15991( 3) - 21-Jan-2020 16:48:42 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15991 Version: 3 Check-in Time: 21-Jan-2020 16:48:42 STScI Edit Number: 0 Title The Deaths of Stellar Dynamos: Digging in the Magnetic Graveyard for Old Cold Coronae ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Travis S. Metcalfe White Dwarf Research Corporation Y CoI: Dr. Jeremy J. Drake Smithsonian Institution Astrophysical N Observatory CoI: Dr. Steven H. Saar Smithsonian Institution Astrophysical Y Observatory ------------------------------------------------------------------------------------ Abstract Sun-like stars exhibit three distinct phases of magnetic evolution. In the saturated regime, the X-ray luminosity is independent of the rapid rotation. For slightly older stars in the unsaturated regime, the X-ray luminosity declines in tandem with rotation. Recent observational evidence suggests that near the middle of their main-sequence lifetimes, stars may enter a third regime in which rotation remains nearly constant while magnetic activity continues to decline. We propose to measure X-ray luminosities for three stars with a range of spectral types and metallicities, to identify the signature of this third regime in the old cold coronae of stars that appear to have shut down their global dynamos. We will use previous observations to help constrain the coronal temperatures. ------------------------------------------------------------------------------------ Observations Description ------------------------ We desire FUV low resolution (G140L) observations of two bright, low activity stars, one orbit each. Both have GAIA coordinates, so an ACQ/SEARCH is not needed. Both are bright and so target ACQ is in spectroscopic mode (PEAKXD and PEAKD), but UV dim enough that time-tag mode is possible. After target ACQ, the remainder of the orbit is spent with the science observation for each star. ------------------------------------------------------------------------------------ 15991( 3) - 21-Jan-2020 16:48:42 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 -LAM-SER STAR, G V-IV RA=15H46M26.3809S +/- 0.001", J2000 V = 4.42 DEC=+07D21'9.97" +/- 0.02" Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Confirmed to be ICRS J2000 epoch 2015.5 from GAIA. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 -0.015064340775332072 -0.06938400006220036 0.0846 ------------------------------------------------------------------------------------------------------------------------------------ 2 -B-AQL STAR, G V-IV RA=19H24M58.9618S +/- 0.001", J2000 V = 5.17 DEC=+11D56'49.85" +/- 0.02" Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Confirmed to be ICRS J2000 epoch 2015.5 from GAIA. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.04913376048920273 0.643379 0.06685 ------------------------------------------------------------------------------------------------------------------------------------ 15991( 3) - 21-Jan-2020 16:48:42 - [ 3] Visit: 01 Visit Requirements: 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 -LAM-SER COS/FUV ACQ/PEA PSA G140L 1280 NUM-POS=3, STEP-SIZE=1.3, 1 3 S (3 S) KXD CENTER=FLUX-WT ------------------------------------------------------------------------------------------------------------------------------------ 2 -LAM-SER COS/FUV ACQ/PEA PSA G140L 1280 STEP-SIZE=1.3, NUM-POS=3, 1 3 S (3 S) KD CENTER=FLUX-WT ------------------------------------------------------------------------------------------------------------------------------------ 3 -LAM-SER COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=2056, FP-POS=ALL 1 495 S G see below (1976 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 | ------------------------------------------------------------------------------------------------------------------------------------ -LAM-SER 1 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A KXD -LAM-SER 2 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A KD -LAM-SER 3 COS/FUV TIME-TA PSA G140L 1280 none none none 1 1 494.0 S G -LAM-SER 3 COS/FUV TIME-TA PSA G140L 1280 none none none 2 1 494.0 S G -LAM-SER 3 COS/FUV TIME-TA PSA G140L 1280 none none none 3 1 494.0 S G -LAM-SER 3 COS/FUV TIME-TA PSA G140L 1280 none none none 4 1 494.0 S G 15991( 3) - 21-Jan-2020 16:48:42 - [ 4] Visit: 02 Visit Requirements: 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 -B-AQL COS/FUV ACQ/PEA PSA G140L 1280 NUM-POS=3, CENTER=FLUX-WT, 1 19 S (19 KXD STEP-SIZE=1.3 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 -B-AQL COS/FUV ACQ/PEA PSA G140L 1280 STEP-SIZE=1.3, CENTER=FLUX-WT, 1 19 S (19 KD NUM-POS=3 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 -B-AQL COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=5892, FP-POS=ALL 1 361 S G see below (1940 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 | ------------------------------------------------------------------------------------------------------------------------------------ -B-AQL 1 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A KXD -B-AQL 2 COS/FUV ACQ/PEA PSA G140L 1280 none none none none 1 N/A KD -B-AQL 3 COS/FUV TIME-TA PSA G140L 1280 none none none 1 1 485.0 S G -B-AQL 3 COS/FUV TIME-TA PSA G140L 1280 none none none 2 1 485.0 S G -B-AQL 3 COS/FUV TIME-TA PSA G140L 1280 none none none 3 1 485.0 S G -B-AQL 3 COS/FUV TIME-TA PSA G140L 1280 none none none 4 1 485.0 S G 15991( 3) - 21-Jan-2020 16:48:42 - [ 5] Summary Form for Proposal 15991 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAKD, ACQ/PEAKXD, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=2056, BUFFER-TIME=5892, CENTER=FLUX-WT, FP-POS=ALL, NUM-POS=3, STEP-SIZE=1.3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names -B-AQL, -LAM-SER ------------------------------------------------------------------------------------------------------------------------------------