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Vol. 7, No. 9             29 September 1997                  ISSN 1065-3597
	  (C) 1997, Regents of the University of California

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 (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
	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

The reflector address for the meeting is:

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

		     ***** 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 +

  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
	"*" 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

   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


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.


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

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 anonymous FTP:

 o EUVE Electronic Newsletters

     Past issues -- available via the UCB/CEA WWW site
     Subscriptions -- mail ("subscribe
     Post message (moderated) to all subscribers:

 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

 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
     (  Mail all proposals to

 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)

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

  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).


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