Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/irlab/luna/news/near/dunham_mail.txt Дата изменения: Thu Jul 28 18:24:41 2005 Дата индексирования: Sat Dec 22 10:09:11 2007 Кодировка: Поисковые слова: m 81

From dunham@erols.com Fri Jan 9 09:09 MET 1998
Received: from smtp3.erols.com (smtp3.erols.com [205.252.116.103]) by hercules.arcetri.astro.it (8.7.1/8.7.1) with ESMTP id JAA03630 for ; Fri, 9 Jan 1998 09:09:10 +0100 (MET)
Received: from hp-customer (spg-tnt1s131.erols.com [207.172.111.131])
by smtp3.erols.com (8.8.8/8.8.5) with SMTP id CAA11093;
Fri, 9 Jan 1998 02:37:05 -0500 (EST)
Message-Id: <3.0.1.32.19980109022419.00789540@pop.erols.com>
X-Sender: dunham@pop.erols.com
X-Mailer: Windows Eudora Pro Version 3.0.1 (32)
Date: Fri, 09 Jan 1998 02:24:19 -0500
To: astro@uibk.ac.at, ToplicM@Klagenfurt.Spardat.at, pinter@ping.at,
minnah@spirit.com.au, DHerald@aipo.gov.au,
heraldd@canberra.dialix.oz.au, kkramer@ozemail.com.au,
northp@ozemail.com.au, donaldc@b130.aone.net.au,
observatory@halenet.com.au, martin@qvmag.tased.edu.au,
AKruijsh@vtrlmel1.trl.oz.au
From: Joan and David Dunham
Subject: NEAR Sunglint tonight - S/C dist. record?
Mime-Version: 1.0
Status: RO
X-Lines: 107
Content-Type: text/plain; charset="us-ascii"
Content-Length: 5877

Date: Fri, 09 Jan 1998 00:41 -0500 (EST)
From: "Dunham, David W"
Those with moderate to large telescopes have a chance later
today to beat the spacecraft distance detection record, currently
held by observations of Galileo, I believe with the Spacewatch
Telescope, at a distance of about 3 million km from the Earth.
There will be two opportunities, just after 16:01 U.T., when the
NEAR spacecraft slews from its normal Sun-pointing attitude to an
Earth-pointing attitude in order to perform a small trajectory
correction maneuver at 20:00 U.T. (it is needed to precisely target
the Jan. 23rd Earth swingby), and then again just after 23:56 U.T.,
when NEAR slews back to the Sun-pointing attitude. At the first
time, NEAR will be 8,201,500 km from the Earth, and 7,999,900 km at
the later time. In spite of these distances, NEAR may briefly (for
only a few seconds, probably) shine at mag. 12.4 as its 9 square
meters of solar panels reflects sunlight back at the Earth halfway
through the slews. At the time, NEAR will be near J2000
R.A. 81.9 deg., or 5h 27.6m, and Dec. +20.7 deg. The area of
visibility for the first event will be Australia, Asia, Japan,
eastern Europe, the Middle East, and the northeasternmost part of
Africa. The second event might be seen from Africa, Europe, the
Middle East, North America east of the Mississippi River, and most
of South America.

It is not certain that the NEAR sunglint will happen; it may
pass north or south of the Earth. By 15h U.T., only an hour before
the first event, I will have more detailed information about the
predicted pointing during the slew, and I will then distribute an
update message that should be able to specify more precisely when
and if the sunglint will occur. Besides beating a distance record,
timed observations of the glint would be useful for measuring the
exact orientation of the solar panels, which may have bent slightly
when they swung up and locked into place shortly after launch. Any
bend angle could be important when NEAR reaches Eros since it will
change the solar radiation pressure force on the satellite,
information that we will want to know in order to navigate savely in
Eros's weak but complex gravitational field.

