Stellar mass loss is a ubiquitous property of stars, and most stars may host planetary companions. While we are just in the initial stages of assessing how common exoplanets may be, there already exists a rich body of work that seeks to understand the profound connection between a star and its planets, particularly their atmospheres. The unique properties of a star's electromagnetic radiation and particle wind can dictate a planet's thermal and chemical atmospheric structure. Indeed, the solar wind likely eroded a warm and wet ancient Martian atmosphere. As our capability to discover and characterize exoplanets and their atmospheres continues to improve, the habitability of these planets will become a central and potentially radical scientific research question. At the heart of this question will be the relationship of the planet with its host star. The detection of the relatively weak winds of cool, solar-like stars can only be made with high resolution UV spectra. The interaction of a stellar wind with its surrounding interstellar medium produces detectable HI Lyman-alpha absorption, where the amount of absorption is proportional to the mass loss rate. We propose observations of a sample of 4 nearby exoplanetary host stars in order to measure their winds and enable an evaluation, not only of the current stellar conditions, but to reconstruct its evolution over the course of its lifetime. These measurements by HST will provide exclusive insight into how stellar winds influence planetary atmospheres that the community will draw upon long after HST has ended its mission, as the detection and characterization of planets like our own is just beginning. We plan to obtain observations of four late-type (F-K) stars that host exoplanetary systems, in order to inventory the mass-loss rates impacting these specific exoplanets, while simultaneously improving the general relationship between mass-loss, activity, and age. Desired Spectral Coverage and Resolution: We plan to use the high resolution E230H grating to observe MgII and FeII. Because the hydrogen at the astrospheric interface is hot (T ~ 100,000 K), it has a broad absorption profile, and does not necessarily require high spectral resolution, and therefore, to maximize S/N, we plan to use the E140M setting. Desired Aperture Size and Geocoronal Emission: The narrow aperture sizes of STIS are critical in order to minimize the contamination by the geocoronal Lyman-alpha emission. Depending on the time of year, the Earth's motion can Doppler shift the geocoronal line into the region of astrospheric absorption and contaminate our measurement. For 3 of our targets, we require a minimal timing constraint to ensure that the geocoronal line is in the core of the ISM absorption (still allowing >6 months to perform observations). Desired Signal-to-Noise and Exposure Times: Because cool star spectra are emission line sources in the UV, estimating expected S/N for our planned spectra requires first estimating Lyman-alpha and MgII fluxes, which we can do by extrapolating from previously observed stars. Chromospheric line fluxes (such as MgII and Lyman-alpha) are related to X-ray fluxes (Ayres et al. 1995). Wood et al. (2005a) provide Lyman-alpha spectra for many stars, which serve as the comparison stars for our purposes here. After acquisition, peakup, and observational overhead are considered, we expect at least 28 minutes to be available in the first orbit for the E230H exposure. This provides time to attain very high S/N of >50 at the half-maximum (that is, one half FWHM from the line center, because it is unlikely that the ISM absorption will be centered at the same velocity as the star) of the strong MgII lines. After acquisition and overheads are considered, we expect at least 41 minutes of exposure time to be available in the second orbit for the E140M exposure, and 48 minutes in subsequent orbits. Brightness Limits: All of our targets are late-type stars which have UV spectra characterized by minimal continua, but strong emission lines. For this reason, all of our targets fall far short of the global brightness limit. IUE spectra for our stars confirm this. For example, in the E230H setting, using IUE data, our earliest spectral type target (GJ61; F8V) only results in 5.8 counts/s. The emission lines also fall far short of the local brightness limit. The two emission lines of interest in this proposal (Lyman-alpha and MgII) are also the brightest, and therefore, the procedure given above for estimating the S/N near their peaks is also utilized to test for brightness limit violations. Again, GJ61 is among the strongest MgII emission line sources in our sample, and in the brightest pixel, only generates 3.0 counts/s. For 3 of our 4 targets, it will be necessary to restrict the time of observation to ensure that geocoronal emission centered on the Earth's rest frame is well within the saturated core of the broad ISM Lyman-alpha absorption, and therefore does not contaminate the region where astrospheric absorption is expected. Indeed, the geocoronal emission actually becomes a very useful wavelength calibrator. This is not a major time constraint, and there are windows of at least 6 months where the observations can be performed. EXTRA-SOLAR PLANETS 12 false 0.0 0.0 false false false false SUPPORTED STAR EXTRA-SOLAR PLANETARY SYSTEM K V-IV GJ785 GSC2S333002246410 J2000 J2000 TYPE=K1V, B-V=0.908, E(B-V)=0, F-LINE(2796)=4.20E-12, W-LINE(2796)=0.6, F-LINE(1216)=2.90E-12, W-LINE(1216)=0.7 STAR EXTRA-SOLAR PLANETARY SYSTEM G V-IV GJ9559 GSC2S2303310248 J2000 J2000 TYPE=G5V, B-V=0.597, E(B-V)=0, F-LINE(2796)=8.58E-12, W-LINE(2796)=0.6, F-LINE(1216)=5.70E-12, W-LINE(1216)=0.7 STAR EXTRA-SOLAR PLANETARY SYSTEM G V-IV GJ3021 GSC2S0100200192 J2000 J2000 TYPE=G8V, B-V=0.757, E(B-V)=0, F-LINE(2796)=4.82E-12, W-LINE(2796)=0.6, F-LINE(1216)=3.44E-12, W-LINE(1216)=0.7 STAR EXTRA-SOLAR PLANETARY SYSTEM F3-F9 GJ61 GSC2N3303311819 J2000 J2000 TYPE=F8V, B-V=0.54, E(B-V)=0, F-LINE(2796)=1.61E-11, W-LINE(2796)=0.75, F-LINE(1216)=7.83E-12, W-LINE(1216)=1.0 STIS/NUV-MAMA Spectroscopic No No E230H 2713 STIS/FUV-MAMA Spectroscopic No No E140M 1425 STIS/NUV-MAMA Spectroscopic No No E230H 2713 STIS/FUV-MAMA Spectroscopic No No E140M 1425 STIS/NUV-MAMA Spectroscopic No No E230H 2713 STIS/FUV-MAMA Spectroscopic No No E140M 1425 STIS/NUV-MAMA Spectroscopic No No E230H 2713 STIS/FUV-MAMA Spectroscopic No No E140M 1425 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1322454927000 82.05877685036683 (Tic-Visit :proposal-id 12475 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "06-Jul-2011 11:31:35.0" :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 279984 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12475 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12475 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :al-overhead-at-end 0 :internal-dur-at-end 115 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 196 :internal-dur-at-end 321 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 3 0 Exposure time (seconds) = 1,885.0000 at wavelength 2796.00 Å gives: SNR = 54.0639 (per resolution element) Exposure time (seconds) = 6,010.0000 at wavelength 1216.00 Å gives: SNR = 31.0419 (per resolution element) Exposure time (seconds) = 6,010.0000 at wavelength 1216.00 Å gives: SNR = 31.0419 (per resolution element) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12475 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "06-Jul-2011 11:35:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 366992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12475 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12475 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2968 :al-overhead-at-end 0 :internal-dur-at-end 115 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3079 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3079 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3079 :al-overhead-at-end 196 :internal-dur-at-end 321 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) true 4 0 Exposure time (seconds) = 1,929.0000 at wavelength 2796.00 Å gives: SNR = 78.3816 (per resolution element) Exposure time (seconds) = 9,147.0000 at wavelength 1216.00 Å gives: SNR = 61.8090 (per resolution element) Exposure time (seconds) = 9,147.0000 at wavelength 1216.00 Å gives: SNR = 61.8090 (per resolution element) Exposure time (seconds) = 9,147.0000 at wavelength 1216.00 Å gives: SNR = 61.8090 (per resolution element) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1338710753000 244.09178613405385 (Tic-Visit :proposal-id 12475 :visit-id "03" :proposal-version -1 :trans-version "20110509" :date "06-Jul-2011 11:55:06.0" :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 279984 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12475 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3300 :al-overhead-at-end 0 :internal-dur-at-end 115 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3411 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3411 :al-overhead-at-end 196 :internal-dur-at-end 321 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) true 3 0 Exposure time (seconds) = 2,259.0000 at wavelength 2796.00 Å gives: SNR = 62.0043 (per resolution element) Exposure time (seconds) = 6,762.0000 at wavelength 1216.00 Å gives: SNR = 35.8792 (per resolution element) Exposure time (seconds) = 6,762.0000 at wavelength 1216.00 Å gives: SNR = 35.8792 (per resolution element) (Tic-Visit :proposal-id 12475 :visit-id "03" :proposal-version -1 :trans-version "20110509" :date "06-Jul-2011 11:55:06.0" :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 279984 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12475 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3300 :al-overhead-at-end 0 :internal-dur-at-end 115 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3411 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3411 :al-overhead-at-end 196 :internal-dur-at-end 321 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3633 :pcs-gap 0 ) false 3 0 Exposure time (seconds) = 2,259.0000 at wavelength 2796.00 Å gives: SNR = 62.0043 (per resolution element) Exposure time (seconds) = 6,762.0000 at wavelength 1216.00 Å gives: SNR = 35.8792 (per resolution element) Exposure time (seconds) = 6,762.0000 at wavelength 1216.00 Å gives: SNR = 35.8792 (per resolution element) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1320834848000 139.5094327432746 (Tic-Visit :proposal-id 12475 :visit-id "04" :proposal-version -1 :trans-version "20110509" :date "06-Jul-2011 12:04:38.0" :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 279984 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12475 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12475 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3008 :al-overhead-at-end 0 :internal-dur-at-end 115 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3341 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3119 :al-overhead-at-end 196 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3341 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12475 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3119 :al-overhead-at-end 196 :internal-dur-at-end 321 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3341 :pcs-gap 0 ) true 3 0 Exposure time (seconds) = 1,969.0000 at wavelength 2796.00 Å gives: SNR = 115.4967 (per resolution element) Exposure time (seconds) = 6,178.0000 at wavelength 1216.00 Å gives: SNR = 47.0706 (per resolution element) Exposure time (seconds) = 6,178.0000 at wavelength 1216.00 Å gives: SNR = 47.0706 (per resolution element)