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Tutorial:
How to find these exciting comets?


Find Comets

  1. Comets
  2. How to see a comet?
  3. How to find a comet
  4. Make your own star/comet chart

1: Comets

Who hasn't heard or read about comets? In earlier time you found information about them in newspapers or more specialized magazines. Nowadays you use the internet.

But why are comets so interesting? Maybe because they look beautiful or they moves relative the stars, something happens up there! The size of them are from a couples of hundred meters to kilometers. A lot of them are active when they are close to the sun and then they could have a very big tail. They are also very old objects, maybe from the age when our solar system was built up, almost five billions years ago. If we can bring parts of a comet back to our laboratories here on Earth we will learn a lot of there compositions and the early history of our solar system.

Here is more to read about comets:

  • https://en.wikipedia.org/ wiki/Comet
  • One of the most famous comets are Halley's Comet. This was the first comet where to find it's periodicity, it was Edmond Halley that calculated this in 1705. It's periodicity are 75 to 76 years.

    Here is more to read about Halley's Comet:

  • https://en.wikipedia.org/ wiki/Halley's_Comet
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    2: How to see a comet?

    If you are lucky it will come a bright comet, I belive if it has a magnitude of 5 (magnitude is how astronomers messaure brightness: https://en.wikipedia.org/ wiki/Apparent_magnitude 4 is brighter than 5!) or more there is a chance to see it by naked eye from dark areas. I have only seen two comets by naked eye, Hyakutake in 1996 and Hale Bopp in 1997.

    With a binocular you will have a better chance to see them, here are some information:

  • http://www.space.com/ 23566-comet-ison-observing-guide-binoculars-telescopes.html
  • With a telescope and camera it could be like this even under hard light pollution:

    Comet Catalina C/2013 US10

    This is my own photo of the comet Catalina, if you want to know more about what equipment I used you can read here:

    C/2013 US10 Catalina

    Nowadays you don't need a very expensive equipment to do photographing on comets, an ordinary DSLR camera will do on the brighter comets.

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    3: How to find a comet

    If you don't want to stay up every night (some people do!) to find a comet by yourselfe there is a lot of information from others. I normally use Seiichi Yoshida's excellent homepage:

  • http://www.aerith.net/
  • Scroll down until you see this:

    Seiichi Yoshida's homepage

    Click on "Weekly Information about Bright Comets" and you will have a list of comets with the brightest at top, he update this list several times per month.

    Seiichi Yoshida comet list

    You see the magnitude (m1) and positions for two dates in the table. Click on a comet and you will get even more data for that one:

    Seiichi Yoshida data Comet 252P/Linear 2016

    Here you have the comets orbital data and a star/comet chart. The circles along the line is the comets position at the labeled day. Scroll down and you have a graph of the comets brightness (magnitude) so you can plan which date to look for it.

    Seiichi Yoshida comet brightness graph

    Now you know if there is any comets to look for, but can you see them from your place? Read on!

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    4: Make your own star / comet chart

    It could be a lot of help to have a star/comet chart drawn from the position where you live. I make my charts from Skychart (CdC), a French program which is free and you can download it here:

  • https://sourceforge.net/ projects/skychart/
  • To draw a chart from your location you have to setup the program correct, I can't explain everything here, just the most important information how to do this:

    CdC Skychart setup>observatory

    First you must setup your location. Select setup-observatory: set the coordinates for your place or if you have a nearby (less than 150 miles, I also use Skychart to control my telescope and need better precision) observatory, use the observatory database. Set your time zone also.

    To make the comets easier too see on the star/comet chart, setup it like this:

    Skychart setup date/time simulation

    This will draw a line with a circle for the comet's position every seventh day and seven steps (49 days).

    Then you have to set how weak comets you want to see:

    CdC comet solarsystem settings

    Select Setup-Solarsystem-Comet: You can try this setting, if you want to see more comets on the star/comet chart, increase "show comets" to magnitude 12 and "fainter than magnitude" to magnitude 18. The weakest comet I have on photo is of magnitude 15, but with a darker place I believe I can catch much weaker ones.

    Skaychart alt az chart coordinates

    It's best to have the chart drawn in Alt-Az coordinates.

    Now setup the the date and time the star/comet chart should show:

    Setting date/time and comet deepsky star objects

    Click on the clock button on the left list. Set the date you want to see and time to something like 10 pm or 22:00 (evening/night, it must be dark!). Afterwards you can step back and forth by one hour too see which time it's easiest too see the comet from your place, high above horizon and when it's darkest.

    Then unmark the star and deep sky objects, it's the buttons most left on the horizontal list, if you have stars activated it will be a little bit crowded on the chart, but later turn it on and decrease the magnitude that will show up with the two small blue button on the horizontal list. You need the stars to be oriented on the sky.

    Now set the comet (click on comet button) to show it on the comet chart, and on the horizontal list.

    Now it's time to see how the chart looks. Click on 310 (degrees) on the list to the right. Use the right scrollbar and move upwards until you see a circular chart like this:

    Starmap, comet overview 310 degree

     The comets are those with white text and a dotted line, in my setup each dot are seven days apart. These are relative weak comets, use Seiichi Yoshidas homepage to find a brighter comet in the future and use the dates when it has it's maximum.

    The above chart are almost all the sky above you. To do detail studies, zoom in on a comet, in this example the comet Temple. Easiest is to right click on the small cross left to the comet label, then select "center on", then right click once again and now select "about" and information about the comet will show up on screen.

    Comet 9P/Temple

    It's hard to see here, but if the setup is correct the tail of the comet will be visible. Here I have turned on the stars and deep sky objects.

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