(Updated 20091119.5UT)
Artist’s impression of the asteroid (234) Barbara. Thanks to a unique
method that uses ESO’s Very Large Telescope Interferometer, astronomers have
been able to measure sizes of small asteroids in the main belt for the first
time. Their observations also suggest that Barbara has a complex concave shape,
best modeled as two bodies that may possibly be in contact.
Credit: ESO/L. Calçada
This announcement of a new
measuring technique was distributed on the IOTA Occultation Yahoo Discussion
Group first by Dave Herald on February 4th, 2009. It announces a new
interferometric technique that allows the VLT-MIDI
team to measure asteroids at greater distances with higher precision than
adaptive optics observing. One asteroid they measured, (234) Barbara, was newly
discovered with this technique to potentially be a binary asteroid. Upon
reading the Press Release from the ESO I became intrigued about the possibility
of finding an occultation of a star by (234) Barbara. Occultation
timing provides the highest resolution
currently available to man. By using video recordings of such occultation
events we have 0.017 second time resolution, and at the average speed of an
asteroid’s shadow on the ground we can then resolve 10s to 100s of meters of
spatial resolution of the asteroid (versus kilometers for adaptive and
interferometric measurements).
A quick search identified
several upcoming asteroidal occultations by (234) Barbara. I sent out a notice
that very day of a list of three potentially viewable occultations, with a
highlight of the November 21st, 2009 involving an exceptionally
bright star passing over many highly populated areas. With a visual magnitude
of 7.5, this target star is easily monitored with nothing more than a steady
pair of binoculars! Thus a large number of amateur astronomers, and even the
general public would have the ability to use a tape recorder and a shortwave
radio to provide timing data. The most valuable data for measuring the utmost
accurate size and shape of Barbara will be derived from video timings. With
this advanced notice of this Press Release, those interested in pursuing simple
video equipment have time to prepare. The significance though of this event is
it gives amateurs the chance to validate a newly emerging technology:
interferometric measurements of asteroids by the VLT-MIDI
method. The brightness of the target star opens up the opportunity for David Dunham, Paul Maley, I, and other occultation video
observers to deploy a very large array of 30 or more Mighty Mini observing
stations in Central Florida, meaning a very high resolution profile will result
(providing weather cooperates). This event will culminate with a planned LIVE
broadcast from one of my remotely deployed stations via Scotty’s Sky, so immediate
results of whether a shadow was captured will be known around the world
instantaneously.
After some discussions within
the group about the importance of this event, IOTA then rearranged the planned
annual meeting to occur in Orlando, Florida so that a higher number of
occultationlists would be in the path of the shadow. Also, Frank Gutowski of the Central Florida Astronomical Society
immediately responded to our initial email offering to provide local support
for both the November 21st occultation and the IOTA annual meeting.
Terry Redding, Tom Campbell, and Hal Povenmire of Central Florida have been our
eyes and ears on the ground there locally and have provided immense amount of
information on potential observing sites already.
Marco Delbo of ESO’s VLT-MIDI
team has responded saying he is very interested in observing the November 21st,
2009 event as well since the shaodw passes through Europe. He and his team are
keenly interested in any results that can be obtained to help verify their
observations.
Please make plans if you are
in or near any of the places the shadow(s) of (234) Barbara pass on the morning
of November 21, 2009 to accurately time the eclipsing of the starlight of 7.5
magnitude HIP 34106. More information follows, feel free to ask if you need more information.
Richard Nugent has a great resource he has
published entitled “Chasing the Shadow”,
which will give you great information on “How To” get started. The IOTA Yahoo Discussion
Group is your best resource for daily information on occultations.
Good luck and CLEAR SKIES!
