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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
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Vol 4, No. 4 12 April 1994 ISSN 1065-3597
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Notes from the Editor
=====================
by Brett A. Stroozas, Data Analysis Support Staff (DASS)
and Archive Manager
Welcome to the electronic newsletter for NASA's Extreme Ultraviolet Explorer
satellite (EUVE), which is compiled and published monthly by the EUVE Public
Science Archive group at the Center for EUV Astrophysics (CEA) in Berkeley,
CA. The EUVE observatory continued to perform extremely well throughout the
month of March, completing observations of the following Guest Observer (GO)
targets: Epsilon and Beta CMa, G191-B2B, Procyon, Vela SNR, Jupiter,
RE0623-374, HZ43, Moon, Alpha, and Beta Cen. There were also brief pointed-
and survey-mode observations during the month for the purposes of trending and
calibrating the satellite's star trackers and sun sensors. EUVE reached a
major milestone on Sunday, 27 March, completing its 10,000th orbit!
The contents of this issue of the EUVE electronic newsletter are as follows:
1. Next EUVE User's Committee Meeting
2. May/June Releases of GO Archival Data
3. The Beta Cen Mystery: Evidence for Recent Degradation of the Al/Ti/C
Filter of Scanner A
4. First Hardware Failure on EUVE
5. Notes from the EUVE Guest Observer Center
6. Notes from the EUVE Public Science Archive
7. Abstracts of Recently *Accepted* EUVE Papers
8. CEA Job Listings
To comment on, make suggestions for, or request subscriptions to the EUVE
electronic newsletter, send e-mail to ceanews@cea.berkeley.edu (Internet).
1. Next EUVE User's Committee Meeting
=====================================
by Dr. Ron Oliversen, Deputy Project Scientist at GSFC
The EUVE User's Committee will meet at Goddard Space Flight Center (GSFC)
on 12 and 13 May. If there are any issues and/or concerns you wish to have
discussed, please contact any of the Committee members (listed below) or the
Project Science Office.
Name e-mail Institution
---------------------- -------------------------------- ------------------
Shipman, Harry (Chair) harrys@strauss.udel.edu U Delaware
Brown, Alex ab@jila.colorado.edu U Colorado
Bruhweiler, Fred bruhweiler@iue.dnet.nasa.gov Catholic U
Cassinelli, Joe cassinelli@madraf.astro.wisc.edu U Wisconsin
Doschek, George doschek@11334.dnet.nasa.gov Naval Research Lab
Dupree, Andrea dupree@cfa.harvard.edu SAO/CfA
Hall, Doyle dthall@pha.jhu.edu Johns Hopkins U
Holberg, Jay holberg@looney.lpl.arizona.edu U Arizona/LPL
Howell, Steve howell@frankenstein.psi.edu Planetary Sci Inst
Judge, Phil judge@hao.ucar.edu HAO/NCAR
Liebert, Jim liebert@as.arizona.edu U Arizona
Nousek, John nousek@astro.psu.edu Penn State U
Polidan, Ron polidan@aesop.gsfc.nasa.gov NASA/GSFC
2. May/June Releases of GO Archival Data
========================================
by Brett Stroozas, DASS/Archive Manager
Beginning on 1 May, proprietary data rights for GO observations begin to
expire. The table below lists those pointings which will go public in May and
June. This list is identical to that which was distributed in the recent news
"flash" (V4#3a, 25 March) except for the following changes:
o HR1099, a calibration and GO target, has been pulled from the release list.
Calibration observations may, in general, be released earlier than the one
year proprietary period. In the case of HR1099, the GO had been awarded
time in addition to that requested for calibration purposes and, therefore,
warrants additional time for the analysis of this observation.
o The February, 1993 observation of WD1254+223 will be released on 1 June
(instead of 1 May), in line with the one-year proprietary period.
