! Proposal 6460, submission 1 ! PI: Michael Shara ! Received Fri Feb 9 13:18:38 EST 1996 ! From: zurek@stsci.edu ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6460,v 3.1 1996/02/09 18:44:15 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6460,v 3.1 1996/02/09 18:44:15 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: Taylor ! Phone: 410-338-4824 , E-mail: dctaylor@stsci.edu ! Denise Taylor (Program Coordinator) (dctaylor@stsci.edu, 410-338-4824) ! John Biretta (Contact Scientist) (biretta@stsci.edu, 410-338-4917) ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0192.shara.prop ! Date generated: Fri Dec 22 18:29:10 EST 1995 ! Proposal_Information ! Section 4 Title: Where are the Dozens of Predicted Cataclysmic Variables in Globular Clusters? Proposal_Category: GO Scientific_Category: BINARIES AND STAR FORMATION Cycle: 6 Investigators PI_name: Michael Shara PI_Institution: Space Telescope Science Institute CoI_Name: David Zurek CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Louis Bergeron CoI_Institution: New Mexico State University Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) WFPC2 imaging of globular cluster cores provides us with a unique opportunity to detect erupting cataclysmic variables (CVs) because they should be relatively common in the core. Two body tidal capture theory predicts that all binary systems should be relatively common in globular clusters, up to several orders of magnitude greater in relative number than in the Galactic field. Among the most common binaries should be CVs because of the high presumed abundance of white dwarfs in globular cores. However, only a handful of confirmed CVs have been discovered in globular clusters to date. This paucity brings into question the dynamical theories which predict great numbers of CVs. We propose to image the cores of two globular clusters with WFPC2 at five epochs to detect outbursting CVs - dwarf novae (DN). We also propose to retrieve from the archive globular cluster WFPC2 data, cycles 4 & 5, that were taken over multiple epochs to search for erupting DN. At any given time ~15\ to find ~30\ two epochs. Clusters for which we have three or more epochs should yield >~50\ DN exist in the cores of globular clusters will either support present dynamical theories or strongly constrain new theories that can adequately explain these results. Questions ! Free format text (please update) Observing_Description: We propose to image the cores of two globular clusters (Table 1) in the filter F336W for one orbit each week for five consecutive weeks. The five epochs of NGC 6093 and NGC 6171 will be combined with 2 or 3 archival epochs to yield a very high detection threshold of >~70% in each epoch ~15% image the cluster cores in HAlpha and ``R'' to determine if the DN candidates have an HAlpha excess in quiescence. Globular Cluster Sample Cluster Log(rho_o) (M-m)_o E(B-V) r_core NGC 6093 (M80) 4.79 14.62 0.20 8.9 NGC 6171 (M107) 3.11 14.03 0.33 32.4 Dwarf novae will typically brighten from sim22^nd magnitude to sim18-19^th magnitude in eruption in a globular at (m-M)~15. We will conduct photometry on candidates to ensure that they have the appropriate color and magnitude to be dwarf novae at their host globular cluster distance. Real_Time_Justification: We request that observations of each cluster be separated by 7-10 days to maximize the detection of DN in the entire data set. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: NGC6093 Alternate_Names: M80 Description: STELLAR CLUSTER, GLOBULAR CLUSTER Position: RA=16H 17M 02.5S +/- 0.05S, DEC=-22D 58' 30" +/- 0.5" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000.0 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: V=21.0+/-0.5, B-V=0.00+/-0.5 ! Include at least V and B-V Comments: Target_Number: 2 Target_Name: NGC6171 Alternate_Names: M107 Description: STELLAR CLUSTER, GLOBULAR CLUSTER Position: RA=16H 32M 31.9S +/- 0.05S, DEC=-13D 03' 13" +/- 0.5" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000.0 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: V=21.0+/-0.5, B-V=0.0+/-0.5 ! 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: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling PCS MODE Fine ! 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