This section provides several examples of RPS2 formatted proposal logsheets for the following types of investigations:
Goal
: Determine the parallax and proper motion of star, "OGF_1".
Scenario:
Special Considerations:
Target Logsheet:
Figure 6.1: illustrates the field geometry and the orient angles of a typical FGS observation, while Table 6.8: summarizes the details of the exposures in the visit.
Figure 6.1: Example 1: Field of View at Special Orientation Target |
V |
FILTER |
FESTIME (default) |
Exposure Time (seconds) |
~NEA for Single Exposure (mas) |
---|---|---|---|---|---|
"OGF_1"a |
9 |
F583W |
0.025 |
20 |
< 1.0 |
OGF-3-REFa |
11.1 |
F583W |
0.025 |
20 |
< 1.0 |
OGF-7-REF1 |
10.3 |
F583W |
0.025 |
20 |
< 1.0 |
OGF-9-REF |
10.2 |
F583W |
0.025 |
20 |
< 1.0 |
OGF-11-REFa |
13.3 |
F583W |
0.050 |
30 |
3.1 |
OGF-12-REF |
13.6 |
F583W |
0.050 |
30 |
3.5 |
OGF-21-REF |
11.5 |
F583W |
0.025 |
20 |
1.0 |
1The "REF" appendix is not required. Rather its use is suggested simply for book keeping purposes. |
Reference/Check Star Pattern:
Check Stars in this observation are REF-7, REF-11, and OGF_1. Observing sequence:
OGF_1--> 12 -- 11 -- 7 -- OGF_1 -- 11 -- 21 -- 3 -- 7 -- OGF_1
-----> 9 -- 7 -- 11 -- OGF_1 -- 21 -- 12 -- 11 -- 9 -- OGF_1
The Exposure Logsheet Template:
The Optional_Parameters entry is missing since, for this example, all Pos mode optional parameters are DEFAULT values
Visit_Number: 1 Visit_Requirements: BETWEEN 14-MAR-1998 AND 15-MAR-1998 ORIENT -18.5D TO -19.5D FROM NOMINAL Visit_Comments: Two Guide Star FineLock Required.Exposure_Number: 01 Target_Name: OGF_1 Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Time_Per_Exposure: 20S Special_Requirements: SEQ 1-4 NON-INT;POS TARG -33,-60. Exposure_Number: 02 Target_Name: OGF-12-REF Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Time_Per_Exposure: 30S Special_Requirements: SAME POS AS 1; Exposure_Number: 03 Target_Name: OGF-11-REF Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Time_Per_Exposure: 30S Special_Requirements: SAME POS AS 1; Comments: Exposure_Number: 04 Target_Name: OGF-7-REF Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Time_Per_Exposure: 20S Special_Requirements: SAME POS AS 1; Comments:
...and continues until the orbit is filled.
6-months after Visit 1, the HST Nominal Orient Angle is 180° from the Nominal HST Orientation in Visit 1. Nominal orient angle = 247°, off-nominal orient angle = 228°, pos targ = (+60,+33).
Visit_Number: 2 Visit_Requirements: BETWEEN 14-SEP-1998 AND 15-SEP-1998; ORIENT -18.5D TO -19.5D FROM NOMINAL Visit_Comments: Two Guide Star FineLock Required. Exposure_Number: 01 Target_Name: OGF_1 Config: FGS Opmode: POS Aperture: PRIME Sp_Element: F583W Time_Per_Exposure: 20S Special_Requirements: SEQ 1-4 NON-INT;POS TARG +33,+60 Comments: Exposure_Number: 02 Target_Name: OGF-12-REF Config: FGS
...Continues until the orbit is filled. Visit 3 is identical to Visit 1 except that it executes 1 year later.
Running the proposal template file through APT will inform the observer whether the syntax is correct, whether the exposures fit in an orbit and how much time is left, and finally whether the observing dates are viable for the requested ORIENT angle.
Goal
: Observe a known faint (V=16) close (separation ~40 mas) binary in Trans mode in order to determine the system's relative orbit from which the orbital element, and hence, the system's mass can be derived.
Scenario:
Special Considerations:
Exposure Time Calculation
Figure 6.2: illustrates the geometry of the binary with respect to the POS TARG and detector reference frames.
Figure 6.2: Example 2: Field of View at Special OrientationVisit_Number: 1 Visit_Requirements: ORIENT 46.6D TO 48.6D Visit_Comments: Two Guide Star FineLock Required. Please notify Contact Scientist if two guide stars cannot be found. Exposure_Number: 01 Target_Name: Close_Binary Config: FGS Opmode: TRANS Aperture: 1 Sp_Element: F583W Optional_Parameters: SCANS=83, STEP-SIZE=0.6 Time_Per_Exposure: 1729S Special_Requirements: Comment: Visit_Number: 2 Visit_Requirements: AFTER 1 BY 30D TO 32D ORIENT -24D TO -25D FROM NOMINAL Visit_Comments: Two Guide Star FineLock Required. Exposure_Number: 01 Target_Name: Close_Binary Config: FGS Opmode: TRANS Aperture: 1 Sp_Element: F583W Optional_Parameters: SCANS=83, STEP-SIZE=0.6 Number_of_Iterations: 1 Time_Per_Exposure: 1729S Special_Requirements:
And similar Visits for 3 and 4.