At 8 million km, NEAR will have a 3' parallax. I have computed
topocentric positions for several cities, as listed below, for both
events. The time 16:01:12 is the U.T.C. when the spacecraft will
first start slewing. The glint may occur a minute or two later due
to the 0.4-minute light time to NEAR, and the slew duration of a
minute or so. Two lines are given in the list below, the second
being 10 minutes after the initial time, by which time the slew will
have certainly been completed. The time of the start of the second
slew (back to Sun-pointing) will be 23:56:22 U.T.C.

Maps showing the Earth as seen from NEAR at the two times, to
portray the region of visibility, will be placed first on IOTA's
asteroidal occultation Web site at
http://www.anomalies.com/iotandx.htm and later, with more
information, on the NEAR site at http://sd-www.jhuapl.edu/NEAR/
Also posted will be some star charts plotting some of the paths
below.

R.A.(J2000) Dec. 1998 U.T.C. Location
o o date h m s
81.9043 20.7064 Jan. 9 16 1 12.0 MOSCOW, Russia
81.9029 20.7067 Jan. 9 16 11 12.0 MOSCOW
81.9170 20.7218 Jan. 9 16 1 12.0 MITZPE RAMON, Israel
81.9153 20.7222 Jan. 9 16 11 12.0 MITZPE RAMON (Wise Obs.)
81.8945 20.7432 Jan. 9 16 1 12.0 KODAIKANAL Obs., India
81.8918 20.7434 Jan. 9 16 11 12.0 KODAIKANAL
81.8644 20.7256 Jan. 9 16 1 12.0 NANKING, China
81.8621 20.7253 Jan. 9 16 11 12.0 NANKING
81.8538 20.7202 Jan. 9 16 1 12.0 TOKYO, Japan
81.8520 20.7197 Jan. 9 16 11 12.0 TOKYO
81.8609 20.7123 Jan. 9 16 1 12.0 KHABAROVSK, Siberia
81.8592 20.7119 Jan. 9 16 11 12.0 KHABAROVSK
81.8663 20.7698 Jan. 9 16 1 12.0 PERTH, Western Australia
81.8640 20.7696 Jan. 9 16 11 12.0 PERTH
81.8455 20.7616 Jan. 9 16 1 12.0 BRISBANE, Queensland
81.8439 20.7610 Jan. 9 16 11 12.0 BRISBANE
81.8524 20.7686 Jan. 9 16 1 12.0 MELBOURNE, Victoria
81.8507 20.7681 Jan. 9 16 11 12.0 MELBOURNE

81.8244 20.7022 Jan. 9 23 56 22.0 MOSCOW, Russia
81.8234 20.7020 Jan. 10 0 6 22.0 MOSCOW
81.8121 20.7184 Jan. 9 23 56 22.0 MITZPE RAMON, Israel
81.8109 20.7180 Jan. 10 0 6 22.0 MITZPE RAMON
81.8202 20.7666 Jan. 9 23 56 22.0 CAPE, South Africa
81.8187 20.7663 Jan. 10 0 6 22.0 CAPE
81.8349 20.7096 Jan. 9 23 56 22.0 HERSTMONCEUX, England
81.8335 20.7094 Jan. 10 0 6 22.0 HERSTMONCEUX
81.8350 20.7204 Jan. 9 23 56 22.0 SAN FERNANDO, Spain
81.8334 20.7203 Jan. 10 0 6 22.0 SAN FERNANDO
81.8421 20.7271 Jan. 9 23 56 22.0 LA PALMA, Canary Islands
81.8403 20.7270 Jan. 10 0 6 22.0 LA PALMA
81.8615 20.7644 Jan. 9 23 56 22.0 RIO DE JANEIRO, Brazil
81.8596 20.7645 Jan. 10 0 6 22.0 RIO DE JANEIRO
81.8798 20.7381 Jan. 9 23 56 22.0 CARACAS, Venezuela
81.8781 20.7383 Jan. 10 0 6 22.0 CARACAS
81.8772 20.7668 Jan. 9 23 56 22.0 SANTIAGO, Chile
81.8757 20.7670 Jan. 10 0 6 22.0 SANTIAGO
81.8634 20.7121 Jan. 9 23 56 22.0 ST. JOHN'S, Newfoundland
81.8619 20.7122 Jan. 10 0 6 22.0 ST. JOHN'S
81.8843 20.7239 Jan. 9 23 56 22.0 MIAMI, Florida
81.8830 20.7242 Jan. 10 0 6 22.0 MIAMI
81.8808 20.7109 Jan. 9 23 56 22.0 Chicago, Illinois
81.8796 20.7111 Jan. 10 0 6 22.0 Chicago
81.8886 20.7180 Jan. 9 23 56 22.0 HOUSTON, Texas
81.8875 20.7183 Jan. 10 0 6 22.0 HOUSTON (near sunset)

