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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
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Vol. 7, No. 9 29 September 1997 ISSN 1065-3597
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(C) 1997, Regents of the University of California
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Notes from the Editor
=====================
by Brett A. Stroozas, EUVE Mission/Flight Director
Welcome to the electronic newsletter for NASA's Extreme Ultraviolet
Explorer (EUVE) satellite, compiled and published monthly by the
Center for EUV Astrophysics (CEA) at the University of California,
Berkeley (UCB). The contents of this issue of the EUVE electronic
newsletter are as follows:
1. EUVE Science News
1.1 ESAB Meeting to be Broadcast Live on Internet
1.2 EUVE/ALEXIS Transient Reobserved
1.3 Public GO/RAP Data Release for 1 October 1997
1.4 Abstracts of Recently *Accepted* EUVE Papers
2. EUVE Satellite Mission Operations News
2.1 EUVE Observes Moon as Science Calibration
2.2 FOT Revises Tape Recorder Management Strategy
2.3 On-Line Access to EUVE
3. EUVE Outsourced Extended Mission Status Report
3.1 UCB Makes Progress on PACOR Replacement
3.2 Tape Recorder Scheduling Software Overhauled
To comment on or make suggestions for the EUVE electronic newsletter,
please send e-mail to ceanews@cea.berkeley.edu (Internet).
The EUVE observatory performed well throughout the month of August
1997, completing and/or beginning observations of the following Guest
Observer (GO) and Right-Angle Program (RAP) targets. For each target
is listed its name, its spectral type (generally from the SIMBAD
database), the observation start day/time (day-of-year:hours:minutes),
name of Principal Investigator (PI), observation type/priority, and
any relevant notes:
=======================================================================
Target SpT GMT Start PI T Notes(*)
=======================================================================
lambda And RSCVn 211:07:30 (30 Jul) Dupree 1 EGO,CON
HU Aqr CV:AM 215:18:50 (03 Aug) Schwope 1 EGO
lambda And RSCVn 219:03:18 (07 Aug) Dupree 1 EGO,CON
ALEXIS (re-obs) NOID 226:04:10 (14 Aug) Bloch 1 EGO,TOF
HD 5294 G5 226:04:10 (14 Aug) Portier 3 RAP
Moon moon 226:16:45 (14 Aug) ------ - CAL,CFG,MOV,MUL,TCO
EUVE J0053-330 WD:DA 226:16:45 (14 Aug) Vennes 3 RAP
QS Tel CV:AM 226:19:50 (14 Aug) Rosen 1 EGO,CON
0006+18 NeutSt 226:19:50 (14 Aug) Edelstein 3 RAP
Abell 4038 ClGal 227:08:31 (15 Aug) Lieu 2 EGO
LHS 3494 M5.5Ve 227:08:31 (15 Aug) Mathioudakis 3 RAP
LHS 3495 M5.5V 227:08:31 (15 Aug) Mathioudakis 3 RAP
PSR J2144-3939 NeutSt 229:17:28 (17 Aug) Bowyer 2 EGO
PSR J2124-3358 NeutSt 230:10:40 (18 Aug) Bowyer 2 EGO
EUVE J1958+550 NOID 230:10:40 (18 Aug) Lampton 3 RAP
lambda Sco B2IV+ 231:00:50 (19 Aug) Berghoefer 2 EGO
ALEXIS Trans NOID 234:00:00 (22 Aug) Bloch 1 EGO,MU3,TOO
lambda Sco B2IV+ 234:04:38 (22 Aug) Berghoefer 2 EGO
AR Psc G5 238:14:14 (26 Aug) Dupree 1 EGO,CON
=======================================================================
(*) Key to Notes:
CAL = Calibration observation to map diffuse response and dead
spot of deep survey detector
CFG = Special payload configuration required for this
observation
CON = Contiguous observation
EGO = EUVE Guest Observer observation
MOV = Moving target
MUL = Two-orbit observation of moving target that requires
multiple pointings (7 per orbit, 14 total)
MU3 = Observation requires multiple (3) pointings
RAP = Right-Angle Program observation
TCO = Time-critical observation
TOF = Follow-up observation of previous Target of Opportunity
TOO = Target of Opportunity
1. EUVE Science News
====================
1.1 ESAB Meeting to be Broadcast Live on Internet
-------------------------------------------------
by Dr. Michael Gunter, EUVE Project Manager
Log on, tune in, and catch up on the latest information on NASA's
EUVE satellite. UCB/CEA invites you to attend our second meeting of
the EUVE Science Advisory Board (ESAB) to be broadcast on the
Internet. The EUVE broadcast can be viewed from anywhere using an
Intel PC or Macintosh and TCP/IP connection to the Internet. For best
results, the TCP/IP connection should be at least 28.8 Kbps. Demo
software (Enhanced CU-SeeMe) for viewing the broadcast can be obtained
at:
http://www.wpine.com
The reflector address for the meeting is:
angel.cea.berkeley.edu
Please join us on Thursday, 2 October 1997. The meeting begins at 8:00
am PDT.
