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Vol 6, No. 10                 29 Oct 1996                    ISSN 1065-3597
	  (C) 1996, Regents of the University of California

Notes from the Editor
   by Brett A. Stroozas, EUVE Science Operations Manager

   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 Recent EUVE Science Highlights
    1.2 Abstracts of Recently *Accepted* EUVE Papers
 2. EUVE Science Operations News
    2.1 Public GO/RAP Data Release for 1 Nov 1996
    2.2 On-Line Access to EUVE
 3. EUVE Outsourced Extended Mission (OEM) Status Report
 4. Science Education Notes
    4.1 Science Information Infrastructure Project
    4.2 Interactive University Project
    4.3 Advisory Board Meeting

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 Sep
1996, conducting observations of the following Guest Observer (GO) and
Right-Angle Program (RAP) targets (name and spectral type information
taken from the SIMBAD or internal CEA databases; "NOIDs" are
unidentified objects):

 Target            EUVE           Spectral      Observation
  Name             Name            Type         GMT Date(s)       Notes

QS Tel           EUVE J1938-46.2  CV:AM     31 Aug - 01 Sep 1996  EGO
0006+18          --------         NeutSt    31 Aug - 01 Sep 1996  RAP
V711 Tau         EUVE J0336+00.6  G9V       01 Sep - 11 Sep 1996  EGO,CO1
EUVE J2135+00.8  EUVE J2135+00.8  NOID      01 Sep - 11 Sep 1996  RAP
HU Aqr           EUVE J2108-05.2  CV:AM     11 Sep - 14 Sep 1996  EGO
VY Ari           EUVE J0248+31.1  K0        11 Sep - 12 Sep 1996  RAP
EF Eri           EUVE J0314-22.5  CV:AM     13 Sep - 14 Sep 1996  RAP
C Hale-Bopp      --------         Comet     14 Sep - 19 Sep 1996  EGO,CO2
LB 9802          EUVE J0317-85.5  Star      19 Sep - 21 Sep 1996  EGO
EUVE J2231+017   EUVE J2231+017   NOID      19 Sep - 21 Sep 1996  RAP
Jupiter          --------         SolSys    21 Sep - 24 Sep 1996  EGO,TCO
LB 9802          EUVE J0317-85.5  Star      24 Sep - 29 Sep 1996  EGO
EUVE J2231+017   EUVE J2231+017   NOID      24 Sep - 29 Sep 1996  RAP
QS Tel           EUVE J1938-46.2  CV:AM     29 Sep - 29 Sep 1996  EGO
0006+18          --------         NeutSt    29 Sep - 29 Sep 1996  RAP
BRI 0021-02      --------         M         29 Sep - 02 Oct 1996  EGO
HD 42250         --------         G5        29 Sep - 02 Oct 1996  RAP

Key to Notes:
	EGO = Guest Observer observation
	RAP = Right-Angle Program observation
	CO1 = Observation coordinated with the ASCA, XTE, and HST
		satellites, and with the VLA and other ground-based
	CO2 = Observation coordinated with the IRTF ground-based
	TCO = Time-critical observation

1. EUVE Science News

1.1 Recent EUVE Science Highlights
	by Dr. Pierre Chayer, CEA Scientist


   Drs. Damian Christian, and Stuart Bowyer of CEA, Dr. Peter Vedder
of Omitron, Inc., Dr. Jeremy Drake of the Harvard-Smithsonian Center
for Astrophysics, and Dr. Robert Patterer of the Goddard Space Flight
Center (GSFC) reported on EUVE photometric eclipse observations of AR

   AR Lacertae is a totally eclipsing RS CVn binary composed of a G2IV
and a K0IV star separated by a distance of about 9.2 solar radius. The
orbital period of this system is 1.983 days. Because the orbital
separation is small, tidal viscosity tends to synchronize the stellar
rotation and orbital periods, increasing the rotation rates beyond
typical values for single late-type stars.  This rapid rotation makes
these stars strongly magnetically active and, therefore, strong
sources of chromospheric and coronal emission.

   AR Lacertae was observed with the EUVE scanning and deep survey
telescopes.  The observations cover approximately two orbital periods,
including both primary and secondary eclipses. The deep survey
observation detected a flare at the time of expected secondary
eclipse. The deep survey and scanner observations show a 40% to 60%
reduction in flux, respectively, when the G star is eclipsed by the K
star. There was no discernible decrease in count rate during the
secondary eclipse (i.e., the K star eclipsed by the G star), which
supports the idea previously put forth that the K star has an extended

   The qualitative similarities between the Lexan/B deep survey and
scanner light curves and those derived from observations made with
EXOSAT and the ROSAT PSPC suggest that either these coronal features
are grossly stable over a time scale of years or else the similarities
in the light curves are purely coincidental.