David Dunham, NEAR Mission Design, 1997 January 9, 5h U.T.



From DunhamDW@space2.spacenet.jhuapl.edu Fri Jan 9 18:00 MET 1998
Received: from aplgate.jhuapl.edu (aplgate.jhuapl.edu [128.244.198.35]) by selene.arcetri.astro.it (8.7.1/8.7.1) with ESMTP id SAA07737 for ; Fri, 9 Jan 1998 18:00:06 +0100 (MET)
Received: from aplcomm.jhuapl.edu ("port 53167"@aplcomm.jhuapl.edu)
by aplgate.jhuapl.edu (PMDF V5.1-10 #22050)
with SMTP id <0EMJ009930IFB4@aplgate.jhuapl.edu> for
richichi@selene.arcetri.astro.it; Fri, 9 Jan 1998 11:59:11 -0500 (EST)
Received: from bix003.jhuapl.edu by aplcomm.jhuapl.edu (5.0/SMI-SVR4)
id AA10760; Fri, 09 Jan 1998 11:57:59 -0500
Received: from ffapi.bisdnet.jhuapl.edu by BISDnet.jhuapl.edu
(PMDF V5.0-5 #10436) id <01IS67JPPHU897H2AA@BISDnet.jhuapl.edu>; Fri,
09 Jan 1998 11:57:52 -0500 (EST)
Date: Fri, 09 Jan 1998 11:52 -0500 (EST)
From: "Dunham, David W"
Subject: New NEAR glint UTs - 16:02:52 & 21:28:03
To: "IT Bologna Di Luca, Roberto" ,
IT all observatories ,
"IT Roma Costa, Claudio" ,
IT Pino Torinese Paulo Tanga ,
IT Catania Piero Massimino a4 ,
IT Catania Piero Massimino ast ,
"IT Firenze Richichi, Andrea" ,
"IT Milan Cavagna, Marco"
Cc: "C ES La Palma A. Fitzsimmons" ,
"C ES Valencia Lopez, Alvaro" ,
"'ES Arturo Montesinos'" ,
"C ES Mallorca, Astron. Obs." ,
C ES Sabadell Casarramona etal ,
"C ES Gandia J.J. Gomez D. M962" ,
"C IT C. Imperatore A.Carusi" ,
C IT Colleverde di Guidonia ,
"C IT Farra dIsonzo L.Bittesini" ,
ES Barcelona David Fernandez-B ,
ES Barcelona Fabra Observatory ,
"C IT Os.PTermini,Montelupo&SV." ,
ES Madrid Jose Gomez Castano ,
C ES LaLagunaIACJavierLicandro ,
ES Castellon Josep Maria Trigo ,
"ES Barcelona Univ. Marc" ,
"C FR Caussols Maury, Alain" ,
C ES LaLaguna IAC Ricard Casas ,
"C IT Sormano (Lecco)" ,
C IT Santa Lucia Stroncone -fi ,
"ES Barcelona Univ.Barc. Xavier"
Message-id: <01IS67JQKUBA97H2AA@BISDnet.jhuapl.edu>
MIME-version: 1.0
Content-transfer-encoding: 7BIT
Posting-date: Fri, 09 Jan 1998 11:52 -0500 (EST)
Priority: urgent
Status: RO
X-Lines: 26
Content-Type: TEXT/PLAIN
Content-Length: 1688