1.2 EUVE/ALEXIS Transient Reobserved
------------------------------------
As reported in last month's issue (V7#8, Section 1.2 -- EUVE
Detects ALEXIS "Bastille Day" Transient), on 14 July a TOO observation
resulted in EUVE's detection of a source very near the position of an
ALEXIS transient. This was the first time -- in half a dozen attempts
(including another one later in the month on 22 August) -- that EUVE
has detected an ALEXIS transient source. On 14 August EUVE conducted
a follow-up reobservation of that transient's position, but this time
detected nothing. The scientific implication of these positive and
negative detections, one month apart, are under review by EUVE and
ALEXIS scientists.
1.3 Public GO/RAP Data Release for 1 October 1997
-------------------------------------------------
by Dr. Nahide Craig, EUVE User Support Scientist
The table below lists the GO/RAP observations that become public on
1 October 1997. For each observation is given the target name, the
approximate exposure time in ksec, the GMT start/end dates, the
target's spectral type, and the assigned data identification code (GO
and RAP data are marked accordingly). All public data sets can be
ordered from the EUVE Science Archive via WWW and electronic or postal
mail (see addresses below). Please be sure to include in your order
the DataID(s) of interest. Processed data sets are shipped via postal
mail on 8mm tape or, if requested, on CD-ROM.
The data rights policies for observations state that PIs have
proprietary rights to their data for a given period of time from the
date (s)he receives it. It is often the case that long observations
are broken up over many months; e.g., an observation approved for 60
ksec may actually be observed for 10 ksec one month, 20 ksec the next,
and 30 ksec three months later. In such cases the proprietary period
begins after the PI is sent the final piece of the completed
observation; note that, per the new ESAB policy, RAP targets observed
as of 15 Mar 1997 do *not* have associated proprietary periods. See
the UCB/CEA WWW site (address below) for a complete list of publicly
available EUVE data products.
