18036( 4) - 28-Jan-2026 18:40:49 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18036 Version: 4 Check-in Time: 28-Jan-2026 18:40:49 STScI Edit Number: 2 Title Multiwavelength Extinction Curves in Distant Galaxies ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Monique C Aller Georgia Southern University Res. & Svc. Y Foundation, Inc CoI: Dr. Varsha Purushottam Kulkarni University of South Carolina N CoI: Dr. Viacheslav Klimenko University of South Carolina N ------------------------------------------------------------------------------------ Abstract Interstellar dust grains significantly impact the formation of new stars and the appearance and derived stellar populations of distant galaxies. Dust grain properties, including composition, size, and structure, reflect both the dust progenitors and subsequent interstellar processing. Variations in dust grain properties lead to wavelength-dependent differences in the UV-to-MIR extinction curves of galaxies. Studies of distant galaxies commonly assume extinction curves similar to the Milky Way, Local Group, and starburst galaxies; this assumption has not been confirmed in normal galaxies. Recent studies using quasar absorption systems (QASs) find that there may be more small grains, silicate dust grains may be larger or have more crystallinity, and that there may be differences in the relative build-up of carbonaceous and silicate dust grain populations. However, such UV-to-MIR analyses have only been possible for a small number of sources. We propose to obtain STIS G230L/G430L spectra to determine the shape of the UV extinction curve and strength of the 2175 A bump produced by carbonaceous dust in a sample of 6 QASs with JWST MIRI-MRS and optical data. The proposed data will allow us to break the fitting-degeneracy between the FUV-rise and 2175 A bump, to determine whether these galaxies have a large population of carbonaceous grains or a large population of small grains relative to the Milky Way. It will also allow a comparison of the UV features from carbonaceous grains with MIR silicate features in the same sightline of z>0.1 galaxies. These results may impact corrections applied to high-z galaxy studies, as well as models for the formation/evolution of dust grains. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain HST STIS G230L-MAMA and G430L-CCD spectra spanning 1570-5700 Angstroms in the observed frame for 6 quasar absorption systems that have JWST MIRI-MRS Cycle 1-3 data covering the 10 micron silicate dust absorption feature. These new data will be utilized to fit the shape and strength of the 2175 Angstrom bump produced by carbonaceous dust, and to break the 2175 Angstrom bump-FUV rise fitting degeneracy. All of the selected sources have archival spectral data at redder optical wavelengths, as well as in the FUV for some of the sources, but lacked spectra fully covering the absorber-frame NUV spectrum. To detemine our spectral exposure times for the observations, we utilized ETC 18036( 4) - 28-Jan-2026 18:40:49 - [ 2] 33.2 with a 52"x0.2" slit assuming a point source. We selected the 52"x0.2" slit in order to simultaneously maximize the resolution and throughput, and to retain sufficient spectral purity to measure any metal ion aborption lines detected in the spectra. For observations with the G230L grating and MAMA detector, we used the unbinned QSO-FOS (100-3387 Angstrom at z=0) template, shifted to the QSO redshift. We normalized the QSO spectrum using the NUV-GALEX magnitude with measured Galactic reddening, using the Av available from NED. We determined the number of exposures required to reach a SNR/resel (signal-to-noise ratio per resolution-element) of at least 10 at the location of the 2175 Angstrom bump center or greater than 9 at 2600 Angstroms. For the G430L observations, we used the unbinned QSO-LBQS (800-6000 Angstrom at z=0) spectrum at the QSO redshift normalized by the NUV-GALEX, g-SDSS, and SIMBAD V-band magnitudes with measured Galactic reddening. We determined the number of exposures required to reach a SNR/resel of at least 10 at 3200 Angstroms. To mitigate the effects of CTI losses and non-uniform dark currents, we utilize the 52x0.2E1 pseudo-aperture for the CCD observations, which places our target closer to the readout amplifier. We also restrict the G430L-CCD observations to < 1000s to minimize cosmic ray (CR) build-up. These SNRs are consistent with several previous STIS QAS studies, and based on analyses of archival data, this SNR is required to break the degeneracy between the strength of the 2175 Angstrom feature and the FUV rise. Our STIS spectra will be combined with archival spectra to maximize wavelength coverage of the extinction curve. For each grating we obtain multiple exposures at dithered positions along the STIS slit to minimize the effects of hot pixels and cosmic rays. Exposures have been grouped into visits of 1-3 orbits, consisent with the current gyro restrictions, and the G230L and G430L are placed into separate visits for scheduling flexibility. We dither by step sizes exceeding the standard extraction apertures, using integer pixel steps, to mitigate the effects of the hot pixels. For G430L observations consisting of a single orbit for the source, we obtain 3 exposures with a single exposure (CRSPLIT=1) at each location in a 3-point dither pattern with step sizes of 0.5" (10 pixels). For observations with 4 total orbits, we obtain 3 exposures per position (i.e., a CRSPLIT of 3) and dither between orbits with 2 step dither patterns of 0.5" and 1.0". For the G230L science exposures, we obtain 2 