This target is not used in this proposal. This target is not used in this proposal. 0 Assigned ID: 526 ----- Attempting Submission 1 (Fri Apr 05 16:41:39 GMT 2019) ----- HST Phase I Proposal 526 (APT_Prop_2.apt) successfully submitted. Receipt: # 526-1 ----- Attempting Submission 2 (Fri Apr 05 20:43:08 GMT 2019) ----- HST Phase I Proposal 526 (APT_Prop_3.apt) successfully submitted. Receipt: # 526-2 ----- Attempting Submission 3 (Fri Apr 05 20:55:55 GMT 2019) ----- Two targets will be included per slit orientation, so that no extra observations were listed for two of our targets. This target is not used in this proposal. This target is not used in this proposal. This target is not used in this proposal. This target is not used in this proposal. As discussed per email with our CS Ms. Tricia Royle, we would like to change the G430M 4194 filter originally requested to the G430M 3936 filter for all epochs and slit orientations. The reason for the change is that, based on high-res unpublished STIS/G430M spectra of our targets provided to us by P. Crowther (priv. com.), the G430M 3936 filter contains more vital diagnostic lines. Moreover, it provides a better coverage of the diagnostic line N IV 4058. Submission II update: Schedulability constraints added to allow more flexibility. % chosen to minimize loss of HST schedulability and loss of exposure times simultaniously. Instead of "BETWEEN", time constraints are now given relative to epoch 1 of each slit poisitioning. Submission III (26.2.2020): (1) coordinates and offsets changed due to inconsistency between 2MASS coordinates of reference star (Mk34) and target coordinates derived from astrometrically-corrected WFC image. New offsets derived consistently from WFC image containing both reference star and targets. Mk34 coordinates taken from Gaia DR2 (epoch 2000, SIMBAD) (2) sub-exposures for a1-a2 pair for the 4961 filter adjusted to be equal. Submission IV (28.2.2020): ORIENTs changed by "-3 deg" for a1-a2 pair due to request by Patricia Royle, HST staff -291650638 ----- Attempting Submission 1 (Sun Jul 14 18:45:16 GMT 2019) ----- HST Phase II Proposal 15942 (Untitled.apt) successfully submitted. Receipt: # 15942-1 ----- Attempting Submission 2 (Wed Jul 17 10:53:52 GMT 2019) ----- ----- Attempting Submission 3 (Wed Feb 26 16:34:08 GMT 2020) ----- ----- Attempting Submission 4 (Fri Feb 28 21:35:52 GMT 2020) ----- Our slit orientations are defined at the mid-points of our targets. The targets are defined as well for orientation and convenient marking in the viewing chart. The chemical evolution and integrated appearance of galaxies are governed by the most massive stars they host. With masses in excess of 50 solar masses (Ms), these stars dominate entire clusters in terms of their energy production. They are ideal progenitors of superluminous / pair-instability supernovae, gamma-ray bursts, and the massive black holes identified through recent gravitational-wave detections. While fundamental to many of our models and predictions, we do not know how massive a star can become. Masses derived from binary orbits generally do not exceed 130Ms. In contrast, a few supposedly-single stars residing in R136 in the Large Magellanic Cloud (LMC) were reported to have masses exceeding 300Ms, twice the canonical upper-mass limit. These mass estimates, however, rely on one risky assumption: that the stars are single. The incidence of multiplicity among the massive stars and the very high crowding in R136 shed doubts on the single-star assumption and warrant a careful investigation of these stars. Several known binaries with components more massive than 100Ms have periods of the order of several months. And yet, the most massive stars in R136 have only been investigated on a time-base of a few weeks and with low-resolution spectroscopy. Here, we propose to collect 3 epochs of HST/STIS spectroscopy of the four most massive candidate stars in the Local Group - R136 a1, a2, a3, and c. With merely 6 orbits, and relying on data quality that is exclusive to the HST/STIS and vital for the study, our analysis will yield statistically-firm constraints on the multiplicity of these objects within a 90% detection limit up to a period of about three years. Goal: Secure 3 epochs of optical spectra (G430 M 3936, 4706, 4961) per target for BAT99 106, 108, 109, and 112 (R136 a3, a1, a2, and c). We define two slit orientations: 1. A1-2: defined between R136 a1 and a2, centered at midpoint of R136 a1 and a2 (5:38:42.3978 -69:06:3.03 orient angle 109 / 289, position angle 64 / 249) 2. A3-C: defined between R136 a3 and c, centered at midpoint of R136 a3 and c (5:38:42.6166 -69:06:4.1785, orient angle 162.2 / 342.2, position angle 116.8 / 