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Vol. 7, No. 8               31 August 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 EUVE Science Program Management Changes
    1.2 EUVE Detects ALEXIS "Bastille Day" Transient
    1.3 Public GO/RAP Data Release for 1 Sep 1997
    1.4 Abstracts of Recently *Accepted* EUVE Papers
 2. EUVE Satellite Mission Operations News
    2.1 Observation of P/Encke a Major Challenge
    2.2 FOT Successfully Implements Payload ATCs
    2.3 On-Line Access to EUVE
 3. EUVE Outsourced Extended Mission Status Report

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 July
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(*)
RXJ 1856.5-3754 NeutSt  181:22:25 (30 Jun)  Walter       1  EGO
AR Lac          RSCVn   184:13:30 (03 Jul)  White        1  EGO,CO1
P/Encke         Comet   187:09:28 (06 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  190:00:28 (09 Jul)  Walter       1  EGO
P/Encke         Comet   190:09:56 (09 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  190:14:40 (09 Jul)  Walter       1  EGO
P/Encke         Comet   191:11:10 (10 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  191:15:54 (10 Jul)  Walter       1  EGO
P/Encke         Comet   192:10:49 (11 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  192:15:33 (11 Jul)  Walter       1  EGO
P/Encke         Comet   193:10:29 (12 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  193:15:13 (12 Jul)  Walter       1  EGO
P/Encke         Comet   194:10:09 (13 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  194:14:53 (13 Jul)  Walter       1  EGO
P/Encke         Comet   195:09:48 (14 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  195:14:32 (14 Jul)  Walter       1  EGO
ALEXIS Trans    NOID    195:17:47 (14 Jul)  Bloch        1  EGO,TOO,MU3
RXJ 1856.5-3754 NeutSt  195:22:31 (14 Jul)  Walter       1  EGO
P/Encke         Comet   196:11:03 (15 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  196:14:53 (15 Jul)  Walter       1  EGO
QS Tel          CV:AM   197:01:20 (16 Jul)  Rosen        1  EGO
EUVE J1759+428  NOID    197:01:20 (16 Jul)  Lampton      3  RAP
RXJ 1856.5-3754 NeutSt  197:21:45 (16 Jul)  Walter       1  EGO
P/Encke         Comet   198:10:22 (17 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  198:15:05 (17 Jul)  Walter       1  EGO
P/Encke         Comet   199:10:02 (18 Jul)  Lisse        1  EGO,CO2,SCA,TCO
RXJ 1856.5-3754 NeutSt  199:14:45 (18 Jul)  Walter       1  EGO
P/Encke         Comet   200:09:42 (19 Jul)  Lisse        1  EGO,CO2,SCA,TCO
EUVE J2249+585  WD:DA   200:14:25 (19 Jul)  Chayer       1  EGO,SPI
P/Encke         Comet   201:09:22 (20 Jul)  Lisse        1  EGO,CO2,SCA,TCO
EUVE J2249+585  WD:DA   201:14:05 (20 Jul)  Chayer       1  EGO,SPI
Survey          ENG     205:23:53 (24 Jul)  ------       -  CAL,CFG
Her X-1         LMXB    206:04:30 (25 Jul)  Leahy        1  EGO,CON,MU8,TCO
EUVE J2041-368  NOID    206:04:30 (25 Jul)  Dupuis       3  RAP
cmaIH2032-358   AGN     206:04:30 (25 Jul)  Fruscione    3  RAP
EUVE J2249+585  WD:DA   210:12:43 (29 Jul)  Chayer       1  EGO,SPI
lambda And      RSCVn   211:07:30 (30 Jul)  Dupree       1  EGO,CON
  (*) Key to Notes:
	CAL = Science calibration observation
	CFG = Special configuration of science payload instruments
	CO1 = Observation coordinated with the Galileo satellite
        CO2 = Observation coordinated with the ROSAT and XTE
                satellites and with ground observatories
        CON = Contiguous observation
	EGO = EUVE Guest Observer observation
	MU3 = Multiple pointings (3) required for this observation
        MU8 = Multiple pointings (8) required for this "nodded" (up
                and down) dithered observation
	RAP = Right-Angle Program observation
        SCA = Scanner imaging observation
	SPI = Spiral-dithered observation
	TCO = Time-critical observation
	TOO = Target of Opportunity