The table below lists a total of 38 pointings to be released, 14 in May and 24
in June. Each entry corresponds to the data for one continuous observation
pointing, typically stored on one 8mm tape. The columns in the table below
are as follows:
o Name -- Name of target. Those names preceded by "*" were also calibration
pointings in the Lex/B filter (on or near boresight); those with "x" were
used for calibrating the Al/C filter (far off boresight).
o Exp -- Approximate exposure time in ksec (actual exposure varies by
spectrometer channel).
o RA -- Target Right Ascension (J2000) in decimal degrees.
o DEC -- Target Declination (J2000) in decimal degrees.
o Q -- Flag indicating the quality of the science data products (see below).
o DataID -- Unique identification code assigned to each pointing. These codes
should be used when ordering data sets.
------------------------------------------------------------------
Name Exp RA DEC Q DataID
------------------------------------------------------------------
Data Sets Available 1 May 1994:
CHI_ORI 115 88.59542 20.27611 1n 930130_chi_ori
* FEIGE24 46 38.77920 3.73694 1n 921027_feige_24
* HZ43 40 199.09125 29.09917 2o 930219_hz_43
* KAPPA_SCO 15 265.62100 -39.03000 1n 920626_kappa_sco
MARS 50 104.50000 26.88333 1n 930123_mars
* MCT2020-4234 40 305.99775 -42.40700 1n 920719_mct2020-4234
* SIGMA_GEM 55 115.82667 28.88333 2o 930207_sigma_gem
VV_PUP 45 123.77833 -19.05489 1n 930209_vv_pup
* WD1123+189 24 171.57958 18.65472 1n 930214_wd1123+189
* WD1123+189 20 171.57958 18.65472 1n 930310_wd1123+189
* WD1254+223 29 194.25958 22.03194 1n 930304_wd1254+223
* WD2309+105 43 348.08958 10.78444 1n 920821_wd2309+105
* WD2309+105 55 348.08958 10.78444 2o 920928_wd2309+105
* XI_UMA 55 169.54542 31.52917 1n 930330_xi_uma
Data Sets Available 1 June 1994:
31_COM 73 192.92417 27.54056 1n 930213_31_com
AD_LEO 90 154.90208 19.87000 2o 930303_ad_leo
* ALPHA_CEN_A 55 219.90100 -60.83530 2o 930531_alpha_cen_a
* ALPHA_CEN_A 27 219.90100 -60.83530 1n 930601_alpha_cen_a
* ALPHA_CEN_A 30 219.90100 -60.83530 1n 930608_alpha_cen_a
AN_UMA 44 166.10750 45.05417 2o 930301_an_uma
* AU_MIC 55 311.29000 -31.33400 1n 930723_au_mic
EPSILON_CMA 65 104.65833 -28.97210 2o 930118_epsilon_cma
JUPITER 65 0.00000 0.00000 2o 930401_jupiter
* MCT2153-4156 2 329.14704 -41.70397 1n 930808_mct2153-4156
PSR0656+14 106 104.95000 14.23917 1n 930203_psr0656+14
RE0515+324 60 78.84875 32.67889 1n 930126_re0515+324
RE1027+322 120 156.79875 32.39000 1n 930308_re1027+322
RE1032+532 60 158.03458 53.48889 1n 930205_re1032+532
RE1149+28 83 177.48208 28.75222 1n 930225_re1149+28
WD1254+223 55 194.25958 22.03194 2o 930211_wd1254+223
* WD1254+223 31 194.25958 22.03194 1n 930406_wd1254+223
* WD1620-391 51 245.89667 -39.22940 1n 930521_wd1620-391
* WD1620-391 54 245.89667 -39.22940 1n 930702_wd1620-391
x WD1620-391 3 245.89667 -39.22940 1n 930702x_wd1620-391
x WD1845+019 1 281.91400 1.95900 1n 930616x_wd1845+019
* WD1845+019 32 281.91400 1.95900 1n 930623_wd1845+019
* WD2309+105 30 348.08958 10.78444 1n 930831_wd2309+105
YZ_CMI 85 116.17360 3.55542 1n 930227_yz_cmi
------------------------------------------------------------------
As indicated above, the "Q" flag is used to give researchers a rough indica-
tion of the quality of the science data products (e.g. the extracted spectra).
Codes are in the form "Nx" where "N" reflects the quality of the processing
software and/or reference data (higher N values are best) and "x" the level of
human interaction -- nominal (n) or optimal (o) -- during the spectral reduction
process (optimal extraction is best as it was done much more carefully). A "2o"
data set is of the current top-of-the-line quality; "2o" is of higher quality
than "2n" which, in turn, is of higher quality than "1o", etc.
Researchers should note that the delivered data sets include the complete
telemetry tables for the observation of interest. By retrieving the most
up-to-date versions of the EGO Center software and reference data from the CEA
anonymous ftp site, the researcher has all that is necessary to reprocess the
data and do the best possible job at the spectral extraction. So, a "1n" coded
data set from the list above is fully complete but will require more work on
the part of the researcher in its analysis. The Archive will (as resources
allow) reprocess the archival data sets as a convenience to the community.
The community is encouraged to order these data sets by sending an e-mail
request to archive@cea.berkeley.edu including your name, mailing address,
telephone number, and the "DataID" code(s) from the table above. Data sets
will be distributed on 8mm tape via postal mail and should arrive within 4
weeks. New sets of observations will go public every month thereafter, lists
of which will be published (e.g. in this newsletter) at least one month in
advance. Mechanisms for previewing and ordering data sets via Mosaic are under
development.
3. The Beta Cen Mystery: Evidence for Recent Degradation
of the Al/Ti/C Filter of Scanner A
=========================================================
by Dr. John Vallerga, CEA Scientist
During a GO observation of HZ43 in the Deep Survey/Spectrometer (DS/S) on
Saturday, 26 March at 03:25 PST, the EUVE payload controllers noticed a bright
source in the Scanner A Al/Ti/C filter quadrant. During that day it was
determined that for this Right-Angle Program (RAP; so-called because the
Scanners observe at 90 degrees to the DS/S) source the count rate when
unobstructed by the filter bar was ~22 counts/second (cps) in Al/Ti/C (Scanner
A), ~1 cps in the Lex/B (Scanner B) and ~2 cps in the "Dagwood" (Scanner C).
Since EUVE was dithering on the GO target, the stellar image moved around the
detector and filter, proving that it was not a "hot spot" or filter pinhole.
It was determined that the position of the source was within a few arc minutes
of beta Centaurus, a bright (m_v = 0.6) B1III star at a distance of 89 parsecs.
Because it was a B star, we immediately considered the possibility of an
ultraviolet (UV) leak, and the Lex/B count rate was consistent with a UV leak
of a star of this magnitude. However, the Al/Ti/C and Dagwood filters did not
have a UV leak during the all-sky survey since NO B stars were detected in
either of these (except for the EUV flux from beta and epsilon Canis Majoris).
A Target of Opportunity was requested to point the DS/S at beta Cen. The
Scanner observation of beta Cen was stopped at 4:08 (PST) on Sunday, 27 March
when the EUVE DS/S slewed to the Moon; at 13:20 PST, EUVE slewed to beta Cen.
The initial detector plots revealed no bright EUV spectrum! When EUVE slewed
back to HZ43 at 10:40 PST on Monday, 28 March, the spacecraft roll angle was
different so beta Cen was not in the field-of-view (FOV) of the Scanners. A
Target Adjustment Request (TAR) was made to change the spacecraft roll and
return beta Cen to the Scanner A Al/Ti/C FOV and the bright source reappeared!
Another TAR moved the source to the Al/Ti/C filter of Scanner B and the source
was not detected. The ratio of the beta Cen count rates between the Scanner A
and B Al/Ti/C filters was a factor of > 3000, indicating that the beta Cen
detection was an out-of-band leak in Scanner A and not a variable source.
