TYCHO

TYCHO

L.T.P. EVENT

10 DECEMBER 1990

11:03 TO 12:49 UT

DAVID O. DARLING

My observing session began at 10:31 UT and I started by examining the craters Aristarchus and Copernicus. I detected nothing unusual with these two formations and moved to the crater Bullialdus and detected nothing unusual there. It was at 11:03 UT that I panned my telescope a (12.5 f5 Cave Newtonian at 63X magnification) over to the crater Tycho.

11:03 UT: The crater Tycho was located along the sunset terminator, the crater was is almost completely filled with shadowed. I can see inside the crater a nebulous region where the central peak is located. Its not a sharp point of light but a soft and glowing patch. It reminds me of a comet nucleus.

11:08 UT: The location of the diffused glow is definitely the central peak. It still remains diffused and not star like in a appearance, it reminds me of a fuzzy little patch. The color appears to be non existent has the appearance of mother of pearl or white glow. I am debating it its the tip of the mountain catching the sunlight. The shadow has nearly filled the crater except for the eastern rim.

11:15 UT: For a brief moment I glimpsed a star like light appearance inside the nebulous patch. It last only for a second and then returned to the comet nucleus appearance. At this time I can also see an arc of light extending over the central peak and connecting to the north wall.

11:16 UT: Leaving the observing site.

11:40 UT: Have returned to the telescope and once again examining the crater Tycho. I see that the central peak is still glowing like a comet nucleus and it still remains as bright as when I first saw it. There is still no star like appearance of the central peak.

11:42 UT: Leaving the observing site.

11:55 UT: Returned to telescope the central peak of Tycho still has fuzzy star appearance. The nebulous patch does appear to vary slightly in size as I watch it. At this time I would say that 90% of the interior of Tycho is shadowed filled except for the eastern rim.

11:59 UT: Departing observing site to load camera with film.

12:05 UT: Tycho central peak continues to remain nebulous. I have loaded my Minolta SRT 101 with High Speed Ektakrome ASA 400 slide film to attempt to get some pictures.

12:16 UT: I took four photographs of the crater Tycho. I examined the crater again and found that the central peak still had the appearance of comet nucleus. I can also see the arc of light again. The sky is starting to get light in the East and it will be getting brighter soon. I decided that I must be witnessing a true L.T.P.

12:20 UT: Leaving the observing site.

12:32 UT: I examined the crater Tycho again and continue to find that the central peak continues glow like a comet nucleus. The seeing is getting worse with the approach of sunrise. To make sure what I was seeing was not the results of poor seeing I monitored some mountains to the East of the Straight Wall. During the whole observing session until they disappeared in the shadow and they remain like stellar points, not behaving like the central peak of Tycho.

12:49 UT: I made on last observation of the crater Tycho and the fuzzy appearance of the central peak was still there.

Below is the my drawing of the phenomena as it appeared in my telescope.

The photograph was taken at 12:15 UT using the 12.5 F5 Newtonian Reflector using 10mm eyepiece projection. The exposure length was 3 seconds. The photograph unfortunately I was unable to detect the faint arc of light or the fuzzy appearance of the central peak

SOLAR TERRESTRIAL ACTIVITY REPORT

When examining the solar data I found that the Planetary A index was not active but the Sunspots and Solar Flux was very energetic.