In the message I sent about half an hour ago, I made an error in
the light-time correction, and a typographical error in the text. The
expected times as seen from the Earth for the NEAR sunglints should be
16h 02m 52s (now past - sorry, but at least it's within the time I
stated in my original message) and 21h 28m 03s U.T., probably accurate
to a few seconds. The rest of my earlier "NEAR sunglints - 16:02 . ."
message is copied below so that it can just be replaced with this one.
The S/C slew rate at the possible glint times will be about 0.4
deg./sec., so the duration of any glint will be about a second. Note
that the 2nd glint will occur nearly 2 hours earlier than information
that I distributed earlier, so that a new view of the Earth, and new
topocentric calculations, will be needed for it, and will be posted
later on NEAR's Web site. The predictions also show that the sunglint
will miss the Earth by about 1.2 deg. for both events, but especially
the 2nd one has several tenths of a deg. of uncertainty, at least. In
addition, Sun sensor data indicate that the perpendiculars of NEAR's
solar panels may very well be tilted over a degree from the S/C's "Z"
axis, so a glint, possibly 1/4th as bright as the 12.4 mag. that I
predicted (that is, one solar panel instead of all four), or maybe even
2 glints like that, are possible. Also, the 91% sunlit waxing Moon is
inconveniently located only 8 deg. west and a little south of the field.
Courtney Ray supplied the details for the information above.
Good luck with your observations - in spite of the problems, I hope
someone sees, and perhaps records, something.
David Dunham, NEAR Mission Design


From DunhamDW@space2.spacenet.jhuapl.edu Fri Jan 9 20:36 MET 1998
Received: from aplgate.jhuapl.edu (aplgate.jhuapl.edu [128.244.198.35]) by selene.arcetri.astro.it (8.7.1/8.7.1) with ESMTP id UAA07860 for ; Fri, 9 Jan 1998 20:36:13 +0100 (MET)
Received: from aplcomm.jhuapl.edu ("port 62226"@aplcomm.jhuapl.edu)
by aplgate.jhuapl.edu (PMDF V5.1-10 #22050)
with SMTP id <0EMJ00AF17T8X2@aplgate.jhuapl.edu> for
richichi@selene.arcetri.astro.it; Fri, 9 Jan 1998 14:36:50 -0500 (EST)
Received: from bix003.jhuapl.edu by aplcomm.jhuapl.edu (5.0/SMI-SVR4)
id AA00559; Fri, 09 Jan 1998 14:36:35 -0500
Received: from ffapi.bisdnet.jhuapl.edu by BISDnet.jhuapl.edu
(PMDF V5.0-5 #10436) id <01IS6D3DVQFK97H2AA@BISDnet.jhuapl.edu>; Fri,
09 Jan 1998 14:36:32 -0500 (EST)
Date: Fri, 09 Jan 1998 14:30 -0500 (EST)
From: "Dunham, David W"
Subject: New data for NEAR glint at 21:28:03 UT
To: a Astronomy - Mindspring ,
"Baalke, Ron Science Astro" ,
"a Astron. & Space Forum, MSNet" ,
"Pettee, Kevin (SOM)" ,
SkypubWWW RFienberg UrgentOnly ,
"a Astro.amateur-news Usenet SH" ,
"a Astro-news,Usenet-ShortHeadr" ,
SeeSat ,
Skypub S Goldman
Cc: In Pune IUCAA Arvind Paranjpye ,
In Udaipur SO Arvind Bhatnagar ,
"In Ind.Inst.Sci.,Phys. Jog, C." ,
"In New Delhi Chander B. Devgun" ,
"IT Bologna Di Luca, Roberto" ,
IT all observatories ,
"IT Roma Costa, Claudio" ,
In Pune IUCAA Mridula Chandola ,
IT Pino Torinese Paulo Tanga ,
In Delhi Prasanto Roy ,
IT Catania Piero Massimino a4 ,
IT Catania Piero Massimino ast ,
"IT Firenze Richichi, Andrea" ,
"In Bangalore Vasundhara, R.-2" ,
"IT Milan Cavagna, Marco" ,
In Mumbai Bharat Adur
Message-id: <01IS6D3FQPPA97H2AA@BISDnet.jhuapl.edu>
MIME-version: 1.0
Content-transfer-encoding: 7BIT
Posting-date: Fri, 09 Jan 1998 14:30 -0500 (EST)
Priority: urgent
Status: RO
X-Lines: 41
Content-Type: TEXT/PLAIN
Content-Length: 2180

