16685( 4) - 06-Mar-2023 17:43:19 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16685 Version: 4 Check-in Time: 06-Mar-2023 17:43:19 STScI Edit Number: 1 Title Low Mass Evaporating Planets: A Search for the Star-Planet Interaction in Kepler-535 ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Raghvendra Sahai Jet Propulsion Laboratory Y CoI: Ms. Cristilyn Nicole Gardner University of Wyoming N ------------------------------------------------------------------------------------ Abstract Exoplanet-host stars with planets at short separations can influence each other (commonly termed the star-planet interaction or SPI), via a variety of mechanisms. Understanding SPI in exoplanet host stars is thus crucial for understanding the evolution of both the planet and its host star, but observational evidence for SPI is generally scarce. An important signature of SPI is UV emission, and time-resolved FUV spectroscopy with HST/COS has provided compelling evidence for, and details of, the SPI phenomenon in HD189733, which has a Jupiter-mass planet. We now propose to search for SPI in the exoplanet host star Kepler-535, which hosts a 0.21 Jupiter-radius (Rjup) planet. Our search is motivated by an intriguing new result that we have found using GALEX data: stars in which the innermost planet has a radius less than about 0.4 Rjup are statistically much more likely to have high FUV/NUV flux ratios, compared to those where the radius is significantly larger. We hypothesize that this is because it may be easier to get mass-loss from the atmosphere of Neptune and sub-Neptune mass planets as a result of irradiation by the star. When material from this evaporated mass falls onto the star, it gets heated to high temperatures (~50, 000K) as has been been observed in HD189733. The high temperature plasma results in a high FUV/NUV ratio. We propose to use COS spectroscopy of diagnostic FUV lines that can effectively probe the amount of mass evaporating from the planet, and help in determining the dynamics of the gas around the planet. The results from this study will enable testing state-of-art MHD models of such systems. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our goal is to obtain time-resolved spectroscopy of the planet bearing star Kepler-535 with COS, at planetary orbital phases in the range ~ 0.5-0.63. We will use the G130M grating with central wavelength set to 1281 A in order to cover the range ~1150-1450 A, as in the study of FUV-line variability in the exoplanet host-star HD 189733 by Pillitteri et al. (2015), in order to cover the major FUV lines that probe hot gas (~20, 000 to 100, 000 K). The main lines in this range are the H Lya, Si II, Si III, Si IV, C II, C III lines, and N V lines. We will need 5 orbits to observe the egress of the planet from secondary transit sampling the same orbital phase range in Petal15 (0.499-0.625). By taking the observations in TIME-TAG mode, we will be able to look for any changes in the line profiles in the 1150-1450 A range on short time-scales (1-40 min). 16685( 4) - 06-Mar-2023 17:43:19 - [ 2] We have used the GALEX FUV-band flux density for Kepler-535 (32 uJy) to estimate the expected line fluxes for it as follows. Taking the average flux of each lines observed with COS in HD189733 (table 4 of Petal15) that lies in the FUV GALEX bandpass (1344-1786A A), from epoch 1, we estimate the contribution of each line to a GALEX band-averaged FUV flux density - the strongest of these lines (e.g., Si IV 1403) have typical fluxes of few X 10|^-15 erg cm^-2 s^-1. In contrast, the brightest lines observed by Petal15 lie shortwards of the blue edge of the GALEX FUV bandpass, e.g., the CII 1335 doublet, which has a typical flux of few X 10^-14 erg cm^-2 s^-1. In order to estimate the contribution of lines that lie within the GALEX FUV band but were not covered in the COS spectra taken by Petal15, we used the following procedure. We (i) constructed three high temperature collisionally excited plasma models using the CLOUDY code, at the temperatures of the three components derived for the plasma flow by Petal15 (25, 000, 50, 000 and 80, 000 K) and averaged them, (ii) scaled the resulting average spectrum to an observed flux of the Si IV1403 line of 3 X 10^-15 erg cm^-2 s^-1, and (iii) integrated the resulting spectrum over the GALEX FUV bandpass (using the FUV filter transmission curve) to derive an expected GALEX FUV-band flux of ~10 uJy for HD189733. Since the observed FUV flux of Kepler-535 is 32 uJy, we expect, conservatively assuming that it is experiencing mass-loss at a rate that is one-third that of HD189733b, that its lines will be roughly as bright as those observed towards HD189733. We note that the signal-to-noise ratio of the bright lines observed with COS towards HD189733 is quite high (S/N~20), so even if the lines we observe are a further factor 2 lower than estimated, we will still be able to detect these lines with adequate sensitivity in order to be able to robustly detect flux variations of 25% or more (note that Petal15 find variations of a factor ~2 towards HD189733). We will 2 sub-exposures per visit (with FP-POS=3 and FP-POS=4since FP-POS=ALL is not available for the grating we need to cover our desired wavelength range) , with typical integration times of 930 sec each, per epoch. Each set of 2 exposures requires one orbit. ------------------------------------------------------------------------------------ 16685( 4) - 06-Mar-2023 17:43:19 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 STAR, EXTRA-SOLAR RA=19H46M15.9981S +/- 0.05", J2000 V = 8.6 V = 13.15 +/- 0.05 B=13.66, J=12.14, PLANET, G III-I DEC=+49D41'46.23" +/- 0.05" H=11.91, K=11.85 Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 -2.2468179957305353E-5 -0.01548500008539122 0.0014297 ------------------------------------------------------------------------------------------------------------------------------------ 16685( 4) - 06-Mar-2023 17:43:19 - [ 4] Visit: 01 Visit Requirements: Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488; SEQ 01, 02 WITHIN 5 H 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 KOI-355 COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, STEP-SIZE=1.767, 1 10 S (10 PHASE 0.498 TO 0.502 RCH CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STRIPE=MEDIUM 1 7.5 S (7.5 KXD S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STEP-SIZE=0.9, NUM-POS=5, 1 10 S (10 KD CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (510 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (510 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOI-355 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH KOI-355 2 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KXD KOI-355 3 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KD KOI-355 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 510 S G KOI-355 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 510 S G 16685( 4) - 06-Mar-2023 17:43:19 - [ 5] Visit: 02 Visit Requirements: Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488; SEQ 02, 03 WITHIN 5 H 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 KOI-355 COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, STEP-SIZE=1.767, 1 1 S (1 S) PHASE 0.528 TO 0.532 RCH CENTER=FLUX-WT-FLR ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STRIPE=MEDIUM 1 1 S (1 S) KXD ------------------------------------------------------------------------------------------------------------------------------------ 3 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STEP-SIZE=0.9, NUM-POS=5, 1 1 S (1 S) KD CENTER=FLUX-WT-FLR ------------------------------------------------------------------------------------------------------------------------------------ 4 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=2155, 1 1050 S G FLASH=NO see below (1 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=2155, 1 1050 S G FLASH=NO see below (1 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOI-355 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH KOI-355 2 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KXD KOI-355 3 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KD KOI-355 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1 S G KOI-355 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1 S G 16685( 4) - 06-Mar-2023 17:43:19 - [ 6] Visit: 03 Visit Requirements: Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488; SEQ 03, 04 WITHIN 3.5 H 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 KOI-355 COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, STEP-SIZE=1.767, 1 10 S (10 PHASE 0.558 TO 0.564 RCH CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STRIPE=MEDIUM 1 7.5 S (7.5 KXD S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STEP-SIZE=0.9, NUM-POS=5, 1 10 S (10 KD CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (660 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (660 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOI-355 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH KOI-355 2 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KXD KOI-355 3 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KD KOI-355 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 660 S G KOI-355 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 660 S G 16685( 4) - 06-Mar-2023 17:43:19 - [ 7] Visit: 04 Visit Requirements: Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488; SEQ 04, 05 WITHIN 3.5 H 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 KOI-355 COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, STEP-SIZE=1.767, 1 10 S (10 PHASE 0.588 TO 0.594 RCH CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STRIPE=MEDIUM 1 7.5 S (7.5 KXD S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STEP-SIZE=0.9, NUM-POS=5, 1 10 S (10 KD CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (660 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (660 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOI-355 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH KOI-355 2 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KXD KOI-355 3 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KD KOI-355 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 660 S G KOI-355 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 660 S G 16685( 4) - 06-Mar-2023 17:43:19 - [ 8] Visit: 05 Visit Requirements: Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488; SEQ 04, 05 WITHIN 3.5 H 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 KOI-355 COS/NUV ACQ/SEA PSA G230L 3000 SCAN-SIZE=3, STEP-SIZE=1.767, 1 10 S (10 PHASE 0.618 TO 0.624 RCH CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STRIPE=MEDIUM 1 7.5 S (7.5 KXD S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KOI-355 COS/NUV ACQ/PEA PSA G230L 3000 STEP-SIZE=0.9, NUM-POS=5, 1 10 S (10 KD CENTER=FLUX-WT-FLR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (230 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KOI-355 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=2155, 1 1050 S G FLASH=YES see below (230 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOI-355 1 COS/NUV ACQ/SEA PSA G230L 3000 none none none none 1 N/A RCH KOI-355 2 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KXD KOI-355 3 COS/NUV ACQ/PEA PSA G230L 3000 none none none none 1 N/A KD KOI-355 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 230 S G KOI-355 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 230 S G 16685( 4) - 06-Mar-2023 17:43:19 - [ 9] Summary Form for Proposal 16685 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAKD, ACQ/PEAKXD, ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=2155, CENTER=FLUX-WT-FLR, FLASH=NO, FLASH=YES, FP-POS=3, FP-POS=4, NUM-POS=5, SCAN-SIZE=3, STEP-SIZE=0.9, STEP-SIZE=1.767, STRIPE=MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PHASE 0.498 TO 0.502, PHASE 0.528 TO 0.532, PHASE 0.558 TO 0.564, PHASE 0.588 TO 0.594, PHASE 0.618 TO 0.624, Period 4.90331667 D AND ZERO-PHASE HJD2454966.674488, SEQ 01, 02 WITHIN 5 H, SEQ 02, 03 WITHIN 5 H, SEQ 03, 04 WITHIN 3.5 H, SEQ 04, 05 WITHIN 3.5 H ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G230L ------------------------------------------------------------------------------------------------------------------------------------ Target Names KOI-355 ------------------------------------------------------------------------------------------------------------------------------------