1.2 Abstracts of Recently *Accepted* EUVE Papers

   Included below are abstracts of EUVE-related papers recently
*accepted* for publication.  For those papers authored by CEA
personnel, the CEA publication numbers are indicated.  Unless
otherwise noted, researchers may obtain preprints of the 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;
abstracts will also be posted under the CEA WWW site.  Please send all
abstracts to


T Lanz, M.A. Barstow, I Hubeny, and J.B. Holberg
To appear in Astrophysical Journal.

   The star G191-B2B is one of a number of hot DA white dwarfs whose
atmospheres have been found to contain significant quantities of heavy
elements, including C, N, O, Si, Fe and Ni. Several earlier studies
have measured their abundances using IUE echelle data in conjunction
with synthetic spectra derived from theoretical model atmosphere
calculations of varying degrees of sophistication. However,
predictions of the EUV spectrum based on these observations failed
completely to match either its shape or absolute flux level. We
present here the results of new non-LTE model calculations including
the effects of line blanketing from more than 9 million (mainly Fe and
Ni) transitions.  For the first time, we are able to find an effective
temperature and composition that can consistently match the optical,
far UV and EUV data.  However, to maintain this agreement below the
HeII 228A Lyman limit, it is necessary to incorporate additional HeII
opacity in the form of photospheric, circumstellar or interstellar

M.A. Barstow, P.D. Dobbie, J.B. Holberg, I. Hubeny, and T. Lanz
To appear in Monthly Notices of the Royal Astronomical Society.

   We present a detailed analysis of the EUV spectra of 13 DA white
dwarfs, observed by the EUVE satellite, paying attention to the
possible sources of absorbing material along the lines-of-sight in
both the local interstellar medium and in the photospheres of the
stars themselves.  The range of interstellar column densities seen are
consistent with our previous understanding of the local distribution
of material.  Absorption from interstellar HeII is found in the
direction of five stars, allowing us to measure directly the He
ionization fraction and estimate, indirectly, that of H. The weighted
mean ionization fractions along these lines-of-sight are 0.27 +/- 0.04
and 0.35 +/- 0.1 respectively. Where HeII is directly detected, the
observed ionization fractions are not correlated with direction or
with the volume/column density of material along the line-of-sight.
Furthermore, the limits on the amount of HeII established in all other
directions completely encompass the range of observed values.  Indeed,
all the data can be consistent with more or less constant He and H
ionization fractions throughout the local ISM.  It is clear that there
is little photospheric opacity, from either He or heavier elements, in
the majority of the stars we have studied. This poses further
difficulties in explaining the observed division of white dwarfs into
H- and He-rich groups, the temperature gap in the He-rich sequence and
the detailed spectral evolution of the H-rich DA white dwarfs as they
cool.  A striking observational result is that our spectroscopic
evidence indicates that radiative levitation effects are only
important at temperatures above 50,000 K, rather than the 40,000 K
suggested by broad band photometry. There is clearly an urgent need
for further theoretical work on the mechanisms that determine the
photospheric composition of white dwarf stars.


S. Vennes, D.T. Wickramasinghe, J.R. Thorstensen, D.J. Christian, and
  M.S. Bessell
To appear in Astronomical Journal.  [CEA publication #762]

   We have obtained phase-resolved spectroscopy (3660-6040A) of the
recently discovered cataclysmic variable EUVE J2115-586 using the
74-inch telescope at Mount Stromlo Observatory.  The radial velocity
is modulated over a period of 110.8 min with a possible
one-cycle-per-day alias of 102.8 min, and a semiamplitude of ~270 km/s
at H-beta and ~390 km/s at HeII lambda 4686.  The spectroscopic
appearance (HI Balmer, CaII, HeI, HeII emission lines), the orbital
period, and the velocity amplitude indicate that this cataclysmic
variable is probably an AM Her type; the absence of cyclotron humps
indicates a low intensity magnetic field (B < 20 MG).  Extreme
ultraviolet emission phased at the orbital period shows evidence of
variability, but additional EUV/soft x-ray observations are


I. Hawkins, R. Battle, and R.F. Malina
Presented at the 47th International Astronautical Federation,
  Symposium P: Space and Education, Session 2: Education Structures,
  held in Beijing, 7-11 Oct 1996.  [CEA publication #764]

