Mid-Atlantic Occultations to mid June - Updated 2008 April 24 EDT

The Crescent Moon will pass through the Preasepe Cluster late Sat. evening, May 10 (Astronomy Day)

Some Bright Pleiades Stars will reappear on the dark side of an 11% sunlit Moon low in the sky Mon. morning, June 30

 
                     Asteroidal Occultations

2008        EDT/                   Planet or      dur. Ap.
Date   Day  EST  Star        mag.  Asteroid   dmag   s  " Location

Apr 27 Sun  0:42 2UC33230431 13.2  2002 GZ32   6.5   9 11 TNO N.America?
Apr 27 Sun 22:05 SAO 98204    7.2  Yano       11.1   1  1 sWV,s&cVA,eNC
Apr 29 Tue  5:07 SAO 139833   9.6  2002 FE7    8.8 0.4  4 MD,DC,VA,PA?
Apr 29 Tue 21:39 TYC18640730 10.4  Bohemia     1.6   2  5 sNY,nePA,nNJ
May  1 Thu  2:56 SAO 188465   8.5  1992 WS3    9.7   1  2 OH,MD,PA
May  2 Fri  1:48 2UC18746728 11.9  Feodosia    1.7   8  9 cen. NC - low
May  3 Sat 22:35 TYC67171249 10.9  1974 FV1    5.9   5  6 NJ,PA,MD?,nVA?
May  4 Sun  2:48 SAO 82381    9.7  Wallonia    5.5   1  4 wNY, nwPA, OH
May  5 Mon  3:24 SAO 188391   9.6 Hotellasillia 8.5  2  4 WV,VA,MD,PA
May  6 Tue  0:13 2UC31689761 12.6  Tombecka    1.6   6  9 NJ,sePA,MD,nVA
May  8 Thu  0:49 SAO 120375   7.9  1999 CB128  8.9   1  2 DE,MD,VA,DC,WV
May  8 Thu  4:40 SD-17d 5862  9.9  2000 RH73   9.3 0.6  4 WV,VA,MD,DE,NJ
May 12 Mon 23:07 2UC37387291 12.9  Varsavia    2.9   4 10 NJ,PA,OH;nMD?
May 15 Thu  1:47 PPM 732830  10.2  Nei Monggo  1.5   2  4 PA,OH;MD,nVA?
May 19 Mon 22:09 TYC61230585 11.3  Libya       3.8   8  8 e&nNC,swVA
May 20 Tue 23:58 SAO 99965    9.3 Hamatonbetsu 6.4   3  2 OH,wVA,wNC,WV?
May 21 Wed  4:08 SAO 146688   8.9  Elliot      9.5   1  2 sGA; sSC?
May 27 Tue  3:03 2UC22726370 11.8  Rosa        2.7   6  8 NC, Tenn.
Jun  7 Sat  3:20 TYC74271593 11.2  Johanna     1.8  13  7 eVA,seMD,DE
Jun 18 Wed  3:17 SAO 186418   8.8  Fortuna     1.9  19  3 Fla,sTex,nMex
Jun 21 Sat  5:13 SAO 141454   9.4  Robeson     6.3   2  6 KY,sWV,nVA-low
Sep 12 Fri  2:32 SAO 93320    6.0  Metis       3.9  51  1 ON,MI,nAZ,sCA
   *** Dates and times above are EDT, those below are EST ***
Nov 16 Sun  4:22 SAO 96841    9.6  Klotilde    4.3  24  4 MD,DC,VA

We now have "final" astrometric updates for these events except the 
TNO ones, and for those after May 24.  Stars with designations 
starting "2UC" are UCAC2 stars; their magnitudes are not as accurate 
as the other catalogs so they might be half a magnitude or more 
fainter than the listed magnitude; if near the limit of your 
telescope, checking the star's some night before the event is 
recommended.  Observers should watch these from convenient home or 
near-home locations without making a significant mobile effort, 
except for some of the better events mentioned below, where the 
chances for an occultation warrant an expedition from the DC region, 
weather permitting. 

If you live within the predicted paths for any of the above events, 
or within the 2-sigma uncertainty limits, please try to observe 
them from convenient home locations.  In addition, you may want to 
help, or join, a possible expedition from the DC area that may be 
undertaken, weather permitting, for the events on May 19 & 27; June 
7, 18, & 21; Sept. 12; and Nov. 16.  Many will probably not be 
attempted due to forecasts of cloudy weather.  I usually give the 
wider paths with better statistics priority. 

April 27, Yano:  This asteroid, (8906) Yano, is only 10 km in 
diameter and the path error is much greater than its size.  The star 
is HIP 43672, spectral type A0.

