Observer: Tony Donnangelo
Date/time of observation: 2003/01/12, 00:15 U.T.
Site location: Hummelstown RD 3, PA, USA (40.26° N., 76.75° W.) 
Instrument: Takahashi FS-102
Magnification: 91x (9mm NaglerT6), 158x (Pentax 5.2mm XL),
               234x (3.5mm Vixen SW)

This was the first time I observed this ray. I began to see the ray develop approximately one hour before its predicted time. I first observed an illuminated area on the inner part of the western wall. The floor of the crater was completely dark. As the sun rose, the ray started at the western wall and began to stretch across the full length of the floor. It was narrow and slightly cone shaped. It began to widen slightly and quickly. After a short time, the widening subsided for the rest of my observation. After approximately 2 1/2 hours, the western half of the floor was illuminated, but the ray was still evident in the still darkened eastern half. It vaguely appeared to be seen slightly in the illuminated western section of the floor, also. Dave Mitsky joined me during this observation session. At 04:00 U.T., we dragged our frozen bodies into my house and called it quits for the night.

Craters Pitatus and the Hesiodus sunrise ray on October 7 05:00 UT (10:00 PM PDT). This is a 9 day old waxing moon. Telescope: 10 inch f/7.3 reflector using a 6m Vixen Lanthanum eyepiece for 309x. Pitatus is a flooded walled plain. Rimae Pitatus, the clefts within Pitatus are visible in the sketch. The ray breaks through a crumbled wall between Pitatus and the small crater Hesiodus. To me the ray appeared to curve a bit. (Rukl 54) - Jane Houston Jones

From: 
Gary Pikegary - pike@bright.net
Date: Fri, 23 Aug 1996 01:30:01 GMT
     In the July issue of Sky & Telescope is an article on a phenomena
called the Hesiodus Ray.  Philip Koch of Las Vegas, Nevada noticed a
ray shining through a break in the wall of Pitatus as the terminator
approached these two craters.
     The walls of Pitatus and Hesiodus touch each other.  The light of
the rising Sun shines through a lowspot and bisects Hesiodus.  An
article by Alan MacRobert highlights this feature and provided dates
and times from June to December to search for the Hesiodus Ray.
     I didn't read the article in time to search in June.  In July,
the sky was cloudy.  The time to search in August was listed at 0 hr
UT for the 23rd, 8:00 EDT.  I carried my ten inch F4.5 Dobsonian out
at 7:30 and began searching.  Pitatus was a challenge to see
because of the bright sky as it was still an hour away from sunset.
     I kept searching and as the evening went on, I was able to see
the shape of Hesiodus.  The top of the crater's rim was in the
sunlight.  There are a couple of bulges in the rim.  These bulges are
opposite the break in the crater's walls.  
     Using the shadows of central peaks of nearby craters, I
determined the direction of sunlight.  One of the bulges in the wall
appeared to extend towards the break in the opposite wall.  If I had
drawn the image at 0:15 UT on August 23rd, I would have drawn
a feature that extended only ten percent of the way towards the break.
     A couple of times, I thought I saw a line extend all the way to
the break, but I felt it was just my mind connecting two points.
     As the sun worked its way to setting, the sky darkened and the
Moon's features were easier to see.  At 0:32 UT, August 23rd, I saw
it.  A definite ray connecting the break in the wall and the far side
of Hesiodus.  I called a fellow astronomer who I knew would be out
looking for it.  Ron Netzley was using his copyscope and had not yet
spied it.  As we were talking, I heard him shout, "There it is!"  He
saw it at 60x.  I could see it at 128x and 230x.  At 44x, there was
something visible in the crater, but I couldn't really make out the
ray.
     So two amateurs from western Ohio were able to find this feature.
As I type this, it is 1:30 UT August 23rd.  The ray is still visible,
some sixty minutes later. 

From: 
Tom Polakis - polakis@indirect.com
Date: Thu, 22 Aug 1996 21:35:37
        An article on p. 74 of the July issue of "Sky & Telescope"
describes the sunrise ray in the lunar crater Hesiodus.  Philip
Koch of Las Vegas, Nevada noticed the phenomenon, which is the
result of a narrow beam of sunlight emerging through a break in the
crater wall, illuminating its floor.  The length of time around
sunrise on this crater that this feature can be seen is not known. 
Alan MacRobert provided a summary of prime times for the rest of
the months in 1996. 
        Last month, the time of sunrise just west of Hesiodus was
13h UT on July 24.  The best I could do in Arizona was look at
around 5h UT, as the Moon was getting low in the western sky.  The
ray was not visible, nor was the rim of Hesiodus.  It was just too
early to see it. 
        The next favorable appearance would occur on August 23 at 0h
UT, or just before sunset in Arizona.  I set up my 8-inch scope as
a desert dust storm was dying at about 2h UT.  Even though the sun
was just setting, and the seeing was about 5 arcseconds, there was
the ray, easily visible at 150x!  About all I could discern in the
shimmering image was something that looked quite a bit like Koch's
sketch in S&T.  The ray did seem a bit more centered inside the
crater, splitting the crater evenly.  Koch draws it north of the
center.  Perhaps this is due to the difference is selenographic
latitude (see the article).  Two hours later, at 4h UT, the eastern
half of the floor of Hesiodus was illuminated, which meant the ray
was no more.  All that was left of it were two symmetrical shadows
around the origin of the ray along the western rim of the crater
wall. 
        The next good opportunity to see the Hesiodus ray for North
American observers occurs on October 21, at 3h UT.  In this case,
we have a chance to see almost exactly what Koch saw.