   We describe a partnership approach in place at UC Berkeley's Center
for Extreme Ultraviolet Astrophysics (CEA) that: (a) facilitates the
adaptation of astrophysics data and information from NASA and other
sources for use in the K-12 classroom, (b) facilitates scientists'
participation in astronomy education, and (c) engages a sustained
collaboration typically including personnel from research
institutions, centers of informal science teaching such as museums and
planetaria, university-based schools of education, and K-12 schools.
We are investigating several ways of engaging scientists in
partnerships for the purpose of making their research results
accessible in appropriate ways to the K-12 community via Internet and
World Wide Web (WWW) technologies. Our investigation addresses the
hypothesis that the transition of scientific data and research results
from the workplace to the classroom can be facilitated by the joint
creation of curriculum materials by teams of cognitive experts,
subject-matter experts, and teachers. In particular, we are
investigating how space science, astronomy, and Earth science research
results can be adapted through a partnership approach into more
effective representations for use in the classroom. Our strategy for
evaluating our partnership approach involves the participation of
personnel from scientific research institutions, centers of informal
science learning, and schools.  We describe several projects led by UC
Berkeley's Center for EUV Astrophysics: "Science On-Line", "Science
Information Infrastructure", and "Satellite Operations Class for
Teachers". Our projects have two primary and complementary components,
namely, implementation in school districts serving students with
wide-ranging socioeconomic backgrounds and a science education
research component based on in-depth project evaluation.  We describe
several specific advantages that arise from a partnership approach in
the context of using the Internet and the WWW as relatively new
authoring and representation media for K-12 curriculum materials.


R.F. Malina
Presented at the 47th International Astronautical Federation, Session
  IAA.11.2: Autonomous Control for Small Satellites, in Beijing, 7-11
  Oct 1996.  [CEA publication #765]

   Since 1994 the NASA Extreme Ultraviolet Explorer Observatory has
operated a Testbed program to test, evaluate and use new operations
technologies which allow the satellite to be operated at lower cost.
The Testbed also provides a test environment where methodologies and
technologies of interest to other programs can be evaluated in an
actual mission operations environment.  Key achievements have been the
reengineering of the EUVE Science Operations Center to allow migration
from around the clock operation to lights out operation; this was
achieved by inserting commercially available artificial intelligence
software.  In 1996, following a proposal from the University of
California, NASA decided to outsource, or transfer, all aspects of
Observatory management and spacecraft operations to the University.
NASA has set three goals for this outsourcing: first that EUVE be
operated in a way by the University which would serve as one model for
future outsourcing of science satellite outsourcings that will be
carried out by NASA to University groups; second that the EUVE
Observatory carry out education activities to involve students at the
University, and use EUVE for education outreach programs to secondary
schools; and third that the EUVE observatory continue to be used as a
Testbed for innovative operations technologies of interest to EUVE and
other missions.  We describe details of the EUVE Testbed program and
outsourcing, identifying lessons learned that may be of interest to
other missions.


S. Vennes, P.A. Thejll, R. Genova Galvan, and J. Dupuis
To appear in Astrophysical Journal.  [CEA publication #766]

   We present new effective temperature and surface gravity
determinations for a sample of 90 hot white dwarfs detected in the
Extreme Ultraviolet Explorer (EUVE) all-sky survey.  The measurements,
based on spectroscopy of the balmer line series obtained at the
Michigan-Dartmouth-MIT observatory (MDM), Mount Stromlo Observatory
(MSO), Lick Observatory, and Cerro-Tololo-Interamerican Observatory
(CTIO), are used to constrain the space density as well as the
population age and mass distribution of a sample of 110 EUV-selected
DA white dwarfs in the solar neighborhood.  We find a mass spectrum
narrowly peaked near 0.56 M_solar, indicative of normal C-O core with
a thin hydrogen layer, and a significant population of 10
ultra-massive (M >= 1.1 M_solar) white dwarfs; we also find that all
objects fall between effective temperatures of ~25,000 and ~75,000 K
and are younger than 30 Myr.  Using Wood's evolutionary models we
determine a DA white dwarf birthrate in the solar neighborhood of
(0.7-1.0)E-12 pc^(-3) yr^(-1).  Although most objects are on normal
C-O cooling tracks, we suggest that a few low-mass white dwarfs and
the population of ultra-massive white dwarfs may follow different
paths with, respectively, He or, possibly, O-Ne-Mg cores.