April 29, (119929) 2002 FE7:  Another tiny asteroid, 5 km.  The star 
is TYC 4979-00305-1, spectral type G5. 

May 1:  (11924) 1992 WS3 is only 4 km across.  The star is HIP 
52547, spectral type K0.

May 4:  The star is TYC 1992-01907-1, spectral type F8.

May 5:  (3705) Hotellasilla is only 11 km across.  The star is TYC 
6307-01759-1, spectral type G5.

May 8, (49582) 1999 CB128, only 10 km across, will occult the star HIP 
69723, spectral type A0.

May 8, (62065) 2000 RH73, only 5 km across, will occult the star TYC 
6314-00172-1, spectral type K0.

May 15:  The star is TYC 6800-01653-1, spectral type M.

May 20:  The star is TYC 1442-01630-1, spectral type K0.
_______________________________________________ 

For these asteroidal occultations, see the path maps, detailed 
finder charts, and other info. at Steve Preston's Web site.
Very detailed maps for most of these are on Derek Breit's interactive Web page 
that links to the very detailed maps and satellite imagery of 
maps.google.com with overlays of the occultation paths (in the 
google maps column).  Also on Breit's Web site are station lists 
giving local circumstances, for many observer stations.  It gives 
the predicted time of the event, distance from the updated central 
line, probability that an occultation will occur there, and 
altitudes of the star and the Sun.  If your station is not in that 
list, please let me and Derek, breit_ideas@hotmail.com , know so 
that you can be added to future lists.  There is also a column that 
has a list of stars with declinations similar to that of the target 
star, with offset times and declination differences, that can be 
used to pre-point a telescope to where the target star will be at 
the time of the occultation.  There are at least a few bright stars 
that can be used to pre-point your telescope during the few hours 
before the event so that you don't have to try to find faint target 
stars directly.  Events not on the above Web sites, generally for the 
fainter stars, are on Steve Messner's Web site.

I recommend installing new software called Occult Watcher, where you 
input your position and it searches Steve Preston's predition Web 
site, informing you of all asteroidal occultations in your region 
during the next 4-5 weeks, giving probabilities and other details.  
Whenever a path is updated, the software lets you know.  It also has 
provision for you to specify your observing intentions, and these 
are displayed along with those of other observers to help plan the 
overall coverage for the event.  Hristo Pavlov in Sydney, Australia 
wrote this program; you can get it here.

Much more information about asteroidal occultations in general is 
here.  Please go to that link to get information for your site and 
help us measure the sizes and shapes of these asteroids.  

For reporting observations, even if the star is monitored and no 
occultation is seen, you should use the new report forms that you 
can get here 
and click on "Templates for Report Forms".  Completed 
reports should be sent to reports@asteroidoccultation.com .  

Observations during the past 2 months, including the SAO 99036 
grazing occultation and a lunar meteor impact flash recorded during 
the recent lunar eclipse, and several asteroidal occultations 
observed in the region, are described here.

Brad Timerson has created a comprehensive site about asteroidal 
occultations, including links to most other known Web sites 
worldwide with useful information (predictions and observations) 
about these events, here.  He also collects, analyzes, and posts 
reports of, observations of these events observed in North America.
_______________________________

Lunar Grazing Occultations to mid June 2008 (and some later)

You can zoom in on some of these paths using Brad Timerson's interactive 
Google maps Web site.  But you need to know the offsets for the 
graze zone in your area; we can help you determine that.  Brad can 
usually add events not on his Web site by request to him at 
btimerson@rochester.rr.com .

DATE   Day  EDT     Star    Mag  % alt  CA  Location, Notes
May  8 Thu 22:32 SAO 78579  9.3 18+ 17 14N Chantilly&DaleC,VA;LaPlata,MD
May  9 Fri 22:43 SAO 79618  7.7 27+ 24 14N Allentown, PA; Fostertown, NJ
May  9 Fri 23:20 S Gem      8.0 28+ 19 14N *Roanoke, VA; Kinston, NC
May 10 Sat 21:43 SAO 97973  7.8 38+ 46 17N *Garner and Cary, NC
May 10 Sat 23:12 ZC 1297    6.8 38+ 28 14N Natural Bridge,VA, Witaker,NC
May 12 Mon 21:05 SAO 118218 7.8 59+ 56 18N Columbia & Odenton,MD; Sun-10
May 13 Tue  1:39 SAO 118297 8.7 61+ 11  9N *s. Erie& Lancaster, PA
May 14 Wed 20:46 ZC 1711    7.9 78+ 47 20N Sykesville, Annapolis, MD
May 29 Thu  4:57 SAO 146779 8.8 37- 31 13N Grnsb,NC;Richmnd,VA;LexPrk,MD
Jun  5 Thu 21:35 ZC 1097    6.9  7+ 13 15N Remington & Fredericksburg,VA
Jun  5 Thu 22:26 SAO 79238  7.3  8+  7 14N *s. of Morgantown, WV
Jun  6 Fri 21:06 SAO 80039  8.4 14+ 26 14N *Somerville &NewBrunswick, NJ
Oct  6 Mon 21:35 phi Sgr    3.2 46+ 14 16S Rockland & Brunswick, VA
Oct 22 Wed  6:01 ZC 1331    6.3 40- 56 10S Centreville & Springfield, VA

