PROJECT BLUE BOOK

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PROJECT 10073 RECORD
. DATE · TIME GROUP LOCATION
7 Dec 66 7 Dec 65 8/0515Z 8/05152 Denver, Colorado Denver, Colorado three witnesses chree wlchesses
3. SOURCE 0. CONCLUSION 10. CONCLUSION
Civilian Astro(Sirius) Va Jif Jrut
4. NUMBER OF OBJECTS NUMBER OF OBJECTS At the time of the sighting Sirius was on an azinuth At the time of the 'sighting Sirius was on an azinuth
of 123 degrees and of 123 degrees and at an elevation of 14 degrces. an elevation of 14 degrees.
One
S. 5. 1 LENGTH OF OBSERVATION LENGTH OF F OBSERVATION 11. BRIEF BRIEF SUMMARY SUMMARY AND ANALYSIS AND ANALYSIS
2 hours
6. TYPE OF OBSERVATION Observers watched a star like object larger than a star
Ground Visual Tx The objects size and brightness was amazing, for if another
7. COURSE star was the size of a pin tip, this object would be the
size of the pin head. It was about five to lo times brighter
ERRatic movements than a regular star. Object could have been a star, but
3. PHOTOS the observer said that he did not think it was a star.
Yos The description is consistent with that of an astrononical
No observation. Sirius would have been fairly low on the
2. PHYSICAL EVIDENCE horizon and wouli have been the brightest astrononical
Yes body in the sky.
No
FORM
CTD SFP43 0-329 (TDE) Previous editions of this form may be used.
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Deax
Reference your letter of 30 December 1966 regarding your obser-
vation of an alleged flying object over the Denver area. A study of
vation was undertaken and revealed that you probably observed the
star, Sirius. The description, size, brightness, movements, etc are
very consistent with that of an observation of that particular star.
Sirius, with a stellar magnitude of approximately -l.5, is the bright-
est star visible in the heavens.
When stars are viewed low on the horizon the observer is looking When stars are viewed low on the horizon the observer is looking
through many more miles of the earth's atmosphere than when looking
at stars overhead. The earth's atmosphere actually acts as a prism,
which in effect causes the incoming rays of light to be broken down
into the various colors of the spectrum. " In technical terns this
phencmena is called scintillation. The closer the stars are to the
horizon, the more they scintillate, simply as mentioned above, because
we are then looking through a thicker layer of air. The most beautiful
scintillation of all is that of the bright star, Sirius, which is
visible in the winter months rather low in the sky. Planets scintil- visible in the win
late for-less than stars. late for less than stars.
From the information submitted it does appear that Sirius was
observed. The Air Force has received several reports during the months observed. The Air Force has received several reports during the months
of November and December describing similar observations such as yours.
In Saficu 20tabeg
8

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Pryict Be totk nte.ice 20220
Safoi
Washington, DC. 20330 Washingon,d!C: 20330 .
Gear Lirs: Jear Lirs:
Ihave writter a report which may be Iave ittea eport whic mayb
an Unidentifed Alying Object, I would Thiect.I would
.
-
9

No 1: rip and dowe ement, lack tooviginal
lace; #2: someuhat same astone, brut indirect
mine hes then 4
specially star of Big ipp Hee  u
acts of first sighting
. . .
.

. /
g Supplementary
It is about
inches to right(measvedon indow.
- sige
SHONIL S7HONIL 5 INEES OBJECT / STAR OBECT STAR
X F 3 INCHES
object travele as much objedt travele as much as 6 inches in one time
dark part of moon not seen
OBJECT ARROWS. SHOW
WABVESENT
1 ix. OBDECT -
3.g
4. OBJECT Y

Reference your letter regarding your December 7 observation of an
alleged flying object over the Denver area study of the information
which you sucmitted was undertaken and that you procably observed
are very consistent with an observation of that particular star. Sirius,
with a stellar magnitude of approximately -l.5, is the brightest star
visible in the heavens.
When stars are viewed low on the borizon the observer is looking
through many more miles of the earth's atmosphere than when locking at
stars overhead. actually acts as a prism, which
in effect causes th e incoming ra ays of light to be broken down into the
various colors or spectrum. This s phenomenon is called refraction.
Another phenomenon, relating to variations in light intensity, is known
as scintillation (twinkle). The closer the stars are to the borizon the
more they scintillate because we are then locking through a thicker layer
of air. The bright star, Sirius, which is visible in the winter months
GEORGE P. FREEMAN, JR.
Lt Colonel, USAJ
Chief, Civil Branch *
Coommunity Relaticns Division WI
3
Office of Information :
COORDINATED By (Office Symbol, Name, Grade, Date) -Geord cy - SAF-OIC
I SAFOL- C Combk cy - SAF-OIC
SAVOI- Reader cy - SAF-OIC.
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