14698( 2) - 22-Jul-2016 15:05:27 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14698 Version: 2 Check-in Time: 22-Jul-2016 15:05:27 STScI Edit Number: 0 Title The first spectrally resolved Ha measurement of an accreting planet ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Christian Schneider European Space Agency - ESTEC Y CoI: Mr. Michael Salz Universitat Hamburg, Hamburger Sternwarte N CoI: Dr. Hans Moritz Guenther Massachusetts Institute of Technology N CoI: Dr. Jan Robrade University of Hamburg, Hamburger N Sternwarte CoI: Dr. Kevin France University of Colorado at Boulder N ------------------------------------------------------------------------------------ Abstract LkCa 15 b was recently detected in Halpha using AO enhanced imaging and we propose to follow-up on this detection with HST STIS observations to provide, for the first time, a velocity resolved profile of planetary Ha emission. The velocity shift of the Ha emission is related to the planetary accretion mode, magnetospheric or boundary layer accretion. If a velocity shift is found that is close to the free-fall velocity, this would point to magnetospheric accretion, and thus, would provide evidence of early planetary magnetic fields. ------------------------------------------------------------------------------------ Observations Description ------------------------ The goal of the observations is to obtain extremly high S/N data on the Halpha line with the slit aligned along the line connecting the star and the planet (separated from the star by about 0, 1 arcsec). We take the P.A. of Sallum et al. (2015) extrapolated to the approx. date of the observations (P.A. about 254 deg, East of North). To exclude systematics, we repeat the observations with HST rotated by 180 deg. The target is moderately variable so that we have to budget for this when calculating exposure times to safely avoid saturation. Exposure times are calculated from an ESO VLT Xshooter spectrum of the source scaled to match the photometry of Grankin et al. (2007). Running the ETC using this spectrum implies that we have to use multiple short exposures to avoid saturation, which is also the rationale for using CCDGAIN=4. To reduce the overhead, in particular the readout time, we use a subarray mode. We readout 64 pixel (or 3.2 arcsec) around the center of the spectral trace. This ensures that the relevant part of the detector is read in all exposures, i.e., the detector region that can be used for background estimates is covered in all 14698( 2) - 22-Jul-2016 15:05:27 - [ 2] exposures despite dithering. Dithering along the slit is implemented to avoid detector artifacts falling in the region of the Halpha line. We specifically implement a 5-point dither with steps of 4.2 pixel (or 0.213 arcsec per step and a total shift of 0.852 arcsec). Thereby, we shift the spectral trace by several PSF-widths to avoid potential detector artifacts and expect that the spatial centroid of the spectral trace falls onto different locations with respect to the pixel center. Target ACQ and ACQ/PEAK: Using the Xshooter spectrum suggests that an exposure time of 0.2 s with the F28x50LP filter provides a similar margin against over- and underexposure. This also applies to the ACQ/PEAK exposure. ------------------------------------------------------------------------------------ 14698( 2) - 22-Jul-2016 15:05:27 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 EM-LKCA-15 STAR, PRE-MAIN SEQUENCE RA=04H39M17.8070S +/- 0.2", J2000 V = 12.03 STAR, T TAURI STAR DEC=+22D21'3.26" +/- 0.2" Reference Frame: ICRS Comments: Coordinates are for 2016.8. Proper motion within one year is on the 10 mas level and can, therefore, be neglected here. The object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 14698( 2) - 22-Jul-2016 15:05:27 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 5 Point_Spacing 0.213 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern YES Pattern_Comments: This is to shift the spectrum in the spatial direction along the slit by half-pixel offsets. ------------------------------------------------------------------------------------------------------------------------------------ 14698( 2) - 22-Jul-2016 15:05:27 - [ 5] Visit: 01 Visit Requirements: SCHED 60%; ORIENT 117D TO 121 D 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 EM-LKCA-15 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: Exposure times calculated from the Xshooter spectrum (date obs: 2011-12-02): ETC gives: Exptime for S/N=40: 0.0367 seconds Time to Saturation (for a single exposure) = 1.86 seconds Exposure times calculated for a Pickles K5 star and V=12: ETC gives: Exptime for S/N=40: 0.0339 seconds Time to Saturation (for a single exposure) = 1.61 seconds This suggests that an exposure time of 0.25 s provides a factor of seven margin against under-exposing and a similar margin against saturation. ------------------------------------------------------------------------------------------------------------------------------------ 2 EM-LKCA-15 STIS/CCD ACQ/PEA 52X0.1 MIRROR 1 0.2 S (0.2 K S) Comments: See Exposure 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 EM-LKCA-15 STIS/CCD ACCUM 52X0.1 G750M 6581 CR-SPLIT=5, SIZEAXIS2=64, 1 830 S PATTERN 1 3 GAIN=4 (4315 S) Comments: See also STIS.sp.827044 for a run with a brighter input spectrum. In fact, we estimate that the Ha line, which we are interested in, can be even a factor of two brighter. Therefore, the current exposure times provide a factor of two margin against saturation. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EM-LKCA-15 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 14698( 2) - 22-Jul-2016 15:05:27 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ EM-LKCA-15 2 STIS/CCD ACQ/PEA 52X0.1 MIRROR none none none none 1 N/A K EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 1 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 2 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 3 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 4 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 5 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 1 1 205.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 2 1 205.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 3 1 205.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 4 1 205.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 5 1 205.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 1 2 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 2 2 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 3 2 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 4 2 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 5 2 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 1 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 2 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 3 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 4 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 5 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 1 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 2 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 3 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 4 2 163.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 5 2 163.0 S 14698( 2) - 22-Jul-2016 15:05:27 - [ 7] Visit: 02 Visit Requirements: SCHED 80%; ORIENT 297D TO 301 D 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 EM-LKCA-15 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: Exposure times calculated from the Xshooter spectrum (date obs: 2011-12-02): ETC gives: Exptime for S/N=40: 0.0367 seconds Time to Saturation (for a single exposure) = 1.86 seconds Exposure times calculated for a Pickles K5 star and V=12: ETC gives: Exptime for S/N=40: 0.0339 seconds Time to Saturation (for a single exposure) = 1.61 seconds This suggests that an exposure time of 0.25 s provides a factor of seven margin against under-exposing and a similar margin against saturation. ------------------------------------------------------------------------------------------------------------------------------------ 2 EM-LKCA-15 STIS/CCD ACQ/PEA 52X0.1 MIRROR 1 0.2 S (0.2 K S) Comments: See Exposure 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 EM-LKCA-15 STIS/CCD ACCUM 52X0.1 G750M 6581 CR-SPLIT=5, SIZEAXIS2=64, 1 826 S PATTERN 1 3 GAIN=4 (4174 S) Comments: See also STIS.sp.827044 for a run with a brighter input spectrum. In fact, we estimate that the Ha line, which we are interested in, can be even a factor of two brighter. Therefore, the current exposure times provide a factor of two margin against saturation. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EM-LKCA-15 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 14698( 2) - 22-Jul-2016 15:05:27 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EM-LKCA-15 2 STIS/CCD ACQ/PEA 52X0.1 MIRROR none none none none 1 N/A K EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 1 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 2 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 3 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 4 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 1 none none 5 1 N/A EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 1 1 193.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 2 1 193.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 3 1 193.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 4 1 193.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 2 none none 5 1 193.0 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 1 2 160.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 2 2 160.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 3 2 160.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 4 2 160.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 3 none none 5 2 160.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 1 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 2 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 3 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 4 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 4 none none 5 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 1 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 2 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 3 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 4 2 158.2 S EM-LKCA-15 3 STIS/CCD ACCUM 52X0.1 G750M 6581 5 none none 5 2 158.2 S 14698( 2) - 22-Jul-2016 15:05:27 - [ 9] Summary Form for Proposal 14698 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/PEAK ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, CR-SPLIT=5, GAIN=4, SIZEAXIS2=64 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 117D TO 121 D, ORIENT 297D TO 301 D, PATTERN 1 3, SCHED 60%, SCHED 80% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G750M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names EM-LKCA-15 ------------------------------------------------------------------------------------------------------------------------------------