18051( 3) - 30-Sep-2025 11:50:04 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18051 Version: 3 Check-in Time: 30-Sep-2025 11:50:04 STScI Edit Number: 1 Title Evolution of the Newly Discovered Jet in the Symbiotic System HM Sge ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Warren J. Hack Eureka Scientific Inc. Y CoI: Dr. Margarita Karovska Smithsonian Institution Astrophysical N Observatory ------------------------------------------------------------------------------------ Abstract We propose HST/WFC3 observations of the interacting Symbiotic binary HM Sge to study the evolution of the jet we discovered using the archival April 2021 observations, which was likely ejected during a powerful outburst during 1975-1980. Since 1975, HM Sge has been slowly getting fainter, that is until recently, when a dramatic dimming of the light curve began in late 2021/early 2022, indicating a new powerful mass ejection and dust formation, similar to the outburst and jet producing events in two nearby Symbiotics CH Cyg and R Aqr. Our goal is to carry out a timely high-angular resolution (0.025") multi-wavelength (UV-Optical) line-emission study of the newly discovered jet and the recent ejecta by zooming in on the central 3" radius (3000 AU) circumbinary region, reaching as close as 25 AU to the central binary. This will allow us to determine the spatial/spectral evolution of the distribution and the characteristics of the new jet and more recent ejecta, and to gain a unique insight into jet formation and early propagation in symbiotic and other accretion-powered systems. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will take multi-wavelength observations of HM Sge to study the newly discovered jet and to measure the line ratios in the region powering the new jet and the recent dimming event. The HST observations are critical because of the required high-angular resolution, and especially the access to UV and optical lines - which are a key to this study. The UV component of this proposal is essential to the science investigation, and is in accordance with the HST UV initiative. We request a total of 5 orbits, in 1 visit. The target visibility is very good. We plan to carry out HST WFC3/UVIS imaging of HM Sge, using the 4-point dither mode in several filters (see table). Combining the dithered images will result in improvement of the sampling of the PSF and will allow us to further enhance the (nominal 0.04"/pixel) resolution using deconvolution techniques such as Richardson-Lucy reaching 0.025"/pixel (~25 AU). We also plan several long exposures to image the fainter outer structures and determine their morphology and evolution when compared to the archival HST observations. We plan to use the following filters (UV-Optical) centered on emission lines and nearby continua. 18051( 3) - 30-Sep-2025 11:50:04 - [ 2] F275W UV cont. set of 4x180s exp F280N Mg II set of 4x120s exp + 4x200s exp F336W U Band cont. set of 4x30s exp F373N [OII] set of 4x85s + 2x500s exp F343N [NeV] set of 4x90s exp F487N H-beta set of 4x30s exp F502N [O III] set of 4x40s + 2x660s exp F547M cont. set of 4x8s exp F656N H-alpha set of 4x10s + 2x600s exp F658N [N II] set of 4x20s exp F673N [S II] set of 4x15s exp F763M cont. set of 4x5s exp The exposure times are based on the online WFC3 ETC calculations as verified by the 2024 WFC3 observations. We will optimize the efficiency of the observing time by using 1024x1024 subarray readouts with a ~40"x40" field of view to minimize the overheads. This field of view also includes a suitable PSF candidate for subsequent deconvolution of the image. ------------------------------------------------------------------------------------ 18051( 3) - 30-Sep-2025 11:50:04 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V-HM-SGE STAR, JET, SYMBIOTIC RA=19H41M57.0796S, J2000 V = 13.00 STAR DEC=+16D44'39.81" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. SIMBAD listed proper motion for this target. When retrieving targets with PM from SIMBAD, APT requests the coordinates be calculated with an epoch of the year 2000. Do not modify this epoch. Always review coordinates using the Target Confirmation tool, which graphically displays the PM.This object was generated by the targetselector and retrieved from the SIMBAD database. SIMBAD listed proper motion for this target. When retrieving targets with PM from SIMBAD, APT requests the coordinates be calculated with an epoch of the year 2000. Do not modify this epoch. Always review coordinates using the Target Confirmation tool, which graphically displays the PM. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -3.084100534537553E-5 -0.007103999973878672 9.735000000000001E-4 ------------------------------------------------------------------------------------------------------------------------------------ 18051( 3) - 30-Sep-2025 11:50:04 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.15 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18051( 3) - 30-Sep-2025 11:50:04 - [ 5] Visit: 01 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 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F502N FLASH=20 1 40 S (160 GS ACQ SCENARIO ONEB1OR; S 1C-SUB S) PATTERN 1 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F547M FLASH=20 1 8 S (32 S) S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 3 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F373N FLASH=20 1 85 S (340 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F280N FLASH=20 1 120 S (480 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F487N FLASH=20 1 30 S (120 PATTERN 1 5-7 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F343N FLASH=20 1 90 S (360 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F656N