The cause of this leak and the time it first occurred are not presently
known. We are certain that the filter UV throughput was low during the survey
phase of the mission and for some time afterwards based on the non-detections
of bright B stars in this filter. We are currently checking more recent data
for B star detections and will soon be performing calibration pointings at UV
and far-UV (FUV) sources (e.g. the Moon, B and A stars) to characterize the
spectral nature of the leak. We also have test filters in storage that will be
checked for physical degradation and transmission changes. There is no evidence
that any change has occurred to the Spectrometer or Deep Survey filters; how-
ever, any unexplained throughput change in orbit is a concern and we will do
our best to find the cause of the one in Scanner A.
Previous observations of B stars during the all-sky survey and RAP did not
detect even the brightest ones (e.g. alpha Vir and alpha Eri) in this filter
bandpass. The fact that the throughput increase was greater than three orders
of magnitude implies that the wavelength region which changed was one of low
throughput to begin with. The region is not in the soft x-ray, as there the
filter is already mostly transparent and the detector has a high quantum
efficiency (QE). In the soft x-ray the telescope is the component that limits
the throughput and it is very unlikely for the telescope to increase its
reflection efficiency by three orders of magnitude.
Somehow the filter/detector developed an FUV or UV leak. The UV leak (2500
A) is unlikely since the count rate in the Al/Ti/C filter was a factor of 20
greater than that in the Lex/B filter, which is already transparent to UV at
this wavelength. That leaves the FUV (>912 A). If the filter has a grey
spectral response, then the throughput will be highest at 912 A since the QE of
the detector is falling like a power law with wavelength. A transmission of
1e-6 is roughly what it would take to see the count rate observed for beta Cen.
But to achieve that transmission would require the complete removal of either
the aluminum or the carbon from the Al/Ti/C filter. Maybe the atomic oxygen in
orbit has managed to oxidize the carbon in the filter, but then we would have
to explain why we don't detect the 584 A geocoronal flux. A collection of very
small pinholes that result in a grey transmission of 1e-6 would result in the
900 A FUV response whose shape is determined by the MgF_2 QE curve and yet not
increase the geocoronal backgrounds. A good test of this would be to observe
the Moon.
4. First Hardware Failure on EUVE
=================================
by Kevin Hartnett, GSFC Project Operations Director
The EUVE spacecraft suffered its first true hardware failure on the afternoon
of Saturday, 2 April during orbit 10,093 with the loss of its "B" side
transmitter. Configured to the high gain antenna (HGA) since shortly after
launch, transmitter "B" -- the return link side of EUVE's second generation
Tracking and Data Relay Satellite (TDRS) transponder "B" -- showed no overt
signs of anomalous performance during its previous two successful uses (a tape
recorder dump and a real-time pass) just hours earlier, but failed to radiate
during a pass scheduled at 18:26 GMT resulting in a negative acquisition by the
TDRS Space Network (SN). Over a period of approximately 12 hours, members of
the Loral Flight Operations Team -- later augmented by engineering
representatives from NASA, Jackson & Tull and Fairchild Space -- determined the
likely occurrence had been the failure of the power amplifier stage in the "B"
transmitter, and reviewed the procedures necessary to switch transponder "A"
(normally configured to the omni antennas) to the HGA. Emergency ground
contacts with Deep SN Madrid and GN Mila were arranged along with numerous omni
SN events to allow for the orderly execution of the plans which culminated in
the switchover during overlapping Mila and TDRS supports at approximately 07:00
GMT on Easter Sunday. Because of the combined 16 hour record capacity of EUVE's
two tape recorders, and their careful management by the Flight Controllers, no
science data was lost during the incident. Subsequent TDRS passes throughout
the day on Sunday were nominal, with HGA commands executing from stored command
loads which had been regenerated overnight. Transponder "A" will remain
configured to the HGA with the transmitter on. This is judged to be the most
prudent operational approach until thorough analysis of the engineering
housekeeping data recorded during the failure is accomplished.
Accolades, congratulation and thanks is due to all the EUVE team who
sacrificed their sleep and Easter morning plans to support the anomaly
investigation and restoration of HGA communications. The planning, execution
and conduct of those involved, including the GSFC and JPL institutional support
elements, were exemplary in every respect.
5. Notes from the EUVE Guest Observer (EGO) Center
==================================================
by Anne Miller, EGO Technical Writer
5.1 Cycle III NRA Slated for Release in May
-------------------------------------------
The the NASA Research Announcement (NRA) to cover the third and, possibly,
last observing year of the EGO program is scheduled to be released in May, 1994.
The following *tentative* schedule has been put forward for the proposal cycle
(dates are subject to change):
15 May, 1994 release of the NRA
15 Aug, 1994 proposals due
Oct, 1994 peer review of proposals
Feb, 1995 beginning of funding and GO observations
Observations in Cycle III will no longer be limited to spectrometer
pointings; researchers will be able to apply for data from the Deep Survey and
Scanning telescope detectors, although some restrictions will apply. In
addition, the NRA will encourage proposals for more extended programs of
research, which will observe five or more sources and require large time
commitments, to focus on particularly challenging astrophysical problems.
Final details of these policies will be included in the NRA.
Researchers who wish to be receive the NRA may ensure their inclusion on the
mailing list by contacting:
Dr. Yoji Kondo, EUVE Project Scientist
Code 684
Building 21, Room G 59
Goddard Space Flight Center
National Aeronautics and Space Administration
Greenbelt, MD 20711 USA
Telephone: (301) 286-7664
euve@stars.gsfc.nasa.gov (Internet)
If you have access to Mosaic, you may also use the Registration service,
described in the next section.
5.2 EGO Center HomePage in Mosaic
---------------------------------
The EGO Center at CEA supports a number of services on the World Wide Web in
Mosaic. The EGO Center may be accessed via the Uniform Resource Locator (URL)
for the CEA "HomePage":
http://ftp.cea.berkeley.edu
The EGO Center provides the user with access to the following information and
programs:
>> What's New: Announcements from the EGO Center.
>> Registration: Registers a subscription for you to the EUVE Electronic
Newsletter. Also signs you up to receive information about the next
NRA.
>> Proposal Database: Information on Cycle I proposals.
>> Target Visibility: Given position and exposure this server will generate
a suitability plot, which describes how well EUVE can observe the target
on any given day for a period of one year.
>> ISM Server: Executes ISM modeling code with user's parameters.
>> EUVE BSL Interactive Skymap: Find EUVE Bright Source List objects on the
sky.
>> EGO Abstracts: Abstracts of GO papers.
The CEA/EUVE anonymous ftp site, which contains public data and archives, may
also be accessed from the CEA HomePage. Those who would like to browse the CEA
ftp site in this manner, but who do not have access to Mosaic, may log in with
telnet and use lynx, a menu-driven program that searches, displays, and
retrieves copies of files. To use lynx, type:
% telnet ftp.cea.berkeley.edu 200
Look for announcements and NRA material in the ftp site later this year.
6. Notes from the EUVE Public Science Archive
=============================================
by Brett A. Stroozas, DASS/Archive Manager
6.1 ISM Server in ADS
---------------------
The EUVE ISM software is used to correct for source flux attenuation at EUV
wavelengths due to the intervening interstellar medium (ISM; based on a model
by Rumph, Bowyer and Vennes). This software, which has been available for some
time in the Archive section of the CEA ftp site, is now available as a service
to users of NASA's Astrophysics Data System (ADS). This service, available
under the ADS "Tools" menu, prompts the user for various input parameters and
a file of unattenuated source flux vs. wavelength. The output is an ADS table
which, using the ADS table editing tools, may be manipulated at will by the
user. We encourage researchers to use this service and send us any comments
and/or suggestions.
