16787( 4) - 28-Oct-2022 15:29:19 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16787 Version: 4 Check-in Time: 28-Oct-2022 15:29:19 STScI Edit Number: 1 Title Cycles and the Seven Dwarfs ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Thomas R. Ayres University of Colorado at Boulder Y ------------------------------------------------------------------------------------ Abstract Somewhat erratic, unpredictable long-term starspot cycles of late-type stars are relevant for understanding the Sun's analogous high-energy modulations, in turn crucial to Earth-impacting "Space Weather" (SW). Similarly, stellar SW counterparts can have equivalent, or more severe, adverse effects on their exoplanets. The solar decadal oscillations are symptomatic of a deep-seated magnetic pump -- the Dynamo -- whose internal workings remain elusive. Key question: is Sun's 11-year cycle normal, or instead a transition state? A 3-year addition to earlier long-term joint Chandra/HST programs (previously involving Alpha Cen [G2V+K1V] and Procyon [F5IV]), will be carried out for two new targets, the nearby binaries Xi Bootis (G8V+K4) and 70 Ophiuchi (K0V+K5V). The HST part of the program will measure FUV subcoronal (T~100, 000 K) emission lines, like Si IV 140 nm, C IV 155 nm, and density-sensitive O IV 140 nm, as well as important chromospheric (T~10, 000 K) features, like O I 130 nm, C II 133 nm, and C I 165 nm, in both pairs of stars, with one COS visit per system each year. Analyses of these emissions, including dynamical information encoded in Doppler shifts and distortions of the line shapes, can provide insight concerning the thermal/pressure structure of the anomalously hot outer layers of these stars; and how these structural properties change with the ebb and flow of a magnetic activity cycle. ------------------------------------------------------------------------------------ Observations Description ------------------------ **Impact of Reduced Gyro Mode** ------------------------------------------------- The two targets, Xi Boo and 70 Oph, would be minimally affected by RGM, because there is only a minor orientation constraint on the observations (having to do with protecting the PSA for the NUV/BOA target acquisition). Further, the Visits are only 2 orbits, minimizing the possibility of re-acquisition failures. However, if target acquisition times are increased by RGM, then one or more of the exposures would have to be shortened. This can be done with minimal loss of science. ------------------------------------------------- Phase II Observing Description (for normal 3-gyro operations) Observational goal is to obtain FUV moderate-resolution spectra of both components of Xi Boo and 70 Oph using Cosmic Origins Spectrograph (COS) . The primaries, Xi Boo A and 70 Oph A, are nearly identical in FUV flux levels, 16787( 4) - 28-Oct-2022 15:29:19 - [ 2] about a tenth of well-studied (by STIS) Alpha Cen A. Normally, high-sensitivity COS would be off-limits for these primaries, because their strong Lyman-alpha features would violate FUV detector bright limits. However, the COS G130M-1222 setting places Lyman-alpha in the gap between detector sides A and B, so can be used for cool stars, as long as their other strong emissions (e.g., C II 133 nm) are "safe" (as is the case for Xi Boo A and 70 Oph A). When combined with COS G160M-1533, the spectral range 107-171 nm can be covered, with only two small gaps: 120.7-122.3 nm (Lyman-alpha) and 151.5-153.3 nm (devoid of important lines). COS's 15 km/s resolution is fully adequate for the relatively broad FUV emission features of these cool stars, especially the "hot" lines like Si III 120.6 nm (T~30, 000 K), Si IV 139.3 nm (80, 000 K), and C IV 154.8 nm (100, 000 K). The COS FUV channel is so sensitive that a mere 1000 s exposure obtains S/N~100 (line peak) at Si III, 80 at Si IV, and 65 at C IV, for both primary stars. Each grating setting requires 4 "FP-Splits" to mitigate fixed pattern noise. The pair of FUV settings plus FP-SPLITs can be done in a single orbit for the primary of each system, including the initial Guide Star and NUV imaging target acquisitions. At the beginning of the second orbit, the secondary star would be centered by a small offset manuever from the primary, given the accurate orbital ephemeris. The same dual-setting FUV sequence then would be carried out, extending over the remaining unocculted part of the second orbit. The COS visits would be once a year for each system (4 HST orbits per year, total): experience with Alpha Cen AB has shown that the FUV variability, while significant, is not as pronounced as that of the X-rays (which are observed twice a year for each system). Helpfully, key coronal forbidden lines Fe XII 134.9 nm (T~2 MK) and Fe XXI 135.4 nm (10 MK) are available in the FUV to assess the stellar coronal states at the times of the COS pointings. For this reason, the HST and Chandra