vertical axis.

Please select "View" - "Setting" menu, and select different colors for each return.

Then the following graph will be displayed.

This graph shows that this comet has been fading gradually in each return in 1988, 1996 and 2004. This graph also shows that this comet will be much fainter in 2013 because of the drastic change of its orbit.

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Copyright(C) Seiichi Yoshida (comet@aerith.net). All rights reserved.