dithered exposures per orbit for all sources, with pixel step sizes ranging from 0.3-0.5". For objects with 4-5 orbits, allowing for more exposures per visit, we center the dither patterns around the source. For the NUV-MAMA observations, we utilize the TIME-TAG mode recommended by the STIS instrument handbook for sources with <20, 000 ct/s. We confirmed with the STIS ETC that all targets are well-below the maximum global count rate for the MAMA detector, and that there are no sources with safetly violations identified by the APT-BOT. For target acquisitions, we utilize the recommended F28X50LP filter. We designed our target acquistions to detect the source with a SNR of at least 40, even if the target is 1.5 magnitudes fainter than the published magnitudes. This will account for possible source variability, which can be as large as a factor of 4 in flux for some sources at some frequencies. We have also confirmed that if the source is 1.5 magnitudes brighter than the catalogued magnitudes, we would be well below the saturation limit for the CCD detector. To determine the exposure times, we utilized ETC Version 33.2, assuming a point 18036( 4) - 28-Jan-2026 18:40:49 - [ 3] source with the QSO SDSS template (covering 800-8554 Angstroms at z=0). This template was redshifted to the QSO redshift (0.4 Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.5 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 1.0 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.5 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18036( 4) - 28-Jan-2026 18:40:49 - [ 7] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 5 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.3 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 6 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 6 Point_Spacing 0.3 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 7 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.4 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 18036( 4) - 28-Jan-2026 18:40:49 - [ 8] Visit: 01 (G430L-J0122) Visit Requirements: 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 WISEA-J0122 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 3 S (3 S) 36.76-28432 1.4 Comments: Calculated using V-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J0122 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 500 S PATTERN 1 2 36.76-28432 CR-SPLIT=NO, GAIN=1 see below 1.4 (2004 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J012236.76-28 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4321.4 WISEA-J012236.76-28 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none none 1 668.0 S 4321.4 WISEA-J012236.76-28 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none none 1 668.0 S 4321.4 WISEA-J012236.76-28 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 3 none none none 1 668.0 S 4321.4 18036( 4) - 28-Jan-2026 18:40:49 - [ 9] Visit: 02 (G430L-Q1416) Visit Requirements: 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 HB89-1416+1 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 18 S (18 59 S) Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnitudes fainter than catalogued to account for variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 HB89-1416+1 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 500 S PATTERN 1 2 59 CR-SPLIT=NO, GAIN=1 see below (1935 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HB89-1416+159 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A HB89-1416+159 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none none 1 645.0 S HB89-1416+159 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none none 1 645.0 S HB89-1416+159 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 3 none none none 1 645.0 S 18036( 4) - 28-Jan-2026 18:40:49 - [ 10] Visit: 03 (G430L-J0741) Visit Requirements: 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 FBQS-J07411 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 8 S (8 S) 0.6+311200 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 FBQS-J07411 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 500 S PATTERN 1 2 0.6+311200 CR-SPLIT=NO, GAIN=1 see below (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ FBQS-J074110.6+3112 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 00 FBQS-J074110.6+3112 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none none 1 662.0 S 00 FBQS-J074110.6+3112 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none none 1 662.0 S 00 FBQS-J074110.6+3112 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 3 none none none 1 662.0 S 00 18036( 4) - 28-Jan-2026 18:40:49 - [ 11] Visit: 04 (G430L-J1619) Visit Requirements: 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 WISEA-J1619 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 8 S (8 S) 16.54+33423 8.4 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1619 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 500 S PATTERN 1 2 16.54+33423 CR-SPLIT=NO, GAIN=1 see below 8.4 (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J161916.54+33 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4238.4 WISEA-J161916.54+33 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none none 1 662.0 S 4238.4 WISEA-J161916.54+33 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none none 1 662.0 S 4238.4 WISEA-J161916.54+33 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 3 none none none 1 662.0 S 4238.4 18036( 4) - 28-Jan-2026 18:40:49 - [ 12] Visit: 05 (G430L-J1017-visit1) Visit Requirements: SCHED 100% 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 WISEA-J1017 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 41 S (41 51.12+47494 S) 0.1 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1017 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 1500 S PATTERN 2 2 51.12+47494 CR-SPLIT=3, GAIN=1 see below 0.1 (4113 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J101751.12+47 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 1 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 2 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 3 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 1 2 762.