Beta Pic Polarimetry with NICMOS

Beta Pic Polarimetry with NICMOS Debris disk stars host transient dust grains that comprise a collisional cascade with sizes ranging from planetesimals to the sub-micron. In addition to the gravity of the host star and any planets present, these grains are subject to size-dependent non-gravitational forces, e.g., corpuscular drag and radiation pressure. When a steep spectrum of grain sizes prevails, such as the Dohnanyi distribution, scattered light images preferentially trace grains with dimensionless size parameter of order unity. Thus images in scattered starlight provide unique windows on the balance of forces acting on grains at a specific size. Therefore, in an A star system such as beta Pic, the near-IR is dominated by grains close to the blow out size and therefore NICMOS traces dust on hyperbolic orbits. Scattering is fundamentally polarization sensitive, and measurements that record intensity literally see only half the picture. If linear polarization is measured then the elements of the complex scattering matrix can be reconstructed. These matrix elements provide fundamental constraints on the size, composition and structure of the scatterers. Notably, polarimetry can be used to break the degeneracy between scattering asymmetry, g, and the radial dust gradient, which are otherwise covariant in an edge-on disk. Thus, we can use polarimetry to localize the parent bodies in the beta Pic disk. In beta Pic, dust is thought to originate mainly from the sublimation of cometary bodies near periastron. The irradiation of cometary material leads to sublimation and photodissociation of ices forming porous grains consisting of a matrix of refractory material. Such grains have a characteristic scattering signature in polarized light that can be distinguished from compact grains that arise from collisional erosion of asteroidal material.

We will use NICMOS NIC-2 coronagraphy to obtain high contrast polarimetric observations of Beta Pictoris. In order to obtain a full complement of angles and to image each disk extension along the long axes of NIC-2 (relative to the upper left corner location of the coronagraphic hole), our observations are split into four groups of four Visits, where each Visit equals one HST orbit. The four visits in each group are to be executed as a GROUP WITHIN, to minimize PSF variations and to facilitate PSF subtraction. The four Visits include two for Beta Pic, one for Sky, and one for a PSF reference star. The two Beta Pic visits have absolute and relative ORIENT constraints in order to image the disk midplane along specific optimum directions across the NIC-2 detector. Each Visit (except for SKY) begins with an acquisition exposure to acquire the stars behind the occulting spot. For the orbits dedicated to SKY, a dither pattern should be implemented to remove background targets during data reduction. ISM AND CIRCUMSTELLAR MATTER 12 false 0.0 0.0 false false false false false false SUPPORTED STAR A4-A9 V-IV This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 05 47 17.0877 -51 03 59.45 J2000 CALIBRATION POINT SPREAD FUNCTION POLARIMETRY This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 08 09 0.6701 -61 18 8.75 J2000 CALIBRATION SKY BACKGROUND This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 05 47 17.0877 -51 03 59.45 J2000 CALIBRATION SKY BACKGROUND Sky Background 2 arcminutes south of Beta Pic. J2000 00 00 0.0000 +00 00 0.00 J2000 CALIBRATION SKY BACKGROUND Sky Background 2 arcminutes south of Beta Pic. J2000 00 00 0.0000 +00 00 0.00 J2000 CALIBRATION POINT SPREAD FUNCTION This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 00 00 0.0000 +00 00 0.00 J2000 NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes NIC2 Imaging Yes Yes Timing link suitability includes constraints ([Group (05 06 07 08) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1207682614000 107.0 (Tic-Visit :proposal-id 11150 :visit-id "05" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:18.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "05" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2590 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (05 06 07 08) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1207688365000 116.0 (Tic-Visit :proposal-id 11150 :visit-id "06" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:20.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "06" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2590 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (05 06 07 08) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1207694116000 111.22866369487309 (Tic-Visit :proposal-id 11150 :visit-id "07" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 187712 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "07" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2417 :al-overhead-at-end 0 :internal-dur-at-end 138 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (05 06 07 08) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1207698871000 81.01593827720097 (Tic-Visit :proposal-id 11150 :visit-id "08" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "08" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2590 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3063 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Sequence (59 60 61 62) within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. This is a PSF star. Should come before the first beta Pic visit. The pattern should be PSF-BetaPic-BetaPic-PSF [HR-2020=BetaPic]. 1212758511000 145.9238938588366 (Tic-Visit :proposal-id 11150 :visit-id "59" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:23.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "59" :obset-id "59" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "59" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2674 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3029 :pcs-gap 0 ) true 1 0 These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. This is the coronagraphic acquisition exposure. Timing link suitability includes constraints ([Sequence (59 60 61 62) within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1212763173000 164.0 (Tic-Visit :proposal-id 11150 :visit-id "60" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:25.