“Some discussions have been ongoing with the French group who
successfully timed the recent Oct 5 occultation of Barbara from the Canary
Islands showing only a very small shift from the predictions, meaning the
ephemeris is pretty good for her. There is the main body of Barbara that is
represented by the shadow path on OW. But the satellite that is the main goal
of this observation (for me) may be up to 100km or so from the main body and is
not represented in the prediction path. David Dunham has calculated our best
odds to image the main body and the (potential) satellite is to cover ± 70km
from centerline. Those who wish to venture that far from centerline must do it
with the understanding that you are statistically likely to have a miss. But
that miss will be valuable constraint data. You also may get one or two of the
only chords through the companion! Those of us who deploy more than 1 station
with unattended remotes are encouraged to set some of the remotes in this outer
region, which is really only a little past the 1 sigma zone anyway. But I wanted
everyone to be aware of this when making your plans. If you want to do the main
body only stick to the current path on OccultWatcher and Derek's site. If you
want to go for the satellite you will be guessing, but an educated guess at
least.”
USA: (Central Florida) Tampa,
St. Petersburg, Lakeland, Orlando, Cape Canaveral, Florida
Atlantic: Saint George’s
Island, Bermuda
Europe: London, England
Amsterdam, Netherlands
The Island chain cities of Borkum, Memmert,
Juist, Norderney, Langeoog, Wangerooge, Mellum, Scharhorn, and Trischen,
Germany
Schleswig-Holstein, Germany
Fehmarn, Germany
Drej, Svenborg, Stryn, and Langland, Denmark
Southern tip of Sweden
RTga, Latvia
Western part of Central, Russia.
Live broadcast
of the (234) Barbara Asteroidal occultation effort in
Central Florida will begin around 2PM EST (19h UT) Friday Nov 20th
(NOTE: some areas I will be traveling in have limited cellular coverage, so
there may be times my signal drops out. Keep watching, as I eventually do come
back online)
·
2:00 pm – 4:00 pm
EST (19h – 21h UT) Friday Nov 20: Preplanning of deployment for the (234) Barbara
occultation at University of Central Florida.
·
4:00 pm – 6:00 pm
EST (21h – 23h UT) Driving to first deployment site.
·
6:00 pm – 10 pm
EST (23h UT Fri – 3h UT Sat ) Deploy up to 20 sites.
·
10 pm EST begin
transmitting live view through telescope near centerline.
·
10:18 pm EST (3h
UT Sat) Dr. Eberhard Bredner will phone from Europe to announce live the
results of the shadow passing there (they get Barbara’s shadow 20 minutes
before we do).
·
10:38 pm EST (3:38: UT Sat) Barbara’s shadow passes through the field of view I
am broadcasting. So you can watch live to see if the star blinks out or not
from Barbara passing in front of it.
·
Final results of
everyone’s data will be posted at: http://www.asteroidoccultation.com/observations/Results/
A special group rate has been established at the Comfort Suites a few blocks from the Orlando Science Center where Saturday afternoon’s meeting will be held. The group rate is $94/night (compared to $119/night) and is a valid offer until November 13th. There are rooms with one King or two double beds available (and cots are available if you need more in a room).
Here is the hotel info:
http://tinyurl.com/yhuymwt
To make your reservation call this number with a credit card:
877-228-4007 (this is direct to the hotel)
Ask for the Group Rate: IOTA
http://www.asteroidoccultation.com/observations/NA/Meeting/
Friday Nov 20: Preplanning of deployment for the (234) Barbara occultation
University of Central Florida, Business Administration Bldg., Room 146, 2:00 pm - 5:00 pm EST
Saturday Nov 21: IOTA 2009 Annual Meeting, Day 1 ***
Orlando Science Center, Imagination Classroom, 9:00 am - 5:00 pm EST
EVO broadcast link: http://evo.caltech.edu/evoGate/koala.jnlp?meeting=MvM2Ml2D2nDaDn999vDe9v
Sunday Nov 22: IOTA 2009 Annual Meeting, Day 2 ***
University of Central Florida, Math and Physics Bldg., Room 359, 9:00 am - 5:00 pm EST
EVO broadcast link: http://evo.caltech.edu/evoGate/koala.jnlp?meeting=MeMMMu292BDIDB9D9vDv9e
*** (I have been discussing with others who will video
tape this event about helping them reduce their data. If you would like me to
help reduce your video data just bring your original recording with the
instrument it was recorded on (i.e. your VCR, camcorder, etc.) to the Saturday
or Sunday meetings and we will dub these off to one of my miniDV recorders for
me to transfer via firewire in DV AVI format to my computer. I'll be more than
happy to do that for those who do not have the tools or experience to reduce
video to lightcurves.)
