Science Keywords: Select from 2 to 5 items. Science Keywords is a required field. Wavelength is a required field. Wavelength is a required field. 0 Assigned ID: 1051 ----- Attempting Submission 1 (Fri Aug 09 11:39:17 GMT 2019) ----- HST Phase I Proposal 1051 (metcalfe.apt) successfully submitted. Receipt: # 1051-1 Joint Chandra/HST 0 ----- Attempting Submission 1 (Thu Sep 19 18:22:17 GMT 2019) ----- HST Phase II Proposal 15991 (apt_cyc27_metcalf.apt) successfully submitted. Receipt: # 15991-1 ----- Attempting Submission 2 (Fri Jan 17 21:18:55 GMT 2020) ----- 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. 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. None Required Stellar Physics 6 false false false false false false false SUPPORTED STAR G V-IV NO This object was generated by the targetselector and retrieved from the SIMBAD database. Confirmed to be ICRS J2000 epoch 2015.5 from GAIA. HD-141004 J2000 J2000 STAR G V-IV NO This object was generated by the targetselector and retrieved from the SIMBAD database. Confirmed to be ICRS J2000 epoch 2015.5 from GAIA. HD-182572 J2000 J2000 COS/FUV Spectroscopic No No G140L COS/FUV Spectroscopic No No G140L 1579295367331 /Users/saar/Documents/OP-cache/apt_cyc27_metcalf-v01.xml The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15991 :visit-id "01" :proposal-version -1 :trans-version "20190514" :date "17-Jan-2020 16:09:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 104496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15991 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15991 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2751 :al-overhead-at-end 0 :internal-dur-at-end 350 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 1 0 1579295560554 /Users/saar/Documents/OP-cache/apt_cyc27_metcalf-v02.xml The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15991 :visit-id "02" :proposal-version -1 :trans-version "20190514" :date "17-Jan-2020 16:12:40.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 34992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15991 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15991 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2754 :al-overhead-at-end 0 :internal-dur-at-end 331 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 1 0