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B Does a partial solar eclipse never completely rise?

  1. Mar 7, 2018 #1
    It seems that a partial solar eclipse is one in which the eclipse circle never completely rises, and it essentially is only a sunrise or sunset eclipse, with the point at which it goes from sunrise to sunset being that location in the polar region where the eclipse is at "high noon" but which it still doesn't completely rise off of the horizon.

    Is this accurate?
     
  2. jcsd
  3. Mar 7, 2018 #2
    I am not certain what you are describing - but it sounds wrong.
    You may see a partial solar eclipse for one of two reasons:
    1) The eclipse will go to totality, but the totality will not be seen from your location because of sunrise, sunset, cloud cover, etc,
    2) The eclipse will never go to totality because the Earth, Moon, and Sun will never align well enough. This can occur because the orbital plane of our moon and the orbital plane of the Earth are not the same.
     
  4. Mar 7, 2018 #3

    Vanadium 50

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    I am also not certain what you are describing - but it also sounds wrong.

    One way to get a partial eclipse is to have it at a time where the moon is farther away on average so does not completely block the sun. This is called an annular eclipse. It has nothing to do with the earth's rotation, so can have nothing to do with sunrise or sunset.
     
  5. Mar 7, 2018 #4

    russ_watters

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    I am also not certain what you are describing, but it feels important to point out that the Earth is round and has people all over it, so when the sun is at the horizon as viewed by one person it may be high in the sky as viewed by another person, somewhere else -- and both may be viewing a partial solar eclipse at the same time. The Great American Eclipse was view-able in roughly seven time zones simultaneously.
     
  6. Mar 7, 2018 #5
    The most common reason you can see only a partial eclipse, is because you're off the path of the total eclipse. The 2017 eclipse could be seen in all of north america, half of south america, and lots of ocean, but the total eclipse could only be seen in a path that was 100 miles wide or so.
     
  7. Mar 7, 2018 #6
    You're right. I was thinking lunar eclipse.
     
  8. Mar 7, 2018 #7
    I meant an eclipse that does not have an umbra or antumbra - or such region does not land on Earth's surface. They all seem to hug the terminator.
     
  9. Mar 7, 2018 #8

    Vanadium 50

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    Where do you get that? The very next eclipse, July 13 2018 happens at midday.
     
  10. Mar 7, 2018 #9
    Yes, but midday in Antarctica in July means the Sun doesn't completely rise above the horizon. That's the point I'm getting at.
     
  11. Mar 7, 2018 #10

    Vanadium 50

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    But it does in Australia. January 6 2019 happens at 2PM in Kamcatcha.
     
  12. Mar 7, 2018 #11

    davenn

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    no it isn't accurate, partial lunar eclipses can occur any time day or nite
    or solar eclipses can happen at any time of the day
    I have personally photo'ed them at a wide variety of times


    Dave

    edited for clarity for those who may not understand :wink:
     
    Last edited: Mar 7, 2018
  13. Mar 7, 2018 #12

    russ_watters

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    Ok, that makes more sense. If the umbra/antumbra misses the earth, the sun must be on the horizon at the location of maximum eclipse. But the penumbra is still up to several thousand miles wide (depending on how near the "miss"). Based on a map of that July eclipse, I calculate it will be 28 degrees above the horizon in southern Australia where they will see just a bit of the eclipse.
     
  14. Mar 7, 2018 #13

    russ_watters

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    *Ahem* A solar eclipse is of course only visible during the day.
     
  15. Mar 7, 2018 #14

    davenn

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    well, as you can note, I was also referencing lunar ones and hoping people would realise the difference :wink::-p

    but just in case people don't get it .... I will edit the post


    Dave
     
  16. Mar 7, 2018 #15

    russ_watters

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    Well, I still have a concern with bringing lunar eclipses into the discussion, since the viewing conditions for a lunar eclipse are wholly different from a solar eclipse. Unlike a solar eclipse, a lunar eclipse can be anywhere in the sky and is visible for the entire earth that is facing it.
     
  17. Mar 7, 2018 #16

    Vanadium 50

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    Um, don't lunar eclipses havbe to be at night?
     
  18. Mar 7, 2018 #17
    Since an eclipsed Moon must be within, I think, 1,5 degrees of the opposite of Sun, it can occur only if Sun is below or near horizon.
    What is maximum Sun centre elevation at which lunar eclipse (as opposed to part of Moon, another part of which is eclipsed) can be observed?
     
  19. Mar 7, 2018 #18

    davenn

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    no

    yes

    I remember one I photo'ed where the moon was almost setting (still several deg above horizon) in western sky and the sun rising in the east

    Dave
     
  20. Mar 14, 2018 #19

    sophiecentaur

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    It seems to me that all solar eclipses are at somebody's Noon and all lunar eclipses are at somebody's midnight but some other people can also see them.
     
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