6066( 3) - 01/19/96 13:22 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6066 Version: 3 Check-in Date: 19-Jan-1996 13:16:51 1.Proposal Title: Distant Futures of Solar Activity ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Thomas Ayres University of Colorado CASA CoI: Kenneth Carpenter NASA/Goddard Space Flight Center N CoI: Richard Robinson Computer Sciences Corp. N CoI: Alex Brown University of Colorado JILA N CoI: Graham Harper University of Colorado JILA N CoI: Philip Bennett University of Colorado JILA N CoI: Jeffrey Linsky University of Colorado JILA & NIST N CoI: Dainis Dravins Lund Observatory N CoI: Philip Judge High Altitude Observatory N ------------------------------------------------------------------------------------ 6. Abstract We will explore possible future fates of solar magnetic activity through high-S/N GHRS spectra of the ancient Sun analog, Arcturus (K1 III). The fundamental mechanisms that drive the hot (T>10^6 K) coronae of cool stars remain elusive. Solving the mystery is a central theme of the ``solar-stellar connection;'' whose importance extends beyond astronomy to areas ranging from basic plasma physics to solar-terrestrial relations. A significant property of the activity is that it subsides with age: G dwarfs in young clusters are intense coronal sources, whereas old low mass K giants are so feable in soft X-rays that most are below current detection limits. For that reason, historical studies of activity have been biased towards the younger stars. Now the HST/GHRS easily can record faint coronal proxies (like Si IV and C IV) in nearby cool subgiants and giants, thereby mitigating the de facto age discrimination. In the solar neighborhood the brightest single star of advanced age (9--11 Gyr) is Alpha Bootis (K1 III). Previous studies have placed the archetype red giant firmly in the ``coronal graveyard.'' Our project focuses on understanding the ``basal'' chromosphere; molecular cooling catastrophes and the structure of the passive ``COmosphere;'' the dynamics and energy balance of the residual subcoronal gas; and mass loss mechanisms. (Secondary target Beta Hydri was eliminated owing to reduced TAC orbit allocation.) ------------------------------------------------------------------------------------ 6066( 3) - 01/19/96 13:22 - [ 2] Observations Description ------------------------ -------------------------------------- NEW Phase II (Jan-1996) version: ------- ------------------------------- (revised owing to A2 ACQ to avoid Digicon saturation) ====================================================== Our observational goal is the detailed mapping of key intervals in the UV spectrum of Arcturus, as follows: ID mode W0 texp NOTES ======================================================================== * Acquire on Side 2 (Mirror A2) in LSA; then ACQ/Peakup in ssa A0 ECH-B/ssa 2800 5M (similar to orig.) A1 --eliminated-- A2 ECH-B/ssa 2328 7M (similar to orig.) B0 --eliminated B1 G200M/ssa 1900 25M (LSA=>ssa, to stay in ssa) * Side 2 => Side 1 B3 G140M/ssa 1213 13M (G160M=>G140M, shorter exp. than orig. B3) C1 G140M/ssa 1307 11M (similar to orig.) D2 G140L/ssa 1464 18M (single lambda setting replaced with 400 A WSCAN) B2 G140M/LSA 1388 25M (G160M=>G140M, and placed at end of sequence so only one ssa=>LSA ap. maneuver) ------------------ ------------------------------------------------------ Owing to the change in acquisition strategy---and the attendant increase of 20 minutes in the overhead ---we have reorganized the program somewhat, eliminating two exposures; shifting some of the previous Side 2 exposures to the equivalent disperser on Side 1; switching the one remaining medium-res Side 2 observation from LSA to ssa (to avoid having to return to the ssa later); and using a G140L WSCAN to recover some of the lost spectral territory. ---------------------------------- ------ Original Phase II (pre-1996) version: ---------------------------------- ------ ID mode W0 texp NOTES ======================================================================== * Acquire on Side 2 (Mirror N2) in LSA; then ACQ/Peakup in ssa A0 ECH-B/ssa 2800 4M (Mg II: same as orig. B3) A1 ECH-B/ssa 2356 4M (Si II]: shorter than orig. B1) A2 ECH-B/ssa 2329 5M (C II]: same as orig. B0) B0 G270M/ssa 2833 4M (Mg I: replaces orig. ECH-B