New topocentric predictions for NEAR are given below in the
same form as the earlier predictions. I have added Kodaikanal Obs.,
India, since with the earlier time, the event might be observed from
India. I have also added the TIRGO Observatory, which requested
predictions for a small-field sensor. And I have removed some
American cities that will now be in daylight.

A new map showing the Earth as seen from NEAR at the new time
for the 21h 28m glint will probably soon be placed on the NEAR Web
site at http://sd-www.jhuapl.edu/NEAR/
Also posted will be a new fine-scale star chart for that event; the
less-detailed charts can be found at the IOTA site,
http://www.anomalies.com/iotandx.htm.

R.A.(J2000) Dec. 1998 U.T.C. Location
o o date h m s
81.8157 20.7329 Jan. 9 21 28 3.0 KODAIKANAL Obs., India
81.8142 20.7322 Jan. 9 21 38 3.0 KODAIKANAL
81.8425 20.7253 Jan. 9 21 28 3.0 MITZPE RAMON, Israel
81.8401 20.7250 Jan. 9 21 38 3.0 MITZPE RAMON (Wise Obs.)
81.8541 20.7709 Jan. 9 21 28 3.0 CAPE, South Africa
81.8516 20.7708 Jan. 9 21 38 3.0 CAPE
81.8472 20.7074 Jan. 9 21 28 3.0 MOSCOW, Russia
81.8454 20.7071 Jan. 9 21 38 3.0 MOSCOW
81.8612 20.7150 Jan. 9 21 28 3.0 TIRGO Obs., Gornergrat,
81.8590 20.7150 Jan. 9 21 38 3.0 TIRGO Obs. Switzerland
81.8650 20.7114 Jan. 9 21 28 3.0 HERSTMONCEUX, England
81.8630 20.7114 Jan. 9 21 38 3.0 HERSTMONCEUX
81.8708 20.7215 Jan. 9 21 28 3.0 SAN FERNANDO, Spain
81.8685 20.7216 Jan. 9 21 38 3.0 SAN FERNANDO
81.8798 20.7263 Jan. 9 21 28 3.0 LA PALMA, Canary Islands
81.8775 20.7265 Jan. 9 21 38 3.0 LA PALMA
81.8956 20.7593 Jan. 9 21 28 3.0 RIO DE JANEIRO, Brazil
81.8937 20.7598 Jan. 9 21 38 3.0 RIO DE JANEIRO
81.9060 20.7299 Jan. 9 21 28 3.0 CARACAS, Venezuela
81.9049 20.7305 Jan. 9 21 38 3.0 CARACAS (near sunset)
81.8888 20.7079 Jan. 9 21 28 3.0 ST. JOHN'S, Newfoundland
81.8875 20.7083 Jan. 9 21 38 3.0 ST. JOHN'S

David Dunham, NEAR Mission Design, 1997 January 9, 19h U.T.