6.2 Archive Access Information
------------------------------
Once again, listed below are the various methods for accessing EUVE archival
material:
o CEA WWW Server:
http://ftp.cea.berkeley.edu (Mosaic/lynx remotely)
telnet ftp.cea.berkeley.edu 200 (lynx locally at CEA)
o NASA's ADS (general and account information):
http://adswww.colorado.edu/adswww/adshomepg.html (Mosaic/lynx)
ads@cuads.colorado.edu
o CD-ROM Series: Volumes 1.1 and 2.1 (four separate CDs) are available
o e-mail: archive@cea.berkeley.edu
(include word "help" -- quotes omitted -- as body of message)
o anonymous FTP (or gopher): ftp.cea.berkeley.edu
o EUVE Electronic Newsletters: ceanews@cea.berkeley.edu (to subscribe)
o Postal Mail:
The EUVE Public Science Archive
Center for EUV Astrophysics
2150 Kittredge St.
Berkeley, CA 94720
510-642-3032 (voice) or 510-643-5660 (fax)
archive@cea.berkeley.edu
7. Abstracts of Recently *Accepted* EUVE Papers
===============================================
Included below are abstracts of EUVE-related papers recently *accepted* for
publication. GOs are encouraged to contribute *accepted* abstracts for inclu-
sion in future editions of this newsletter and for posting under the EGO Center
Mosaic "Home Page". All abstracts should be sent to egoinfo@cea.berkeley.edu.
For those papers authored by CEA scientists, the EUVE publication number is
indicated. Researchers may obtain (p)reprints of these papers by sending an
e-mail request along with the publication number(s) of interest to
pub@cea.berkeley.edu.
--------------------------------------------------------------
LIMITS ON THE HYDROGEN LAYER MASS AND CONSEQUENT HELIUM OPACITY IN HOT DA
WHITE DWARF ATMOSPHERES
M.A. Barstow (U. Leicester, UK), J.B. Holberg (U. AZ) and D. Koester
(ITPS-Kiel, FRG)
to appear in Monthly Notices of the Royal Astronomical Society
The results of the ROSAT sky survey of hot H-rich DA white dwarfs
demonstrated that, at temperatures above ~40,000 K, most stars contain
significant quantities of heavy elements in their atmospheres. Conversely,
below 40,000 K most DA white dwarfs appear to have pure H envelopes with,
at most, only small traces of any other material. However, ROSAT was unable
to exclude a contribution from He to the total photospheric opacity present
in these stars. Consequently, the role of He in hot DA white dwarfs remains
uncertain. New spectroscopic observations made by the Extreme Ultraviolet
Explorer (EUVE) satellite promise to provide direct evidence through a search
for photospheric He absorption features. We have analyzed four well exposed
spectra from the EUVE public archive, finding no evidence for any photospheric
He. Using a grid of stratified model atmospheres we are able to determine
lower limits to the mass of the outer H layer, which are significantly larger
than those derived from earlier broad band results.
--------------------------------------------------------------
EXTREME ULTRAVIOLET EXPLORER SATELLITE OBSERVATION OF JUPITER'S IO PLASMA TORUS
D.T. Hall (JHU), G.R. Gladstone (SRI), H.W. Moos (JHU), F. Bagnel, J.T. Clark,
M.A. McGrath, N.M. Schneider, D.E. Shemansky, D.F. Strobel, and J.H. Waite
to appear in Astrophysical Journal Letters
We present the first Extreme Ultraviolet Explorer satellite observation of
the Jupiter system, obtained during the two day period 1993 March 30 through
April 1, which shows a rich emission line spectrum from the Io plasma torus
spanning wavelengths 370 to 735 A. The emission features correspond primarily
to known multiplets of oxygen and sulfur ions, but a blended feature near 372 A
is a plausible NaII transition. The summed detected energy flux of (7.2 +/-
0.2)e-11 erg cm^(-2) s^(-1) corresponds to a radiated power of approximately
4e11 Watts in this spectral range. All ansa emissions show a distinct dawn-dusk
brightness asymmetry and the measured dusk/dawn ratio of the bright SIII 680 A
feature is 2.3 +/- 0.3, significantly larger than the ratio measured by the
Voyager spacecraft UV instruments. A preliminary estimate of ion partitioning
indicates that the oxygen/sulfur ion ratio is approximately 2, compared to the
value approximately 1.3 measured by Voyager, and that [NaII]/[e] > 0.01.