exp. B4) B1 G200M/LSA 1900 16M (Si III], S I: replaces orig. G160M exp. C5) B2 G160M/LSA 1392 22M (Si IV, CO: shorter than orig. C1) B3 G160M/ssa 1222 22M (H I, Si III, O V], N V: replaces orig. ECH-A exp. A0) * Side 2 => Side 1 C1 G140M/ssa 1305 13M (O I, S I: replaces orig. ECH-A exp. A1) D2 G140L/ssa 1469 18M (C II; C IV, CO; etc.: replaces orig. G160H/LSA exps.: C0,C2,C3) --------------------------------------------------------------------- --- Owing to the reduction in allocated observing time from that requested (13 orbits => 4 orbits), we dropped our second priority target (Beta Hyi) entirely, and heavily modified our original observing plan. In particular, we replaced two deep ECH-A exposures with shorter integrations using medium resolution gratings and the ssa. Post-COSTAR observations with G160M/ssa have shown that the resolving power is adequate to measure the important ISM deuterium absorption, and narrow wind features; G140M/ssa should produce even higher resolution than G160M. (Specifically for the O I 1305 multiplet where narrow wind/ISM features are evident in the spectrum of Gamma Dra.) In addition, we eliminated 2 ECH-B exposures in the 2000-3000 A region, replacing one with shorter but broader-bandpass integration with G270M/ssa. Finally, we substituted a 287-A G140L/ssa exposure (1325-1612) for several G160M integrations, trading for the broad spectral coverage at high sensitivity against the higher resolution, but longer exposures and narrower coverage of G160M. Our substitutions are geared towards preserving as much of our original scientific program on Arcturus as possible, in the face of the much reduced orbit allocation. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6066( 3) - 01/19/96 13:22 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6066( 3) - 01/19/96 13:22 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD124897 STAR, K III-I, Corona, RA=14H 15M 39.68S +/- 2000 V = -5 V = -0.04+/-0.1 Wind 0.05S,DEC=19D 10' 56.7" +/- 1" B-V = +1.23+/-0.1 TYPE=K1III Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.0772 -1.998 0.097 6066( 3) - 01/19/96 13:22 - [ 5] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD124897 HRS ACQ 2.0 MIRROR-A2 BRIGHT=RETURN,S 1 9.0S ONBOARD ACQ FOR 2 EARCH-SIZE=3 Comments: STEP-TIME = 1.0 SEC (Approx. 5000 cts in STEP -TIME) ------------------------------------------------------------------------------------------------------------------------------------ 2 HD124897 HRS ACQ/PEA 0.25 MIRROR-A2 SEARCH-SIZE=5 1 45S ONBOARD ACQ FOR 11-90 KUP Comments: STEP-TIME = 1.8 SEC (Approx. 5000 cts in STEP -TIME) ------------------------------------------------------------------------------------------------------------------------------------ 11 HD124897 HRS ACCUM 0.25 ECH-B20 2799 COMB=FOUR,STEP- 1 326.4S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 12 HD124897 HRS ACCUM 0.25 ECH-B24 2328 COMB=FOUR,STEP- 1 435.2S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 41 HD124897 HRS ACCUM 0.25 G200M 1900 COMB=FOUR,STEP- 1 1523.2S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 61 HD124897 HRS ACCUM 0.25 G140M 1213 COMB=FOUR,STEP- 1 761.6S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 71 HD124897 HRS ACCUM 0.25 G140M 1307 COMB=FOUR,STEP- 1 652.8S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 80 HD124897 HRS WSCAN 0.25 G140L 1256- COMB=FOUR,STEP- 1 1088.0S 1672 PATT=DEF,DOPPLE R=DEF,FP- SPLIT=NO,WAVE- STEP=104 ------------------------------------------------------------------------------------------------------------------------------------ 90 HD124897 HRS ACCUM 2.0 G140M 1388 COMB=FOUR,STEP- 1 1523.2S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 6066( 3) - 01/19/96 13:22 - [ 6] Summary Form for Proposal 6066 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM WSCAN ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=3 SEARCH-SIZE=5 FP-SPLIT=STD DOPPLER=DEF STEP-PATT=DEF COMB=FOUR WAVE-STEP=104 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2 ONBOARD ACQ FOR 11-90 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-A2 ECH-B20 ECH-B24 G200M G140M G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD124897 ------------------------------------------------------------------------------------------------------------------------------------