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Chandra Electronic Bulletin No. 10

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             |              CCC  XX   XX    OOO           |
Chandra      |             CC     XX XX    OO OO          | CXC
Electronic   |            CC       XXX    OO   OO         | Number 10
Bulletin     |             CC     XX XX    OO OO          | January
             |              CCC  XX   XX    OOO           | 2002 
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Welcome to the Chandra X-ray Center's Electronic News Bulletin Number 10.

CXC Web site: cxc.harvard.edu

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1. Chandra Cycle 4 NRA Released 

2. Observer Notification of Observation Status

3. Bulletin for Proposers

Item 1. Chandra Cycle 4 NRA Released 

NASA has released the Chandra Cycle 4 NRA

Proposals are due 15 March 2002
and further information may be found on the CXC website(cxc.harvard.edu).


Item 2.  Observer Notification of Observation Status 

Chandra Data Archive  used to send at least three E-mail messages to PIs 
concerning their observation:

1. A notification that telemetry containing the ObsId has been
received in Automated Processing (AP).

2. A notification that Quick Look (QL) images are available for the user's

3. A notification that Verification and Validation (V&V)-approved 
data products are available for download by the user.

The median time between the observation and the notices, during
September through November 2001 was, respectively: 1, 2, and 7 days.
This system was set up in the early days of the mission when these
delays were considerably longer.  Because of the minimal delay between
the first and second messages, we have discontinued sending the first
message, considering it superfluous.

  - Arnold Rots


Item 3. Bulletin for Proposers                                            

ADVICE FOR CONSTRAINED OBSERVATIONS - Observations with time windows, 
phase windows, roll limits, monitoring requirements, or which require 
simultaneity with other observatories are designated as constrained by
RPS.  The Cycle 4 program will be limited to 20% constrained observations.  

   Even with this limit, scheduling has been more difficult than
anticipated , particularly for long-duration, constrained
observations.  It would be helpful if, when there is a real constraint, 
you could enter the maximum range you will accept.  If a finer
tolerance is desirable, state this in the "remarks" section.  This
will give the CXC maximum scheduling flexibility.

   If your constraint is not mandatory for the science, and you do not
wish to compete within the 20% limit, we urge you to request "Preferred"
rather than "Yes" for the constraint. Not all preferred constraints can 
be accommodated, but often we can work a beneficial compromise with you.
   Note that schedules are often changed for targets of opportunity 
and by solar-particle events. (During Sept-Oct 2001, 17% of the
observing time was lost to high particle-induced backgrounds.)  If a
constrained observation is bumped, there may be a long delay in 

ROLL CONSTRAINTS - For a given target and observation date there
is only one nominal roll angle (with allowed deviation of a few degrees).
For much of the sky, this nominal roll angle changes by about a degree
per day.  Roll tolerance as small as +/- 10 degrees thus provide 
little flexibility in scheduling a target; users are encouraged to 
specify roll tolerances that allow the most scheduling flexibility 
possible while meeting their science goals."

If you are using an offset pointing or a SIM offset to "fine tune" your
field of view, note that this will change with roll angle; i.e., will
depend on the date of observation.

PROPOSAL FORMAT - Please follow the rules set forth in the NRA.
Remember that a peer reviewer has to read 60 proposals and brevity 
is appreciated.  If you go over the page limit, we will discard the
surplus pages.  If you violate the rules for font and margins, we will
not accept the proposal.

TIMELINESS OF SUBMISSION - Please don't wait until the last minute to
discover that RPS is slightly different from last time, that the
system is slower than expected because of heavy traffic, etc. The 
deadline is 7:00 PM EST, 15 March 2002.  Late proposals will not be 
accepted.  Don't assume that if RPS is up, it is OK to submit.
RPS stays up round-the-clock-year-round to handle TOO requests.

PROPOSAL ERRORS - Please check your proposal before submission for
errors, particularly the target and instrument parameters.  We do
search for coordinate errors and each cycle have found about 25
targets with big mistakes - wrong sign for declination, wrong epoch, 
wrong target (name and coord. don't match), and typos in the numbers.
If there is a coordinate error and we don't find it, you
will be disappointed with your data.  We know of 2 targets that have
been missed completely because of typos in the target coordinates.

If you are submitting more than one proposal, please check that the
science justification matches the target form.  It is also a good idea
to put the proposal title on the science justification.  We can then
know that they are matched correctly.

   If you have submitted and find a substantial error before the
deadline, you may resubmit a corrected proposal and we will use your
2nd submission.  If it is after the deadline, contact us and we will 
correct coordinates and instrument parameter errors.  We will not add or
delete Co-Investigators or make changes to the science justification.
Some errors may be described in a letter which we will pass to the
peer review (see Section 13.7.2, Proposers Observatory Guide). 


LARGE PROJECTS must be designated as such.  If your deep proposal is a
Large Project, you should check the appropriate RPS box; otherwise it 
will be evaluated as a standard proposal.  It is permissible to submit,
as a standard proposal, one with total time requested above the
threshold for being a Large Project.

It is possible to submit a science justification with COLOR
ILLUSTRATIONS.  You must send 20 hardcopies (so the CXC does not have
to print them).  You must also submit the science justification

When your proposal is evaluated we will add a SLEW TAX of 1500 s to
each target.  All bookkeeping is still done with observing time but
the peer review considers the actual spacecraft time required.  This
only has a practical effect on proposals which ask for many short

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Last modified: 12/03/10

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