2. EUVE Science Operations News

2.1 Public GO/RAP Data Release for 1 Nov 1996
        by Dr. Nahide Craig, EUVE User Support Scientist

   The table below lists the GO/RAP observations that become public on
1 Nov 1996.  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 data identification code (GO and RAP
data are marked accordingly).  All public data sets can be ordered
from the 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 the 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.

   Target        ~Exp      Observation Dates      SpT      DataID
    Name        (ksec)    Start           End


  CC Eri          100    13 Sep - 16 Sep 1995     M0Vp     go0416 
  CC Eri           61    16 Sep - 18 Sep 1995     M0Vp     go0417 
  ER Vul          100    20 Sep - 23 Sep 1995     G0V      go0418 
  ER Vul          100    23 Sep - 27 Sep 1995     G0V      go0419 
  ER Vul            5    27 Sep - 27 Sep 1995     G0V      go0420
  PW And          100    27 Sep - 30 Sep 1995     G5       go0421 
  PW And          100    30 Sep - 04 Oct 1995     G5       go0422 
  PW And           30    04 Oct - 05 Oct 1995     G5       go0423 
  Moon              2    05 Oct - 05 Oct 1995     SolSys   go0424 
  kappa Cet       100    06 Oct - 09 Oct 1995     G5V      go0425 
  kappa Cet        95    09 Oct - 13 Oct 1995     G5V      go0426
  EUVE J2112+501  100    13 Oct - 16 Oct 1995     WD:DAw   go0427 
  EUVE J2112+501   17    16 Oct - 17 Oct 1995     WD:DAw   go0428 
  EUVE J2112+501   21    18 Oct - 19 Oct 1995     WD:DAw   go0429 
  EUVE J0922+710    8    19 Oct - 19 Oct 1995     NOID     go0430 
  CGCG0212.0-0100  20    05 Oct - 06 Oct 1995     AGN      go0431


  cma1928+73       27    31 Oct - 01 Nov 1995     AGN      rap0047
  EUVE J0249+099    9    07 Nov - 07 Nov 1995     NOID     rap0048
  EUVE J0002-495   84    07 Nov - 10 Nov 1995     NOID     rap0049
  EUVE J0511+225  122    08 Dec - 13 Dec 1995     NOID     rap0050
  EUVE J0648-482  270    19 Nov - 22 Nov 1995     NOID     rap0051 
  EUVE J0521-104    9    13 Dec - 13 Dec 1995     WD:DA    rap0052 
  LHS 5142          4    21 Jan - 21 Jan 1996     M+       rap0053 
  1121+422        149    21 Jan - 27 Jan 1996     AGN      rap0054 
  1229+204         98    07 Feb - 12 Feb 1996     AGN      rap0055
  LHS 3003         95    16 Mar - 20 Mar 1996     M+       rap0056 
  GD 153          133    03 Mar - 07 Mar 1996     WD:DA    rap0057 
  EUVE J1303+22.4 133    03 Mar - 07 Mar 1996     NOID     rap0058
  EUVE J1250+209  133    03 Mar - 07 Mar 1996     NOID     rap0059 


2.2 On-Line Access to EUVE

   Listed below are the various methods for on-line access to EUVE:

 o CEA World Wide Web (WWW)

   telnet 200 (for those without a WWW browser)

 o anonymous FTP

	Name:  anonymous
	Password:  type_your_full_e-mail_address

 o anonymous gopher


 o EUVE Electronic Newsletters

     Past issues -- available via the 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 CEA can help YOU!  For more information see the CEA
     WWW site or contact the Archive (

 o Public RAP

     The Public Right Angle Program (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 CEA WWW site 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 (OEM) Status Report
	by Brett Stroozas, EUVE Science Operations Manager

   The following are some of the recent OEM highlights from Sep 1996:

 o EPOC FOT hiring -- Hired five of the eight positions for CEA's EUVE
   Platform Operations Center (EPOC) Flight Operations Team (FOT):

        * Rob Nevitt -- Platform Operations Manager
        * Chris Smith -- Attitude Control Subsystems (ACS) Engineer
        * Greg Picard -- Communications and Data Handling (C&DH)
		Subsystems Engineer
        * Marty Eckert -- Spacecraft Controller/Scheduler
        * Paul Travis -- Spacecraft Controller/Scheduler

   Positions remaining to be filled include one Power and Thermal
   Engineer, one Ground Systems Engineer, and one more Spacecraft

 o EPOC FOT training at GSFC -- On Mon, 16 Sep, the five newly-hired
   members of the EPOC FOT began training at GSFC with their
   counterpart from the incumbent Lockheed-Martin FOT.  The EPOC FOT
   members will train at GSFC for one month, return to CEA for two
   weeks, and then return to GSFC for an additional month's worth of
   training.  Training at GSFC for the remaining three open EPOC FOT
   positions will begin as soon as the positions are filled.