1. EUVE Science News

1.1 EUVE Science Program Management Changes
	by Dr. Roger Malina, EUVE Observatory Director

   Along with the technical aspects of the outsourcing, the evolution
of the EUVE Project's science management structure has also progressed
over the last year.  The EUVE Science Advisory Board (ESAB) is now
well established, and continues to review and refine science program
operations strategies through regular bi-monthly meetings.  The
following are some of the recent highlights and/or changes:

 o Annual ESAB Meeting at CEA -- The members of the ESAB will meet
   with the EUVE Project at CEA on 1-2 October to review science
   program operations and plans for the upcoming year.  If you have
   questions or issues that you would like to have discussed at this
   meeting, please send them to the ESAB Chair, Professor Steve Howell
   (University of WY;  The other members of
   the ESAB are Dr. Andrea Dupree (Harvard Smithsonian Center for
   Astrophysics), Dr. Jim Liebert (University of AZ), and Professor
   Chris Mckee (University of CA, Berkeley).

 o ESAB Charter -- A Charter for the ESAB has been written and is
   available on the EUVE WWW site at:

   The Charter outlines the rules governing the functioning of the
   ESAB (information on the ESAB members and how to contact them is
   also available in an Appendix).  The Charter contains various
   policy guidelines that are used to govern operation of the EUVE
   observatory, including the following: roles and responsibilities of
   the EUVE Observatory Director (and his Deputy), conflict of
   interest policies and procedures, observation selection parameters,
   data rights, TOO policies, and GO and RAP policies and procedures.

 o RAP Data Proprietary Period -- In order to streamline the
   processing of RAP observations and to support rapid utilization of
   the data, RAP observations conducted as of 15 March 1997 no longer
   have any associated proprietary data period.  CEA will, however,
   continue to notify RAP PIs when their targets have been scheduled,
   and to process and deliver to those PIs their associated RAP data.

 o RAP Data Processing -- Processing of RAP observations since March
   1997 continues to be delayed due to processing queue priorities
   associated with the generation of the permanent EUVE archive.  RAP
   processing is expected to resume as soon as resources allow.
   Observers with a critical need for their RAP data should contact with a justified request for special

 o TOO Bumping Priorities -- The EUVE program has established the
   following "bumping priority" for TOOs in order to minimize their
   impact on coordinated and time-critical observations (observation
   categories are listed from highest priority and least likely to be
   interrupted, to lowest priority and most likely to be interrupted):

	 1. Type 1 pre-approved TOO in progress 
	 2. Director's Discretionary Time (DDT) TOO in progress 
	 3. Type 1 coordinated observation 
	 4. DDT coordinated observation 
	 5. Type 2 coordinated observation 
	 6. Type 1 time-critical observation 
	 7. DDT time-critical observation 
	 8. Type 1 contiguous observation 
	 9. DDT contiguous observation 
	10. Type 1 ordinary observation 
	11. DDT ordinary observation 
	12. Type 2 time-critical observation 
	13. Type 2 contiguous observation 
	14. Type 2 ordinary observation 
	15. Calibration observation 
	16. Testbed experiment 
	17. Engineering test 

1.2 EUVE Detects ALEXIS "Bastille Day" Transient
	by Brett A. Stroozas, EUVE Mission/Flight Director

   Since its launch on 25 April 1993, the ALEXIS satellite has been
detecting transient EUV sources (see the ALEXIS WWW site at for the mission's
objectives and other related information).  The rapid fall-off of the
intensity of these detections make these transients especially
interesting to scientists.  Since early 1996, in support of an
approved EUVE GO proposal from the ALEXIS team, the EUVE Project has
carried out TOOs to ALEXIS transient detections; the ALEXIS team has
called five EUVE TOOs so far this year.  Unfortunately, EUVE TOO
response has never been rapid enough to detect the ALEXIS transient.
This situation changed, however, on 14 July with the EUVE detection of
the so-called ALEXIS "Bastille Day" Transient.

