!__Proposal-Section__ !6116 ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 6116,v 9.1 1995/07/31 18:38:12 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Christian Ready ! Phone: 410 338-4546 , E-mail: ready@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Mon Dec 19 08:18:13 EST 1994 ! Proposal_Information ! Section 4 Title: A search for the optical counterpart of the triple pulsar system PSR B1620-26 in M4 Proposal_Category: GO Scientific_Category: Hot Stars Cycle: 5 Investigators PI_name: Charles Bailyn PI_Institution: Yale University CoI_Name: Terrence M. Girard CoI_Institution: Yale University Contact: ! Y or N (designate at most one contact) CoI_Name: Frederic A. Rasio CoI_Institution: Institute for Advanced Study Contact: ! Y or N (designate at most one contact) CoI_Name: Brian Yanny CoI_Institution: Fermi National Accelerator Laboratory Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The accurate optical identification of the millisecond pulsar B1620-26 in the globular cluster M4 (NGC6121) is crucial for determining the nature of this unique hierarchical triple system. Ground based imaging has revealed a potential condidate, which may well be blended and/or a chance superposition. We propose a short WF/PC II observation which will unambiguously demonstrate whether an optical counterpart exists, and if so, determine its magnitude and color. The results will be of great interest both for issues relating to the origin of pulsars, and in terms of dynamical processes in globular clusters. Questions ! Free format text (please update) Observing_Description: We wish to detect or rule out the presense of a V=23th magnitude object without overly saturating nearby stars (1sec point 5 to 5'', corresponding to 30 to 100 pixels from the target), which have magnitude 16. A 16th magnitude star saturates in the F555W filter (hereafter ``V'') in about 10 seconds (based on the exposure time calculations given in the WFPC-2 Instrument Handbook and on previous WFPC-2 images of the globular cluster M30, Yanny et al 1994b). To reach V=23 with S/N=10, requires a total exposure of about 120 secs. Additionally, to determine the color of the object, which if a star, will be quite red, we request I (F814W) exposures of the same field. The sensitivity of the WFPC-2 in the I filter is about half that of the V band and so we require similar exposure times for objects with colors expected to have V-I~ 1. Several short exposures in F555W and F814W will be used to model the PSF and subtract the wings of the target's bright neighboring stars. Then a series of longer exposure in both filters will be used to obtain the full required S/N for faint objects. Thus we request three 10 sec and three 40 second exposures in each filter, for a total exposure time of 5 minutes. With acquisition time of 12 minutes, and overhead of 3* 12=36 minutes, all the exposures can be completed in one 53 minute orbit. Real_Time_Justification: In order to avoid bleeding and diffraction spikes from a very bright saturated V=13.0 mag star onto the target 5 arcseconds distant, we request that the roll angle of the spacecraft be such that the orientation of the y-axis of the WFPC-2/PC CCD with respect to the east-west axis be less than 25 degrees. New photographic plates are scheduled to be taken with the double astrograph of the Yale Southern Observatory at El Leoncito Argentina next spring. This plate material will serve to tie the optical images to a standard system without the need for proper motion corrections. We also hope to obtain improved ground based CCD images (deeper and better seeing) when the WIYN telescope comes on line next spring. With these new data, we expect to be able to tie the PC data requested here to the FK5 astrometric system with an accuracy better than 0sec point1. Thus the dominant systematic error in locating the pulsar position on the PC image will be the accuracy of the transformation between the solar system ephemeris used to determine the pulsar timing positions, and the FK5 system. This error is estimated to be ~ 0sec point1 (Standish, 1990). Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: PSR-B1620-26 Alternate_Names: Description: STAR, pulsar Position: RA=16H 23M 38.22S +/- 0.1S, DEC=-26D 31' 53.7" +/- 0.2", PLATE-ID=02J6 Equinox:2000 Flux:V=21 +/- 2 ! Include at least V and B-V Comments: ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ORIENT 18D TO 72D ! Section 7.1 ! Most of these requirements (including ORIENT) will limit scheduling Visit_Comments: The orientation requirement is to avoid bleeding from a 13th magnitude star located 5" due north of the target. Also, we are informed by our scientific contact (Howard Lanning) that the diagnostic relating to overfull tape recorders can be waived for orbits containing up to 14 WFPC2 images, since a second tape recorder was installed during the refurbishment mission. Exposure_Number:1 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:40S Comments: Exposure_Number:2 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:40S Comments: Exposure_Number:3 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:3S Comments: Exposure_Number:4 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:3S Comments: Exposure_Number:5 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:3S Comments: Exposure_Number:6 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:40S Comments: Exposure_Number:7 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:120S Exposure_Number:11 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:120S Comments: Exposure_Number:12 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:40S Comments: Exposure_Number:13 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:3S Comments: Exposure_Number:14 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:3S Comments: Exposure_Number:15 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:3S Comments: Exposure_Number:16 ! Section 6.5 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F814W Time_Per_Exposure:40S Comments: Exposure_Number:17 Target_Name:PSR-B1620-26 Config:WFPC2 Opmode:IMAGE Aperture:PC1 Sp_Element:F555W Time_Per_Exposure:40S Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_Address ! STSCI or PI_Address or ! PI Address from Phase I is: ! ! Dept. of Astronomy , ! P. O. Box 208101,New Haven, ! CT 06520-8101 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator