! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 6048,v 7.1 1996/04/25 17:30:15 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: Denise Taylor ! Phone: 410 338-4824 , E-mail: dctaylor@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Sun Dec 18 11:37:24 EST 1994 ! Proposal_Information ! Section 4 Title: Separate Spectra of Stars of Known Very Low Mass in Nearby Close Binaries Proposal_Category: GO Scientific_Category: Cool Stars Cycle: 5 Investigators PI_name: Dr. John L. Hershey PI_Institution: Computer Sciences Corp. at Space Telescope Science Institute CoI_Name: Don Chance CoI_Institution: Computer Sciences Corp at Space Telescope Science Institute Contact: N ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The Hubble Space Telescope has recently demonstrated its ability in astrometry to separate and measure with high precision the relative orbital position of faint, nearby, low- mass binaries which are barely resolvable by ground based techniques. Since the servicing mission it has the capability of making an even greater advance over ground-based spectroscopy by acquiring separate spectra of the members of faint, close binaries, the only ones where mass can be determined. It is impossible to get these spectra from the ground because the separations of these binaries are too small to be isolated at the spectrograph slit. Knowledge of stellar masses at the ``brown dwarf'' boundary is important in many interrelated areas such as the end of the stellar mass function, theory of stellar evolution,end of the main sequence, and the galactic mass, age and evolution. Currently the objects of low stellar and sub-stellar mass are strong candidates as a source of ``missing'' galactic mass, but a means of estimating the masses of the many known single, low-luminosity and late-type M-dwarf objects is needed. Good separate spectra of these low-mass objects are needed for advancement of the mass calibration of very late-type dwarfs in order to extend the mass function lower. Questions ! Free format text (please update) Observing_Description: For the two single reference stars a simple FOS spectrum will be taken as a routine FOS observation. Because the primary targets in this program are closely spaced double stars, great care must be taken in doing the target acquisitions in order to accurately separate each star in the pair. In fact, the majority of the time on each pair must be spent doing the target acquisition. In general, the observing sequence will start by acquiring the brighter of the pair in the large FOS aperture and proceed through a series of target acquisitions to center this star in an ever smaller progression of apertures. This sequence should end with the brighter of the pair centered in the 0.25-pair aperture. A short exposure using the G780H grating will then be taken. An offset maneuver will then be performed to the fainter of the pair. Depending on how well the orbit for the pair is known, a finely spaced peakup target acqusition may be necessary at this point to accurately center the star in the aperture. Finally, a spectrum of the fainter of the pair of stars will be obtained. Simulations provided by FOS instrument scientist A. Keyes have shown that exposure times of about 20 minutes should provide S/N of 20-30 for an M2V star with a V magnitude of 15. Although target acquisition sequence for each pair will follow the general pattern described above, the details will vary slightly in each case. For example, L722-22 has a V magnitude near the limit for use with ACQ/BINARY. Detailed planning and consultation in Phase 2 may indicate it is possible to use ACQ/BINARY rather than ACQ/PEAK for the initial acquisition. This will result in a savings of several minutes and possibly reducing the number of orbits required from 3 to 2. The choice of the 0.25-pair aperture deserves some explanation. While the 0.1-pair aperture would seem at first to be a better choice because of the high spatial resolution required to provide unblended spectra for these close pairs, the 0.25-pair aperture is actually a better choice. The advantages of 0.25-pair aperture over 0.1-pair are listed below: 1. The 0.25-pair aperture gives ~ 2 times greater aperture thoughput. The 0.1 -pair aperture only covers a fraction of the PSF. 2. The 0.25 -pair aperture will be much less affected by spacecraft jitter. 3. The 0.25-pair aperture is better calibrated. No flat fields exist for the 0.1-pair aperture 4. The target acquistion is simplified by use of the larger aperture. Real_Time_Justification: none Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: !////////FIXED TARGET TEMPLATE /////////////// !Fixed_Targets ! Section 5.1 ! Target_Number: ! Target_Name: !Alternate_Names: ! Description: ! Position: ! Most common specification format is ! ! RA=0H 0M 0.00S +/- 0S, ! ! DEC=0D 0' 0.0" +/- 0", ! ! PLATE-ID=0000 ! Equinox: ! 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: ! Include at least V and B-V ! Comments: ! !------------------END TARGET TEMPLATE----------------- Fixed_Targets Target_Number: 1 Target_Name: L722-22A Description: star, M V-IV Position: RA= 3.8640416D +/-0.00139D, DEC=-16.1307D +/-0.00139D, PLATE-ID=03Y6 Equinox: J2000 RA_PM: 0.0455 Dec_PM: -0.5950 Epoch: 1983.8 Annual_Parallax: 0.1890 Flux: V=12.62 +/- 0.5 Comments: scientific target GASP coordinate from plate S608 03Y6 target_number: 2 target_name: L722-22B description: star, M V-IV position: XI-OFF= -0.28" +/-0.05", ETA-OFF= +0.135" +/-0.05", FROM 1, PLATE-ID=03Y6 equinox: J2000 ! ra_pm: 0.0455 ! dec_pm: -0.5950 ! epoch: 1983.8 ! annual_parallax: 0.1890 flux: V=15.0 +/- 0.5 comments: GASP coordinate from plate S608 03Y6 Coordinates given for 18-AUG-1996. Coordinates for this star need to be updated when it is known on what SMS it will be scheduled. target_number: 3 target_name: Ross-614A description: Star, M V-IV position: RA= 97.3440857D +/-0.00139D, DEC= -2.8103888D +/-0.00139D, PLATE-ID=02NZ equinox: J2000 ra_pm: +0.04721 dec_pm: -0.7025 epoch: 1983.9 annual_parallax: 0.248 flux: V=11.1 +/- 0.5 comments: Scientific Target, GASP coordinate from plate S770 02NZ target_number: 4 target_name: Ross-614B description: Star, M V-IV position: XI-OFF= +0.47" +/-0.1", ETA-OFF= -0.48" +/-0.1", FROM 3, PLATE-ID=02NZ equinox: J2000 ! ra_pm: +0.04721 ! dec_pm: -0.7025 ! epoch: 1983.9 flux: V=14.4 +/- 0.5 comments: GASP coordinate from plate S770 02NZ Coordinates for this star need to be updated when it is known on what SMS it will be scheduled. ! ! !---------END TARGET LIST--------------------------- ! ! ! ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed ! !Visits ! Section 6 ! Visit_Number: !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 ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN