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VERNAL POINT NOT CORRECT

In an attempt to visualize the vernal point, the crossing each year of ecliptic and celestial equator on 20 march (vernal equinox), I could by no means get this crossing on the right date. When I mark under “Grids” the celestial equator and the ecliptic path and under “Date and Time” for example year 2005 AD month 3 (march)  day 20 with time 13.30 or 01 hour 30 minutes 0 sec PM and “Calendar system” automatic, then I should get the sun exact on the crossing of ecliptic and celestial equator. With my other programme Redshift this works perfect. But in my SkySafari 5 Pro for MAC not. The first crossing of the sun with those two paths is on may 16 on 01h:30m PM.

How is this possible? What did I do wrong? For me an riddle. Do you know why this happens or how I must do this wright?

Paul Schoenmakers

 

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8 comments

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    Bill Tschumy

    Paul,

    I'm not sure what is going wrong for you.  I believe this is working fine.  Turn on both the Celestial Equator and the Ecliptic and set the time to March 20th.

     

  • 0
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    Pljschoenmakers

    Bill,

    Those were the adjustments which I used when I did not get the sun in de crossing of ecliptic and celestial equator. I have done it now again and get exact the same result..... an crossing on 17 may and not 20 march. I don't get it. Very strange.  By the way... the same happens with the autumn point that I get on 17 november instead of 21/22 september. Curious.

    The solstices on the crossings ecliptic and galactic equator are correct on 21 june and 21 december.

    Paul

     

  • 0
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    Bill Tschumy

    Two things to check.

    1. Make sure you are on Earth and not orbiting some other object.

    2. Are you sure the year is correct?  If the year is several thousand years in the past or future the equinoxes will be different.

  • 0
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    Pljschoenmakers

    O sure Bill, I am on earth, I used several city's in Europe. The last was Bonn, Germany. The year I have used was 2005 AD. No orbiting other objects.

  • 0
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    Pljschoenmakers

    The problem with de crossing of the ecliptic and celestial equator on de wrong day is still the same, on 17 may in stead of 20 march in the year 2005, view from earth. And the same is with the second on 17 november in stead of 21/22 september.

    The solstices however are correct on 21 june and 21 december.

    I'm curious why this is the case and how to solve it.

    Paul Schoenmakers

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    Bill Tschumy

    Paul,

    I'm not sure what is wrong since I cannot reproduce this.  Perhaps you can send me your settings file demonstrating the problem.

    On Mac, go to the Settings panel and click the + to save a new settings file.  Change the name from "Current Settings" to "Equinox Problem".  Now export this to you file system.  

    Then email the file to "bill at simcur dot com"

    I will take a look at it.

     

     

  • 0
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    Bill Tschumy
    I’m sorry it has taken me this look to look at your problem.  We are swamped getting SkySafari 6 ready for iOS.
     
    There are two problems in your settings file.
     
    1. You have the precession epoch as -2000.0 rather than 2000.0.  That is a 4000 year difference which is a lot of precession.
    2. In the Time settings, you are using the Julian calendar.  The March 20th equinox is in the Gregorian calendar way of marking time.  If you change the calendar setting back to “Automatic” (or Gregorian) you will get the correct date.
     
  • 0
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    Pljschoenmakers
    OK Bill, this is indeed the solution for my problem. I was not aware that the precession stood on -2000, so I adjusted this to 2000 and got indeed the right crossing on march 21.
     
    Great job Bill. Many thanks. I’m looking forward to SkySafari 6.
     
    Paul
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