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Centaur
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Reged: 07/12/04

Loc: Chicago
January New Moon Spotting
      #5612389 - 01/08/13 05:46 PM

Itís nearly time for my monthly New Moon spotting challenge, which becomes much easier for observers north of the tropics as we move past the winter solstice. Most North Americans should be able to sight the one-day-old Moon on January 12th. For many that will be a personal record.

My more detailed article describing the waxing crescent Moonís first appearance of the coming lunar month appears under the links for my preview graphics at www.CurtRenz.com/moon

Photos and descriptions of the young Moon would be welcome additions to this thread. Please include your location, date, time and time zone.

Here is link to a photo that I took from Arlington Heights, Illinois of the Moon aged 1.4 days with Mercury and Venus above it on 2008 DEC 28 at 17:05 CST: http://www.curtrenz.com/NM081228.jpg


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drbyyz
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Re: January New Moon Spotting new [Re: Centaur]
      #5619519 - 01/12/13 05:44 PM

Just got it a second ago. 530PM Eastern Time.

Fraction of the moon: 0.026438039906645
Illumination of the moon disk: 1 %
info from: http://lunaf.com/english/live-data/moon-phase/

Might be a record for me, but I don't keep track. Only managed to spot it in the binocs, definitely not naked eye visible yet(still too bright outside) and it will be below the tree line before it is. Pretty cool to see that super thin sliver.


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Centaur
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Re: January New Moon Spotting new [Re: drbyyz]
      #5619602 - 01/12/13 06:31 PM

Quote:

Just got it a second ago. 530PM Eastern Time.

Fraction of the moon: 0.026438039906645
Illumination of the moon disk: 1 %
info from: http://lunaf.com/english/live-data/moon-phase/

Might be a record for me, but I don't keep track. Only managed to spot it in the binocs, definitely not naked eye visible yet(still too bright outside) and it will be below the tree line before it is. Pretty cool to see that super thin sliver.





Congratulations, drbyyz. Thanks for sharing your experience. I hope you are able to spot it with naked eyes, which is what really counts. A photo would be even better. Itís cloudy here near Chicago, so I canít participate in this monthís contest.

What is meant by fraction of the Moon? Why is the number so incredibly precise? You also mention the illumination of the Moon disk as a different value. Usually we refer to the ďilluminated fraction of the Moonís disk.Ē The different values require explanation. Currently the illuminated fraction of the disk is 1.9% in Chicago and 2.1% geocentrically. It would be slightly different elsewhere. Although my being that precise is a bit unrealistic, since the terminator has some width and a single percentage point of precision is perhaps more proper.

Edited by Centaur (01/12/13 07:22 PM)


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Centaur
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Re: January New Moon Spotting new [Re: Centaur]
      #5619636 - 01/12/13 06:50 PM

For Summerville, SC on 2012 JAN 12 at 17:30 EST the illuminated fraction of the Moon's disk was 1.7%. Geocentrically the value at that time was was 2.0%. That refers to the area of the apparent two-dimensional disk that is illuminated. It is equivalent to the illuminated fraction of the lunar diameter that intersects the center of the illuminated limb.

Edited by Centaur (01/12/13 07:25 PM)


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drbyyz
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Reged: 11/04/12

Re: January New Moon Spotting new [Re: Centaur]
      #5620010 - 01/12/13 11:24 PM

Honestly I'm not positive what the "fraction of the moon" value is. I just copied it off the website in case someone found it to be a useful value lol. I can't seem to find an explanation on the website as to what it is either. The illumination percentage seems to just be a truncated value.

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Centaur
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Reged: 07/12/04

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Re: January New Moon Spotting new [Re: drbyyz]
      #5620029 - 01/12/13 11:44 PM

Quote:

Honestly I'm not positive what the "fraction of the moon" value is. I just copied it off the website in case someone found it to be a useful value lol. I can't seem to find an explanation on the website as to what it is either. The illumination percentage seems to just be a truncated value.




I understand. Thanks for looking into the matter. I now see that it is an astrological website, not truly astronomical. The operator does not seem sufficiently knowledgeable regarding astronomy or mathematics.


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