--------------------------------------------------------------
EUVE SPECTROSCOPY OF XI UMA, SIGMA GEM, AND CHI^1 ORI
R. Mewe, C.J. Schrijver (SRON-Utrecht), J.S. Kaastra (SRON-Leiden), F.J.M.
Alkemade (SRON-Utrecht), and B.M. Haisch (CEA/Lockheed)
to appear in "Proc. Eighth Cambridge Workshop on Cool Stars, Stellar Systems,
and the Sun", ed. J.P. Caillault, ASP Conf. Series, 1994, in press.
The analysis of the EXOSAT Transmission Grating Spectrometer (TGS) (10-200 A)
spectra of two RS-CVn systems, Capella and sigma^2 CrB, as presented by Lemen
et al. (1989), showed the coronae of these stars to be dominated by emission
from two temperature intervals, one around solar coronal temperatures, the other
in excess of 10 MK. The lack of strong emission from plasma at < 1 MK was shown
to be consistent with models of quasi-static loops that were narrower at the
footpoints than at the tops (Schrijver et al. 1989). Recent high-resolution
observations by YOHKOH suggest, however, that the solar coronal loops do not
have such a strongly changing cross section with height, at least for plasma
above ~1 MK. We observed other cool stars (the RS CVn's xi Uma, sigma Gem, and
the single MS star chi^1 Ori) with the EUVE spectrometers to study the
temperature structure of stellar coronae and the geometry of coronal loops.
Here we report preliminary results of a differential emission measure analysis.
--------------------------------------------------------------
DETECTION OF EUV EMISSION FROM THE LOW ACTIVITY DWARF HD 4628: EVIDENCE FOR
A COOL CORONA
M. Mathioudakis, J.J. Drake (CEA), P.W. Vedder (CEA/NASA), J.H.M.M. Schmitt
(MPIE), and S. Bowyer (CEA)
to appear in Astron. & Astrophys.
[CEA publication #580]
We present observations of low activity late-type stars obtained with the
Extreme Ultraviolet Explorer (EUVE). These stars are the slowest rotators, and
acoustic heating may dominate their outer atmospheric heating process. We report
detection of EUV emission from the low activity K dwarf HD 4628 during the EUVE
Deep Survey in the Lexan/boron band. This detection, in conjunction with the
non-detection of this object in the ROSAT PSPC all-sky survey, suggests the
existence of a cool corona with a characteristic temperature of less than
1e6 K. The flux and spectral signature are consistent with current theories
of acoustic heating.
Keywords: coronal heating -- late-type stars -- extreme ultraviolet
--------------------------------------------------------------
8. CEA Job Listings
===================
by Cathie Jones, CEA Personnel Manager
Postgraduate/Assistant Research (depending on experience)
University of California
Center for EUV Astrophysics
Attn: Cathie Jones/Personnel
2150 Kittredge St.
Berkeley, CA 94720
The Extreme Ultraviolet Explorer (EUVE) Program at the Center for EUV
Astrophysics, of the University of California, Berkeley, has opening for a
Research Scientist. Successful applicant will support the acquisition, and
reduction of pointed data from the EUVE satellite. Duties will include
monitoring the progress of observation scheduling and data acquisition,
pipeline processing and data reductions and analysis. The researcher will
assist Guest Investigators, through the Guest Observer program and the EUVE
Archive program, in understanding the performance of the EUVE scientific
instruments as well as provide scientific advice regarding use of the EUVE
spectrometer analysis packages, written primarily in IRAF. Additional duties
will involve assisting in the development of complex data analysis algorithms
and models, to be made available to the Guest Investigator community in the
EUVE IRAF packages and EUVE public archive.
The work will be performed under the direction of the EUVE Science Support
Project Manager, and will interact with the associated science and programming
staff in the EUVE Public Archive and Guest Observer Center. A fraction of time
(10%) will be available to allow pursuit of independent research.
Applicants must have a Ph.D. in astronomy, physics, or a related field.
