The Moon, just a day past first quarter, will occult dozens of
stars in the Pleiades for observers throughout western North America
late Sunday night, February 5/6. The UT date is Feb. 6 for all
events, but it is late Sunday evening, or just after midnight, local
time. Extensive predictions of the total occultations are on the
main IOTA Web site at http://www.lunar-occultations.com/iota or,
specifically for the occultations of the seven brightest Pleaides
stars predicted for hundreds of cities, including maps showing the
region of visibility of each occultation, see
http://www.lunar-occultations.com/iota/200...am/pleiadna.htm and
click on "view" for each event in the "predictions" column of the
table.

If you can locate yourself within a mile or two of the northern
or southern limits of the region of visibility of these
occultations, you can see a spectacular grazing occultation, with
the star disappearing and reappearing amoung mountains and craters
in the lunar polar regions. The northern limits of 4 3rd and 4th-
mag. stars during the Feb. 6 (UT) passage are shown on my map on p.
71 of this month's issue of Sky and Telescope. You can see these
and 4 other graze paths on Charlie Ridgway's Web site at
http://digitalmagic.i8.com/Astronomy/Occul...060206_M45.html
which is an interactive map that you can zoom in for much more
details, like the ones he has for asteroidal occultations.

I have captured and posted that map on my Web site in a Word file at
http://iota.jhuapl.edu/pld6fbna.doc (beware, the first page is
blank; the 2nd has the color code key; and the third page has the
map) and have some more detailed maps of the Electra graze path
across southern California in another Word file at
http://iota.jhuapl.edu/6fbelect.doc . For the individual grazes,
it's better to go to Charlie's general Pleiades graze page at
http://digitalmagic.i8.com/Astronomy/Occul...Grazes/M45.html
and click on the link for the graze for which you want more details.
Then you can see the plot with an offset distance in km that you can
specify. Also on the page for each event, below the map, is the
table of WinOccult predictions (in a zipped Word file) for the
event; you can use it to tell the U.T. of central graze at your
longitude, as well as the altitude and azimuth of the Moon, and
other information.

Later I will give some advice for some of these events
about where the best area will be relative to the limit lines shown,
and to correct them for height above sea level (they shift south as
your height increases). If you are planning an expedition to
observe one of these, let me know at dunham@starpower.net and I'll
include an estimate of the best offset for your area.

The graze of 9 Tauri, visible along a path from northern Baja
California to Louisiana and the only southern-limit graze, actually
occurs a few hours before the Pleiades passage but is included since
it occurs the same night. The grazes are listed below; there are
some other grazes of 8th-mag. stars that won't be as easy, but
predictions can be made available for them, too.

R west Approximate
ZC# mag. # Lim U.T. path location Star name

521 6.7 30 S 2:36 n. Baja Calif. - Louisiana 9 Tauri
537 3.7 31 N 8:01 s. Calif. - n. Mexico Electra = 17 Tauri
545 4.1 32 N 8:21 Brit. Columbia - S. Dakota Merope = 23 Tauri
549 6.3 33 N 9:03 n. Calif. - Arizona 24 Tauri
551 7.4 -- N 8:46 Alberta - Saskatchewan
552 2.9 34 N 9:06 s.w. Oregon - Arizona Alcyone = eta Tauri
560 3.6 35 N 9:37 Brit. Columbia - Montana Atlas = 27 Tauri
561 5.0 36 N 9:47 Oregon - Nevada Pleione = 28 Tauri

The first column gives the star's Zodiacal Catalog number. The 3rd
column, "R#", is the number of the graze line on the lower map on
p. 164 of the 2006 RASC Observer's Handbook. "Lim" tells whether
the graze is a northern-limit or southern-limit graze (all except
the first one, ZC 521, are northern limits). "west U.T." gives the
Universal Time of 2006 Feb. 6 at the western end of the path,
usually near the Pacific coast; the time is always later farther
east. Note that the times are of central graze; the graze will last
2 - 4 minutes, so observers should start watching 2 to 3 minutes
before the central graze time for their area.

David Dunham, IOTA

home dunham@starpower.net 301-474-4722 cell 301-526-5590
office david.dunham@jhuapl.edu 240-228-5609