===============================================================
Target ~Exp GMT Observation Dates SpT DataID
Name (ksec) Start End
===============================================================
GO DATA SETS AVAILABLE 1 OCTOBER 1997:
***** Cycle 4 Targets *****
NGC 246 62 02 Aug - 05 Aug 1996 PlanNeb go0592
NGC 246 17 09 Aug - 10 Aug 1996 PlanNeb go0593
Moon 1 20 Dec - 20 Dec 1996 Moon go0594
Moon 1 21 Dec - 21 Dec 1996 Moon go0595
Moon 1 22 Dec - 22 Dec 1996 Moon go0596
Moon 1 23 Dec - 23 Dec 1996 Moon go0597
Moon 1 26 Dec - 26 Dec 1996 Moon go0598
Moon 1 27 Dec - 27 Dec 1996 Moon go0599
Moon 1 28 Dec - 28 Dec 1996 Moon go0600
Moon 1 29 Dec - 29 Dec 1996 Moon go0601
GJ 205 226 03 Jan - 11 Jan 1997 M1.5V go0602
GJ 205 256 13 Jan - 23 Jan 1997 M1.5V go0603
HD 12230 194 23 Jan - 29 Jan 1997 F0Vn go0604
Alexis 5 4 28 Jan - 28 Jan 1997 NOID go0605
V471 Tau 119 30 Jan - 03 Feb 1997 K0 go0606
gamma Tau 128 07 Feb - 11 Feb 1997 K0IIIa go0607
2EUVE J0512-00.6 195 12 Feb - 19 Feb 1997 WD:DA go0608
GD 71 121 18 Dec - 22 Dec 1996 WD:DA go0609
GD 71 43 19 Feb - 21 Feb 1997 WD:DA go0610
GJ 205 21 23 Feb - 24 Feb 1997 M1.5V go0611
alpha Cen 115 10 Mar - 14 Mar 1997 G+... go0612 *
HZ 43 33 25 Jun - 26 Jun 1997 WD:DA go0613 *
***** Cycle 3 Targets *****
VY Ari 27 11 Sep - 12 Sep 1996 K0 go0614 +
EF Eri 28 13 Sep - 14 Sep 1996 CV:AM go0615 +
----------------------------------------------------------------
RAP DATA SETS AVAILABLE 1 OCTOBER 1997:
1217+023 264 27 Mar - 05 Apr 1996 AGN rap0127
1136+1551 4 11 Apr - 11 Apr 1996 NeutSt rap0128
HD 97334 128 07 Feb - 11 Feb 1997 G0V rap0129
Mrk 421 128 07 Feb - 11 Feb 1997 AGN rap0130
EXO0317+1834 8 11 Feb - 11 Feb 1997 AGN rap0131
HD 88746 14 12 Feb - 12 Feb 1997 G8V rap0132
================================================================
Notes:
"*" indicates calibration observation
"+" indicates scanning telescope imaging observation
1.4 Abstracts of Recently *Accepted* EUVE Papers
------------------------------------------------
by Brett A. Stroozas, EUVE Mission/Flight Director
Included below are abstracts of EUVE-related papers recently
*accepted* for publication. For those papers authored by UCB/CEA
personnel, the UCB/CEA publication numbers are indicated. Unless
otherwise noted, researchers may obtain preprints of the UCB/CEA
papers by sending an e-mail request containing the publication
number(s) of interest to pub@cea.berkeley.edu.
Researchers are encouraged to contribute *accepted* EUVE-related
abstracts for inclusion in future editions of this newsletter and for
posting under the UCB/CEA/EUVE WWW site. Please send all abstracts to
archive@cea.berkeley.edu.
--------------------------------------------------------------
DETECTION OF SOFT X-RAYS AND A SENSITIVE SEARCH FOR NOBLE GASES IN
COMET HALE-BOPP (C/1995 O1)
V.A. Krasnopolsky, M.J. Mumma, M. Abbott, B.C. Flynn, K.J. Meech, D.K.
Yeomans, P.D. Feldman, and C.B. Cosmovici
Science, 277, 1488 - 1491, 1997.
An image of comet Hale-Bopp (C/1995 O1) in soft x-rays reveals a
central emission offset from the nucleus, as well as an extended
emission feature that does not correlate with the dust jets seen at
optical wavelengths. Neon was found to be depleted in the cometary
ice by more than a factor of 25 relative to solar abundance, which
suggests that ices in Hale-Bopp formed at (or later experienced)
temperatures higher than 25 Kelvin. A helium line emission at a
wavelength of 584 angstroms was detected and may be attributable to
charge transfer of solar wind alpha particles in the cometary coma.
Ionized oxygen and another helium line contribute to an emission
observed at 538 angstroms.
--------------------------------------------------------------
HALE-BOPP'S TEPID BIRTHPLACE
In "Newsnotes", Sky and Telescope, V94, No. 4 (October 1997), p. 24.
