16654( 7) - 08-Nov-2021 21:12:24 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16654 Version: 7 Check-in Time: 08-Nov-2021 21:12:24 STScI Edit Number: 1 Title A wide, red-giant plus non-interacting black hole binary, or triple stellar system? ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Luciana C. Bianchi The Johns Hopkins University Y CoI: Dr. Ralph C. Bohlin Space Telescope Science Institute N CoI: Dr. John Hutchings Dominion Astrophysical Observatory N CoI: Dr. David Thilker The Johns Hopkins University N CoI: Emanuele Berti The Johns Hopkins University N ------------------------------------------------------------------------------------ Abstract Black hole (BH) demographics in binaries is critical in view of recent results on massive stars binarity, and the proven multi-messenger detectability of compact objects mergers. Close systems are relatively simple to identify and study as the black hole accretes mass from an evolving companion, and develops an X-ray emitting accretion disk. However, identification and characterization of non-interacting BHs is elusive, but may represent a significant unstudied population. 2MASS-J05215658+4359220 is the only candidate binary presumed to harbour a non-interacting stellar-mass black hole: it consists of a red giant and an optically undetected, compact companion of about 3.3 solar masses. In the scenarios proposed so far, based on a broad ensemble of data, the origin of near-UV flux detected by GALEX and Swift remains unexplained and may be the key to understanding the system. We propose STIS UV spectroscopy and WFC3 multi-band imaging (including UV), that uniquely will reveal the origin of the NUV flux, and hence provide a decisive clue to the nature of the system. Compatible scenarios include the presence of a white dwarf (WD) or tight WD pair or a low-mass stellar close pair orbiting the red-giant primary at a larger separation, an accretion disk, or chromospheric/TZ line emission from the red giant. The HST UV data will uniquely allow us to conclusively discern the source of the UV emission, to detect a stellar companion (or pair) or accretion disk if present, derive physical parameters, characterize the entire system also refining the red-giant parameters, and to conclusively address the BH companion scenario postulated in recent literature. ------------------------------------------------------------------------------------ Observations Description ------------------------ We spend three orbits on a red giant star which shows periodic RV variations but an unseen companion. Two orbits will be mostly spent on STIS/MAMA NUV spectroscopy to reveal the nature of the unseen companion, and establish the nature of the NUV flux detected by GALEX (NUV=21.5 ABmag). 16654( 7) - 08-Nov-2021 21:12:24 - [ 2] In one of the two STIS orbits, two short exposures with G430L (2900-5700A) + G750L (5240-10265A) will provide a high-quality, simultaneous spectrum of the red giant, to better characterize its stellar parameters and make an overall fit of the system SED from NUV to near-IR. The observations will be executed according to the standard policy for standard star observations in order to achieve the best spectrophotometric precision and efficiency of observation. These procedures include, in addition to the choice of a photometric slit (52x0.5''), the suppression of the MAMA monthly offsets, the placement of the G750L fringe flat and wavecal in the occultation and the mixing of the very short CCD and long MAMA observations in the same orbit. In the third orbit the target will be imaged with WFC3 in filters F218W, F275W, F336W, F475W, F606W. The filter choice is tuned to optimize derivation of physical parameters and extinction for a range of possible companions, based on simulations with our model grids. We only need to image a small area around the target, therefore we use the UVIS2-M1K1C subarray option, signicantly reducing buffer dumps, so that all exposures can easily be accomodated in one orbit. Exposures will be dithered, for mitigation of hot pixels and cosmetic defects in the array. Exposures in the red filter will be split in very short exposures (using CTE mitigation strategy) so to not saturate the primary RG. EXPOSURE TIMES: The red giant is variable (Period about 83days), V=12.78 -- 12.88 (from the main paper of Thompson et al. 2019), or V=12.75 to 12.90 from the smooth l.c. in Thompson+2019 Fig1.; the raw photometry l.c. (from Thompson supplement) spans from V= 12.7 to almost 13, therefore I run ACQ and science-exposure simulations for V=13, then check that there is no saturation for V=12.7, for a conservative estimate. Note: In the proposal we had asked to cover the UV range using UVIS/NUV-MAMA prism, because from initial simulations we thought G230L would give insufficient S/N. However, we have now done more extensive ETC runs using the actual exposure times that can be accommodated in the orbits, and we find that G230L is much preferable, because the small loss in S/N wrt the prism can be compensated by some rebinning (in the spectral regions where this may be needed), which would yield comparable resolution to the prism spectrum, and - more important - there will be a critical gain in precision, since the G230L spectrum can be extracted (with routine scripts available to the proposers) with a few percent flux precision, while the prism may yield at best a 10% flux accuracy. In addition, since the origin of the NUV