----- Submission 4 (Tue Jul 05 20:44:54 GMT 2005) ----- We are in communication with our PC and understand the remaining diagnostic. Probing Asteroid Families for Evidence of Ultraviolet Space Weathering Effects We propose six HST orbits to obtain UV reflectance spectra covering 200-460 nm of two Vesta asteroid family members, asteroid 832 Karin, and two Karin family members. These observations extend work done under a Cycle 13 AR grant, where we analyzed all of the existing IUE and HST S-class asteroids in the MAST database to investigate the effects of space weathering at UV wavelengths. Our hypothesis is that the manifestation of space weathering at UV wavelengths is a spectral bluing, in contrast with a spectral reddening at visible-NIR wavelengths, and that UV wavelengths can be more sensitive to relatively small amounts of weathering than longer wavelengths. The proposed observations will address two objectives: (1) Measure the UV-visible spectra of 832 Karin and two members of the young Karin family (absolute age of 5.8 My), in order to determine whether intermediate space weathering is observable in objects likely pristine when they originated from the interior of Karin's pa rent body. (2) Measure the UV-visible spectra of two members of the Vesta family to compare with our analysis of IUE Vesta spectra. These observations will probe Vesta's interior, and test our hypothesis by contrasting the apparent amount of alteration on the surfaces of Vestoids with excavated material on Vesta.
We will obtain reflectance spectra of five main-belt asteroids covering 200-460 nm using the ACS/HRC with the PR200L prism. All asteorids are point sources. We will visit asteroid 832 Karin twice, with the second visit timed so that we obtain spectra at 180 deg longitude intervals of the asteroid in its 18.82 hour period. All other asteroids will be observed during one orbit only. The observing constraints will ensure that the asteroids are all observed near opposition; observations minimizing the phase angle are preferred. The number and length of exposures for each asteroid varies depending on the range of apparent magnitues of the asteroids. Visit 2 should be offset from Visit 1 by 7.1n to 11.2n hours, where n is an odd integer. 12 false 0.0 false false false false false AVAILABLE SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 832 Karin TYPE=ASTEROID,A=2.8634314,E=0.081503099999,I=1.00321,O=254.60852,W=118.1131,M=70.47575999,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-832-KARIN-2 EARTH LT 2.2, PHASE OF ASTEROID-832-KARIN-2 FROM EARTH BETWEEN -10.5 10.5 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 1906 Naef TYPE=ASTEROID,A=2.3732287,E=0.135166,I=6.47238,O=354.99879,W=14.67278,M=294.79939,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-1906 EARTH LT 1.16, PHASE OF ASTEROID-1906 FROM EARTH BETWEEN -19.0 19.0 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 4507 (1990FV) TYPE=ASTEROID,A=2.8703058,E=0.0130695,I=2.67055,O=47.63573,W=98.87228,M=57.25201,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-4507 EARTH LT 2.4, PHASE OF ASTEROID-4507 FROM EARTH BETWEEN -19.0 19.0 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 7719 (1997GT36) TYPE=ASTEROID,A=2.86666807753379,E=0.05025142152465,I=2.08380562414954,O=173.6745067419738,W=249.9506264155356,M=107.6710685824747,EQUINOX=J2000,EPOCH=07-JUL-2001:00:00:00 RANGE ASTEROID-7719 EARTH LT 1.89, PHASE OF ASTEROID-7719 FROM EARTH BETWEEN -3.0 3.0 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 832 Karin TYPE=ASTEROID,A=2.8634314,E=0.081503099999,I=1.00321,O=254.60852,W=118.1131,M=70.47575999,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-832-KARIN-1 EARTH LT 2.2, PHASE OF ASTEROID-832-KARIN-1 FROM EARTH BETWEEN -10.5 10.5 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 10783 TYPE=ASTEROID,A=2.864185476898071,E=0.06322448728282803,I=1.953128436899108,O=178.2033469860155,W=233.5990163776583,M=2.600264249740454,EQUINOX=J2000,EPOCH=31-DEC-2001:00:00:00 RANGE ASTEROID-10783 EARTH LT 1.89, PHASE OF ASTEROID-10783 FROM EARTH BETWEEN -5.5 5.5 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 3494 Purple Mountain TYPE=ASTEROID,A=2.3496975,E=0.1299372,I=5.83713,O=234.56412,W=72.27039,M=4.21124,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-3494 EARTH LT 1.4, PHASE OF ASTEROID-3494 FROM EARTH BETWEEN -13.2 13.2 SOLAR SYSTEM U- V = 1.25 +/- 0.03 ASTEROID asteroid 3265 Fletcher TYPE=ASTEROID,A=2.4102613,E=0.1424453,I=6.93767,O=72.93719,W=297.8231,M=278.78983,EQUINOX=J2000,EPOCH=30-JAN-2005:00:00:00 RANGE ASTEROID-3265 EARTH LT 1.2, PHASE OF ASTEROID-3265 FROM EARTH BETWEEN -15.0 15.0 POS-TARG DITHER 0.084 LINE false false 2 32.14 ACS-HRC-DITHER-LINE 1 false /var/tmp/OPVisit64913.xml (Tic-Visit :proposal-id 10557 :visit-id "01" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:38:23.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "01" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3120.0 :pcs-gap 0 ) true 1 0 /var/tmp/OPVisit64914.xml (Tic-Visit :proposal-id 10557 :visit-id "02" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:38:50.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "02" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3120.0 :pcs-gap 0 ) true 1 0 /var/tmp/OPVisit64915.xml (Tic-Visit :proposal-id 10557 :visit-id "03" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:39:09.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 110416 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "03" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2269 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10557 :visit-id "03" :orbit-number 2 :pcs-time 367 :si-vis-utilization 1703 :al-overhead-at-end 0 :internal-dur-at-end 159 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 2 0 STScI should choose between Visit 3, Visit 4 and Visit 5. We need TWO of these three visit (for two Karin daughter asteroids). /var/tmp/OPVisit64916.xml (Tic-Visit :proposal-id 10557 :visit-id "04" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:39:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 73616 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "04" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2678 :al-overhead-at-end 0 :internal-dur-at-end 119 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3060.0 :pcs-gap 0 ) true 1 0 STScI should choose between Visit 3, Visit 4 and Visit 5. We need TWO of these three visit (for two Karin daughter asteroids). /var/tmp/OPVisit64917.xml (Tic-Visit :proposal-id 10557 :visit-id "05" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:39:48.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 73616 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "05" :orbit-number 1 :pcs-time 365 :si-vis-utilization 2868 :al-overhead-at-end 0 :internal-dur-at-end 119 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 STScI should choose between Visit 3, Visit 4 and Visit 5. We need TWO of these three visit (for two Karin daughter asteroids). /var/tmp/OPVisit64918.xml (Tic-Visit :proposal-id 10557 :visit-id "06" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:40:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "06" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2858 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 /var/tmp/OPVisit64919.xml (Tic-Visit :proposal-id 10557 :visit-id "07" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:40:28.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "07" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 STScI should choose between Visit 7 and Visit 8. We require just one of those two visits (for a Vesta daughter asteroid). /var/tmp/OPVisit64920.xml (Tic-Visit :proposal-id 10557 :visit-id "08" :proposal-version -1 :trans-version "20050502" :date "05-Jul-2005 13:40:46.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10557 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10557 :visit-id "08" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 STScI should choose between Visit 7 and Visit 8. We require just one of those two visits (for a Vesta daughter asteroid).