296.8) Due to crowding, slit positioning is relative to initial acquisition + peakup of the bright and isolated star BAT99 116 (Melnick 34, Brey 84). Our team is composed of experts in their respective fields, including seasoned HST observers, binary experts, and specialists in atmosphere analysis and quantitative spectroscopy of Wolf-Rayet stars and binaries. On the observational side, Shenar (PI) successfully obtained about 20 h of observing time with ESO instruments in the last few cycles that focused on unique WR binaries (e.g., Shenar et al. 2016 A&A, 591, 22; Shenar et al. 2017, A&A, 598, 85; Shenar et al. 2018, A&A, 616, 103), and was co-I on multiple HST-related projects. Sana has broad expertise in multiwavelength spectroscopy and is a former HST instrument scientist in COS/STIS team. Mahy is an expert in atmosphere modelling of massive stars and their winds and in binary systems, with many HST orbits already awarded (e.g., observing program GO15629). On the analysis side, Shenar (PI) performed radial velocity measurements and orbital analyses of dozens of Wolf-Rayet binary and multiple systems in the Magellanic Clouds (Shenar et al. 2016; 2017; 2018; 2019, submitted). Sana is the main developer of the statistical tools used in the framework of the successful VLT/FLAMES Tarantula survey (VFTS) (Sana et al. 2012, Science, 337, 444; Sana et al. 2013, A&A, 550, 107). Mahy has led an extensive campaign of quantative spectroscopy of dozens of O-type binaries in the Galaxy and in the Tarantula region (Mahy et al. 2018, A&A, 616, 75; Mahy et al. 2019, submitted). our team hosts key developers of the PoWR model atmosphere code (Hainich, Sander, Shenar, Oskinova) and in the CMFGEN model atmosphere code (Mahy, Sana). Stellar Physics 6 false false false false false false false SUPPORTED STAR WOLF RAYET - WN NO VEGAMAG Photometry from WFC3 F555W Early Release Obervation IB6WD6050 (De Marchi et al. 2011). ICRS astrometry of Melnick 34 from Gaia DR2 (Gaia DR2 4657685534828257792). Used for acquision due to severe crowding within R136 itself. Coordinates of Mk34 in *astrometricallty-uncorrecred" WFC image: '05 38 44.2416', '-69 06 5.930' J2000 B-V=0.25 STAR WOLF RAYET - WN Center between R136a1 and R136a2 (BAT99 108 and 109), -1.862 sec (RA) and 2.975 (DEC) offset relative to Brey 84 (Melnick 34). Determined from F336W WFC3 image of R136 (de Marchi et al. 2011, Crowther et al. 2016). Brightest cluster star in slit R136a1 (BAT99 108). VEGA V = 12.28 STAR WOLF RAYET - WN Center between R136a3 and R136c (BAT99 106 and 112), -1.62935 sec (RA) and 1.6715 (DEC) offset relative to Brey 84 (Melnick 34). Determined from F336W WFC3 image of R136 (de Marchi et al. 2011, Crowther et al. 2016). Brightest cluster star in slit R136 C (BAT99 112). VEGA V = 12.86 STAR WOLF RAYET - WN coordinates obtained from attached astrometrically-corrected WFC3 r136_thumb_ast.fits image. J2000 J2000 STAR WOLF RAYET - WN coordinates obtained from attached astrometrically-corrected WFC3 r136_thumb_ast.fits image. J2000 J2000 STAR WOLF RAYET - WN coordinates obtained from attached astrometrically-corrected WFC3 r136_thumb_ast.fits image. J2000 J2000 STAR WOLF RAYET - WN coordinates obtained from attached astrometrically-corrected WFC3 r136_thumb_ast.fits image. J2000 J2000 STIS/CCD Spectroscopic No No G430M 4194 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 STIS/CCD Spectroscopic No No G430M 4194 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 STIS/CCD Spectroscopic No No G430M 4194 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 STIS/CCD Spectroscopic No No G430M 3936 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 STIS/CCD Spectroscopic No No G430M 3936 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 STIS/CCD Spectroscopic No No G430M 3936 STIS/CCD Spectroscopic No No G430M 4706 STIS/CCD Spectroscopic No No G430M 4961 POS-TARG DITHER 0.35546 0.35546 arcsec = 7 CCD pixels x 0.05078 arcsec/pix (= pixels over which 1D spectra extracted) LINE false false 2 90.0 STIS-ALONG-SLIT 4 false 1582925549591 Timing link suitability includes constraints ([02 After 01 by 50.0 to 230.0 days] [03 After 01 by 250.0 to 540.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. /private/var/folders/h1/k7xdsqj13m38y65j2tf3f3s0dpknzs/T/OPVisit15216516196210055972.xml (Tic-Visit :proposal-id 15942 :visit-id "01" :proposal-version -1 :trans-version "20191203" :date "28-Feb-2020 22:32:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2733 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3130 :pcs-gap 0 ) true 1 0 ETC predicts S/N=174 for 1 sec exposure through F28X50LP aperture for Melnick 34 (V=13.09). Peakup on Melnick 34 for accurate positioning prior to offset. ETC predicts 58,000 e- from source in 0.5 sec exposure through 52x0.1 aperture for Melnick 34 (V=13.09), order of magnitude below saturation level. ETC run for fainter R136a2: 1367278 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are somewhat shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2:1367279 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2: 1367422 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. 1582925550981 Timing link suitability includes constraints ([02 After 01 by 50.0 to 230.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. /private/var/folders/h1/k7xdsqj13m38y65j2tf3f3s0dpknzs/T/OPVisit10514322120246585385.xml (Tic-Visit :proposal-id 15942 :visit-id "02" :proposal-version -1 :trans-version "20191203" :date "28-Feb-2020 22:32:30.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2775 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3172 :pcs-gap 0 ) true 1 0 ETC predicts S/N=174 for 1 sec exposure through F28X50LP aperture for Melnick 34 (V=13.09). Peakup on Melnick 34 for accurate positioning prior to offset. ETC predicts 58,000 e- from source in 0.5 sec exposure through 52x0.1 aperture for Melnick 34 (V=13.09), order of magnitude below saturation level. ETC run for fainter R136a2: 1367278 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2:1367279 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2: 1367422 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. 1582925552204 Timing link suitability includes constraints ([03 After 01 by 250.0 to 540.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. /private/var/folders/h1/k7xdsqj13m38y65j2tf3f3s0dpknzs/T/OPVisit8653393548192728168.xml (Tic-Visit :proposal-id 15942 :visit-id "03" :proposal-version -1 :trans-version "20191203" :date "28-Feb-2020 22:32:31.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "03" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2775 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3172 :pcs-gap 0 ) true 1 0 ETC predicts S/N=174 for 1 sec exposure through F28X50LP aperture for Melnick 34 (V=13.09). Peakup on Melnick 34 for accurate positioning prior to offset. ETC predicts 58,000 e- from source in 0.5 sec exposure through 52x0.1 aperture for Melnick 34 (V=13.09), order of magnitude below saturation level. ETC run for fainter R136a2: 1367278 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2:1367279 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136a2: 1367422 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. 1582711261703 Timing link suitability includes constraints ([05 After 04 by 50.0 to 230.0 days] [06 After 04 by 250.0 to 540.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15942 :visit-id "04" :proposal-version -1 :trans-version "20190514" :date "26-Feb-2020 11:01:01.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "04" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2641 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3036 :pcs-gap 0 ) true 1 0 ETC run for fainter R136c: 1367432 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367433 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367434 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. 1582711262918 Timing link suitability includes constraints ([05 After 04 by 50.0 to 230.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15942 :visit-id "05" :proposal-version -1 :trans-version "20190514" :date "26-Feb-2020 11:01:02.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "05" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2887 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3284 :pcs-gap 0 ) true 1 0 ETC run for fainter R136c: 1367432 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367433 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367434 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. 1582711264105 Timing link suitability includes constraints ([06 After 04 by 250.0 to 540.0 days]) The scheduling data was generated by CASM 28.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15942 :visit-id "06" :proposal-version -1 :trans-version "20190514" :date "26-Feb-2020 11:01:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15942 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15942 :visit-id "06" :orbit-number 1 :pcs-time 393 :si-vis-utilization 3091 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) true 1 0 ETC run for fainter R136c: 1367432 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367433 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable. ETC run for fainter R136c: 1367434 ETC runs performed for exposure times in first phase II submission. The exposure times in ths second submission are slightly shorter, S/N and other parameters are easily scalable.