 o "epworks" test-bed -- The epworks test-bed was configured in the
   ESOC to run autonomously and continuously on all incoming Explorer
   Platform (EP) telemetry data.  This test-bed uses an AI software
   package called RTworks (which CEA currently uses to monitor the
   science payload telemetry).  Engineers at GSFC have reviewed the
   epworks testbed knowledge base, which will be modified, improved,
   and strengthened accordingly.

 o CMS testing -- A successful preliminary test was conducted with the
   EPOC's Command Management System (CMS) system to verify the payload
   commanding interface.  Execute On Receipt (EOR) commands were sent
   through the CMS system, which generated and filed the appropriate
   microprocessor commands and then replied with the appropriate
   verification messages.

 o TPOCC -- Received notification of approval from GSFC regarding developer
   support to install and configure the Transportable Payload
   Operations Control Center (TPOCC) -- the command and control system
   to be used in the EPOC -- at CEA.  The TPOCC developer at GSFC will
   send three persons to CEA (for 2-3 days each) in mid-Oct to install
   and configure the TPOCC hardware and software systems.

4. Science Education Notes
	by Dr. Isabel Hawkins, CEA Astronomer
			and Science Education Director

4.1 Science Information Infrastructure Project

   Year two of this exciting project is underway. Dr. Carol Christian
(Space Telescope Science Institute) and Dr. Isabel Hawkins (UCB/CEA)
attended the NASA Information Infrastructure and Technology
Applications (IITA) yearly meeting at NASA Headquarters, where the SII
project was highlighted along with other IITA projects. The
Exploratorium, Lawrence Hall of Science, and National Air and Space
Museum continue to develop and pilot-test their classroom modules with
teachers. The Science Museum of Virginia will be developing new
on-line activities based on NASA remote-sensing data.  CEA released an
updated SII World Wide Web Home Page where K-12 resources and other
project information can be found:

4.2 Interactive University Project

   CEA is a member of the UC Berkeley campus-wide coalition - led by
UC Information Systems and Technology - which established the
"Interactive University" to carry out effective outreach to the
surrounding K-12 community. The Interactive University (IU) Project
has become the technological branch of the "Berkeley Pledge" which is
the UCB Chancellor's official outreach program to neighboring school
districts. The IU Project has received funding from the Department of
Commerce Technology Information Infrastructure and Applications
Program (TIIAP) for two years beginning Oct 1996. Dr. Hawkins has
become a key member of the project's management team and CEA has
received funding to pursue its education activities in the areas of
educational evaluation and development of on-line curricula. For its
part in the Interactive University Project, CEA will focus largely on
the SII/Science On-Line Program methodology, which will be adopted by
the San Francisco and Oakland school districts in their professional
development program for science teachers. An important component of
the Interactive University effort will include the design and
implementation of a methodology for the participation and contribution
of scientists and UCB faculty to K-12 education.

4.3 Advisory Board Meeting

   The CEA Education Advisory Board met in Berkeley on 19 Aug
1996. The advisors not only reiterated their recommendation that CEA
continue to focus on Internet and WWW programs, but also advised that
we continue the very worthwhile activities of programs such as the
bilingual "Family Astronomy/Astronomia Para La Familia" project.  The
consensus was very positive, as summarized by Dr. Emily van Zee of the
University of Maryland College of Education: "I have been very
impressed by the work that CEA is doing [in Education], both in the
projects themselves and in your communications about the projects in
papers and presentations." Our next advisory board meeting will take
place at CEA in Jan 1997. We look forward to continue sharing our
progress with our colleagues.

  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.  Newsletter Editor: Brett A.
  Stroozas.  Funded by NASA contract NAS5-29298.  Send newsletter
  correspondence to

  The EUVE project is managed by NASA's GSFC: Paul Pashby, GSFC
  Project Manager; Dr. Yoji Kondo, Project Scientist; Dr. Ronald
  Oliversen, Deputy Project Scientist; Mr. Kevin Hartnett, Mission
  Director.  NASA HQ: Dr. Guenter Riegler, Program Manager.
  Information on the EUVE GO Program is available from Dr. Yoji Kondo,
  Mail Code 684, GSFC, Greenbelt, MD 20771 at (301) 286-6247 or e-mail

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