Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2238c Report Date: 09-May-96:16:58 Version: ********** Check-in Date: ********** 1.Proposal Title: LYMAN-ALPHA OBSERVATIONS OF HIGH RADIAL VELOCITY STARS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS GO Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Jay Bookbinder CFA USA (617) 495-7058 ASTROPHYSICIST ------------------------------------------------------------------------------------ 7. Abstract H I LYMAN -ALPHA (LY-A) IS ONE OF THE MOST IMPORTANT LINES EMITTED BY PLASMA IN THE TEMPERATURE RANGE OF 7000 TO 10 TO THE FIFTH POWER K IN LATE-TYPE STARS. IT IS A MAJOR COMPONENT OF THE TOTAL RADIATIVE LOSS RATE, AND IT PLAYS A CRUCIAL ROLE IN DETERMINING THE ATMOSPHERIC STRUCTURE AND IN FLUORESCING OTHER UV LINES. YET IT IS ALSO THE LEAST STUDIED MAJOR LINE IN THE FAR UV, BECAUSE MOST OF THE LINE FLUX IS ABSORBED BY THE ISM ALONG THE LINE OF SIGHT AND BECAUSE IT IS STRONGLY COMTAMINATED BY THE GEOCORONAL BACKGROUND. A KNOWLEDGE OF THE Ly-A PROFILE IS ALSO IMPORTANT FOR STUDIES OF DEUTERIUM IN THE INTERSTELLAR MEDIUM. BY OBSERVING HIGH RADIAL VELOCITY STARS WE WILL OBTAIN FOR THE FIRST TIME HIGH RESOLUTION SPECTRA OF THE CORE OF A STELLAR H I LYMAN-A EMISSION LINE PROFILE. ------------------------------------------------------------------------------------ 8. Scientific Key Words: STARS: CHROMOSPHERES; STARS: LYMAN-ALPHA EMISSION, STARS: FLUORESCENCE, ISM: DEUTERIUM ABUNDANCE. ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 3.00 par: 0 10. Num targs pri: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2238c PI: Dr. Jay Bookbinder Proposal Title: LYMAN-ALPHA OBSERVATIONS OF HIGH RADIAL VELOCITY STARS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Prof. Alexander Brown COLORADO, UNIVERSITY OF USA Prof. Wayne Landsman ST SYSTEMS CORPORATION USA Prof. Phillip D. Judge COLORADO, UNIVERSITY OF USA Prof. Jeffrey L. Linsky COLORADO, UNIVERSITY OF USA P.I. Jay Bookbinder CFA USA Prof. James E. Neff NASA, GODDARD USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. The observational goal of this program is twofold: (1) obtain good S/N spectra of intrinsic Ly-alpha and Mg II line profiles, and (2) to observe diagnostic lines that will constrain the atmospheric modeling. Three spectra for each target star will be obtained. The first will be a moderate dispersion (R=20,000) spectrum using G160M (centered at 1213 A) to obtain the Ly-alpha line. To minimize contamination of the Ly-alpha line profile by geocoronal emission, we will use the SSA (0.25") for this exposure. Our second spectrum will use G270M grating (centered at 2800 A) and the SSA to obtain the Mg II emission lines. Our final exposure, using G140L (centered at 1530 A), will cover the range from 1388 A to 1673 A, including emission lines of Si IV, O IV], C IV, He II, O I, C I, O III],and lines of neutral elements. These lines act as diagnostics of the temperature structure within the atmosphere; the intersystem lines O IV] and O III] provide density constraints. We will use the LSA to maximize the signal in faint lines. Page 3 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. IUE measurements of low dispersion spectra of two high radial velocity stars, HD 39364 (delta Lep) and HD 41312 have been obtatined. HD 39364 has an integrated Ly -alpha flux of 5 x 10(-12) erg/sec/cm**2. Its Mg II k line flux is 6 x 10(-12) erg/sec/cm**2 with a FWHM of about 1 A. Its radial velocity relative to the ISM flow velocity (Crutcher 1982) is +120 km/s, which corresponds (at Ly-alpha ) to 0.4 A. Moreover, this star is in the third galactic quadrant, where N(H) is intrinsically low, on the order of 10(18) cm**-3. HD 41312 has an integrated Ly- alpha flux of 2 x 10(-12) erg/s/cm**2, a radial velocity relative to the LISM of +200 km/s, and it lies along a line of sight similar to that toward HD 39364. No Mg II observation exists for this star. For HD 39364, a GHRS moderate resolution (R = 20,000) exposure time of 8 minutes has been estimated on the basis of its IUE low-dispersion flux, an expected FWHM (1.6 A) of the Ly-alpha line, use of the small science aperture, and the sensitivities quoted for the G160M grating on the GHRS (neither scattered light nor dark counts are important in this experiment). This observation will be of sufficient duration to produce a spectrum with a S/N about 15 at the half-power point, which is