0 Assigned ID: 1628 ----- Attempting Submission 1 (Thu Apr 08 14:56:51 GMT 2021) ----- Resubmission on Jan 12, 2022: ORIENT values have been specified for visits 4 and 5 (HIP 117795) to avoid a nearby bright M star Previous resubmission: A new co-I has been added to the team to assist in the PHOENIX modeling efforts. Dr. Hintz is an expert in chromopsheric modeling and will provide necessary guidance in this portion of the project. -118552192 ----- Attempting Submission 1 (Tue Jul 27 19:27:02 GMT 2021) ----- ----- Attempting Submission 2 (Wed Jan 12 19:58:22 GMT 2022) ----- Exposing the Lyman-alpha Profiles of Low-Mass Stars Characterizing potentially habitable planets around low mass stars is a key focus of current and upcoming missions such as JWST and TESS. This focus stresses the need for a comprehensive understanding of the radiation environments in which such planets reside. Low-mass stars are typically much more active than solar type stars and the proximity of their habitable zones can be one tenth the distance. The far-ultraviolet (FUV) radiation emitted by these stars has the potential to alter an orbiting planet's atmospheric photochemistry, while the extreme-ultraviolet (EUV) radiation can cause the loss of planetary atmospheres and surface volatiles. Ly-a emission at 1216 A is the dominant radiation source for low mass stars at FUV wavelengths and is critical for informing stellar atmosphere models used to predict the EUV spectrum, but directly measuring a low-mass star's Ly-a emission is almost always impossible because of the contaminating effects of interstellar hydrogen. Using Gaia DR2, we have identified a unique sample of six low mass stars for which a complete and accurate measurement of their Ly-a line profile is possible due to their very large radial velocities. Stars with very large radial velocities (>100 km/s) will have their Ly-a emission Doppler shifted away from contaminating sources allowing for the rare opportunity to measure intrinsic Ly-a emission. These proposed observations of this rare sample of stars will triple the number of stars with Ly-a emission measured in this way and will improve the accuracy of computed spectra for all low-mass stars across wavelengths that drive planetary atmospheric evolution. We will use HST/STIS to observe unobstructed Lyman-alpha emission from six low-mass stars (HD 64090 (K0), HD 134439 (K1), HD 134440 (K2), HIP 117795 (K8), Ross 451 (M0), L 802-6 (M3)) with large radial velocities (> 100 km/s). For each target we will first perform a STIS target acquisition sequence (ACQ/SEARCH and ACQ/IMAGE), which take seconds. We will then use the STIS/G140M grating to observe the Lyman-alpha wavelength region with the 52"x0".1 slit centered at 1222 Angstroms. These settings have been used successfully in the past for similar observations of high radial velocity M and K dwarfs. All of our targets are field-age or older dwarf stars, and should thus be considered inactive stars with low probabilities of flaring events that could potentially harm the STIS detector. Our estimated count rates for all targets are well below any overlight limits for STIS. In response to the Bright Object Protection Considerations for M Dwarf Flare Events HST Instrument Science Report (Osten 2017), we evaluated the possibility of a destructive flaring event for our two inactive M dwarfs. Following the steps outlined in the ISR, we find global and local count rates less than the detector limits for a simulated flare for both spectroscopic and target acquisition observations. These targets are thus safe to observe with STIS. Further, because our targets are all field age or older, they are likely to have spun down, with rotation periods of 10s of days, much longer than our proposed observations. Therefore, rotational variability should have little effect on the observed Lya fluxes. Dr. Sarah Peacock is an expert in modeling stellar atmospheres of cool stars using PHOENIX. She has computed several realistic synthetic spectra for cool stars that reproduce HST/COS and STIS observations, including ones guided solely by Ly-alpha observations (Peacock et al. 2019). Dr. Peacock will take responsibility for the execution of this program and will lead the data analysis, atmosphere modeling, and resulting publications. Dr. Adam Schneider has expertise in the study of low-mass stars and the evolution of their ultraviolet activity. Dr. Schneider also led the Cycle 25 HST program (#15286), a pilot study of this current proposal, to observe unobstructed Ly-alpha from two low-mass stars with extremely large radial velocities known prior to the release of Gaia DR2. The data from this program were published in Schneider et al. 2019 (ApJ, 886, 19). Dr. Schneider will assist in the data analysis and publication efforts. Dr. R. O. Parke Loyd has extensive experience in the reduction and analysis of UV spectra from HST, with seven first-author papers published using such data since 2014. Dr. Loyd will aid in the data reduction and analysis for this program. Dr. Travis Barman is an expert in modeling stellar, brown dwarf, and exoplanet atmospheres. He is a lead developer of the PHOENIX model atmosphere code, which has been used in a multitude of papers for comparisons with data from HST observations. Dr. Barman will assist in the modeling portion of this program. Dr. Evgenya Shkolnik is an expert in the study of high-energy stellar radiation and its effect on the formation and evolution of extrasolar planets. She is also the PI of a large HST program approved in Cycle 24 (#14784) to study the evolution of UV environments of early M stars (e.g., Loyd et al. 2018, ApJ, 867, 70). Dr. Shkolnik will aid in the analysis and publication efforts resulting from this program. Dr. Kenneth Carpenter, Co-I, has years of experience with IUE and HST data and their analysis, especially in regard to the study of the chromospheres and winds of evolved stars. He will provide guidance on the analysis of the observations, the modeling and spectral synthesis work, and the comparison of the theoretical results to the observations. He will also serve as GSFC Administrative PI for Science PI Dr. Sarah Peacock. Dr. Dominik Hintz is has extensive experience in modeling the chromospheres of cool stars using the PHOENIX atmosphere code. Dr. Hintz will assist in the atmospheric modeling portion of this program. Stellar Physics and Stellar Types Exoplanets and Exoplanet Formation 6 false false true false false false false SUPPORTED STAR K III-I This object was generated by the targetselector and retrieved from the SIMBAD database.This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 NUV=12.79, FUV=21.04 STAR K III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 STAR K III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 STAR K V-IV M III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 STAR M III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 J=9.409, H=8.901, K=8.667 STAR M III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:44.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 157056 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2787 :al-overhead-at-end 0 :internal-dur-at-end 440 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3180 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:45.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 313600 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2763 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "02" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "03" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:46.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 313600 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "03" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2763 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "03" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "04" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:54:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 470144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "04" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2996 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3389 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "04" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2997 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3389 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "04" :orbit-number 3 :pcs-time 392 :si-vis-utilization 2997 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3389 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "05" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:53:00.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 313600 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "05" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2995 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3389 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "05" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2997 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3389 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "06" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:47.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 470144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "06" :orbit-number 1 :pcs-time 393 :si-vis-utilization 3093 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "06" :orbit-number 2 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "06" :orbit-number 3 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) true 3 0 /private/var/folders/bl/s7q0tqnn5gbcbyvcfnrhj2rh0004nc/T/OPVisit8422766026817084151.xml The scheduling data was generated by CASM 30.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "07" :proposal-version -1 :trans-version "20211222" :date "02-Mar-2022 10:30:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 470144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "07" :orbit-number 1 :pcs-time 393 :si-vis-utilization 3093 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "07" :orbit-number 2 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "07" :orbit-number 3 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) false 3 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "08" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:49.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 470144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "08" :orbit-number 1 :pcs-time 393 :si-vis-utilization 3093 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "08" :orbit-number 2 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "08" :orbit-number 3 :pcs-time 392 :si-vis-utilization 3094 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16646 :visit-id "09" :proposal-version -1 :trans-version "20210514" :date "12-Jan-2022 14:56:50.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 470144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16646 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16646 :visit-id "09" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2756 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "09" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2757 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16646 :visit-id "09" :orbit-number 3 :pcs-time 392 :si-vis-utilization 2757 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 3 0