Running the proposal template file through APT will inform the observer whether the syntax is correct, whether the exposures fit in an orbit and how much time is left if they do not; and finally, whether the observing dates are viable for the requested ORIENT angle.
Goal
: A bright (V=13), wide binary system (separation = 0.4") is to be observed with FGS1r. Pos mode observations of the binary and neighboring reference stars will be used to determine the binary's parallax, proper motion, and barycenter. Trans mode observations will be used to establish the system's relative orbit so that its orbital elements can be derived. Combining these data from several epochs will allow for a dynamical mass determination of the system's components.
Scenario:
Special Considerations:
Texposure = 0.025 * [ScanLength/StepSize] * Nscans
where in this example ScanLength = 1.6 arcsec, StepSize = 0.0006 arcsec, and the number of scans Nscans = 25
Figure 6.3: illustrates the geometry of the target and reference stars, while Table 6.9: and Table 6.10: summarize the details of the exposures in the visit.
Figure 6.3: Example 3: Trans + Pos Mode Visits Target |
V |
FESTIME (use defaults) |
FILTER |
Total Exposure |
~NEA for one exposure (mas) |
---|---|---|---|---|---|
Wide_Binary1 Pos mode |
13.0 |
0.050 |
F583W |
20 sec |
2.0 |
Wide_binary Trans mode |
13.0 |
0.025 |
F583W |
28 min |
![]() |
BL-1-REF2 |
10.8 |
0.025 |
F583W |
20 sec |
<1.0 |
BL-2-REF |
14.1 |
0.100 |
F583W |
35 sec |
5.0 |
BL-3-REF |
11.5 |
0.025 |
F583W |
20 sec |
1.0 |
BL-4-REF |
12.5 |
0.025 |
F583W |
20 sec |
1.7 |
BL-5-REF |
13.0 |
0.050 |
F583W |
20 sec |
2.5 |
1The primary target needs only be listed once in the fixed target list. 2The "REF" appendix is not required. Rather its use is suggest simply for book keeping purposes. |
Mode |
Overhead + Exposure Time (Minutes) |
---|---|
GS ACQ + Instrumental Overheads. |
12 |
Trans mode
|
28 |
Pos mode:
|
2 1 2.5 1 2 1 1 2 |
Goal
: A faint (V=15) object suspected to be a close (sep < 30 mas) binary is embedded in nebulosity which contributes about 20% of the light in the vicinity of the target. The putative binary is to be observed in Trans mode. Special additional observations are needed accurately measure the background. To do so, the RA,Dec of two points on the sky about 1 arcmin from the target and to either side of it are specified as "targets" in the proposal. These "targets" are to be observed in Pos mode after the Trans mode observation of the faint science target (the FGS high voltage, which enable the PMTs to count photons, does not get turned on until after the IFOV is placed at the expected location of the first target to be observed in the visit. The background data is to be acquired as the IFOV slews away from the science object to the reference "targets". During this time the PMTs record the background counts.)
Scenario:
Exposure Time Calculations:
Figure 6.4 illustrates a possible geometry of the field, while Table 6.11 summarizes the total exposure times for the target and reference star, and dark sky observations.
Figure 6.4: Example 4: Trans + Pos Mode Exposures Target |
V |
FILTER |
Total Exposure |
---|---|---|---|
HDFAINT Trans mode |
15 |
F583W |
39 min. |
Dark_Sky1 Pos mode |
10 |
F583W |
1 min. |
Dark_Sky2 Pos mode |
12 |
F583W |
30 S |
Specify the background targets to be bright (V=8) to minimize target acquisition overheads. Note: these targets will fail to be acquired in FineLock since no coherent source is present. However, the desired photometry will be recorded.
Visit_Number: 1 Visit_Requirements: Visit_Comments: Exposure_Number: 01 Target_Name: HDFAINT Config: FGS Opmode: TRANS Aperture: 1 Sp_Element: F583W Optional_Parameters: SCANS=69, STEP-SIZE=0.6 Time_Per_Exposure: 1380S Special_Requirements: POS TARG = 0,0 SEQ 1-3 NON-INT Exposure_Number: 02 Target_Name: DARK_SKY1 Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Optional_Parameters: Time_Per_Exposure: 60 S Special_Requirements: SAME POS AS 1 Exposure_Number: 03 Target_Name: DARK_SKY2 Config: FGS Opmode: POS Aperture: 1 Sp_Element: F583W Optional_Parameters: Time_Per_Exposure: 60 S Special_Requirements: SAME POS AS 01
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