desirable for modeling. More S/N is not required since the Ly-alpha line of giants is relatively broad and will therefore cover many pixels. The Mg II lines for HD 39364 (also R=20,000) can be obtained with a 2 minute exposure (S/N about 50 near the half-power point), based on the observed IUE flux and GHRS handbook sensitivities of the G270M grating using the large science aperture. For HD 41312, with slightly fainter lines, the estimated GHRS exposure times for the two medium dispersion gratings are 20 minutes and 5 minutes. Finally, a 15 minute low -dispersion spectrum from 1388 A to 1673 A will be obtained (using the LSA), and will provide information on many emission lines formed over a wide range of temperature down to a limiting flux (S/N above 3) about 6 x 10(-16) erg/s/cm**(2)/A. Our sensitivity calculations are based on recent revisions and we recognize that these values are still uncertain below 3000 A. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. To avoid Lyman alpha contamination by the geocorona, we request "dark time" for the appropriate exposures (G160M gratings). ------------------------------------------------------------------------------------ 11. Address Information Name: JAY BOOKBINDER Category: PI Institution: SMITHSONIAN ASTROPHYS. OBS. Address: 60 GARDEN ST City: CAMBRIDGE State: MA Zip Code: 01238 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2238c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD41312 A,140 RA = 06H 01M 14.578S +/- 1950.0 V=182.6 1 V = 5.04 +/- 0.05 0.02S, 2 B-V = 1.34 +/- 0.01 DEC = -26D 16' 58.55" +/- 3 U-B = 1.44 +/- 0.02 0.22" 4 F-LINE(1216) = 1.5 +/- 1 E-12 5 W-LINE(1216) = 2.5 +/- 0.5 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950.00 0.0038 +/- 0.0003 0.0910 +/- 0.0040 0.0000 +/- 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2238c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD41312 HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=3 1 25S 2 1 ONBOARD ACQ FOR BRIGHT=65535.0 3 1.1 FAINT=13000.0 SEQ 1.0-4.1 NO GAP LOCATE=YES DARK TIME CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 HD41312 HRS ACQ/ 2.0 MIRROR-N2 1 46S 2 1 ONBOARD ACQ FOR PEAKUP 3 2.0-4.1 DARK TIME CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WAVE HRS ACCUM SC2 ECH-B 2802.0 STEP-PATT=7 1 DEF 20 2 1 SEQ 2.0-2.1 NON- 3 INT CALIB FOR 2.1 CYCLE 1 Comments: WAVE CAL FOR THE MGII LINES ------------------------------------------------------------------------------------------------------------------------------------ 2.1 HD41312 HRS ACCUM 2.0 ECH-B 2802.0 STEP-PATT=7 4 326.4S 20 2 1 CYCLE 1 FP-SPLIT=STD 3 Comments: THE MGII LINES ------------------------------------------------------------------------------------------------------------------------------------ 3 HD41312 HRS ACCUM 2.0 G160M 1550.5 STEP-PATT=5 8 326.4S 20 2 1 CYCLE 1 FP-SPLIT=STD 3 4 Comments: THE C IV LINE ------------------------------------------------------------------------------------------------------------------------------------ 3.1 HD41312 HRS ACCUM 2.0 G200M 1901.7 STEP-PATT=5 8 326.4S 20 2 1 CYCLE 1 FP-SPLIT=STD 3 4 Comments: THE SI III AND C III LINES ------------------------------------------------------------------------------------------------------------------------------------ 4 WAVE HRS ACCUM SC2 G160M 1223.9 STEP-PATT=5 1 DEF 20 2 1 SEQ 4.0-4.1 NO GAP 3 CALIB FOR 4.1 4 CYCLE 1 Comments: WAVE CAL FOR THE LYMAN ALPHA LINE ------------------------------------------------------------------------------------------------------------------------------------ 4.1 HD41312 HRS ACCUM 0.25 G160M 1223.9 STEP-PATT=5 19 326.4S 20 2 1 DARK-TIME FP-SPLIT=STD 3 CYCLE 1 4 Comments: THE LYMAN ALPHA LINE ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2238c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=3 BRIGHT=65535.0 FAINT=13000.0 LOCATE=YES STEP-PATT=7 FP-SPLIT=STD STEP-PATT=5 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 3.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 1.1; SEQ 1.0-4.1 NO GAP; DARK TIME; CYCLE 1 ONBOARD ACQ FOR 2.0-4.1; SEQ 2.0-2.1 NON-INT; CALIB FOR 2.1; SEQ 4.0-4.1 NO GAP; CALIB FOR 4.1; DARK-TIME; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 ECH-B G160M G200M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD41312 ------------------------------------------------------------------------------------------------------------------------------------