17792( 3) - 11-Mar-2025 15:22:43 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17792 Version: 3 Check-in Time: 11-Mar-2025 15:22:43 STScI Edit Number: 0 Title STIS Analysis of the metal-poor r-element-rich star TYC 3814-1598-1 ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Heitor Ernandes Lund University Y CoI: Dr. Beatriz Barbuy Universidade de Sao Paulo N CoI: Dr. Christopher Evans Space Telescope Science Institute - ESA - N JWST ------------------------------------------------------------------------------------ Abstract The formation site of rapid neutron-capture ('r-process') elements is still uncertain. The two most accepted mechanisms are magneto-rotational MHD-jet supernovae and neutron-star mergers, with the latter channel confirmed by observations of the kilonova counterpart of the gravitational-wave event GW170817. However, predictions from the latest nucleosynthesis models argue that neutron-star mergers cannot be the main contributor to r-process enrichment, and we require further empirical constraints on the r-process abundance pattern from early nucleosynthesis in the Galaxy. Here we propose STIS E230M echelle spectroscopy of TYC~3814-1598-1, a metal-poor ([Fe/H]~-3.0), actinide-enriched ([Eu/Fe] > 1.3) star that will provide new observational constraints on r-process enrichment. The STIS observations will provide the first abundance determinations for at least seven elements for this star, as well as much improved abundances for more than ten other heavy elements that have better diagnostics in the space ultraviolet than from optical spectroscopy. As the brightest known star of this rare class, the proposed analysis of TYC~3814-1598-1 will be a benchmark case for the abundance pattern of the so-called 'actinide boost' stars and provide much needed constraints on galactic chemical-evolution models. ------------------------------------------------------------------------------------ Observations Description ------------------------ The spectra should be acquired with the E230M grating of the STIS echelle spectrograph and the 0.2" 0.2" slit for a resolving power R = 30, 000. The E230M setting c2707 spectra provide complete high-resolution coverage of the stellar spectrum in the interval 2300 - 3111 \AA. The observation was organized into groups of 3-orbits visits to minimize overheads allowing some scheduling flexibility. Each group is divited into 4 exposure: Orbit 1 ACQ and SCIENCE, Orbists 2 and 3, SCIENCE. To acount for the 13 orbits we also included the 5th visit that has a single orbit, Orbit 1 ACQ and SCIENCE. The coordenates and propermotion are taken from Gaia DR3. ------------------------------------------------------------------------------------ 17792( 3) - 11-Mar-2025 15:22:43 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 TYC-3814-159 STAR, K III-I, RA=09H54M42.7402S, J2000 V = 10.1 8-1 POPULATION II DEC=+52D46'41.13" Reference Frame: ICRS 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. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2016 -0.001974672632237063 -0.0268062 0.3179 ------------------------------------------------------------------------------------------------------------------------------------ 17792( 3) - 11-Mar-2025 15:22:43 - [ 3] Visit: 01 (V1) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Each visit should contain three orbits. 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 TYC-3814-15 STIS/CCD ACQ F28X50LP MIRROR 1 0.1 S (0.1 98-1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 1801 S 98-1 -MAMA see below (2245 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA see below (2668 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA (2668 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 | ------------------------------------------------------------------------------------------------------------------------------------ TYC-3814-1598-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TYC-3814-1598-1 2 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 1 2245.0 S -MAMA TYC-3814-1598-1 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 2 2668.0 S -MAMA TYC-3814-1598-1 4 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 3 N/A -MAMA 17792( 3) - 11-Mar-2025 15:22:43 - [ 4] Visit: 02 (V2) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Each visit should contain three orbits. 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 TYC-3814-15 STIS/CCD ACQ F28X50LP MIRROR 1 0.1 S (0.1 98-1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 1801 S 98-1 -MAMA see below (2245 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA see below (2668 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA (2668 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 | ------------------------------------------------------------------------------------------------------------------------------------ TYC-3814-1598-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TYC-3814-1598-1 2 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 1 2245.0 S -MAMA TYC-3814-1598-1 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 2 2668.0 S -MAMA TYC-3814-1598-1 4 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 3 N/A -MAMA 17792( 3) - 11-Mar-2025 15:22:43 - [ 5] Visit: 03 (V3) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Each visit should contain three orbits. 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 TYC-3814-15 STIS/CCD ACQ F28X50LP MIRROR 1 0.1 S (0.1 98-1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 1801 S 98-1 -MAMA see below (2245 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA see below (2668 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA (2668 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 | ------------------------------------------------------------------------------------------------------------------------------------ TYC-3814-1598-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TYC-3814-1598-1 2 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 1 2245.0 S -MAMA TYC-3814-1598-1 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 2 2668.0 S -MAMA TYC-3814-1598-1 4 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 3 N/A -MAMA 17792( 3) - 11-Mar-2025 15:22:43 - [ 6] Visit: 04 (V4) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Each visit should contain three orbits. 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 TYC-3814-15 STIS/CCD ACQ F28X50LP MIRROR 1 0.1 S (0.1 98-1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 1801 S 98-1 -MAMA see below (2245 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA see below (2668 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA (2668 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 | ------------------------------------------------------------------------------------------------------------------------------------ TYC-3814-1598-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TYC-3814-1598-1 2 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 1 2245.0 S -MAMA TYC-3814-1598-1 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 2 2668.0 S -MAMA TYC-3814-1598-1 4 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 3 N/A -MAMA 17792( 3) - 11-Mar-2025 15:22:43 - [ 7] Visit: 05 (V5) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Each visit should contain three orbits. 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 TYC-3814-15 STIS/CCD ACQ F28X50LP MIRROR 1 0.1 S (0.1 98-1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TYC-3814-15 STIS/NUV ACCUM 0.2X0.2 E230M 2707 1 2668 S 98-1 -MAMA see below (2245 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 | ------------------------------------------------------------------------------------------------------------------------------------ TYC-3814-1598-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TYC-3814-1598-1 2 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none none none 1 2245.0 S -MAMA 17792( 3) - 11-Mar-2025 15:22:43 - [ 8] Summary Form for Proposal 17792 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 0.2X0.2, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements E230M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names TYC-3814-1598-1 ------------------------------------------------------------------------------------------------------------------------------------