پــایــگــــــاه اطــــلاع رســـــانـــی هــــلال مـــــاه

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امروز : پنجشنبه مورخ 6 آبان 1400 هجری شمسی ، مطابق با 21 ربیع الاول 1443 هجری قمری ، مطابق با 28 اکتبر 2021 میلادی

گزارش بسیار مهم جیمز استم از رصد هلال رمضان 1435

New Moon Crescent Observation Report

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Observed:   Friday; June 27, 2014  -  19:47 (Local)

Location (WGS 84)     = Tucson, Arizona (USA)
   Longitude = 110.9525 W
   Latitude  =  32.3886 N
   Elevation = 837 meters
   Time Zone = -7.0 hours

Surface conditions at location:
   Temperature =  34 °C
   Humidity    =   9  %
   Pressure    =  29.88 in.

This observation was under the clearest and steadiest sky that I can remember.  The usual 2 degree wide band of translucent atmosphere along the horizon was not evident.

Topocentric and local time values from “Accurate Times”:
   Sunset (at sea level)   =  19:40
   Moonset (at sea level)  =  19:54
   Time from new moon at   19:47   =  18 hr. 54 min.
   Moon lag time                   =         14 min.
   Relative Altitude               =    2.5  degrees
   Elongation from sun             =    9.7  degrees
   Crescent width                  =     13  arc seconds
   Illumination                    =   0.72  percent

Crescent first observed through 8” SC telescope:
   Time   =   19:47 
   Moon Altitude  =   -0.5 degrees

Final observation with telescope:
   Time   =   19:48 
   Moon Altitude  =   -0.7 degrees

I did not invite others to join me in this observation because I did not expect to see anything, but being the Ramadan crescent, I felt compelled to make the attempt.  

I set up at a location that gave me an unobstructed horizon to under -0.3 degrees.  Jupiter at 12 degrees altitude was as clear and crisp as though it was at an altitude of 50 degrees - before the sun had set.  The bands were not distinct, but the image was steady, and there was noticeable detail on the surface,  I slewed to Procyon, but could not see that star.

I usually have to wait 12 minutes or more after sunset before it is dark enough to see a close crescent, so I checked alignment and focus for several minutes and then slewed to the position of the crescent.  The Earth (horizon) was already within the field of view of the eyepiece.  I did not immediately see any crescent, and maybe a minute later (with so little time, I failed to turn on my WWV radio) I began scanning a little back and forth in declination.  In a few seconds I saw a familiar yellowish crescent.  It was right where I had centered the scope to begin with.  I tried to improve the focus and the image disappeared.  I set the focus back to the correct numbered setting and the image reappeared, but it was more pinkish - orange this time.  It was also distinct but shorter than the first observed crescent.  I was convinced that I was seeing a real crescent (rather than those false white crescents that populate this type of observation), but as I was trying to confirm for certain, the image set behind the trees on the horizon.  At that time, I looked at my watch, and estimated first contact at 19:47 and setting at 19:48

Again, while I was confident that I had seen the crescent, two things troubled me.  If I had acquired Procyon at 1.5 degree altitude I could have been absolutely sure of my pointing and focusing.  Also, previous thicker crescents had exhibited much more arc-length under poorer skies as they set.  Primarily because of these two aspects, I can not say for 100% certainty that I saw the crescent during this observation.

Observer   :       Jim Stamm
E-mail Address:    StammJim@gmail.com


 

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