   During the observation of this transient on 14 July EUVE detected a
weak but highly significant source very near the ALEXIS source
position.  Various sanity checks were conducted to verify that the
source was real.  Everyone is very excited about this EUVE detection
and the nature of the underlying source.  The ALEXIS team is currently
conducting follow-up analysis and additional ground-based
observations.  Further information on the EUVE detection of this
transient is available on the WWW at

   Rapid response time is critical in order to catch these transients
in action.  EUVE's TOO response to the Bastille Day Transient was the
Project's fastest ever.  At 8:38am Pacific time on that day the EUVE
Flight Operations Team (FOT) received preliminary notification of a
possible EUVE TOO opportunity from the ALEXIS team, who formally
called an EUVE TOO at 9:39am.  By 10:30am the EUVE FOT had completed
all the necessary planning and scheduling activities, and had uploaded
the relevant information to the EUVE spacecraft.  The observation of
the ALEXIS transient began just minutes later, at 10:47am.  This rapid
TOO response -- 2 hours and nine minutes between the preliminary
notification to "first light" (and only one hour and eight minutes
after the TOO was formally called) -- was a new record for the EUVE

   Historically, the typical EUVE TOO response time was ~8 hours,
which is comparable with that of other satellites.  Late last year CEA
worked with the pre-outsourced FOT at GSFC to cut EUVE TOO response in
half to ~4 hours (note that due to budgetary considerations TOOs are
restricted to the staffed day shift).  Since completion of the
outsourcing and the integration of payload and spacecraft operations
at UCB, CEA has been able to further cut this response nearly in half
once again to the current average of ~2.5 hours.  Although we know of
no published survey of satellite TOO response times, those of the EUVE
Project would surely be near -- if not at -- the top.

1.3 Public GO/RAP Data Release for 1 Sep 1997
        by Dr. Nahide Craig, EUVE User Support Scientist

   The table below lists the GO/RAP observations that become public on
1 Sep 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 Principal
Investigators (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 Observations -----

  EUVE J2206+63.7    25   08 Dec - 09 Dec 1996    NOID     go0582
  2EUVE J0908+32.6   25   09 Dec - 10 Dec 1996    NOID     go0583
  NGC 4051           80   11 Dec - 14 Dec 1996    AGN:Sy1  go0584
  PC 0025+0447       17   22 Dec - 23 Dec 1996    M        go0585
  PC 0025+0447       63   25 Dec - 27 Dec 1996    M        go0586
  ACO 1795          106   03 Feb - 07 Feb 1997    ClGal    go0587
  HU Aqr            144   23 Oct - 28 Oct 1996    CV       go0588     
  NGC 246           100   28 Oct - 31 Oct 1996    PlanNeb  go0589

		   ----- Cycle 3 Observations -----

  QQ Vul            144   11 Aug - 16 Aug 1996    XRB      go0590 **
  QQ Vul            144   16 Aug - 21 Aug 1996    XRB      go0591 **

	** --> Scanner observation


  EUVE J0249+099     25   09 Dec - 10 Dec 1996    NOID     rap0124
  EUVE J0642-046     82   23 Jan - 26 Jan 1997    NOID     rap0125
  CN Leo            110   26 Jan - 29 Jan 1997    M6V:e    rap0126


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


J.J.Drake, A. Fruscione, M.G. Hoare, and P. Callanan
To appear in Astrophysical Journal.

   We report on the analysis of a deep Extreme Ultraviolet Explorer
(EUVE) observation made with the Deep Survey and Spectrometer
telescope which included in the field the remarkable bright extreme
ultraviolet (EUV) transient source RE J1255+266 discovered in 1994
June by the ROSAT Wide Field Camera (WFC).  A careful analysis of the
resulting Deep Survey (DS) Lexan/B (67-178 A) image, whose aggregated
exposure time is 137 ks, has not revealed any trace of the source, but
has yielded a quite stringent formal upper limit on the quiescent EUVE
DS count rate of 0.003 count/s (3 sigma), and a "visual" upper limit
of 0.002 count/s.  An analysis based on black body spectra, pure
hydrogen DA white dwarf models, and optically thin plasma model
spectra has provided constraints on the source counterpart.  The
observed count rate upper limit is consistent with the optical
identification proposed by Watson et al. in which a DA white dwarf is
the primary component of a CV-like system involving a very low mass M
dwarf secondary star.  Our upper limit to the EUVE DS count rate, when
compared with the count rate observed with the ROSAT WFC at the peak
of the outburst, implies a brightening of the EUV source flux relative
to quiescence by a factor >54000.


