From: LARRY KLAES (ljk4_at_msn.com)
Date: Mon Jul 17 2006 - 08:09:52 PDT
>From: David Dunham <dunham_at_starpower.net>
>Subject: AstroAlert: Spectacular Pleiades passage, probably grazes near
>you, July 20 am
>Date: Sun, 16 Jul 2006 22:15:45 -0400
>This Is SKY & TELESCOPE's AstroAlert for Occultations
>Spectacular Pleiades Passage by crescent Moon Thurs. am, July 20,
>eastern N.America, Caribbean
>The Alcyone graze is one of the best of 2006 in the USA, with the
>path passing from Texas to Michigan and Ontario; expedition planned
>to observe Alcyone & SAO 76249 grazes near Gaines, Michigan, s.w. of
>Flint, in the zone where the 2 graze paths overlap; there are many
>other grazes, probably one near you (especially, grazes of Atlas in
>British Columbia n.w. of Vancouver; of Pleione near Ogden, UT; of
>Merope n. of Omaha and near Minneapolis; and of 6th-mag. 24 Tauri
>near or over Louisville, Cincinnati, Columbus, & Akron) - NEW Web
>sites are given for detailed path plots via google maps.
>Also, TONIGHT there will be an occultation of 4.6-mag. epsilon
>Piscium (ZC 146) by the 56% sunlit waning Moon. The northern-limit
>graze path crosses eastern S. Dakota and central Minnesota (passing
>very close or over parts of Duluth, but more likely over Superior,
>Wisc.) at about 5:45 UT (12:45 am CDT). You can see it on the map
>on p. 71 of the Jan. issue of Sky and Telescope; a total occultation
>reappearance on the dark side will be visible from most of eastern
>North America, with predictions given in the RASC Observer's
>Handbook, and for some more North American cities on IOTA's Web site
>at http://www.lunar-occultations.com/iota .
>At the end I give some preliminary information about two good
>asteroid occultations next week is also given, one visible from
>eastern Virginia and the other from a path extending from Wyoming to
>Chicago, s. Mich., & s. Quebec.
> General information about the occultations of bright Pleiades
>stars Thursday morning, July 20, can be found on pages 68-69 of this
>month's Sky and Telescope and on IOTA's main Web site at
>http://www.lunar-occultations.com/iota/2006plnam/pleiadna.htm . The
>latter gives predictions of total occultations of the brightest
>Pleiades stars for hundreds of North American cities.
> My map on page 71 of the January issue of Sky and Telescope
>shows the paths of the four brightest Pleiades stars crossing North
>American on July 20, including the northern limit for the
>spectacular graze of 2.9-mag. Alcyone from central Texas to Quebec.
>Many more paths, of stars down to mag. 7.5, are in the RASC
>Observer's Handbook for 2006. But these are small-scale maps; more
>detailed maps are needed to get into the graze zones, which are only
>about 2 km wide.
> Interactive Web-based google interactive maps for several
>Pleiades grazes are on two Web sites; you can use them to zoom in on
>the paths to see exactly where they cross minor local roads, and
>the paths can even be superimposed on satellite or aerial
>photography. Unfortunately, Charlie Ridgway's site, mentioned in
>the July issue of Sky and Telescope, can no longer be updated and
>has no information about the July 20th Pleiades grazes. Most of the
>graze paths can be found on Derek Breit's Web site at
>but some in the northeastern USA can be found instead on Brad
>Timerson's Web site at
>Timerson's site includes the interactive path maps for the grazes of
>SAO 76188, 76191, and 76236; others are on Derek's site. If the
>path you need is not on these sites, Derek Breit can add one if you
>send him a request at breit_ideas_at_hotmail.com .
> If you want to try one of the Pleiades grazes in your area, let
>us know so we might help you set it up, and possibly find some more
>observers who might help you. I'll distribute other expedition
>plans as they become available.
> There are other very good grazes, but the best during the
>passage will be the one of the brightest Pleiad, 2.90mag. Alcyone,
>whose path starts in central Texas, then crosses s.e. Okla., n.w.
>Ark., s.e. Missouri (not far s. of St. Louis), s. Ill., Ind. (near
>Lafayette & Howe), s.e. Mich. (over Flint), and Ont. (Bruce Peninsula
>and on northeast from there). Bob Sandy, bobgraze_at_planetkc.com,
>will probably try to observe it from Illinois or Indiana, while Hal
>Povenmire and I plan to try to observe it from sites just west of
>Gaines, Michigan, about 15 miles s.w. of Flint and about 50 miles
>n.w. of Detroit. We selected this location because from locations
>w. of Byron to the western and northern suburbs of Flint, the 2-km-
>wide zone of visibility of the Alcyone grazing occultation overlaps
>by over 80% the zone of visibility of another graze, of 7.5-mag. SAO
>76249 that will occur an hour and 8 minutes after the Alcyone graze.
>You can see this intersection zone on maps that Derek Breit has
>posted at http://www.poyntsource.com/BREIT_IDEAS/Gaines.htm . Our
>expedition will meet at 2 am EDT July 20 at the intersection of Ray
>Rd. and S. County Line Rd., several tenths of a mile west of
>downtown Gaines. On the DeLorme Atlas for Michigan, S. County Line
>Rd. is labelled Sheridan Ave.; it marks the boundary between Genesee
>County to the east and Shawassee County to the west. I have
>annotated (to mark the meeting place) a copy of the detailed map of
>the graze zones on Breit's Web site and will post that on my Web
>site at http://iota.jhuapl.edu/exped.htm tomorrow (Mon.) afternoon.
>The observation sites will extend westward from the meeting place
>for one mile along Miller Rd. (the name of Ray Rd. in Shawassee
>County) and for about 0.6 mile south from the meeting place along S.
>County Line Rd. (or Sheridan Ave.). There are many other roads that
>could be used in the large overlap graze zone from s.w. of Gaines to
>Flint, but the aerial photography on the local live web site shows
>many houses along those roads, the area is more suburban than rural;
>the selected roads have fewer houses than the others (I hope to
>arrive early enough to alert the residents of some of them, at least
>the ones closest to the road that might detect us). Besides the
>grazes, there are, of course, many total occultations that those who
>get set up in time can observe; a few of them are listed below, as
>computed for the observation sites just described (all
>reappearances, R, are on the dark side of the 23% sunlit Moon):
>2:33 1st R, 7.9-mag. SAO 76103, alt. 6 deg.
>3:04 D of 4.1-mag. Merope on bright side, alt. 11 deg.
>3:49-53 Alcyone graze, cusp angle 13N, alt. 19 deg.
>4:56:02 R of 3.6-mag. Atlas
>4:56:53 R of 5.1-mag. Pleione
>4:57-61 SAO 76249 graze, cusp angle 14N, alt. 32 deg., Sun -13 deg.
>4:59:19 R of 8.0-mag. SAO 76237, cusp angle 48N (this is near the
> center of the SAO 76249 graze period so ignore it if you are
> observing visually; video observers might want to try to get
> their field of view positioned to image both events)
>5:26 R of 7.0-mag. ZC 570, Sun alt. -8 deg. -last July 20th event
>There are many other events that will be in a text file that I will
>post on my Web site given above tomorrow afternoon. We expect to
>keep one station set up at or very near the meeting place, so
>depending on what you want to observe from the list above and your
>setup time, you can arrive when you want. We don't know how cell
>phone coverage will work in that area; you can try mine at 301-526-
>5590; Hal Povenmire's at 321-794-0807, or Wayne Warren's at 301-518-
> Mobile observers anywhere along the path across Michigan, and
>with a little more difficulty in Indiana and possibly Ontario or
>even e. Illinois, might also be able to observe both the Alcyone and
>SAO 76249 graze, if they can move their equipment between the two
>events in the 64 min. between the end of the Alcyone observing
>period and the start of the SAO 76249 one. We decided to use the
>major overlap zone in the area of Michigan described above since I
>want to set up some unattended stations that I wouldn't have time to
>move in other areas (this way, I can get both grazes with them), and
>others don't want to miss some total occultations that will occur
>during the time between the two grazes.
> The Accuweather forecast for Flint, MI for the time of the
>graze calls for about 50% clouds, which in my view is that they
>don't know what will happen, just can't predict with any reliability
>yet. I will be leaving home in Maryland, and possibly last chance
>for e-mail contact, at about 10 am EDT Wed. July 19; those of us
>from the Maryland - DC area will be carpooling to the graze (we'll
>probably go in just my minivan, but if there are more than 3 of us,
>we'll use two vehicles). If the Astro Meteo (Clear Sky Clock)
>forecast is good for the Flint, MI area, we'll procede with our
>plans to go to Gaines; we hope to get a motel room with wifi so that
>we might have e-mail & Web (for weather information) access during
>the evening before the passage. Of course, if the weather forecast
>is not good for Michigan, we'll consider going instead to locations
>in Indiana or even farther s.w. along the Alcyone path, or possibly
>even to Ontario. If the weather forecast is poor for the Alcyone
>path from Illinois to Ontario, we'll try one of the other grazes
>instead in the Mid-Atlantic area from the list copied below, if the
>forecast is reasonably good there.
> Possible Pleiades Grazing Occultations
>DATE Day EDT Star Mag % alt CA Location
>Jul 20 Thu B 3:01 SAO 76158 7.9 24- 12 13N *Stedman,Greenville,Barco,NC
>Jul 20 Thu X 3:42 SAO 76188 8.3 23- 20 13N *Warnbg,Indiana,PA;Syracs,NY
>Jul 20 Thu B 3:42 24 Tauri 6.3 23- 17 13N *Loisv,KY;nCinci,Col,Akron,OH
>Jul 20 Thu X 3:44 SAO 76191 8.5 23- 21 13N *near Somerset, PA &Utica,NY
>Jul 20 Thu B 3:51 Alcyone 2.9 23- 19 13N Gaines,MI orHowe,Lafayette,IN
>Jul 20 Thu B 4:37 SAO 76234 7.5 23- 33 16N *Coinjock, NC
>Jul 20 Thu B 4:42 ZC 562 6.6 23- 34 16N Easton,MD;Richmond,VA;Sun-13
>Jul 20 Thu B 4:59 SAO 76249 7.5 23- 32 15N Gaines, MI; Sun -13
>Jul 20 Thu B 5:16 SAO 76259 7.5 23- 40 16N Waldorf&Annapolis,MD;Sun-8
>This is almost the same list I distributed to Mid-Atlantic observers
>in late May, but after the day I've added B or X to indicate that
>the detailed graze path can be viewed with google maps on either
>Derek Breit's Web site given above (B), or on both his and Brad
>Timerson's web sites (X).
>in other areas on July 20 (see Breit's Web site for path maps):
>Local time Star Mag Location
>2:22-2:30 CDT Merope 4.1 e.Nebr.,n.w.Iowa,Minneapolis,n.w.Wisc.
>2:32 MDT-3:42CDT Pleione 5.0 n.Utah,n.w.Wyo.,s.e.Mont.,nwND,s.w.Man.
>1:45 PDT Atlas 3.6 Brit. Columbia nw of Vancouver&Victoria
>Notes for the Mid-Atlantic grazes:
>Some grazes will not be attempted if expeditions are undertaken for
>asteroidal occultations within 36 hours of the graze. * in the
>Notes column means that no DC-area expedition is planned.
>July 20: These grazes will occur during a spectacular passage of the
>Moon across the Pleiades cluster that will occur Thursday morning, July
>20, almost as good as the one on April 1/2, but the Moon will be waning,
>not waxing, on July 20. And we don't have a bright graze passing near
>DC, or anywhere in the Mid-Atlantic States, like we had with Maia early
>in April. Nevertheless, the grazes below can be observed with small
>telescopes and should be of interest to observers who don't mind losing
>some sleep on a weekday morning.
>24 Tauri = ZC 549. Besides passing over Louisville, KY and diagonally
>across populous parts of Ohio (n. Cincinnati, near Columbus, near
>Akron), the path also passes over St. Catherines, Ont., a very good
>graze for those who can't travel a little farther n.w. to the
>spectacular Alcyone graze path (see next).
>Alcyone (eta Tauri = ZC 552): At mag. 2.9, this will be the most
>spectacular Pleiades graze in the USA this year. It is quite distant
>from DC, but if the weather forecast is favorable for Indiana, I'll
>consider an expedition for it from the DC area; anyone interested in
>joining such an effort please let me know.