observations need not be simultaneous. In fact, it is better to have them separated, since the FUV coronal forbidden lines would then provide an additional point on the high-energy timeline. Given the very deep COS exposures proposed here (especially at 134.9 nm and 135.4 nm, which receive double coverage in the 2 nm overlap between G130M and G160M), these coronal forbidden lines should be easily detectable in the primary stars (based on previous STIS experience), and perhaps even in the UV-fainter secondaries. ------------------------------------------------------------------------------------ 16787( 4) - 28-Oct-2022 15:29:19 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD-131156A STAR, CORONA, G V-IV RA=14H51M23.3880S +/- 0.2", J2000 V = +1.5 V = +4.68 +/- 0.1 DEC=+19D06'1.64" +/- 0.2" Reference Frame: ICRS Extended: NO Comments: Target coords for epoch 2000 from SIMBAD, based on Gaia measurements for a mean epoch of 2015.5 corrected for Gaia proper motions Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.009030495425071158 -0.042 0.149 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-131156B STAR, CORONA, K V-IV RA-OFF=-0.325S, DEC-OFF=+2.03", J2000 V = +2.3 V = +6.82 +/- 0.1 FROM 1 Extended: NO Comments: Target offset based on orbital model, good for 2021 +/- 1 yr ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-165341A STAR, CORONA, K V-IV RA=18H05M27.4620S +/- 0.2", J2000 V = -6.9 V = +4.03 +/- 0.1 DEC=+02D29'43.36" +/- 0.2" Reference Frame: ICRS Extended: NO Comments: Target coords based on Gaia measurements for a mean epoch of 2015.5 (no proper motions cited in DR2); proper motions from Hipparcos. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.008274513079296998 -0.963 0.149 ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-165341B STAR, CORONA, K V-IV RA-OFF=+0.388S, DEC-OFF=-3.31", J2000 V = V = +6.07 +/- 0.1 FROM 3 -10.0 Extended: NO Comments: Target offset based on orbital model, good for 2021 +/- 1 yr ------------------------------------------------------------------------------------------------------------------------------------ 16787( 4) - 28-Oct-2022 15:29:19 - [ 4] Visit: 10 Visit Requirements: ORIENT 131D TO 11 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD-131156A COS/NUV ACQ/IMA BOA MIRRORB 1 11 S (11 GS ACQ SCENARIO BASE1BE GE S) Comments: Castelli-Kurucz Models G8V, renormalized to vegamag = 4.68 in filter Johnson/V ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-131156A COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=2400, FP-POS=ALL 1 190 S (760 G S) Comments: h_hd131156_uvsum_1m_51163_etc.dat from StarCAT (STIS E140M-1425) ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-131156A COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=4000, FP-POS=ALL 1 200 S (800 G S) Comments: h_hd131156_uvsum_1m_51163_etc.dat from StarCAT (STIS E140M-1425) ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-131156B COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=9300, FP-POS=ALL 1 225 S (900 G S) Comments: B fluxes scaled by 0.14 from A [h_hd131156_uvsum_1m_51163_etc.dat from StarCAT (STIS E140M-1425)] ------------------------------------------------------------------------------------------------------------------------------------ 5 HD-131156B COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=13400, FP-POS=ALL 1 237 S (948 G S) Comments: B fluxes scaled by 0.14 from A [h_hd131156_uvsum_1m_51163_etc.dat from StarCAT (STIS E140M-1425)] ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-131156A 1 COS/NUV ACQ/IMA BOA MIRRORB none none none none 1 N/A GE HD-131156A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 1 1 N/A G HD-131156A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 2 1 N/A G HD-131156A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 3 1 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 5] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-131156A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 4 1 N/A G HD-131156A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 1 1 N/A G HD-131156A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 2 1 N/A G HD-131156A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 3 1 N/A G HD-131156A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 4 1 N/A G HD-131156B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 1 2 N/A G HD-131156B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 2 2 N/A G HD-131156B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 3 2 N/A G HD-131156B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 4 2 N/A G HD-131156B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 1 2 N/A G HD-131156B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 2 2 N/A G HD-131156B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 3 2 N/A G HD-131156B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 4 2 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 6] Visit: 11 