67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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The "Lunar X" (Werner X), will be observable from North America starting Friday Night, August 8, approx. 2306 UT. Good luck viewing and photographing the "X-shaped" lunar illumination near the terminator!
Dana T
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Hi Dana,
I was just passing through when I saw this notice and thought I'd give it a look. The seeing was quite unsteady and the Moon low, but still, not too bad for a first-timer.
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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Tommy5
Pooh-Bah
Reged: 03/28/04
Posts: 1382
Loc: Chicagoland
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Nice capture Phil, i saw this event tonight as well thanks for posting.
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dmdouglass
member
Reged: 12/23/07
Posts: 89
Loc: Tempe, AZ
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Phil, many thanks. I was trying to find a reference as to the location of this object, and you came through perfect.
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David M. Douglass
Tempe, Arizona
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Thanks, Tommy and David. First time I've been able to see it, although I have heard about it previously.
I wonder if Dana might discuss the source of the visibility timetable. I understand it's based on the terminator's precise lunar longitude, but my question is, what program/web site did you use to come up with your original post?
Thanks!
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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Jim Mosher
sage
Reged: 05/22/06
Posts: 228
Loc: Newport Beach, CA
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Phil,
According to the information collected on the-Moon Wiki, the appearance of the X is controlled by the Sun's altitude over a point on the Moon's surface at about 0.9° east longitude and 25.2° south latitude. Various observers have reported seeing a "perfect" X when the Sun's altitude above the horizon (at that point on the Moon) is anywhere from about -2° to 0°. At the time of your photo, the Sun was at an altitude of -0.06°, which I guess the more expert observers would regard as near where the X starts to merge with its surroundings. You can see examples of what the X looks like at several sun angles on the Wiki page and elsewhere.
I don't know the exact source of Dana's predictions, but there is a quite suitable Moon Event Predictor in the freeware LTVT software. Simply go to the "Sun Altitude" mode, enter 0.9 for the target longitude, -25.2 for the target latitude and -1 for the target sun angle, or better ask the software to calculate the altitude (-0.06) and azimuth (89.96) of the Sun at the time of you observation. "Filter" the output, if you wish, to suppress the events with the opposite solar azimuth (that is, sunset, rather than sunrise, events).
The next repetition of the -0.06° lighting shown in your photo (it is visible somewhere on Earth every month) will be on September 7 at 11:51 UT. Weather permitting, the next repetition visible from Long Island, NY will be on October 6 at 23:37 UT, with the Moon 20° above your horizon (very slightly better than last night). An hour earlier that evening, at sunset, you should be able to see the Lunar X illuminated at the slightly more "perfect" sun angle of -0.6°. Dana seems to be giving the times when the sun angle is a still more perfect -1.0° (which, in October, as it did this month, will occur before sunset from your location).
-- Jim
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Tom and Beth
sage
Reged: 01/08/07
Posts: 429
Loc: Tucson, AZ
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By the way, you don't HAVE to have dark skies in order to observe this phenomenon. Yesterday's event was at 4 in the afternoon (Tucson, AZ) and easily visible even in the finder.
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desertstars
Deja moo
Reged: 11/05/03
Posts: 29970
Loc: Tucson, AZ
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Quote:
By the way, you don't HAVE to have dark skies in order to observe this phenomenon. Yesterday's event was at 4 in the afternoon (Tucson, AZ) and easily visible even in the finder.
You saw the Moon yesterday?
From Tucson???
I must live in the wrong part of town... 
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Tom W.
SVP8 'She turned me into a 3-legged Newt' EQ
Ralph, the All-Purpose 102mm Refractor
Under the Desert Stars
"If we don't change direction soon, we'll end up where we're going." Professor Irwin Corey
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Tom and Beth
sage
Reged: 01/08/07
Posts: 429
Loc: Tucson, AZ
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Quote:
Quote:
By the way, you don't HAVE to have dark skies in order to observe this phenomenon. Yesterday's event was at 4 in the afternoon (Tucson, AZ) and easily visible even in the finder.
You saw the Moon yesterday?
From Tucson???
I must live in the wrong part of town...
Not sure if you're on the wrong side of town, but I'm on the SE part of town North of the Fairgrounds.
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Quote:
I don't know the exact source of Dana's predictions, but there is a quite suitable Moon Event Predictor in the freeware LTVT software.
Excellent, Jim! That's just what I was looking for. I just d/l'ed it and ran it through as you described to generate a list of coming appearances. Doing a quick check against another source, it appears to line up very well. I don't need predictions to the minute; I think to the nearest quarter hour should be fine.
Great tool you created there! Bravo! 
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Phil,
I'm very pleased you finally captured it! I typically post predicted times where "sun alt" is 1.2 at crater Werner, as calculated by my spreadsheet program reworked from a BASIC program from George Rosenberg of ALPO.