2. EUVE Satellite Mission Operations News
	by Brett A. Stroozas, EUVE Mission/Flight Director

   The month of July was, once again, a very busy one for EUVE mission
operations.  The Observatory conducted observations of twelve separate
targets -- eight GO and three RAP targets, and one engineering test.
These targets included an ALEXIS TOO (described above), coordinated
observations of AR Lac (with the Galileo satellite) and Comet P/Encke
(see below), and a "nodded" dithered multi-pointing observation of Her
X-1.  The observation of Comet P/Encke posed a special challenge and
is discussed below.  Another topic that warrants special discussion is
the (final!) successful implementation of payload absolute time
commands (ATCs).

2.1 Observation of P/Encke a Major Challenge

   During the period of 6-20 July the EUVE Observatory conducted
observations of the periodic comet P/Encke.  The science goals of this
observation dictated that it be conducted with the scanning imaging
telescopes instead of the primary GO instrument, the deep/survey
spectrometer telescope.  The observation was also time-critical, being
coordinated with the ROSAT and XTE satellites as well as with various
ground-based observatories.  P/Encke, a moving target, required ~80
separate and individual pointings, and was conducted as one 3-day
continuous observation followed by brief monitoring observations (~3
orbits each) almost every day over the course of the subsequent two

   These various constraints, when interspersed and juggled with the
other observations conducted during this same time period, made this
observation a major challenge for the UCB FOT to plan, schedule, and
implement.  The FOT, however, successfully pulled it off without any
major problems.

2.2 FOT Successfully Implements Payload ATCs

   In last month's newsletter (Vol. 7, No.7; Section 2.3) we discussed
the 26 June reset of the payload command, data, and power (CDP) unit,
which was the result of the on-board execution of a "bad" payload ATC
load; this, in turn, was a result of a bug in some ground software
that has since been patched.  During the month of July the FOT used
this patched software to generate and remotely test payload ATC
execution using the Explorer Platform (EP) spacecraft simulator (with
its attached payload CDP) at GSFC.  These tests were a qualified
success, although the simulator setup provided only limited visibility
into the flight EP/CDP interface.

   To allow engineers to properly verify ATC execution, the FOT then
conducted a follow-on "operational test" that consisted of dumping the
payload RAM via ATC during a realtime contact with the satellite.
This test was a complete success.  The FOT subsequently used payload
ATCs to reconfigure for the Her X-1 observation that started later
that day, and we plan to use them on an ongoing basis from now on.

   This final successful implementation of payload ATCs is *long*
overdue -- literally by years!  On multiple occasions in the past CEA
had attempted to implement payload ATCs.  The major hurdle was always
the complications of implementing payload ATC software at CEA with the
relevant interfaces with the FOT and systems at GSFC.  Since all
spacecraft operations are now conducted at UCB, there is no need for
such interface software and the problem was significantly simplified
-- a very valuable lesson learned!

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 paragraphs describe some of the
outsourcing highlights from July 1997.

   On 3 July UCB received from GSFC a new software release (v4.4a) for
the Transportable Payload Operations Control Center (TPOCC) that is
used to command and control the spacecraft.  The FOT installed this
release on the backup TPOCC equipment "string" at CEA, and is
conducting full operational testing.  In general, v4.4a is running
well; it includes a number of improvements over the previous release
(v4.3), the most notable one being a significant improvement (>5x) in
the speed of TPOCC's command processing.  A number of minor issues and
a few major ones remain open.  The UCB FOT and the GSFC TPOCC
development team continue to work together to resolve and test these
issues for the final GSFC-funded EUVE-specific TPOCC release (v4.4b)
that is scheduled for later this year.  During the last year the
GSFC's development team has done an outstanding job in support of
TPOCC for UCB and the outsourced EUVE mission -- we owe them our

   Also, on 15 July UCB received from GSFC a new software release
(v5.1) for the Generic Trend Analysis System (GTAS).  This system
works with TPOCC to provide a trend analysis tool for use by
spacecraft engineers.  The FOT immediately installed the new GTAS
release and is using it in 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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