Experience supporting NASA Archival Research, Guest Observer, and Guest
Investigator programs required. Experience in satellite or ground-based
astronomical data analysis and the ability to carry out research in the field
of EUV astronomy is highly desirable. Experience with IRAF would be most
helpful.
Applications should include a curriculum vitae, bibliography and three
letters of recommendation and should be submitted by April 30, 1994. EOE/AAE.
Staff Research Associate I
Box 03-144-10
Personnel Office
University of California
2200 University Ave.
Berkeley, California 94720
The Center for Extreme Ultraviolet Astrophysics, seeks applicants for the
position of Staff Research Associate I. Duties include support of astronomical
research and data acquisition, reduction, and analysis for the Extreme
Ultraviolet Explorer (EUVE) Satellite Project. Work will be related to the
reduction of EUVE science data. The Staff Research Associate will assist
scientists in the development and application of data analysis programs to data
taken using ground-based astronomical instruments. Process data from raw
telemetry into time-tagged photon files and spectra. Monitor processing flow,
involvement in processing Guest Observer multispectral data into primary and
secondary products. Other duties include producing documentation of results,
and publication support assisting in the simulation of scientific data related
to the EUVE Satellite Project.
Qualifications: Background in Astronomy, Physics or other applicable
science, plus experience in the kind of work to be performed is required.
Demonstrated knowledge of general astronomical data reduction and acquisition
techniques is required. Experience with FORTRAN or C programming is required.
Knowledge of the IRAF system and packages required. Knowledge of UNIX
operating system is highly desired.
Applications should include a curriculum vitae and names of three references
and be submitted promptly. Position is open until filled. No resumes will be
accepted after May 25, 1994.
Associate Development Engineer
Box 03-143-10
Personnel Office
University of California
2200 University Ave.
Berkeley, California 94720
Associate Development Engineer, Center for Extreme Ultraviolet Astrophysics,
UC Berkeley NASA Extreme Ultraviolet Explorer Satellite Project. Oversee the
engineering efforts of the Science Operations Center. Coordinate the activities
of payload subsystems engineers in both routine analysis and anomaly resolution.
Provide scheduling and planning expertise on engineering activities. Determine
payload and spacecraft activities needed for calibration and maintenance.
Identify operational areas and develop training strategies. Identify future
needs for the extended mission engineering effort. Qualifications: Background
in electrical, mechanical or aerospace engineering. Experience with engineering
analysis techniques. Good communications skills. Unix experience. Familiarity
with NASA institutions, research projects and satellite operation procedures
preferred. Managerial experience preferred. Experience with Unix shell and C
programming helpful.
Send resume and three reference names by 4/20/94.
For additional job information, contact Cathie Jones @ 510-642-1263.
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The EUVE Electronic Newsletter is issued by the Center for Extreme Ultra-
violet Astrophysics, University of California, Berkeley, CA 94720, USA.
The opinions expressed are those of the authors. EUVE Principal Investi-
gators and Newsletter Publishers: Drs. R.F. Malina and C.S. Bowyer. EGO
and Archive Science Manger: C.A. Christian. Archive Manager and News-
letter Editor: B.A. Stroozas. Funded by NASA contracts NAS5-30180 and
NAS5-29298. Send newsletter correspondence to: ceanews@cea.berkeley.edu.
The EUVE project is managed by NASA's GSFC. The GSFC Project Manager:
Paul Pashby, Project Scientist: Dr. Yoji Kondo, Deputy Project Scientist:
Dr. Ronald Oliversen. NASA HQ Program Scientist: Dr. Robert Stachnik,
Deputy Program Scientist: Dr. D. Buzasi, Program Manager: Dr. G. Riegler.
GSFC Project Operations Director: Mr. Kevin Hartnett. Information on the
EUVE Guest Observer Program is available from: Dr. Y. Kondo, Mail Code
684, GSFC, Greenbelt, MD 20771 at (301) 286-6247 or e-mail to
euve@stars.span.nasa.gov.
END-----------EUVE------------ELECTRONIC---------------NEWS-------------END
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