Did Comet Hale-Bopp (C/1995 O1) originate in the Kuiper Belt beyond
Neptune or in the more distant Oort Cloud? Astronomers have leaned
toward the latter source because the comet's orbit is so large and
highly inclined.
This supposition has now been strengthened by spectra from the
Extreme Ultraviolet Explorer (EUVE) satellite, which homed in on the
comet last September. EUVE did not detect any neon in Hale-Bopp's
outflowing gas and dust. While the gas may not have been completely
absent, its abundance relative to oxygen was no more than 1/25 that
observed in the Sun.
Neon is a sensitive indicator of formation temperature: at 25
degrees Kelvin it condenses to ice and incorporates readily into a
cometary nucleus or other solid body. The observing team, led by
Michael J. Mumma and Vladimir A. Krasnopolsky (NASA/Goddard Space
Flight Center), concludes that the comet must have formed in an
environment too warm for neon to freeze out. That apparently rules
out an origin within the frigid Kuiper Belt, the huge band of cometary
objects beyond the orbit of Neptune. But it's a good temperature
match to a location somewhat nearer the Sun. So Hale-Bopp's lack of
neon supports the notion that Oort Cloud comets originated in the
vicinity of Uranus and Neptune, only to be flung thousands of
astronomical units outward after close planetary encounters.
--------------------------------------------------------------
2. EUVE Satellite Mission Operations News
=========================================
by Brett A. Stroozas, EUVE Mission/Flight Director
The month of August was a relatively smooth one for EUVE mission
operations. During the month the EUVE Observatory conducted
observations of 17 separate targets -- 12 GO, 6 RAP, and one science
calibration. The following subsections discuss a few of the month's
highlights.
2.1 EUVE Observes Moon as Science Calibration
---------------------------------------------
On 14 August EUVE conducted a special calibration observation of
the Moon. The purpose of this observation was to collect some
baseline data on the deadspot region and the surrounding area on the
deep survey (DS) detector. This calibration required that the payload
be configured such that only the DS instrument was on (all six others
off) and that the DS "rate-shutdown" parameters be opened wide in
order to handle the high count rates from the Moon. This payload
configuration required that new rate-shutdown commands be built,
tested, and released. The calibration was then conducted as planned,
after which the payload was reconfigured back to its nominal state for
the subsequent QS Tel observation. Analysis of the resulting
calibration data is in progress.
2.2 FOT Revises Tape Recorder Management Strategy
-------------------------------------------------
During the month the EUVE Flight Operations Team (FOT) revised its
strategy for managing the on-board tape recorders (TRs). This
revision is in response to the TR electronics units (EU) consistently
operating warm and near their associated upper yellow limits (>45
degrees C).
The new TR management strategy includes two major revisions: (1)
the FOT will schedule (where possible) a period of at least one full
orbit between TR record and dump operations in order to minimize
heating effects; and (2) the FOT will once again begin routinely
dumping the TRs at 512 Kbps (instead of 1024 Kbps). This revised
strategy is already paying off in lower EU operating temperatures.
In implementing the above changes the EUVE Project continued to
receive excellent support from GSFC's Network Control Center (NCC).
The NCC is responsible for managing the scheduling of realtime
contacts between user spacecraft -- like EUVE -- and NASA's Tracking
and Relay Data Satellite (TDRSS) network. To help support the revised
EUVE TR management strategy, the NCC has granted the EUVE Project two
new services: (1) a new configuration code for scheduling TDRSS events
that will preconfigure the ground systems for TR dumps at 512
kilobits/second; and (2) a third "critical science" event that gives
the EUVE FOT additional priority and flexibility when scheduling TR
dump times. The EUVE Project sends along a hearty "thanks" to the NCC
team for their continued excellent support of the mission.