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.                

We had many good grazing occultations in the region during early 
April, but the weather remained bad most of the time and as can be 
seen here, most of them were hosed..  I managed to vidoe record a single D & R 
through thickening cirrus during the 136 Tauri graze on April 10 in 
s. NJ about 6 miles s.e. of the Delaware Memorial Bridge; the IR 
satellite image showed that it was clear just a few miles farther 
s.e., towards Millville, NJ.

May 10:  During Praesepe passage.
_______________________________________________ 

                       Total Lunar Occultations

     The better total lunar occultations through mid June 2008
visible from throughout the Washington-Baltimore greater metropolitan
area are listed below.  Some can be accurately timed by aiming a
camcorder into a low-power eyepiece of your telescope and recording
WWV with the audio. 

DATE   Day  EDT  Ph Star      Mag  %  alt  CA Sp. Notes

Apr 25 Fri  4:16 R SAO 187318 7.7 71- 21  58N A3
Apr 25 Fri  5:40 R SAO 187363 7.2 71- 24  88N K0 Sun alt. -7 deg.
Apr 26 Sat  4:10 R ZC 2879    6.7 62- 19  90N A3
Apr 28 Mon  3:09 R iota Cap   4.3 42-  2  77N G8 Azimuth 114 deg.
May  1 Thu  5:22 R ZC 3385    6.7 22- 18  52N F8 Sun alt. -9 deg.
May  6 Tue 21:31 D X05643     8.5  4+  5   2S F8 Az 299; 20" to chi Tau
May  6 Tue 21:32 D chi Tauri  5.4  4+  5  -1S B9 ZC 647; Azimuth 299
May  7 Wed 22:09 D ZC 833     7.1 10+ 10  78S B5 Az 296
May  9 Fri 22:33 D SAO 79618  7.7 28+ 26  37N F5 Graze in PA & NJ
May  9 Fri 22:35 D SAO 79616  8.2 28+ 26  42S A0
May  9 Fri 23:07 D SAO 79621  7.4 28+ 20   2S K0
May  9 Fri 23:48 D SAO 79663  7.5 28+ 13  87N K0 Azimuth 289 deg.
May 10 Sat 20:13 D 35 Cancri  6.6 37+ 60  54S G0 ZC 1282; Sun -2 deg.
May 10 Sat 21:40 D ZC 1287    6.7 38+ 44  59S A5 rest Praesepe stars
May 10 Sat 22:35 D SAO 98009  7.6 38+ 34  67N A7
May 10 Sat 23:07 D SAO 98027  7.8 38+ 28  47N A8
May 10 Sat 23:47 D BY Cancri  7.9 39+ 20  74N A7 SAO 98054
May 12 Mon 21:00 D SAO 118218 7.8 59+ 58  26N F5 cen. MD graze
May 12 Mon 21:10 R SAO 118218 7.8 59+ 57  11N F5
May 13 Tue 23:54 D SAO 118693 7.7 70+ 34  71N G5
May 14 Wed 20:41 D ZC 1711    7.9 78+ 47  29N G0 cen. MD graze
May 14 Wed 20:52 R ZC 1711    7.9 78+ 48  12N G0 Sun alt. -8 deg.
May 21 Wed  1:08 R ZC 2397    6.5 99- 23  50S K1 WA 253; term. 15" away
May 27 Tue  5:15 R SAO 164779 7.2 58- 34  82S G5 Sun alt. -6 deg.
May 28 Wed  3:19 R SAO 146272 7.7 48- 17  67N G5
May 29 Thu  3:47 R 13 Piscium 6.4 37- 18  83S K1
May 31 Sat  3:47 R SAO 92318  7.9 17-  8  61N G0 Azimuth 81 deg.
Jun  1 Sun  3:50 R ZC 317     6.4  9-  2  71S F5 Azimuth 70 deg.
Jun  6 Fri 20:51 D ZC 1242    6.9 14+ 30  46S F2 Sun alt. -4 deg.
Jun  6 Fri 21:16 D SAO 80051  8.2 14+ 25  84S K0 Sun alt. -8 deg.
Jun  9 Mon  0:21 D SAO 118138 7.1 35+  3  63N M3 Azimuth 280 deg.
Jun 10 Tue 21:22 D SAO 138313 7.6 54+ 42  80S F9 Sun alt. -9 deg.
Jun 11 Wed 21:30 D ZC 1778    7.0 64+ 40  78N K0 Sun alt. -10 deg.
Jun 15 Sun  1:24 D SAO 182861 7.3 89+ 15  41S F2 Azimuth 224 deg.

