0Assigned ID: 2948
----- Attempting Submission 1 (Thu Mar 24 05:34:20 GMT 2022) -----Changed IR Box dither spacing to 10.5 x 10.5 pixels. Re-submit.554824663----- Attempting Submission 1 (Fri Jul 08 21:04:53 GMT 2022) -----
HST Phase II Proposal 17136 successfully submitted.
Receipt: # 17136-1
----- Attempting Submission 2 (Mon Sep 19 07:03:47 GMT 2022) -----Photometry of a Young Planetary-Mass Companion to a Taurus M Dwarf StarStudies of directly imaged planets extend exoplanet surveys to greater separations from the stars, test giant planet formation models, probe the composition of the progenitor disks and can reveal circumplanetary disks, but these objects are rare. We report a faint, co-moving companion to an M dwarf member of the Taurus star-forming region with a brightness and color consistent with super-Jupiter mass planet. This companion is one of the youngest, least massive planets that has been directly imaged. While the object is readily detected in K-band (2.2 microns) AO imaging, key observations at shorter wavelengths are marginal or infeasible from the ground and the host star is too faint for "extreme" high-order AO systems. We propose imaging of this object with HST and WFC3 to (1) determine the spectral energy distribution of 2M0437b and compare it to model atmospheres to determine the companion's temperature, luminosity, radius and, via evolutionary models, estimate its mass; (2) constrain the cloudiness and metallicity of the atmosphere via detailed modeling of atmospheric radiative transfer; and (3) search for evidence for an accreting circumplanetary disk in the form of H-alpha or excess UV emission. Multi-planet systems have been found around other young stars and our imaging could also reveal additional, fainter companions of the star at smaller separations.Photometry in multiple pass-bands that cover the blue part of the SED (< 2 microns for 2M0437b) can usefully constrain an object's Teff , which, along with luminosity, is a key input parameter to models of young giant planets. Clouds can complicate the SED-Teff relation; disambiguation is possible by comparing the emission inside and outside the absorption bandpass of a strong gaseous absorber, i.e. H2O, but the H2O bands are inaccessible from the ground. Photometry in the near UV can detect or constrain accretion from a circumplanetary disk but these are not possible to perform on faint objects from the ground.
We will obtain photometry of 2M0437 in the UV, optical, and infrared using Wide Field Camera 3 (WFC3). WFC3 and its UVIS and IR channels are the only option in the IR (>1 microns) and its lower dark current and read noise and smaller pixel scale make it the preferred instrument over the Advanced Camera for Surveys (ACS) to study faint companions at UV/optical wavelengths. The instrument has been previously used to obtain photometry and spectra of many resolved ultra-cool dwarf companions and giant planets. We will obtain imaging in nine pass-bands: F814W, F105W, F125W, and F160W to determine the overall shape of the SED, F127M and F139M to measure absorption in the H2O band and constrain cloudiness and water abundance, and F336W, F625W, F656N (H-alpha), and F625W filters to assess UV excess and H-alpha emission due to accretion. (The F625W photometry serves as a continuum control for the F336W and F656N measurements.) A complete set of observations will be repeated at a different (25 deg offset) roll angle to carry out angular differential imaging (ADI) in order to construct difference images in which the roll-invariant stellar PSF, a significant source of systematics, is mostly removed, leaving positive and negative images of the companion. Different roll positions will occur on different orbits. The UVIS (336W, 625W, F656N, F814W) and IR channels (F105W, F125W, F127M, F139M, F160W) observations will also occur on separate orbits, and the complete program requires 6 orbits. Within each orbit the observations will take place at 2 or 4 dither positions for optical or IR, respectively, cycling through the 2 (UVIS) or 5 (IR) filters at each position. The star is at +26 deg declination and visible for 53 minutes during each orbit. We used the WFC3 Exposure Time Calculator to apportion the available time to achieve, as far as possible, uniform sensitivity across all filters. For the calculations in the wide and medium filters we assumed a Phoenix model of the SED of