Jim, thank you very much for the wiki note. That's the best info on the web right now concerning this optical event.
Dana T
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Quote:
By the way, you don't HAVE to have dark skies in order to observe this phenomenon. Yesterday's event was at 4 in the afternoon (Tucson, AZ) and easily visible even in the finder.
You are correct, but it helps. Try imaging it in the daylight!
 
dt
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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Dave Chapman
member
Reged: 01/27/07
Posts: 17
Loc: Halifax, Nova Scotia, Canada
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Nice observations and pictures, folks! A rough approximation for the event is when the selenographic colongitude equals 358 degrees. I consult the RASC Observer's Handbook which gives the s.c. at day 1.0 of each month, then count forward 12.2 degrees per day. For October 6, I calculate 22h 55m, but I would certainly start looking a couple of hours before that.
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Dave 17 of the Royal Astronomical Society of Daves
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Thanks Dave!
Phil, Dave's the man on this subject. He had collected a lot of data on this a couple years ago.
I just try to keep the interest up and inform people who have never heard of it, because I'm STILL obsessed with it... (sad but true) HA-HA.
I only have one over on Dave, I saw it before he did!  LOL
dana t
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4120
Loc: illinois, usa
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Great info Dave. I just happen to have the RASC Handbook in reach.
VMA concurs with a solar inclination of -1.3°. Three hours earlier
(terminator inside Werner's east wall) gives a colong of 356.4°.
I'll be watching for the exact VMA offset.
Dana: It's a worthy obsession. Thanks for keeping it alive here.
Saber Does The Stars at
www.astronomyblogs.com/member/saberscorpx/
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Thanks Saber.
dt
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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Ishtim
super member
Reged: 11/10/07
Posts: 162
Loc: N. Alabama, USA
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X marks the spot. 300D & 14" LX200 @ prime (cropped)
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Nice job. I think you captured the Lunar "V" as well...
dt
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
Edited by 67champ (08/17/08 01:23 PM)
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Quote:
Nice job. I think you captured the Lunar "V" as well...
Very cool! That's a new one on me. Just took a look at one of my shots and sure enough, it's there.
Okay, so tell me, *what* is it (the V)?
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Hi Phil,
Carol????? You know this don't you??? Isn't it "the horn(s)" something....? If no body ID's it tonight I'll look it up and post sometime Monday...
dt
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Phil,
AND, the "other" COOL illumination is what I call the Curtiss Cross (Named after Robert Curtiss of New Mexico) who took what I believe is the first photograph of it back in the 1950's:
The "Curtiss Cross", X-shaped lunar illumination (similar to the first quarter lunar X) is located between craters Parry and Gambart. It is an "X" shaped or "cross" shaped illumination that can be seen near the terminator, thanks to the low angle of lunar sunset and the topography of this area (with the aid of a telescope of course).
This "X" or "cross" may not be quite as obvious in contrast to the dark side of the terminator as the First Quarter Lunar X, but it is just as fleeting of a optical event and it is definately something to look for in my opinion. Appears at approx. 194 Co-Long. (After last quarter phase).
PM me if you want more info...
dana t
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4120
Loc: illinois, usa
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The Lunar V is formed by the east wall of Ukert and adjacent angled mountain ridge. [Rukl's 33]
Nice catch guys.
http://the-moon.wikispaces.com/Ukert
Saber Does The Stars at
www.astronomyblogs.com/member/saberscorpx/
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Yep, you got it Saber. Now is that nicknamed something with "horn" or "horns" in the name, or am I thinking of something else?
dt
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Quote:
The Lunar V is formed by the east wall of Ukert and adjacent angled mountain ridge. [Rukl's 33]
Excellent, Stephen! Thank you.
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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Carol L
Reged: 07/05/04
Posts: 5880
Loc: Tomahawk, WI 45N//89W
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Hi Dana, yes I have this one.. had to dig into my pics to find it. 
Ukert M is the larger upper central hollow in the 'V', and the lower one is Ukert N. Crater Ukert itself is the shadowed arched curve on the lower left side of the 'V'.
And to round things out, here's my 'X' pic from the same night.  (Had I known Chuck was going to use my email as the LPOD text, I'd have written something a lot better.  )
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 *Step-by-Step Lunar Sketching*
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8"SCT ~ 120achro ~ 90Mak ~ 80ST ~ 11x70s ~ 22x100s
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67champ
sage
Reged: 07/03/06
Posts: 324
Loc: Ohio, USA
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Carol, Very good! I thought you did a fine job on the LPOD text. Maybe it was on a different site, but I know someone had another name for this "Lunar V", and it was something "horns" or "horns of " something...? (anyone recall?)
dana t
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"To the Moon!"
Orion 127mm Mak-Cass
Meade 60mm Refractor
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