From: 
Jeffrey R. Hapeman - jhapeman@students.wisc.edu
 
Date: Fri, 23 Aug 1996 00:47:19
I also caught the Hesiodus Ray, although by the time the clouds
cleared enough for me to observe, it was more of a 'Hesiodus Cone'
than a thin ray. I'm located in central wisconsin, and the clouds did
not clear here until about 4:30UT, August 23. One nice thing was to
look just a little distance north from Hesiodus into Mare Nubium,
wher Rupes Recta, the 'Straight Wall' was clearly visible. Two lunar
treats in one night! --

From: 
Jay Reynolds Freeman - freeman@netcom.com 
Date: Fri, 23 Aug 1996 08:12:17 GMT
  I am glad someone had success.  I was observing from Palo Alto, California,
at almost exactly the times reported (from about 0015 through 0045 UT,
23 August 1996), but because of full daylight, slight haze and poor
seeing, I could not see much of any detail along the terminator.  I was
using a 60 mm refractor at 41x, 70x and 117x.  With this instrument I
had seen the ray on June 24, rather late in its apparition (clouds had
blocked it earlier).  I was hoping for a better view, but I guess I will
have to try October.

From: 
Jay Reynolds Freeman - freeman@netcom.com
Date: Sun, 20 Oct 1996 22:49:43 -0700
I observed the Hesiodus ray on the evening of 20 October, 1996,
from my yard in Palo Alto, California, using a 102 mm f/9.8 Vixen
refractor (conventional doublet) at 250x.  Seein was such that the
Airy disc of a fifth or sixth magnitude star showed continuously,
but that the first diffraction ring rarely showed at all.
    At 0330 UT 21 October, 1996, the ray extended all the way across
the floor of Hesiodus, which was still in shadow, although the western
part of it was beginning to brighten, even as I watched.  The ray was
interrupted about a third of the way from the origin (at the Pitatus
end) to the western wall of Hesiodus.  At 0430, when I looked again,
the shadow of the eastern wall had withdrawn about a third of the
way across the crater floor, but the ray was still well-defined
in the shadowed area, and still intermittant at approximately the
same place on the crater floor.

From: 
Jeffrey R.Hapeman  
Date: Mon, 21 Oct 1996 07:45:21 -0500
I observed the Hesiodus ray from approximately 0250 UT to 0315 UT
from the front yard of my residence in Madison WI. At that point clouds
interrupted the viewing. The seeing was good, but I was pushing the limits
of my 70mm f/6.8 Pronto at 200x. The ray did not become visible until about
0255 UT form my position, and slowly grew across toward the western wall of
Hesiodus. By 0314 UT, just before the clouds rolled in, the ray could be
seen extending nearly all the way across the floor of Hesiodus, and the
eastern wall and floor of the crater were beginning to become illuminated.
Like Jay, I also observed a small break in the ray about 1/3-1/4 the
distance of the western wall of Hesiodus (near Pitatus). Upon returning
indoors, I checked the July issue of Sky and Telescope, and found that what
I saw was nearly identical to the sketch made by the ray's discovere, Mr.
Koch. Upon checking the chart, I was this was not surprising as the moon
was in nearly the same relative position to the sun and the earth as when
he observed the ray first in 1988.
        I would say the appearance of the ray was much different than my
last observation in August, when the ray appeared much more cone-like. This
time the ray was thin and dagger-like, slicing across the dark floor of
Hesiodus. Very impressive! And of course, while I was there, I took the
time to take a quick glance at Rupes Recta (like last time), a favorite
lunar site!


From: 
freeman@netcom.com (Jay Reynolds Freeman)
Date: Thu, 19 Dec 1996 07:46:00 GMT
    Despite a cold and the prospect of having to get up early, I
stayed up late enough on December 18-19 to watch the start of the
Hesiodus ray apparition from my yard in Palo Alto, California.  Seeing
was pretty good -- diffraction rings around Polaris were continuously
visible, but continuously in motion, in my "Baby Brandon" 63 mm f/5.6
refractor at 141x.  I was using my Vixen Lanthanum 2.5 mm eyepiece for
the first time with this instrument; it worked very well, and gave
sharp images all the way across the field.  The Brandon was doing a
fine job as a "quick look" telescope.
    At about 0655 UT 19 December (1055 PST on the 18th), Hesiodus lay
with its bright-rimmed bowl almost completely filled with darkness,
but the gap in its wall into Pitatus was clearly visible, as was the
bright spot on the opposite wall of Hesiodus where sunlight was
already streaming across the crater.  Over the next 25 minutes the ray
developed, starting at the west wall and growing back toward the gap
at the east, narrow and fine, wider at the west than the east.  By the
time I went back inside at 0720 UT, it was at least 75 percent of the
way across the crater, and a little south of center.  The ray was not
sharply defined; larger apertures may have seen more of it than I did,
or sooner, or both.