Tuesday, October 10, 2006

Suspended Animation - Pleiades Occulted

Session name: 20061009.2340
Equipment: Takahashi 22x60 binoculars; Homemade 6" F/6 reflector, a.k.a. Harry
Location: Starbucks, 57th Street, NYC
Moon Age/Illumination: 17.6 days/87.1%
Conditions: Clear skies, slight haze.

Even though this was an occultation event, I could not help but admire Moon in the clear, crisp Fall night. Mare Crisium almost engulfed by sunset projected itself with the broken western wall casting shards of light on to the mare floor. Normally described as smooth, this scene revealed a molested ground with ribbing, craters and detached hills. Light and shadow intersected. Collided violently.

And if I looked to the background stars I could see that Moon covers some ground - reasserting Galileo's whisper in another context-
"Eppur si muove". Yet caught in each moment the Moon is delicate as teardrop suspended in the space with in my eyepiece. I sort of get the same feeling naked eye, but not quite. The magic happens in the eyepiece.

Prior to the event I copied John Pazmino's timeline for the event and planned around that. His information appears as follows, copied from PazMiniBits, Oct 2006 obtained from the NYSkies Yahoo group.

Lunar occulttn of Pleiades on 06 Oct 9-10. Timetable is in EDST
for NYC, Flamsteed numbers are: Celaeno = 16 Tauri, Electra = 17
Tauri, Taygeta = 19 Tauri, Maia = 20 Tauri, Asterope = 21 Tauri
EDST Event Remarks
----- ---------------- ------------------------------
19:45 moonrise 87% illuminated, 137W elongation
00:00 Electra ingress 86d from S cusp on bright limb
00:09 Celaeno ingress 59d from N cusp on bright limb
00:37 Maia ingress 66d from N cusp on bright limb
00:40 Taygeta ingress 27d from N cusp on bright limb
01:05 Asterope ingress 24d from N cusp on bright limb
01:06 Electra egress 68d from S cusp on dark limb
01:12 Celaeno egress 76d from N cusp on dark limb
01:21 Taygeta egress 44d from N cusp on dark limb
01:43 Asterope egress 40d from N cusp on dark limb
01:46 Maia egress 83d from N cusp on dark limb
03:31 moon transit

Times by my wristwatch. Actual timestamp may not be accurate, but the intervals between events should be close. When an event is indicated that I saw it, a margin of error from 1~2 seconds may exist from spotting the event and then looking to the wrist for time.

Takahashi 22x60 bins, tripod-mounted
00:01:29 - Electra disappears, up to pimpling on limb, time stamp to when I thought "D"
00:10:18 - Celaeno disappears, difficult, lost in the glare as it approached limb

Harry, 6" F/6 reflector,
00:39:06 - Maia disappears,
00:41:39 - Taygeta disappears
01:02:21* - Sterope I disappears,
v. difficult, lost in the glare as it approached limb
01:05:42* - Sterope II disappears, v. difficult, lost in the glare as it approached limb
01:07:33 - Electra reappears, bang!
01:14:45* - Celaeno reaapears, did not see the blink on, because I was taking photographs.
01:22:29 - Taygeta reappears - bang!
01:44:01 - Sterope I reappears, bang!
01:47:35 - Maia reappears, bang! After I saw Maia reaapear I noticed a dimmer star to the west.
01:53:24 - Sterope II reaapears, bang!

Asterisks indicate a degree of uncertainty or a greater degree of error. All the reaapearences were "snap on", except Celaeno.

I observed the last two reappearances at 135x & 34' field of view using a TV Nagler 7mm T6. Sterope II sort of felt drawn on - it still blinked but I had a sensation that it had gradual brightening versus the others that I had seen.

After the event was over, I spent some time walking along the crater rims of Atlas and Hercules. I descended into the crater inside of Hercules, trying to avoid the blackness but no use. Eventually I arrived at the southwestern wall climbing back into the light. There was another craterlet sitting atop of the rim. Imagine perched on top looking to the northeast and the horizon falls away hiding Atlas from my view.

As I mentioned earlier Mare Crisium was fabulous. M. Crisium also has craterlets along the top of its rim. I counted three. Is there anything more striking than Mare Crisium in sunset?

(maybe Altai Scarp in sunset)