a nominal L7 spectral type, normalized by the K-band magnitude. We also repeated the calculations for L5 and T2 spectral types as bracketing cases. We divided one UVIS-dedicated orbit evenly between 814W and 656N. For the H-alpha feasibility calculations we considered accretion rates of 1e-8,3e-8,1e-7 MJup/yr used a magnetospheric model relation for planets to estimate the flux. We calculated stellar (chromospheric) emission in H-alpha we assumed a fractional luminosity relative to the bolometric luminosity value of 1.5e-4, appropriate for young rapidly rotating stars with magnetic saturation. For the F625W calculations we assumed that the flux in H-alpha dominates. Since the F625W observations are only to determine a baseline, we minimized the resource commitment, adjusting the exposure time to 240 sec for a minimal detection (SNR=5) at the lower accretion rate and avoidance of saturation at the higher accretion rate. The remaining available 832 sec in that orbit will be used for the F336W observation. For the feasibility calculations in that band, we linearly scaled from HST observations of DH Tau b which were modeled24 to infer an accretion rate of 3e-9 Mjup/yr To calculate the contrast with the chromospheric emission from the star, we used typical colors and absolute magnitudes of active M4 dwarfs. We included an overhead of 6.5 min for guide star acquisition, 2.6 min for each UVIS integration or 1 min for each IR integration, and 20 sec or 1 min for the small angle maneuvers (dithering, <1".25) for UVIS and IR, respectively. Integration times in the IR filters were adjusted to achieve a uniform SNR=70 (without the stellar scattered light noise contribution) for each filter. We then used the TinyTim HST+WFC3 PSF simulator and our SNR and contrast ratios estimates from the ETC to generate simulated images at two roll angles and the difference images. These predict the clear detection of the companion in all pass-bands. N.B.: We are breaking the UVIS observations into two epochs separated by at least three days to be more robust to potential variability in H-alpha emission. One epoch (4 orbits) will include both UVIS and all IR observations. The second epoch will consist of an identical set of UVIS observations only.Eric Gaidos (PI) has more than a decade of experience with spectroscopy and AO observations and characterization of M dwarfs and young stellar objects, including young exoplanet host stars and ``dipper" stars. He is the (co)author of over 150 manuscripts on exoplanets, planet formation, and astrobiology and led the work reporting the discovery of 2M0437b.
Teruyuki Hirano (Co-I) is an expert on the data analyses including near-infrared spectroscopy and high-contrast imaging. In the last five years, he has been leading the project to detect and characterize exoplanets around low-mass stars using the transit and radial-velocity methods.
Adam Kraus (Co-I) uses observations from the Hubble and Spitzer Space Telescopes, as well as large ground-based telescopes, to study the formation and evolution of planetary systems, including directly imaging gas giant planets as they form in orbit around other stars. Kraus has led several programs with WFC3/UVIS and WFC3/IR, including programs aimed at characterizing the spectral energy distributions of accreting planetary-mass companions and a Large program aimed at wide-field mapping of young brown dwarfs and planetary-mass objects in dense star clusters.
Jonathan Fortney (Co-I) is an expert in modeling the atmospheric spectra and thermal evolution of giant planets. He has led pioneering work on connecting planet evolution and composition to formation models and was a member of the Gemini Planet Imager science team.
Brendan Bowler (co-I) is an expert in detecting and characterizing planets and brown dwarfs with high-contrast imaging. He has led large planet-finding surveys with adaptive optics imaging from the ground as well as several related programs with HST.
Yifan Zhou (co-I) is an expert in HST high-contrast imaging observations and planet formation studies. He led multiple papers in using HST observations to characterize the formation and atmospheres of planetary-mass objects. He is the PI of two and co-I of multiple HST programs that involve WFC3/UVIS and WFC3/IR observations.
Ya-Lin Wu (Co-I) utilizes multi-wavelength observations to study the physical properties of planetary-mass companions.