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 2 2 762.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 3 2 762.0 S 4940.1 18036( 4) - 28-Jan-2026 18:40:49 - [ 13] Visit: 06 (G430L-J1017-visit2) Visit Requirements: SCHED 100% 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 WISEA-J1017 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 41 S (41 51.12+47494 S) 0.1 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1017 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 1500 S PATTERN 3 2 51.12+47494 CR-SPLIT=3, GAIN=1 see below 0.1 (4113 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J101751.12+47 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 1 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 2 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 3 1 609.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 1 2 762.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 2 2 762.0 S 4940.1 WISEA-J101751.12+47 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 3 2 762.0 S 4940.1 18036( 4) - 28-Jan-2026 18:40:49 - [ 14] Visit: 07 (G430L-J1037-visit1) Visit Requirements: 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 WISEA-J1037 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 46 S (46 18.76+01443 S) 0.9 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1037 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 1500 S PATTERN 2 2 18.76+01443 CR-SPLIT=3, GAIN=1 see below 0.9 (4242 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J103718.76+01 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 1 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 2 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 3 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 1 2 793.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 2 2 793.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 3 2 793.0 S 4430.9 18036( 4) - 28-Jan-2026 18:40:49 - [ 15] Visit: 08 (G430L-J1037-visit2) Visit Requirements: 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 WISEA-J1037 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 46 S (46 18.76+01443 S) 0.9 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1037 STIS/CCD ACCUM 52X0.2E1 G430L 4300 BINAXIS1=1, BINAXIS2=1, 1 1500 S PATTERN 3 2 18.76+01443 CR-SPLIT=3, GAIN=1 see below 0.9 (4242 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J103718.76+01 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 1 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 2 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none 3 1 621.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 1 2 793.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 2 2 793.0 S 4430.9 WISEA-J103718.76+01 2 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none 3 2 793.0 S 4430.9 18036( 4) - 28-Jan-2026 18:40:49 - [ 16] Visit: 09 (G230L-J0122) Visit Requirements: 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 WISEA-J0122 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 3 S (3 S) 36.76-28432 1.4 Comments: Calculated using V-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J0122 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1274 1 800 S PATTERN 4 2 36.76-28432 -MAMA G see below 1.4 (1858 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J012236.76-28 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4321.4 WISEA-J012236.76-28 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 929.0 S 4321.4 -MAMA G WISEA-J012236.76-28 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 929.0 S 4321.4 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 17] Visit: 10 (G230L-Q1416) Visit Requirements: 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 HB89-1416+1 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 18 S (18 59 S) Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 HB89-1416+1 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1597 1 800 S PATTERN 5 2 59 -MAMA G see below (3990 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HB89-1416+159 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A HB89-1416+159 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 895.0 S -MAMA G HB89-1416+159 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 895.0 S -MAMA G HB89-1416+159 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 3 none none none 2 1100.0 S -MAMA G HB89-1416+159 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 4 none none none 2 1100.0 S -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 18] Visit: 11 (G230L-J0741) Visit Requirements: 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 FBQS-J07411 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 8 S (8 S) 0.6+311200 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 FBQS-J07411 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1326 1 800 S PATTERN 4 2 0.6+311200 -MAMA G see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ FBQS-J074110.6+3112 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 00 FBQS-J074110.6+3112 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 921.0 S 00 -MAMA G