14162( 5) - 15-Oct-2015 18:34:33 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14162 Version: 5 Check-in Time: 15-Oct-2015 18:34:33 STScI Edit Number: 2 Title The magnetic activity puzzle of the super-earth host star KOI-314 ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Katja Poppenhaeger Smithsonian Institution Astrophysical Y Observatory CoI: Dr. David Kipping Harvard University N CoI: Dr. Scott J. Wolk Smithsonian Institution Astrophysical N Observatory CoI: Prof. John Asher Johnson Harvard University N CoI: Prof. Simon Albrecht Aarhus University N ------------------------------------------------------------------------------------ Abstract Magnetic activity is an ubiquitous phenomenon of cool stars and causes stellar high-energy emission, which is thought to be the driver of atmospheric evaporation of exoplanets in close orbits around their host stars. We have recently observed the super-earth hosting star KOI-314 in X-rays, in order to characterize the evaporation and evolution of its planets. However, we found the star to be very X-ray dim, indicating very low magnetic activity. This is in direct contrast with archival NUV observations with GALEX and optical high-resolution spectra, which show strong magnetic activity in the upper and lower chromosphere. We propose to obtain a new NUV spectrum with the WFC3/UVIS UV grism in one HST orbit in order to characterize the current activity level in the upper chromosphere, and compare this to current X-ray measurements of the coronal activity and optical spectra of the lower chromosphere activity. Investigating this stellar atmosphere that seems to deviate from the usual coronal and chromopsheric heating standard model is relevant for understanding the high-energy environment and evolution of exoplanetary atmospheres. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to observe the planetary system KOI-314 with WFC3/UVIS using the G280 UV grism to cover a wavelength region of 2000-4000 Angstrom, using one HST orbit split into four spectral exposures. We request 4 moderate duration spectra of 600 s each during one orbit, which we will later stack to reach higher S/N. This is within the data transmission constraints for WFC3. For the sequence of exposures during the orbit, we request first blind target acquisition; the proper motion of the target is small. Guide star acquisition will take 6 minutes according to the HST handbook. After that, we request several (identical) exposures of 600 s duration in UVIS-ACCUM mode. The readout overhead for the first exposure is 2.6 minutes, and 2.1 minutes for the subsequent exposures. The buffer can be dumped into the 14162( 5) - 15-Oct-2015 18:34:33 - [ 2] solid state recorder during each subsequent exposure, so that no additional overhead occurs for the buffer dump. We request to use the post-flash at the end of every exposure to mitigate effects of degrading charge transfer efficiency. This will add 0.1 minutes to each science exposure. This setup will require a total of 3318 s to perform, using 97% of the available visibility time of 3420 s in a single orbit. ------------------------------------------------------------------------------------ 14162( 5) - 15-Oct-2015 18:34:33 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2MASS-J19213 STAR, CORONA, RA=19H21M31.5710S +/- 0.06", J2000 V = 13.3 +/- 0.2 J=10.3, H=9.7, K=9.5 157+4317347 EXTRA-SOLAR PLANETARY DEC=+43D17'34.70" +/- 0.06" SYSTEM, M V-IV Reference Frame: Other: SIMBAD Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 14162( 5) - 15-Oct-2015 18:34:33 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: I have dithered the exposures 1, 2, and 3 by hand, by setting different POS TARG arguments. This should be equivalent to a dither of 5 pixels between exposures. 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 2MASS-J1921 WFC3/UVI ACCUM UVIS G280 CR-SPLIT=2 1 695 S (695 POS TARG null, -50 3157+431734 S S) 7 ------------------------------------------------------------------------------------------------------------------------------------ 2 2MASS-J1921 WFC3/UVI ACCUM UVIS G280 CR-SPLIT=2 1 695 S (695 POS TARG null, -49.8 3157+431734 S S) 7 ------------------------------------------------------------------------------------------------------------------------------------ 3 2MASS-J1921 WFC3/UVI ACCUM UVIS G280 1 348 S (348 POS TARG null, -49.6 3157+431734 S S) 7 ------------------------------------------------------------------------------------------------------------------------------------ 4 2MASS-J1921 WFC3/UVI ACCUM G280-REF F300X CR-SPLIT=2, FLASH=12 1 75 S (75 POS TARG null, -49.6 3157+431734 S S) 7 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASS-J19213157+431 1 WFC3/UVI ACCUM UVIS G280 none none none 1 1 N/A 7347 S 2MASS-J19213157+431 1 WFC3/UVI ACCUM UVIS G280 none none none 2 1 N/A 7347 S 2MASS-J19213157+431 2 WFC3/UVI ACCUM UVIS G280 none none none 1 1 N/A 7347 S 2MASS-J19213157+431 2 WFC3/UVI ACCUM UVIS G280 none none none 2 1 N/A 7347 S 2MASS-J19213157+431 3 WFC3/UVI ACCUM UVIS G280 none none none none 1 N/A 7347 S 2MASS-J19213157+431 4 WFC3/UVI ACCUM G280-REF F300X none none none 1 1 N/A 7347 S 2MASS-J19213157+431 4 WFC3/UVI ACCUM G280-REF F300X none none none 2 1 N/A 7347 S 14162( 5) - 15-Oct-2015 18:34:33 - [ 5] Summary Form for Proposal 14162 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures G280-REF, UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2, FLASH=12 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG null, -49.6, POS TARG null, -49.8, POS TARG null, -50 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F300X, G280 ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2MASS-J19213157+4317347 ------------------------------------------------------------------------------------------------------------------------------------