Contents:
1) The New FUSE Observatory: Open for Business
2) New Data Sets Publically Available
1) The New FUSE Observatory: Open for Business
After months of development and testing of operations with a single
reaction wheel in the control loop, the New FUSE Observatory is coming online!
In early November, the Observatory was declared "green" and we are now giving
new science observations priority over continued development, which will
continue in the background. See the latest FUSE Mission Status Report for
more information:
The FUSE Project, with the unanimous support of our users committee, is
referring to FUSE as a "new" observatory because its modes of operation and
observing capabilities and constraints are sufficiently different from those
prior to the Dec. 2004 wheel failure, even though the scientific instrument's
performance is the same as before. The capabilities of the New FUSE are being
applied to the Cycle 7 proposal review scheduled for next week.
2) New Data Sets Publically Available
The New FUSE Observatory largely manages the momentum of the remaining
reaction wheel by pointing alternately in directions that spin the wheel up or
down as needed to keep its rate of spin in the operational range. As such, we
need a high density of targets in the available part of the sky in order to
perform efficient operations. Since the Cycle 7 selections are still in
progress, the FUSE Project Scientist has approved plans to address a near-term
target shortage in two ways. He has given permission to schedule additional
observations of previous FUSE targets that are in available regions of the sky,
and he has allowed the expansion of the "sky backgrounds" program to
accommodate operations with the New FUSE.
Observations of previous targets will all be scheduled under program
IDs that begin with the letter "U". Programs U101, U102, U103, and U104
include approximately 300 previously observed FUSE targets above 50 degrees
declination (north), and programs U106, U107, U108 and U109 contain
approximately 300 targets below -50 degrees declination (south). No Magellanic
Cloud targets are included in these programs as there are plenty of requested
new observations in those regions. Targets with nominal fluxes approaching the
FUSE brightness limit have also been removed. All U program observations are
"plain vanilla" LWRS observations benchmarked for 8 ks. Actual observation
times will scale upward and downward from this value as needed for efficient
operations. We have just begun observing U program targets in early November.
The FUSE project instituted a "Sky Backgrounds" program early in the
mission to use time during thermalization periods that would otherwise go
unused. These data were collected under program IDs S405 and S505. Since the
reaction wheel failure in December 2004, we have expanded this concept to
include additional pre-selected and randomly selected sky background pointings.
The new program IDs S605 (north circumpolar grid) and S705 (south circumpolar
grid) contain pre-defined circles of sky background positions at +/-60, 65, and
70 degrees on 5 degree centers. Programs S805 and S905 will be used for random
positions defined by FUSE MP to assist in momentum management. As with the
earlier background programs, the data can have significant integration times
and/or can build up significant integration time for those positions that are
reobserved multiple times. In certain cases, total integrations of many 10's of
ks are built up at a given position. They have (and we trust they will in the
future) provided interesting detections and constraints on faint O VI 1032
emission at locations across the celestial sphere. Using MAST to search for
publications by program ID, for example reveals a number of references relating
to the background program S405.
Targets for these programs are available for scheduling at low priority,
and are used to help manage momentum or fill in schedule gaps only when a
peer-reviewed target is not available in the stable region of sky. All U and
S program data will be archived and will go public immediately. It is left to
the user community to periodically visit the archive and see what has been
observed in these programs and determine their interest. We hope that this
creative use of the FUSE resource will pay unexpected dividends to the FUSE
user community. Users can reach the FUSE archive at the following URL:
http://archive.stsci.edu/fuse/
The Observer's Electronic Newsletter is published by the FUSE project and is aimed at the FUSE user community.
Editor: B-G Andersson, FUSE Guest Investigator Officer.
The FUSE Project is managed by the Johns Hopkins University's Center for Astrophysical Sciences in Baltimore, MD, for NASA's Goddard Space Flight Center. The FUSE Principal Investigator is Dr. Warren Moos, the FUSE Program Manager at JHU is Mr. Randy Ewing, and the NASA Project Scientist for FUSE is Dr. George Sonneborn.