FBQS-J074110.6+3112 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 921.0 S 00 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 19] Visit: 12 (G230L-J1619) Visit Requirements: 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 WISEA-J1619 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 8 S (8 S) 16.54+33423 8.4 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1619 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1271 1 800 S PATTERN 4 2 16.54+33423 -MAMA G see below 8.4 (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J161916.54+33 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4238.4 WISEA-J161916.54+33 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 921.0 S 4238.4 -MAMA G WISEA-J161916.54+33 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 921.0 S 4238.4 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 20] Visit: 13 (G230L-J1017-visit1) Visit Requirements: SCHED 100% 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 WISEA-J1017 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 41 S (41 51.12+47494 S) 0.1 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1017 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1608 1 700 S PATTERN 7 2 51.12+47494 -MAMA G see below 0.1 (3756 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J101751.12+47 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4940.1 WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 814.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 814.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 3 none none none 2 1064.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 4 none none none 2 1064.0 S 4940.1 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 21] Visit: 14 (G230L-J1017-visit2) Visit Requirements: SCHED 100% 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 WISEA-J1017 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 41 S (41 51.12+47494 S) 0.1 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1017 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1608 1 800 S PATTERN 6 2 51.12+47494 -MAMA G see below 0.1 (6026 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J101751.12+47 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4940.1 WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 814.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 814.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 3 none none none 2 1064.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 4 none none none 2 1064.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 5 none none none 3 1135.0 S 4940.1 -MAMA G WISEA-J101751.12+47 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 6 none none none 3 1135.0 S 4940.1 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 22] Visit: 15 (G230L-J1037-visit1) Visit Requirements: 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 WISEA-J1037 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 46 S (46 18.76+01443 S) 0.9 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1037 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1607 1 902 S PATTERN 5 2 18.76+01443 -MAMA G see below 0.9 (3884 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J103718.76+01 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4430.9 WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 841.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 841.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 3 none none none 2 1101.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 4 none none none 2 1101.0 S 4430.9 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 23] Visit: 16 (G230L-J1037-visit2) Visit Requirements: 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 WISEA-J1037 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 46 S (46 18.76+01443 S) 0.9 Comments: Calculated using SDSS r-band magnitude, assuming it could be 1.5 magnirudes fainter than catalogued to account for possible variability. ------------------------------------------------------------------------------------------------------------------------------------ 2 WISEA-J1037 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=1607 1 902 S PATTERN 7 2 18.76+01443 -MAMA G see below 0.9 (3884 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WISEA-J103718.76+01 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 4430.9 WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 1 none none none 1 841.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 2 none none none 1 841.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 3 none none none 2 1101.0 S 4430.9 -MAMA G WISEA-J103718.76+01 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 4 none none none 2 1101.0 S 4430.9 -MAMA G 18036( 4) - 28-Jan-2026 18:40:49 - [ 24] Summary Form for Proposal 18036 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, 52X0.2E1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, BINAXIS1=1, BINAXIS2=1, BUFFER-TIME=1271, BUFFER-TIME=1274, BUFFER-TIME=1326, BUFFER-TIME=1597, BUFFER-TIME=1607, BUFFER-TIME=1608, CR-SPLIT=3, CR-SPLIT=NO, GAIN=1 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 2, PATTERN 2 2, PATTERN 3 2, PATTERN 4 2, PATTERN 5 2, PATTERN 6 2, PATTERN 7 2, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G230L, G430L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names FBQS-J074110.6+311200, HB89-1416+159, WISEA-J012236.76-284321.4, WISEA-J101751.12+474940.1, WISEA-J103718.76+014430.9, WISEA-J161916.54+334238.4 ------------------------------------------------------------------------------------------------------------------------------------