2.3 On-Line Access to EUVE
--------------------------
Listed below are the various methods for on-line access to EUVE:
o UCB/CEA WWW URL: http://www.cea.berkeley.edu/
o anonymous FTP: ftp.cea.berkeley.edu
o EUVE Electronic Newsletters
Past issues -- available via the UCB/CEA WWW site
Subscriptions -- mail majordomo@cea.berkeley.edu ("subscribe
euvenews")
Post message (moderated) to all subscribers:
mail euvenews@cea.berkeley.edu
o GI Program
Are you interested in finding out about or using EUVE data? Do
you need help in understanding EUVE data sets? Do you need help
in using the available EUVE data analysis software tools? If you
answer "yes" to any of the above, the Guest Investigator (GI)
Program at UCB/CEA can help YOU! For more information see the
UCB/CEA WWW site or contact the EUVE Science Archive
(archive@cea.berkeley.edu).
o Public RAP
The Public RAP is a simple and easy method for researchers to
propose for long-exposure EUVE imaging data. For more
information on the Public RAP and the simple proposal process see
the UCB/CEA WWW site (address below) or contact the EGO Center
(egoinfo@cea.berkeley.edu). Mail all proposals to
euverap@cea.berkeley.edu.
o Contact information for the EUVE Science Archive or EGO Center:
Center for EUV Astrophysics
2150 Kittredge St.
Berkeley, CA 94720-5030
510-642-3032 (voice)
510-643-5660 (fax)
archive@cea.berkeley.edu
egoinfo@cea.berkeley.edu
3. EUVE Outsourced Extended Mission Status Report
=================================================
by Brett Stroozas, EUVE Mission/Flight Director
Work continues to clean up the remaining open issues from the
outsourcing of EUVE Explorer Platform (EP) spacecraft operations from
GSFC to UCB/CEA. The following subsections describe some of the
outsourcing highlights from August 1997.
3.1 UCB Makes Progress on PACOR Replacement
-------------------------------------------
Since launch, GSFC's PACOR (Packet Processor) facility has been
responsible for packaging and routing to UCB all science telemetry.
As the final part of the successful outsourcing of EUVE spacecraft
operations from GSFC, UCB programming and FOT personnel have been
working to outsource the PACOR functions as well. Significant
progress was made during the month and a full-up prototype system has
been implemented that, over the course of the next month or so, will
be refined and tested. UCB continues to strive toward a 1 October
completion date on this project.
3.2 Tape Recorder Scheduling Software Overhauled
------------------------------------------------
During the month one of the UCB undergraduate students (Ken Tateno)
supporting EUVE mission operations completely overhauled the software
developed a few years ago at GSFC to support the move to an
orbital-night-data-only tape recording strategy. The newly revised
software, which runs under Sun/UNIX instead of the original VAX/VMS,
is much more flexible and robust, and further simplifies the overall
data product processing path. The FOT has exhaustively tested the new
version and is now using it in daily operations.
--------------------------------------------------------------------------
The EUVE Electronic Newsletter is issued by the Center for Extreme
Ultraviolet Astrophysics, University of California, Berkeley, CA
94720, USA. The opinions expressed are those of the authors. EUVE
Principal Investigators and Newsletter Publishers: Dr. Roger F.
Malina and Professor Stuart Bowyer. EUVE Newsletter Editor: Brett
Stroozas. Funded by NASA/UCB Cooperative Agreement NCC5-138. Send
newsletter correspondence to ceanews@cea.berkeley.edu.
The EUVE project is managed for NASA by UCB: Dr. Roger F. Malina,
EUVE Observatory Director; Dr. John Vallerga, EUVE Observatory
Deputy Director; Dr. Mike Gunter, EUVE Project Manager; Mr. Brett
Stroozas, EUVE Mission/Flight Director; Mr. Rob Nevitt, EUVE
Operations Manager. NASA HQ: Dr. Guenter Riegler, Program Manager.
EUVE Science Advisory Board: Dr. Steve Howell (Chair).
END-----------EUVE------------ELECTRONIC---------------NEWS-------------END
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