On Mon. morning, June 30, the 11% sunlit waning Moon will pass 
through the Pleiades, with the reappearance of a few of the bright 
stars visible on the dark side, but the Moon will be only a few deg. 
above the east-northeastern horizon then.  Mark your calendar; some 
details will be given in a future update.

D following the time denotes a disappearance, while R indicates that 
the event is a reappearance.  When a power (x; actually, zoom 
factor) is given in the Notes, the event can probably be recorded 
directly with a camcorder of that power with no telescope needed.  
The times are for Greenbelt, MD, and will be good to within +/-1 
min. for other locations in the Washington-Baltimore metropolitan 
areas unless the cusp angle (CA) is less than 30 deg., in which 
case, it might be as much as 5 minutes different for other locations 
across the region.  Some stars in Flamsteed's catalog are in the 
wrong constellation, according to the official IAU constellation 
boundaries that were established well after Flamsteed's catalog was 
published.  In these cases, Flamsteed's constellation is in 
parentheses and the actual constellation is given in the notes 
following a /. 

     Mag is the star's magnitude.  % is the percent of the Moon's 
visible disk that is sunlit, followed by a + indicating that the 
Moon is waxing and - showing that it is waning.  So 0 is new moon, 
50+ is first quarter, 100+ or - is full moon, and 50- is last 
quarter.  The Moon is crescent if % is less than 50 and is gibbous 
if it is more than 50.  Cusp Angle is described more fully at the 
main IOTA Web site - see above.  Sp. is the star's spectral type 
(color), O,B,blue; A,F,white; G,yellow; K,orange; M,N,S,C red.  Also 
in the notes, information about double stars is often given.  "Close 
double" with no other information usually means nearly equal 
components with a separation less than 0.2".  "mg2" or "m2" means 
the magnitude of the secondary component, followed by its separation 
in arc seconds ("), and sometimes its PA from the primary.  If there 
is a 3rd component (for a triple star), it might be indicated with 
"mg3" or "m3".  Double is sometime abbreviated "dbl".  Sometimes the 
Watts angle (WA) is given; it is aligned with the Moon's rotation 
axis and can be used to estimate where a star will reappear relative 
to lunar features. The selenographic latitude is WA -270.  For 
example, WA 305 - 310 is near Mare Crisium. 

Many more total occultations will be visible with 5" and larger 
telescopes than are listed here.  If you want to try to observe some 
of these events, it is better to use predictions computed for your 
location, such as those given in the IOTA annual predictions that 
have been distributed to IOTA members, and are available to others 
upon request. 

For Pleiades occultations, region of visibility maps and 
predictions for hundreds of N. American cities for the brightest 7 stars 
are on this page at IOTA's lunar occultation Web site, while 
predictions for all of 2008 for stars to mag. 6.0 for 40 of the larger 
N. American cities can be downloaded in .zip files from here.
There are no Pleiades occultations visible from the Mid-Atlantic 
region from now to early June; we'll have a good passage the morning 
of June 30. The links just mentioned don't work now, the whole main 
IOTA Web site is down, the server it was on was shut down.  In about 
a week, the webmaster hopes to rehost the site. 
________________________________________________________

Timing equipment and even telescopes can be loaned for most expeditions
that we actually undertake; we are always shortest of observers who can
fit these events in their schedule, so we hope that you might be able to.
Information on timing occultations is here.  Good luck with your 
observations.

Much information about observing occultations of all types is in 
"Chasing the Shadow:  The IOTA Occultation Observer's Manual" 
available for free download at
http://www.poyntsource.com/IOTAmanual/Preview.htm .
_____________________________

David Dunham, 2008 April 24, 6 pm EDT
Phones home 301-474-4722; office 240-228-5609; cell 301-526-5590 
office e-mail david.dunham@kinetx.com with Blackberry for mobile use
home e-mail:  dunham@starpower.net .