! Proposal 6769, submission 1 ! PI: V. M. Kaspi ! Received Thu Feb 1 22:44:29 EST 1996 ! From: mhvk@astro.caltech.edu ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6769,v 3.1 1996/02/05 16:50:34 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6769,v 3.1 1996/02/05 16:50:34 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: Ready ! Phone: 410-338-4546 , E-mail: ready@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0978.kaspi.prop ! Date generated: Fri Dec 22 17:46:59 EST 1995 ! Proposal_Information ! Section 4 Title: The Eclipsing Binary Pulsar PSR B1718-19: A Clean RS CVn System? Proposal_Category: GO Scientific_Category: BINARIES AND STAR FORMATION Cycle: 6 Investigators PI_name: V. M. Kaspi PI_Institution: IPAC/Caltech/JPL CoI_Name: M. H. van Kerkwijk CoI_Institution: California Institute of Technology Contact: ! Y or N (designate at most one contact) CoI_Name: S. Kulkarni CoI_Institution: California Institute of Technology Contact: ! Y or N (designate at most one contact) CoI_Name: D. Van Buren CoI_Institution: IPAC/Caltech/JPL Contact: ! Y or N (designate at most one contact) CoI_Name: A. G. Lyne CoI_Institution: University of Manchester/Jodrell Bank Contact: ! Y or N (designate at most one contact) CoI_Name: A. R. Klemola CoI_Institution: Lick Observatory Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) We request WFPC2 observations of the eclipsing binary pulsar PSR B1718-19. This slowly-rotating pulsar lies in the direction of the globular cluster NGC 6342, and defies standard binary pulsar formation models in which the pulsar is ``spun-up'' via mass accretion. Furthermore, the observed eclipses cannot be explained with standard models. This pulsar's unusual properties can be explained elegantly if its companion is an active, non-degenerate star like those observed in RS CVn systems, but in this case, subject only to gravity. Following Keck observations of the field, we propose HST observations of PSR B1718-19 to detect and study variability in the companion, in order to answer the following questions. 1- Are the eclipses seen in PSR B1718-19 indeed a result of RS CVn-type activity in the companion, and what is the evolutionary history of the binary? 2- Is the activity in RS CVn systems purely a tidal effect? 3- How are mass loss, rotation, and surface activity related in RS CVn stars? 4- Is PSR B1718-19 in NGC 6342? Questions ! Free format text (please update) Observing_Description: The proposed observations are straightforward. We will make a continuous series of exposures over the course of a single 6.2 hr orbit of \psr, or 4 HST orbits. Per orbit, we have 40 minutes of exposure time, which will give us adequate sensitivity to measure 10\% light variations of an I=24 optical counterpart at the 3Sigma level. Note that given the small number of stars with such brightnesses expected in the error box, a 3Sigma deviation will be truly significant. Each orbit, we will take three 800 second exposures through F702W. This will minimize the effect of cosmic-ray hits. Combining these images per orbit, we will obtain an SNR of 25--30 for an I=24 object. For all orbits combined, we expect to reach a 3Sigma limiting magnitude of I=27.4. We note that the F702W filter provides us with 10\% more SNR than F814W, which is better matched to the expected source spectrum, but less well matched to the CCD sensitivity roll-off at long wavelengths. This assumes an M0 spectrum. At later spectral types F814W becomes marginally better, but a counterpart for which this is true will be too faint to detect photometric variations. Since the SNR limit on detection is less stringent than the limit on modulations of the light, F702W covers the bases better. These numbers were derived from the WWW exposure estimator online at STScI. Real_Time_Justification: Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: STAR-172102-193637 Alternate_Names: PSR-B1718-19 Description: STAR, PULSAR, BINARY PULSAR, RS CVN STAR, NEUTRON STAR Position: RA=17H 21M 01.54S +/- 0.02S, DEC=-19D 36' 36.6" +/- 0.2" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: I=24.5 +/- 1.5, R-I=1 +/- 0.5 ! Include at least V and B-V Comments: We are trying to find the pulsar companion and do not know its flux in advance. We have put a best guess. ! 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: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! DROP TO GYRO IF NECESSARY [NO REACQuisition] ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! SCHEDulability ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN