10114( 10) - 10/17/05 20:36 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10114 Version: 10 Check-in Time: 17-Oct-2005 20:35:35 Title Lyman_alpha FUV observations of the Sun in time and effects on planetary atmospheres ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Edward F. Guinan Villanova University CoI: Dr. Ignasi Ribas Institut d'Estudis Espacials de Catalunya N CoI: Dr. Graham M. Harper University of Colorado at Boulder N CoI: Dr. Brian E. Wood University of Colorado at Boulder N ------------------------------------------------------------------------------------ Abstract The chromospheric H I Ly_alpha 1215.6 feature is the dominant source of short-wave emission in the Sun and solar-type stars, contributing about 80-90% of the total FUV flux and 30-60% of the total flux between 1 and 1500 A. Also, this important chromospheric line is the major cooling channel for cool star atmospheres. Accurate Ly_alpha fluxes are the only missing element of our ongoing "Sun in Time" program. This program studies a sample of single G0-5 V stars with well-known physical properties that serve as proxies for the Sun (and solar-mass stars) over their main sequence lifetimes. One of the major goals of the program is the determination of the spectral irradiance of the early Sun. Our analyses indicate that the strong XUV emissions of the young Sun have played a crucial role in the developing planetary system. In particular, the expected strong Ly_alpha line flux may have greatly influenced the photoionization, photochemical evolution and possible erosion of planetary atmospheres, as well as played a role in the origin and development of life on Earth. The "Sun in Time" data can also be applied to investigate the atmospheric loss of exoplanets around solar-type stars resulting from XUV heating, which can eventually lead to the evaporation of "hot Jupiters". We propose to use HST/STIS-MAMA/E140M to determine accurate FUV and Ly-alpha fluxes and irradiances for 4 representative solar proxies with ages from 130 Myr to 6.7 Gyr. It is only with HST's high-resolution UV spectroscopy (to correct for ISM absorption) and the small aperture (to eliminate geocoronal emission) that the stellar Ly-alpha profile can be reliably modeled and its flux measured. The proposed study is of capital importance in reconstructing the evolutionary histories of exoplanets already known and additional planets that missions such as COROT, Kepler, SIM, and Darwin/TPF will discover in the coming years. ------------------------------------------------------------------------------------ 10114( 10) - 10/17/05 20:36 - [ 2] Observations Description ------------------------ The observations proposed require moderately spectroscopy and photometry in the FUV for a sample of Sun in Time targets, i.e. solar proxies that cover different ages of the Sun across the main sequence (covering ages from 130 Myr to 6.7 Gyr). The strengths of the emission lines vary from star to star, and correlate with the level of chromospheric and coronal activity (decreasing with age). Using chromospheric activity proxies such as CII we have derived rough estimated for the intrinsic strength of the Lyalpha feature of the proposed targets as compared to the current Sun: ~15x for EK Dra, ~7x for pi1 UMa, ~2.5x for beta Com, and ~1x for beta Hyi. Note that all targets are expected to have similar HI column densities as derived from the analysis of our ASCA, ROSAT, EUVE and FUSE observations. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10114( 10) - 10/17/05 20:36 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD129333 STAR, G V-IV, CORONA RA=14H39M0.4000S +/- 0.1", J2000 V = 7.6+/-0.05 DEC=+64D17'30.10" +/- 0.1" Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0213 -0.01192 0.02946 2 HD72905 STAR, G V-IV, CORONA RA=08H39M11.7400S +/- 0.1", J2000 V = 5.64+/-0.05 DEC=+65D01'14.50" +/- 0.1" Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.00438 0.0879 0.07007 3 HD149661 STAR, G V-IV, CORONA RA=16H36M21.4500S +/- 0.1", J2000 V = 5.76+/-0.05 DEC=-02D19'28.50" +/- 0.1" Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.03037 -0.30764 0.10227 4 HD17925 STAR, CORONA, K V-IV RA=02H52M32.1300S +/- 0.1", J2000 V = 6.03+/-0.05 DEC=-12D46'11.00" +/- 0.1" Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.02588 -0.18954 0.09633 10114( 10) - 10/17/05 20:36 - [ 4] Visit: 10 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD129333 ACS/SBC ACCUM SBC F122M 1 500 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 2 HD129333 ACS/SBC ACCUM SBC PR110L 1 1000 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 3 HD129333 ACS/HRC ACQ HRC-ACQ F250W 1 1 S ------------------------------------------------------------------------------------------------------------------------------------ 4 HD129333 ACS/HRC ACCUM HRC-CORON F814W 1 192 S USE OFFSET 101141 1.8 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD129333 1 ACS/SBC ACCUM SBC F122M none none none none 1 N/A HD129333 2 ACS/SBC ACCUM SBC PR110L none none none none 1 N/A HD129333 3 ACS/HRC ACQ HRC-ACQ F250W none none none none 1 N/A HD129333 4 ACS/HRC ACCUM HRC-CORO F814W none none none 1 1 N/A N1.8 HD129333 4 ACS/HRC ACCUM HRC-CORO F814W none none none 2 1 N/A N1.8 10114( 10) - 10/17/05 20:36 - [ 5] Visit: 20 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD72905 ACS/SBC ACCUM SBC F122M 1 500 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 2 HD72905 ACS/SBC ACCUM SBC PR110L 1 1000 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 3 HD72905 ACS/HRC ACQ HRC-ACQ F250W 1 0.8 S ------------------------------------------------------------------------------------------------------------------------------------ 4 HD72905 ACS/HRC ACCUM HRC-CORON F814W 1 234 S USE OFFSET 101142 1.8 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD72905 1 ACS/SBC ACCUM SBC F122M none none none none 1 N/A HD72905 2 ACS/SBC ACCUM SBC PR110L none none none none 1 N/A HD72905 3 ACS/HRC ACQ HRC-ACQ F250W none none none none 1 N/A HD72905 4 ACS/HRC ACCUM HRC-CORO F814W none none none 1 1 N/A N1.8 HD72905 4 ACS/HRC ACCUM HRC-CORO F814W none none none 2 1 N/A N1.8 10114( 10) - 10/17/05 20:36 - [ 6] Visit: 30 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD149661 ACS/SBC ACCUM SBC F122M 1 450 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 2 HD149661 ACS/SBC ACCUM SBC PR110L 1 900 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 3 HD149661 ACS/HRC ACQ HRC-ACQ F250W 1 0.9 S ------------------------------------------------------------------------------------------------------------------------------------ 4 HD149661 ACS/HRC ACCUM HRC-CORON F814W CR-SPLIT=2 1 193 S USE OFFSET 101143 1.8 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD149661 1 ACS/SBC ACCUM SBC F122M none none none none 1 N/A HD149661 2 ACS/SBC ACCUM SBC PR110L none none none none 1 N/A HD149661 3 ACS/HRC ACQ HRC-ACQ F250W none none none none 1 N/A HD149661 4 ACS/HRC ACCUM HRC-CORO F814W none none none 1 1 N/A N1.8 HD149661 4 ACS/HRC ACCUM HRC-CORO F814W none none none 2 1 N/A N1.8 10114( 10) - 10/17/05 20:36 - [ 7] Visit: 40 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD17925 ACS/SBC ACCUM SBC F122M 1 450 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 2 HD17925 ACS/SBC ACCUM SBC PR110L 1 900 S SHADOW ------------------------------------------------------------------------------------------------------------------------------------ 3 HD17925 ACS/HRC ACQ HRC-ACQ F250W 1 1 S NEW OBSET FULL ACQ ------------------------------------------------------------------------------------------------------------------------------------ 4 HD17925 ACS/HRC ACCUM HRC-CORON F814W 1 202 S USE OFFSET 101144 1.8 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD17925 1 ACS/SBC ACCUM SBC F122M none none none none 1 N/A HD17925 2 ACS/SBC ACCUM SBC PR110L none none none none 1 N/A HD17925 3 ACS/HRC ACQ HRC-ACQ F250W none none none none 1 N/A HD17925 4 ACS/HRC ACCUM HRC-CORO F814W none none none 1 1 N/A N1.8 HD17925 4 ACS/HRC ACCUM HRC-CORO F814W none none none 2 1 N/A N1.8 10114( 10) - 10/17/05 20:36 - [ 8] Summary Form for Proposal 10114 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures SBC HRC-ACQ HRC-CORON1.8 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/SBC ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SHADOW USE OFFSET 101141 USE OFFSET 101142 USE OFFSET 101143 NEW OBSET FULL ACQ USE OFFSET 101144 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F122M PR110L F250W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD129333 HD72905 HD149661 HD17925 ------------------------------------------------------------------------------------------------------------------------------------