The following ZIP files contain prepoint charts for the Mighty Mini and Mighty Midi observing systems. These charts allow a person the ability to arrive at any location in Central Florida at any time after Civil Twilight on Friday evening November 20th and identify which star to point to so that at exactly the time of the occultation the target star will drift into the center of the field of view without the need for having a clock drive system. Details on these types of charts can be found at:
http://scottysmightymini.com/PR/Effects_miniature_optics_occultations.html
http://scottysmightymini.com/tools/How_to_make_Guide8_prepoints.htm
ZIP file with Post Script prepoint charts for printing:
Mini: http://scottysmightymini.com/PR/20091121(234)BarbaraPostScriptMiniPrepoint.zip
Midi: http://scottysmightymini.com/PR/20091121(234)BarbaraPostScriptMidiPrepoint.zip
ZIP files with PDF prepoint charts for printing:
Mini: http://scottysmightymini.com/PR/20091121(234)BarbaraPDFMiniPrepoint.zip
Midi: http://scottysmightymini.com/PR/20091121(234)BarbaraPDFMidiPrepoint.zip
Weather:
Kissimmee Clear Sky Chart: http://cleardarksky.com/c/KssmFlkey.html?1
National Weather Service forecast: http://forecast.weather.gov/MapClick.php?CityName=Kissimmee&state=FL&site=MLB&textField1=28.3035&textField2=-81.4105&e=0
Realtime Florida IR satellite loop: http://adds.aviationweather.gov/satellite/displaySat.php?region=TPA&isingle=multiple&itype=ir
Intellicast National satellite loop: http://www.intellicast.com/Global/Satellite/Infrared.aspx?location=USKS0112&enlarge=true&animate=true
Site selection and
declaration:
OccultWatcher is the
preferred method of declaring your observing site. It is used to prevent two
people from observing on the same chord.
OccultWatcher by Hristo Pavlov: http://www.hristopavlov.net/OccultWatcher/OccultWatcher.html
If you cannot use
OccultWatcher, please locate you longitude and latitude with the Google Maps
below and send these to scotty@scottysmightymini.com
Scotty’s NOTE on sites: If you need a site assigned to you I have 152
sites and their GPS coordinates for the Orlando, Florida USA area. Contact me at scotty@scottysmightymini.com and I will be glad
to give you a few options.
