README web version of /home/usg/OPS/MTS/readme_xml/readme_84065701
Principal Investigator Email Address
Estimated Total Execution Time (hours, including overheads)
General Description
This long-term FORS2 program monitors the orbital motions of Eps Indi
Ba,Bb, the nearest known binary brown dwarf system, against a network of background
field stars. The system has a very high proper motion of 4.7 arcsec/yr. Four epochs
of observations are needed in P84, spaced roughly by 1 month throughout the period
when the target is available (Oct-Jan). A dithered set (10 x 20 secs) of FORS2 I-band
images is taken at each epoch: the SR collimator is used to get a wide field-of-view,
with the 200kHz,1x1,low read-out mode to simultaneously get best possible spatial
resolution.
Target coordinate is an empty point in the sky, roughly where Eps Indi B was in
late 2007, halfway through a multi-year monitoring campaign. Plan is to use same
basic pointing for all observations, to ensure same net of field stars is seen throughout.
Waiver Requests
384.C-0657B.01.WAV: waiver granted 25/07/09
Request for delayed submission of OBs approved
384.C-0657B.02.WAV: waiver granted 25/07/09
Request to use non-standard 200kHz,1x1,low read-out mode of FORS2 in SR optical
mode, to ensure both a wide field-of-view to measure a large astrometric reference
frame, and the best possible spatial resolution, to separate the binary components.
Critical Observing Condition Constraints
Observations should be made with best possible seeing, 0.6 arcsec or better
if possible, in order to separate two sources and obtain accurate relative positions.
The better the image resolution, the better the results. All efforts taken to take
data in excellent seeing conditions greatly appreciated, since the objects are now
relatively close in their orbit.
Clear conditions required for relative photometric measurements within field.
Time-Critical Aspects
To ensure good sampling of the motions of Eps Indi Ba, Bb, we require
4 observations roughly evenly spaced throughout P84, i.e. ideally once per month
while target is available (Oct-Jan). As this clearly depends on schedule, weather,
etc., spacings of 2-6 weeks would be ok. Thus we have imposed time constraints in
the OBs with each epoch in an 5 week window, i.e. Sep 22 - Nov 01, Oct 15 - Nov
22, Nov 08 - Dec 15, Dec 01 - Jan 08.
IMPORTANT: These windows are designed to allow for flexibility (e.g. due to long
periods of bad weather etc.) and thus there is some overlap. However, please try
and space the epochs evenly throughout P84 as far as possible, although data taken
on two consecutive nights is better than missing out an epoch altogether.
Special Execution Requirements
Special Calibration Information
ToO Information
ToO Activators List
Is this a Pre-imaging run ?
Pre-imaging Requirements
Source(s) of Pre-imaging
Pre-imaging sources not listed above
Do all your OBs comply with the instrument-specific requirements listed
on the instrument-specific Phase 2 web page ?
If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
Category for each Observing Template ?
Do all your finding charts comply with both the general and instrument-specific
Phase 2 Web Pages ?
If you submitted OBs for standard stars, did you specify the magnitude
and spectral type of all standard stars in the OBs ?
Have you included OBs for any calibrations that you need but which are
not part of the Calibration Plan ?
If you are observing Moving Targets, have you attached suitable ephemeris
files to your OBs?
If you have preferences which OBs should be executed first, did you make
use of the User Priority field in the OBs ?
If this is a run that requires coordinated observations with other facilities,
did you give proper instructions in the Time-Critical Aspects Section ?
If you have prepared your finding charts with tools other than FIMS,
do they comply with the specifications on the FORS1 Phase 2 web page ?
Last creation of page: Tue Oct 6 15:40:32 2009
If you have comments, please contact usd-help@eso.org