Visit Requirements: ORIENT 316D TO 196 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD-165341A COS/NUV ACQ/IMA BOA MIRRORB 1 8 S (8 S) GS ACQ SCENARIO BASE1BE GE Comments: Castelli-Kurucz Models K0V, renormalized to vegamag = 4.22 in filter Johnson/V (from BSC and WDS) ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-165341A COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=2800, FP-POS=ALL 1 189 S (756 G S) ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-165341A COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=4300, FP-POS=ALL 1 199 S (796 G S) ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-165341B COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=9200, FP-POS=ALL 1 225 S (900 G S) ------------------------------------------------------------------------------------------------------------------------------------ 5 HD-165341B COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=12700, FP-POS=ALL 1 234 S (936 G S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-165341A 1 COS/NUV ACQ/IMA BOA MIRRORB none none none none 1 N/A GE HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 1 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 2 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 3 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 4 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 1 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 2 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 3 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 4 1 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 7] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 1 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 2 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 3 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 4 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 1 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 2 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 3 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 4 2 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 8] Visit: 12 (HOPR_11) Visit Requirements: ORIENT 316D TO 196 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD-165341A COS/NUV ACQ/IMA BOA MIRRORB 1 8 S (8 S) GS ACQ SCENARIO BASE1BE GE Comments: Castelli-Kurucz Models K0V, renormalized to vegamag = 4.22 in filter Johnson/V (from BSC and WDS) ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-165341A COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=2800, FP-POS=ALL 1 189 S (756 G S) ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-165341A COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=4300, FP-POS=ALL 1 199 S (796 G S) ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-165341B COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=9200, FP-POS=ALL 1 225 S (900 G S) ------------------------------------------------------------------------------------------------------------------------------------ 5 HD-165341B COS/FUV TIME-TA PSA G160M 1533 BUFFER-TIME=12700, FP-POS=ALL 1 234 S (936 G S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-165341A 1 COS/NUV ACQ/IMA BOA MIRRORB none none none none 1 N/A GE HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 1 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 2 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 3 1 N/A G HD-165341A 2 COS/FUV TIME-TA PSA G130M 1222 none none none 4 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 1 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 2 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 3 1 N/A G HD-165341A 3 COS/FUV TIME-TA PSA G160M 1533 none none none 4 1 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 9] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 1 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 2 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 3 2 N/A G HD-165341B 4 COS/FUV TIME-TA PSA G130M 1222 none none none 4 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 1 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 2 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 3 2 N/A G HD-165341B 5 COS/FUV TIME-TA PSA G160M 1533 none none none 4 2 N/A G 16787( 4) - 28-Oct-2022 15:29:19 - [ 10] Summary Form for Proposal 16787 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures BOA, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=12700, BUFFER-TIME=13400, BUFFER-TIME=2400, BUFFER-TIME=2800, BUFFER-TIME=4000, BUFFER-TIME=4300, BUFFER-TIME=9200, BUFFER-TIME=9300, FP-POS=ALL ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1BE, ORIENT 131D TO 11 D, ORIENT 316D TO 196 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G160M, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD-131156A, HD-131156B, HD-165341A, HD-165341B ------------------------------------------------------------------------------------------------------------------------------------