Google Earth KML file of path: http://www.poyntsource.com/New/Google/20091121_18170.KML
Steve Preston’s page: http://www.asteroidoccultation.com/2009_11/1121_234_18170.htm
Derek Breit’s main asteroid
occultation page: http://www.poyntsource.com/New/Global.htm
Derek Breit’s Google Maps: http://www.poyntsource.com/New/Google/20091121_18170.HTM
Distance (Occult) Prob. Station info Event Time (UT)
------------------------------------------------------------------------------------------
113.8 km 0.1% == Right limit plus 3-Sigma ==
85.9 km 2.3% == Right limit plus 2-Sigma ==
72.9 km @349° 6.3% (6) Barb Harris Home : video + gps 03:38:12 UT
70.3 km @346° 7.5% (47) Dunham 01 : video + gps 03:38:19 UT
65.7 km @349° 10.1% (48) Dunham 5 : video + gps 03:38:19 UT
60.0 km @348° 14.2% (49) Dunham 10 : video + gps 03:38:20 UT
58.1 km 15.8% == Right limit plus 1-Sigma ==
57.9 km @347° 15.9% (23) One : video + gps 03:38:21 UT
52.5 km @345° 21.0% (24) Four : video + gps 03:38:22 UT
46.7 km @349° 27.5% (25) Three : video + gps 03:38:23 UT
46.3 km @350° 27.9% (50) Dunham 16 : video + gps 03:38:21 UT
43.1 km @351° 31.9% (51) Dunham 20 : video + gps 03:38:22 UT
40.3 km @351° 35.4% (14) Paul Maley 23 : video + gps 03:38:22 UT
36.9 km @341° 39.8% (46) Eddie Mac : visual + radio 03:35:34 UT
35.4 km @346° 41.7% (22) Four : video + gps 03:38:24 UT
33.5 km @334° 44.3% (44) Talbot J Home : video + other 03:20:13 UT
33.4 km @349° 44.4% (15) Paul Maley 30 : video + gps 03:38:23 UT
30.3 km 48.5% === Right limit ===
29.3 km @350° 49.7% (52) Dunham 33 : video + gps 03:38:23 UT
28.6 km @348° 50.6% (8) Campbell T Mobile #1 : video + gps 03:38:26 UT
26.6 km @349° 53.2% (16) Paul Maley 38 : video + gps 03:38:24 UT
25.5 km @348° 54.5% (57) Dunham 39 : video + gps 03:38:24 UT
18.7 km @342° 62.1% (17) Paul Maley 41 : video + gps 03:38:25 UT
15.6 km @341° 65.1% (58) Dunham 45 : video + gps 03:38:25 UT
15.2 km @348° 65.4% (19) Campbell T Mobile #2 : video + gps 03:38:28 UT
13.8 km @336° 66.6% (43) Mánek J mobile (unsure) : video + gps 03:18:00 UT
11.0 km @0° 68.6% (18) Paul Maley 5 : video + gps 03:38:26 UT
6.6 km @333° 71.0% (42) Scotty TX 109 : video + gps 03:38:20 UT
3.3 km @315° 72.0% (12) Redding T Mobile 3 : video + gps 03:38:20 UT
0.6 km @278° 72.3% (53) Dunham 157 : video + gps 03:38:27 UT
0.0 km 72.3% ==== Centre Line ====
-0.5 km @236° 72.3% (21) Paul Maley 47 : video + gps 03:38:27 UT
-0.9 km @100° 72.3% (41) Scotty 116 : video + gps 03:38:21 UT
-4.2 km @148° 71.8% (54) Mike Hoskinson 118 : video + gps 03:38:21 UT
-4.3 km @182° 71.7% (13) Frank Gutowski : visual + other 03:38:23 UT
-4.6 km @185° 71.6% (1) Campbell T #3 Home : video + gps 03:38:32 UT
-6.4 km @161° 71.0% (9) Eberhard Bredner : video + gps 03:18:08 UT
-7.3 km @157° 70.7% (40) Scotty 120 : video + gps 03:38:21 UT
-10.8 km @157° 68.7% (39) Scotty 122 : video + gps 03:38:22 UT
-13.6 km @162° 66.8% (55) Mike Hoskinson 124 : video + gps 03:38:22 UT
-14.0 km @162° 66.4% (36) Scotty 125 : video + gps 03:38:22 UT
-15.8 km @163° 64.9% (11) Redding T Mobile 2 : video + gps 03:38:22 UT
-16.4 km @164° 64.4% (56) Mike Hoskinson 128 : video + gps 03:38:22 UT
-17.4 km @165° 63.5% (35) Scotty 130 : video + gps 03:38:23 UT
