Proposal 12048 (STScI Edit Number: 0, Created: Friday, August 19, 2011 2:11:56 PM EST) - Overview
12048 - COS-GTO: Sleuthing the Source of Distant Cometary Activity
Cycle: 18, Proposal Category: GTO/COS
(Availability Mode: SUPPORTED)
INVESTIGATORS
Name
Dr. James C. Green (PI)
Dr. Cynthia Froning (CoI) (AdminUSPI)
Dr. John R. Spencer (CoI) (Contact)
Dr. S. Alan Stern (CoI)
Dr. Nathaniel J. Cunningham (CoI)
VISITS
Visit Targets used in Visit
01
(1) 2060-CHIRON
Institution
University of Colorado at Boulder
University of Colorado at Boulder
Southwest Research Institute
Southwest Research Institute
University of Nebraska - Lincoln
E-Mail
james.green@colorado.edu
cfroning@casa.colorado.edu
spencer@boulder.swri.edu
astern@swri.edu
Configurations used in Visit
Orbits Used Last Orbit Planner Run
COS/FUV
COS/NUV
3
19-Aug-2011 15:11:48.0
OP Current
with Visit?
yes
3 Total Orbits Used
ABSTRACT
Distant comets and Centaurs often show cometary activity and outbursts well beyond 3 AU, the boundary of the sublimation zone of water. Supervolatiles (most likely CO, but possibly CH4, N2, or S2) are suspected to be responsible, but have never been detected in distant comets in the UV.
We will obtain FUV spectra of active bodies to cover important CO emission bands. We plan two sets of observations: comet 29P/SchwassmannWachmann at 6 AU, whose outbursts are too short to capture as a Target of Opportunity, but which also shows persistent cometary activity in
quiescence; and Target of Opportunity observations of the Centaur 2060 Chiron (at ~15.5 AU) in outburst.
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Proposal 12048 (STScI Edit Number: 0, Created: Friday, August 19, 2011 2:11:56 PM EST) - Overview
OBSERVING DESCRIPTION
TOO observations of Chiron. 3 consecutive orbits, with grating G160M at central wavelength 1589Å.
ADDITIONAL COMMENTS
This program will be withdrawn if the GTO ToO observation of the same target (in Phase II ID 11536) is carried out in Cycle 17. (I.e., this program
to be carried out only if the same ToO is not executed in Cycle 17.)
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Solar System Targets Diagnostics
Visit
Proposal 12048 - Visit 01 - COS-GTO: Sleuthing the Source of Distant Cometary Activity
Proposal 12048, Visit 01, implementation
Fri Aug 19 19:11:56 GMT 2011
Diagnostic Status: Warning
Scientific Instruments: COS/NUV, COS/FUV
Special Requirements: ON HOLD
Comments: On hold as Target of Opportunity waiting for outburst. Also, COS acquisition sequence as recommended for Cycle 17 takes about 1 orbit on this faint target. Relaxing acquisition approach to skip
acq/search, and do acq/image with S/N = 20.
On Hold Comments: Target of Opportunity: to be observed in outburst, after absolute brightening beyond 0.7 visual magnitudes, with brightness not (yet) decreasing
(Visit 01) Warning (Orbit Planner): INEFFICIENT ORDERING OF FP-POS POSITIONS
(Visit 01) Warning (Form): If the target coordinates are not known to 0.4" (or better) an ACQ/SEARCH should precede the ACQ/IMAGE.
(Visit 01) Warning (Orbit Planner): VISIBILITY OVERRUN
(Visit 01) Warning (Orbit Planner): VISIBILITY OVERRUN
(Visit 01) Warning (Orbit Planner): VISIBILITY OVERRUN
#
(1)
Exposures
#
1
Name
2060-CHIRON
Label
Level 1
Level 2
TYPE=ASTEROID,A=13.7092893,E=
0.3801131,I=6.93350,O=209.26187,W
=340.03634,M=86.81892,EQUINOX=
J2000,EPOCH=14-MAY2008:00:00:00
Target
(1) 2060-CHIRON
Config,Mode,Aperture
COS/NUV, ACQ/IMAGE, PSA
Spectral Els.
MIRRORA
Level 3
Opt. Params.
Window
Exp. Time/[Actual Dur.]
254 Secs
[==>]
Comments: Acquisition time from ETC COS78916, assuming 19th magnitude point source with solar spectrum and average airglow. S/N = 40 time is prohibitive, so relaxed acquisition to S/N = 20.
2
(1) 2060-CHIRON
COS/FUV, TIME-TAG, PSA
G160M
BUFFER-TIME=17
1702 Secs
02;
1589 A
[==>]
EXTENDED=YES;
FP-POS=2
Comments: ETC COS67398: 2" diameter (1" radius), 18th magnitude = 19.2 mags per sq arcsec, 8 R = 2.0e-16 erg/cm^2/s/sq. arcsec @ 1510Ã (5Ã wide band). Calculated buffer time is 2/3 of 93000s
3
(1) 2060-CHIRON
COS/FUV, TIME-TAG, PSA
G160M
BUFFER-TIME=12
1409 Secs
99;
1589 A
[==>]
FP-POS=3;
EXTENDED=YES
4
(1) 2060-CHIRON
COS/FUV, TIME-TAG, PSA
G160M
BUFFER-TIME=14
1409 Secs
09;
1589 A
[==>]
FP-POS=4;
EXTENDED=YES
5
(1) 2060-CHIRON
COS/FUV, TIME-TAG, PSA
G160M
BUFFER-TIME=12
1376 Secs
66;
1589 A
[==>]
FP-POS=3;
EXTENDED=YES
6
(1) 2060-CHIRON
COS/FUV, TIME-TAG, PSA
G160M
BUFFER-TIME=13
1375 Secs
87;
1589 A
[==>]
FP-POS=4;
EXTENDED=YES
3
Special Reqs.
Groups
Ephem Center
EARTH
Orbit
[1]
[1]
[2]
[2]
[3]
[3]
Orbit Structure
Proposal 12048 - Visit 01 - COS-GTO: Sleuthing the Source of Distant Cometary Activity
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Proposal 12048 - Visit 01 - COS-GTO: Sleuthing the Source of Distant Cometary Activity
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