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "60" :obset-id "60" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "60" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2683 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. This is the coronagraphic acquisition exposure. Timing link suitability includes constraints ([Sequence (59 60 61 62) within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1212768721000 173.0 (Tic-Visit :proposal-id 11150 :visit-id "61" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "61" :obset-id "61" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "61" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2682 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. This is the coronagraphic acquisition exposure. Timing link suitability includes constraints ([Sequence (59 60 61 62) within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. This is a PSF star. Should come after the last beta Pic visit. The pattern should be PSF-BetaPic-BetaPic-PSF. 1212773954000 137.3794849421247 (Tic-Visit :proposal-id 11150 :visit-id "62" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:28.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 194336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "62" :obset-id "62" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "62" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2691 :al-overhead-at-end 0 :internal-dur-at-end 152 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3063 :pcs-gap 0 ) true 1 0 These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. These are sky background. ORIENT and GUIDESTAR constraints are not important. This is the coronagraphic acquisition exposure. Timing link suitability includes constraints ([Group (13 14 15 16) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1220037544000 246.0 (Tic-Visit :proposal-id 11150 :visit-id "13" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 125888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "13" :obset-id "13" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "13" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2600 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 This is a coronagraphic acquisition exposure. Timing link suitability includes constraints ([Group (13 14 15 16) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1220043296000 251.0 (Tic-Visit :proposal-id 11150 :visit-id "14" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:30.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 125888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "14" :obset-id "14" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "14" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2600 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 This is a coronagraphic acquisition exposure. Timing link suitability includes constraints ([Group (13 14 15 16) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. 1220049048000 255.0 (Tic-Visit :proposal-id 11150 :visit-id "15" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:31.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 125888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "15" :obset-id "15" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "15" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2600 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3043 :pcs-gap 0 ) true 1 0 This is a coronagraphic acquisition exposure. Timing link suitability includes constraints ([Group (13 14 15 16) Within 0.2 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. This is a PSF star (target #9) 1220055067000 234.4933321818289 (Tic-Visit :proposal-id 11150 :visit-id "16" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:20:31.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 125888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "16" :obset-id "16" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "16" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2600 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3029 :pcs-gap 0 ) true 1 0 This is a coronagraphic acquisition exposure. Timing link suitability includes constraints ([Group (70 71 72 73) Within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11150 :visit-id "70" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:36:14.0" :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 1569680 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "70" :obset-id "70" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "70" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2606 :al-overhead-at-end 0 :internal-dur-at-end 706 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (70 71 72 73) Within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11150 :visit-id "71" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:40:27.0" :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 1569680 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "71" :obset-id "71" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "71" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2606 :al-overhead-at-end 0 :internal-dur-at-end 706 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (70 71 72 73) Within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11150 :visit-id "72" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:39:49.0" :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 1569680 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "72" :obset-id "72" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "72" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2606 :al-overhead-at-end 0 :internal-dur-at-end 706 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([Group (70 71 72 73) Within 0.3 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11150 :visit-id "73" :proposal-version -1 :trans-version "20090702" :date "03-Nov-2009 06:39:40.0" :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 1569680 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11150 :visit-id "73" :obset-id "73" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11150 :visit-id "73" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2606 :al-overhead-at-end 0 :internal-dur-at-end 706 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0