>ZC 562: At mag. 6.6, this is the best graze in the region, a
>moderately bright star easy to see with small telescopes (but not
>binoculars). The path passes over part of Charlotte, NC, and near
>Greensboro. In Virginia, it passes over the southern and eastern
>suburbs of Richmond. It crosses the Delmarva Peninsula a few miles
>s.e. of Easton, MD (the closest point for an expedition from the DC
>area) and near Milford, DE. It then crosses southern New Jersey and
>Long Island, where twilight becomes noticeable, Sun alt. -9 deg.
>The path crosses New England from the New Haven, CT area to the coast
>of Maine, passing over Concord and Carlisle, n.w. of Boston, Mass.
>By the time the path reaches Maine, the twilight will be quite bright
>and will make observation a little difficult.
>SAO 76259: At mag. 7.5, this is a good graze, too, still visible with
>small telescopes and signicantly closer to DC- and Baltimore-area
>observers than the ZC 562 graze. The path passes near Salisbury, NC
>and then across central Virginia, crossing I-95 near Thornburg south
>of Fredericksburg. It passes over the Southern Maryland Astronomical
>Society's observatory in Nanjemoy, then extends northeastward to
>Waldorf and Annapolis; sites in the semi-rural country between those
>cities will probably be the closest access to a good graze from the DC
>region during this passage. The path also passes over n.e. Maryland
>and the n.w. suburbs of Philadelphia, where the twilight is becoming
>rather bright. Nevertheless, observation might be possible in
>northern New Jersey, where the path passes n.w. of Princeton and over
>the Sperry Observatory in Cranford.
>Mid-Atlantic Asteroidal Occultations next week & during August 2006
> dur. Ap.
>Date Day EDT Star Mag Asteroid dmag s in. Location
>Jul 24 Mon 21:25 TYC02670292 9.7 Huenna 5.9 3 4 e. Virginia
>Jul 25 Tue 22:54 SAO 163453 8.4 Carmen 4.8 5 2 n&wNY,nOhio
>Aug 2 Wed 5:21 2UC42184775 11.9 Alexandra 1.4 7 8 se N.Car.
>Aug 5 Sat 20:35 TYC68042216 12.0 Fama 3.4 10 8 eVA,DE,NJ
>Aug 11 Fri 1:00 2UC19282707 11.7 Zelia 1.1 7 8 NY,NewEng.
>Aug 15 Tue 0:56 2UC21627363 11.0 Bondia 3.5 13 8 Pennsylvnia
>Aug 21 Mon 4:42 TYC13101942 10.1 Vibilia 2.7 5 4 nOhio,w&nNY
>Aug 25 Fri 5:58 2UC37477545 11.8 Charybdis 2.1 26 8 wSC,wNC,WV
>Updated paths, and often detailed finder charts, can be found at
>Steve Preston's Web site at http://www.asteroidoccultation.com .
>Very detailed maps for these events can often be found now on Derek
>Breit's interactive Web page at
>http://www.poyntsource.com/BREIT_IDEAS/google/index.htm (he has ones
>now for the Huenna and Carmen events). Derek also has comprehensive
>station lists for these events at
>http://www.poyntsource.com/BREIT_IDEAS/index.htm . We'll be using
>his station lists to plan coverage for the good Huenna and Carmen
>events after I return from the Pleiades graze trip. Note that the
>Carmen occultation path passes over southern Michigan (same region
>as the Alcyone graze), a good event with a reasonably bright star.
>That path also extends over Wyoming, Nebraska (Omaha near the n.
>limit), s. Iowa, n. Illinois (Chicago n. of s. limit, Milwaukee n.
>of n. limit but could have an event), s. Mich., s. Ont. (Toronto at
>s. limit), and Quebec (s. limit along St. Lawrence River). Carmen
>is an unusual M-class (metallic spectrum) asteroid that could have
>an unusual shape (its light curve amplitude is relatively small, but
>there was an unusual observation during another Carmen event in
>Europe last month, so observations of the July 25/26 event are
>David Dunham, 2006 July 16 evening
>phones home 301-474-4722; office 240-228-5609; cell 301-526-5590
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