-19.1 km @166° 61.8% (34) Scotty 133 : video + gps 03:38:23 UT
-21.5 km @172° 59.2% (33) Scotty 134 : video + gps 03:38:24 UT
-22.8 km @166° 57.8% (10) Redding T mobile 1 : video + gps 03:38:23 UT
-26.3 km @168° 53.5% (37) Scotty Mobile : video + gps 03:38:25 UT
-28.5 km @167° 50.7% (32) Scotty 135 : video + gps 03:38:25 UT
-30.3 km 48.5% === Left limit ===
-31.0 km @166° 47.6% (38) Scotty 136 : video + gps 03:38:25 UT
-33.3 km @165° 44.5% (31) Scotty 137 : video + gps 03:38:25 UT
-37.1 km @166° 39.5% (30) Scotty 138 : video + gps 03:38:26 UT
-41.7 km @167° 33.6% (29) Scotty 143 : video + gps 03:38:26 UT
-46.3 km @166° 27.9% (28) Scotty 145 : video + gps 03:38:27 UT
-50.1 km @158° 23.6% (4) Bulder H Home : visual + other 03:18:36 UT
-52.2 km @169° 21.4% (27) Scotty 147 : video + gps 03:38:27 UT
-57.6 km @167° 16.2% (5) Scotty 149 : video + gps 03:38:28 UT
-58.1 km 15.8% == Left limit plus 1-Sigma ==
-63.7 km @168° 11.5% (26) Scotty Mobile : video + gps 03:38:28 UT
-71.2 km @166° 7.1% (20) Scotty Mobile : video + gps 03:38:29 UT
-85.9 km 2.3% == Left limit plus 2-Sigma ==
-113.8 km 0.1% == Left limit plus 3-Sigma ==
-264.2 km @159° - (59) Rothe W. Home : video + gps 03:17:22 UT
-715.6 km @161° - (45) Dangl G Home : video +
gps 03:17:00 UT
(click on 2009 locations to view
the predicted path with Google Earth KML
file)
September
16, 2009 19:24 UT: Mongolia and
Northern China
October
05, 2009 04:15 UT: Northwestern
Africa
October
23, 2009 13:09 UT: Northwest USA,
faint star, combined brightness 11.8 magnitude.
November
30, 2009 22:52 UT: Northern United
Kingdom, Southern Norway and Sweden, Estonia, Central Russia. Combined brightness
10.8
magnitude.
December
14, 2009 11:18 UT: Crosses the
entire USA. Combined brightness of star and asteroid about 11.3 magnitude.
January
10, 2010 04:41 UT: Crosses the
entire USA. Combined brightness of star and asteroid about 11.2 magnitude.
January
17, 2010 12:11 UT: Mongolia, Northeast China, Japan. Combined
brightness 11.6 magnitude.
USA Event Coordinator for IOTA: Scotty Degenhardt scotty@scottysmightymini.com
888-687-5444
toll free to cell
http://www.ustream.tv/channel/scottys-sky
LIVE broadcast
at event time from the shadow path!
IOTA Yahoo
Discussion Group: IOTAoccultations-subscribe@yahoogroups.com
IOTA path
predictions sources: Steve
Preston stevepr@acm.org
http://www.asteroidoccultation.com/2009_11/1121_234_18170.htm
Derek
Breit breit_ideas@hotmail.com
http://www.poyntsource.com/New/Google/20091121_18170.HTM
How to observe an
occultation: Chasing the Shadow
by Richard
Nugent
Central
Florida Astronomical Society: Frank
Gutowski fgutowski@yahoo.com
IOTA members in
Central Florida: Terry Redding tredding@mac.com
Tom
Campbell thcamp@verizon.net
Barbara
Harris barbharris1@earthlink.net
(yes, Barbara will observe Barbara!)
Hal
Povenmire katiehal1@yahoo.com
IOTA Annual
Meeting Coordinator: Paul Maley pdmaley@yahoo.com
Europe Event Coordinator for
IOTA: Dr. Eberhard Bredner Eberhard@Bredner.eu
VLT-MIDI
Team: Marco
Delbo delbo@obs-nice.fr
Observatoire
de la Côte d'Azur, Nice, France
Phone:
+33 (0)4 9200 1944
Sebastiano
Ligori ligori@oato.inaf.it
INAF-
Osservatorio Astronomico di Torino, Italy
Phone:
+39 011 8101 964