FLASH=20 1 10 S (40 S 1C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F502N 1 none none none 1 N/A S K1C-SUB V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F502N 2 none none none 1 N/A S K1C-SUB V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F502N 3 none none none 1 N/A S K1C-SUB V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F502N 4 none none none 1 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F547M 1 none none none 1 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F547M 2 none none none 1 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F547M 3 none none none 1 N/A S K1C-SUB 18051( 3) - 30-Sep-2025 11:50:04 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F547M 4 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F373N 1 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F373N 2 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F373N 3 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F373N 4 none none none 2 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F280N 1 none none none 1 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F280N 2 none none none 1 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F280N 3 none none none 1 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F280N 4 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F487N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F487N 2 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F487N 3 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F487N 4 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F343N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F343N 2 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F343N 3 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F343N 4 none none none 2 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F656N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F656N 2 none none none 2 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F656N 3 none none none 2 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F656N 4 none none none 2 N/A S K1C-SUB 18051( 3) - 30-Sep-2025 11:50:04 - [ 7] Visit: 02 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 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F373N FLASH=20 2 500 S S 1C-SUB (1000 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F763M FLASH=20 1 5 S (20 S) PATTERN 1 2-5 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 3 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F336W FLASH=20 1 30 S (120 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F275W FLASH=20 1 180 S (720 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F658N FLASH=20 1 30 S (120 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F280N FLASH=20 1 200 S (400 PATTERN 2 6-9 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F673N FLASH=20 1 15 S (30 S 1C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 8 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F502N FLASH=20 1 600 S S 1C-SUB (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 V-HM-SGE WFC3/UVI ACCUM UVIS2-C1K F656N FLASH=20 1 600 S S 1C-SUB (1200 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F373N none none 1 none 1 N/A S K1C-SUB V-HM-SGE 1 WFC3/UVI ACCUM UVIS2-C1 F373N none none 2 none 1 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F763M 1 none none none 1 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F763M 2 none none none 1 N/A S K1C-SUB 18051( 3) - 30-Sep-2025 11:50:04 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F763M 3 none none none 2 N/A S K1C-SUB V-HM-SGE 2 WFC3/UVI ACCUM UVIS2-C1 F763M 4 none none none 2 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none none 1 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F336W 3 none none none 2 N/A S K1C-SUB V-HM-SGE 3 WFC3/UVI ACCUM UVIS2-C1 F336W 4 none none none 2 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F275W 1 none none none 1 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F275W 2 none none none 1 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F275W 3 none none none 2 N/A S K1C-SUB V-HM-SGE 4 WFC3/UVI ACCUM UVIS2-C1 F275W 4 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F658N 1 none none none 1 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F658N 2 none none none 1 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F658N 3 none none none 2 N/A S K1C-SUB V-HM-SGE 5 WFC3/UVI ACCUM UVIS2-C1 F658N 4 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F280N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 6 WFC3/UVI ACCUM UVIS2-C1 F280N 2 none none none 3 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F673N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 7 WFC3/UVI ACCUM UVIS2-C1 F673N 2 none none none 3 N/A S K1C-SUB V-HM-SGE 8 WFC3/UVI ACCUM UVIS2-C1 F502N 1 none none none 2 N/A S K1C-SUB V-HM-SGE 8 WFC3/UVI ACCUM UVIS2-C1 F502N 2 none none none 3 N/A S K1C-SUB V-HM-SGE 9 WFC3/UVI ACCUM UVIS2-C1 F656N 1 none none none 3 N/A S K1C-SUB V-HM-SGE 9 WFC3/UVI ACCUM UVIS2-C1 F656N 2 none none none 3 N/A S K1C-SUB 18051( 3) - 30-Sep-2025 11:50:04 - [ 9] Summary Form for Proposal 18051 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=20 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO ONEB1OR, PATTERN 1 1-4, PATTERN 1 2-5, PATTERN 1 5-7, PATTERN 2 6-9 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F280N, F336W, F343N, F373N, F487N, F502N, F547M, F656N, F658N, F673N, F763M ------------------------------------------------------------------------------------------------------------------------------------ Target Names V-HM-SGE ------------------------------------------------------------------------------------------------------------------------------------