! Proposal 6680, submission 1 ! PI: Wayne Landsman ! Received Fri Feb 2 04:36:47 EST 1996 ! From: landsman@idlastro.gsfc.nasa.gov ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! 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: Alice Berman ! Phone: 410-338-4462 , E-mail: aberman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. Proposal_Information ! Section 4 Title: The post mass-transfer binary S1040 in M67 Proposal_Category: GO Scientific_Category: BINARIES AND STAR FORMATION Cycle: 6 Investigators PI_name: Wayne Landsman PI_Institution: Hughes STX CoI_Name: Theodore Stecher CoI_Institution: NASA/Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Allen Sweigart CoI_Institution: NASA/Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Ben Dorman CoI_Institution: NASA/Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The yellow giant S1040 (V=11.52, \bv = 0.88) in M67 is a single-lined spectroscopic binary that shows the following two anomalies. First, S1040 occupies a ``red straggler'' position in the M67 color-magnitude diagram, 0.2 mag blueward of the red giant branch. Second, S1040 was detected at 1520 Angstrom\ on an image of M67 obtained with the Ultraviolet Imaging Telescope (UIT), with an ultraviolet flux far above that expected from its optical colors. The most likely explanation for these two anomalies is that the secondary of S1040 is a hot white dwarf, and that the peculiar position of S1040 in the color-magnitude diagram is due to previous mass transfer from the white dwarf progenitor. If this scenario is correct, then S1040 is an evolutionary descendant of a M67 blue straggler. We propose to obtain a GHRS G140L spectrum of S1040 centered at 1320 Angstrom, in order to confirm the white dwarf identification, and to derive the white dwarf temperature and gravity from the Ly alpha profile. The white dwarf cooling age and mass can then be derived using evolutionary models. Used in conjunction with the known age and metallicity of M67, these parameters will allow us to constrain models of the binary stellar evolution of S1040, and evaluate its possible origin as a blue straggler. Questions ! Free format text (please update) Observing_Description: We propose to obtain a 120 minute large-aperture G140L exposure of S1040 centered at 1320 Angstrom. Using the white dwarf model which matches the observed UIT flux at 1520 Angstrom\ (Figure 2), and the procedure PREDICT\_GHRS available at Goddard Space Flight Center, we estimate that a 120 minute exposure will give S/N ~ 12 near Ly-alpha. Due to the large width of the white dwarf Ly-alpha\ profile, it will be possible to improve the S/N by smoothing the spectra to ~ 8 Angstrom\ resolution without losing senstivity to T(eff)\ and \logg. The UV flux of S1040 is too faint to allow an acquisition with side 1 on GHRS, so we are asking for an FOS/BL assisted acquisition. Note that an ACQ/BIN acquisition with FOS should suffice, since S1040 is an HST Guide Star Catalog source, and relatively bright at wavelengths longer that 2500 Angstrom. After the FOS/BL acquisition, we will obtain a 5 minute FOS low-dispersion spectrum using the G270H blue side to cover the 2400 -- 3300 Angstrom\ spectral region where the flux from the K star is predicted to drop by more than a factor of 100. This short exposure will provide a sensitive diagnostic of the K star effective temperature. Real_Time_Justification: None. None. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: NGC2682-S1040 Alternate_Names: GSC814-1119 M67-S1040 Description: STAR,COMPOSITE SPECTRAL TYPE,K III-I,DA Position: ! Most common specification format is RA = 08H 51M 23.85S +/- 0.01S, ! RA=0H 0M 0.00S +/- 0S, DEC = 11D 49' 49.3" +/- 0.2", ! DEC=0D 0' 0.0" +/- 0", PLATE-ID=028I Equinox: J2000 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=11.52 +/- 0.02 ! Include at least V and B-V B-V=0.88 +/- 0.03 E(B-V)=0.03 +/- 0.02 F(1520) = 2.3 +/- 0.5E-15 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: 01 Visit_Requirements: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! SEQ WITHIN