Sagnick Mukherjee (Co-I) creates theoretical models of exoplanetary and brown dwarf atmospheres to understand their atmospheric physics and chemistry. He has led multiple publications on the use of theoretical models of brown dwarf and exoplanet atmospheres to probe different aspects of these atmospheres, like clouds and mixing processes.Exoplanets and Exoplanet FormationExoplanets and Exoplanet Formation6falsefalsetruefalsefalsefalsefalsefalseSUPPORTEDSTARYSOThis object was generated by the targetselector and retrieved from the SIMBAD database.2M0437J2000J2000Gaia G=14.3WFC3/IRImagingNoNoF105WWFC3/IRImagingNoNoF125WWFC3/IRImagingNoNoF127MWFC3/IRImagingNoNoF139MWFC3/IRImagingNoNoF160WWFC3/UVISImagingNoNoF656NWFC3/UVISImagingNoNoF814WWFC3/UVISImagingNoNoF336WWFC3/UVISImagingNoNoF625WPOS-TARGDITHER0.145LINEfalsefalse246.84WFC3-UVIS-DITHER-LINE3falsePOS-TARGDITHER1.408LINE1.274falsefalse9040BOX4falseTiming link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days])Hst Same orient constraint links visits (01 02 05)The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.This visit (1 orbit) consists of complete set of UVIS observations at the first epoch at the first roll angle.1693935588000258.5(Tic-Visit
:proposal-id 17136
:visit-id "01"
:proposal-version -1
:trans-version "20220516"
:date "18-Sep-2022 22:46:27.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "29"
:si-bright-earth-limb-angle 20.0
:data-volume 27472
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "01"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2782
:al-overhead-at-end 47
:internal-dur-at-end 67
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)false10Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days] [03 After 02 by 0.0 to 0.1 days])Hst Same orient constraint links visits (01 02 05)The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.The visit (1 orbit) consist of a complete set of IR observations at the first roll angle.1693941291000258.5(Tic-Visit
:proposal-id 17136
:visit-id "02"
:proposal-version -1
:trans-version "20220516"
:date "18-Sep-2022 23:36:18.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "30"
:si-bright-earth-limb-angle 20.0
:data-volume 350416
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "02"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2775
:al-overhead-at-end 0
:internal-dur-at-end 464
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)true10Timing link suitability includes constraints ([03 After 02 by 0.0 to 0.1 days] [04 After 03 by 0.0 to 0.1 days])The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.This visit (1 orbit) consists of a complete set of UVIS observations at the first epoch at the second roll angle (about +25 deg).1693946993000281.5(Tic-Visit
:proposal-id 17136
:visit-id "03"
:proposal-version -1
:trans-version "20220516"
:date "18-Sep-2022 22:48:37.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "29"
:si-bright-earth-limb-angle 20.0
:data-volume 27472
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "03"
:obset-id "03"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "03"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2782
:al-overhead-at-end 47
:internal-dur-at-end 67
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)true10Timing link suitability includes constraints ([04 After 03 by 0.0 to 0.1 days] [05 After 04 by 3.0 to 100.0 days])The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.The visit (1 orbit) consist of a complete set of IR observations at the second roll angle (+25 deg).1693952696000281.5(Tic-Visit
:proposal-id 17136
:visit-id "04"
:proposal-version -1
:trans-version "20220516"
:date "18-Sep-2022 23:40:47.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "30"
:si-bright-earth-limb-angle 20.0
:data-volume 350416
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "04"
:obset-id "04"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "04"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2775
:al-overhead-at-end 0
:internal-dur-at-end 464
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)true10Timing link suitability includes constraints ([05 After 04 by 3.0 to 100.0 days] [06 After 05 by 0.0 to 0.1 days])Hst Same orient constraint links visits (01 02 05)The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.This visit (1 orbit) consists of complete set of UVIS observations at the second epoch (>3 days later) at the first roll angle.(Tic-Visit
:proposal-id 17136
:visit-id "05"
:proposal-version -1
:trans-version "20220516"
:date "18-Sep-2022 22:50:46.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "29"
:si-bright-earth-limb-angle 20.0
:data-volume 27472
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "05"
:obset-id "05"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "05"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2782
:al-overhead-at-end 47
:internal-dur-at-end 67
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)false10Timing link suitability includes constraints ([06 After 05 by 0.0 to 0.1 days])The scheduling data was generated by CASM 30.3.CASM was run in Phase II mode.This visit (1 orbit) consists of a complete set of UVIS observations at the second epoch (>3 days later) at the second roll angle (about +25 deg).(Tic-Visit
:proposal-id 17136
:visit-id "06"
:proposal-version -1
:trans-version "20220516"
:date "08-Jul-2022 13:51:42.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "29"
:si-bright-earth-limb-angle 20.0
:data-volume 27472
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 17136
:visit-id "06"
:obset-id "06"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 17136
:visit-id "06"
:orbit-number 1
:pcs-time 383
:si-vis-utilization 2782
:al-overhead-at-end 47
:internal-dur-at-end 67
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3165
:pcs-gap 0
)true10