6136( 7) - 08/23/95 11:14 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6136 Version: 7 Check-in Date: ********** 1.Proposal Title: Positioning and proper motion measurement of the PSR0656+14 optical counterpart. ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Hot Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Roberto Mignani Universita degli Studi di Milano and Istituto di Fisica Cosmica del CNR CoI: Giovanni F. Bignami Istituto di Fisica Cosmica del CNR N CoI: Patrizia A. Caraveo Istituto di Fisica Cosmica del CNR N CoI: Sandro Mereghetti Istituto di Fisica Cosmica del CNR N ------------------------------------------------------------------------------------ 6. Abstract PSR0656+14, is one of the few radio pulsars for which an optical counterpart has been proposed. Two ground based ESO (1989 and 1991) observations detected a m_V ~ 25 object at the radio position. This detection seems confirmed by the HST/FOC and by EUVE data. We now propose to image the field of PSR0656+14 with the PC to perform very accurate relative astrometry of the suggested optical counterpart, both as a reference for future observations, and in order to compare its present position with those measured in our 1989 and 1991 frames. Since the radio pulsar exhibits a proper motion towards the SE of ~ 70 mas /year, the corresponding angular displacement of the optical counterpart over 6 years (>= 0sec point 4) could be measurable. If observed, this will confirm the proposed identification, and yield interesting constraints on the emission mechanism(s), expecially in comparison with EUVE and X- ray data. ------------------------------------------------------------------------------------ 6136( 7) - 08/23/95 11:14 - [ 2] Observations Description ------------------------ We plan to do deep imaging of the region around PSR0656+14 in order to position accurately the candidate counterpart. To estimate the exposure time needed to detected our target (m_V <= 25) we take advantage of the experience wa have now gathered during Cycle 4 with the program 5484 focussed on the Geminga optical counterpart, a target of comparable brightness. In order to clearly detect such a faint target with the PC and reduce contamination from cosmic ray hits 6 images of 7-800 secs are required, split in two exposures per orbit, to fulfill our science goal with the necessary overheads. We choose the F555W filter since the target has been observed close to this passband from the ground. Real Time Justification ----------------------- Our previous ground based observations represent the only accurate reference both to the target position in the PC field and to sufficient nearby stars. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6136( 7) - 08/23/95 11:14 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR- STAR,NEUTRON STAR RA=6H 59M 48.12S +/- 0.001S, J2000 V=25 065948+14142 DEC=14D 14' 29.53" +/- 0.01" 1 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1995.03 0.0044 -0.028 0.0 6136( 7) - 08/23/95 11:14 - [ 4] Visit: 01 Visit Requirements: ORIENTation 45.0D TO 45.0D PCS MODE F On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR- WFPC2 IMAGE PC1-FIX F555W 5407 CR-SPLIT=0.5,CR 1 1600S 065948+1414 -TOLERANCE=0.2 21 ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR- WFPC2 IMAGE PC1-FIX F555W 5407 CR-SPLIT=0.5,CR 1 1600S 065948+1414 -TOLERANCE=0.2 21 ------------------------------------------------------------------------------------------------------------------------------------ 3 STAR- WFPC2 IMAGE PC1-FIX F555W 5407 CR-SPLIT=0.5,CR 1 1600S 065948+1414 -TOLERANCE=0.2 21 ------------------------------------------------------------------------------------------------------------------------------------ 4 STAR- WFPC2 IMAGE PC1-FIX F555W 5407 CR-SPLIT=0.5,CR 1 1400S 065948+1414 -TOLERANCE=0.2 21 ------------------------------------------------------------------------------------------------------------------------------------ 6136( 7) - 08/23/95 11:14 - [ 5] Summary Form for Proposal 6136 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Hot Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENTation 45.0D TO 45.0D PCS MODE F ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names STAR-065948+141421 ------------------------------------------------------------------------------------------------------------------------------------