flux detected by GALEX is unknown (the objective of this proposal is to discover it), rebinning in some regions within the G230L range may not be necessary (depending on what source causes the GALEX NUV broad-band flux) and there we will gain both in flux accuracy and resolution by using G230L (avg dispersion 1.58Ang/pxl, R=500-1010 for G230L, vs 0.2-72Ang/px , R=10-2500 for prism). We simulated with ETC the S/N and spectrum obtained with either prism or G230L, assuming that the source of flux is the red giant primary, or an (unseen in the optical-IR) companion with Teff about 15000K, and scaling the flux to the GALEX broad-band NUV. In these ETC run plots the gain with G230L can be appreciated in both cases: For 2790sec exposure (orbit 2): if the GALEX NUV flux is from the red giant: https://etc.stsci.edu/etc/results/STIS.sp.1524275/ G230L https://etc.stsci.edu/etc/results/STIS.sp.1524366/ prism 16654( 7) - 08-Nov-2021 21:12:24 - [ 3] if it were from a companion with a B5V-like SED: https://etc.stsci.edu/etc/results/STIS.sp.1524276/ G230L https://etc.stsci.edu/etc/plot_page/STIS.sp.1524364/ prism Also, after we submitted the HST proposal, we have imaged with long exposures of the target with UVIT in two FUV bands. These data yielded an upper limit in FUV (about 23 mag in CaF2), which rules out the alternative possibility that the GALEX NUV detection comes from a hot white dwarf, and leaves open scenarios of a lower-Teff WD or accretion disk, making the extension shortwards of the G230L range not necessary. ------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2MASS-J05215 STAR, K III-I RA=05H21M56.5909S +/- 0.0482", J2000 V = 12.8 +/- 0.1 GALEX NUV=21.5 AB mag, 658+4359220 DEC=+43D59'21.96" +/- 0.0362" The bright optical companion (V=12.8) is a late-type giant, not emitting in UV Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Then I updated it with : http://simbad.u-strasbg.fr/simbad/sim-id?Ident=2MASS+J05215 658%2B4359220 ICRS coord. (ep=J2000) : 05 21 56.5909176121 +43 59 21.957588885 (Optical) [ 0.0482 0.0362 90 ] A Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 5] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 6] 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 2MASS-J0521 STIS/CCD ACQ F28X50LP MIRROR 1 1.5 S (1.5 5658+435922 S) 0 Comments: The red giant is variable with a P=83days, V=12.78 -- 12.88 from the main paper of Thompson et al. 2019: V=12.75 to 12.90 from the smooth l.c. in Fig1.; the raw photometry l.c.(from Thompson supplement) spans from V= 12.7 to almost 13, therefore I run ACQ simulations for V=13 and check that there is no saturation for V=12.7 . for V=13, K0III Castelli 4750 logg2.0 , EBV=0.44 applied before normalization; filter F28x50LP : https://etc.stsci.edu/etc/results/STIS.ta.152 3807/ V=13 Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0843 seconds gives: Time to Saturation (for a single exposure) = 4.10 seconds WARNING MESSAGE: Result of the calculation 0.0843291 is less than the minimum exposure time for this detector (0.1) V=12.7 https://etc.stsci.edu/etc/results/STIS.ta.152 3810/ Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0640 seconds gives: Time to Saturation (for a single exposure) = 3.11 seconds WARNING MESSAGE: Result of the calculation 0.06397 is less than the minimum exposure time for this detector (0.1) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAVE STIS/NUV ACCUM 31X0.05ND G230L 2376 1 DEF (0 S) -MAMA C ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 3 2MASS-J0521 STIS/NUV ACCUM 52X0.5 G230L 2376 WAVECAL=NO 1 727 S (727 5658+435922 -MAMA S) 0 Comments: For STIS/MAMA we used the GALEX NUV =21.5ABmag in the ETC for normalization For STIS/MAMA we used the GALEX NUV =21.5ABmag in the ETC for normalization If all the GALEX NUV flux were coming from the red giant: https://etc.stsci.edu/etc/results/STIS.sp.152 4271/ if the source of the UV GALEX flux were a B1V-like companion: https://etc.stsci.edu/etc/plot_page/STIS.sp.1 524268/ ( STIS.sp.1523567 was for MAMA/NUV prism, as in the proposal ) This exposure will be combined with the longer exposure in the second orbit ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 2MASS-J0521 STIS/CCD ACCUM 52X0.5 G430L 4300 CR-SPLIT=3 1 600 S (600 5658+435922 S) 0 Comments: For the red giant, we used in the ETC a model K0III Castelli 4750 logg2.0 , ebv=0.44, aperture: 52x0.5 V=13 S/N=200 https://etc.stsci.edu/etc/results/STIS.sp.152 4529/ Requested Signal/Noise Ratio = 200.000 at wavelength 4451.00 (per resolution element) gives: Time = 871.1998 seconds gives: Time to Saturation (for a single exposure) = 1, 384.13 seconds WARNING MESSAGE: "Electrons per pixel due to background (12) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in the STIS Instrument Handbook." V=12.7 S/N=200 https://etc.stsci.edu/etc/results/STIS.sp.152 4534/ Requested Signal/Noise Ratio = 200.000 at wavelength 4451.00 (per resolution element) gives: Time = 659.6185 seconds gives: Time to Saturation (for a single exposure) = 1, 050.27 seconds ------------------------------------------------------------------------------------------------------------------------------------ 5 WAVE STIS/CCD ACCUM 52X0.1 G430L 4300 1 DEF (0 S) ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 9] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 6 2MASS-J0521 STIS/CCD ACCUM 52X0.5 G750L 7751 CR-SPLIT=3 1 300. S 5658+435922 (300 S) 0 Comments: V=13. https://etc.stsci.edu/etc/results/STIS.sp.152 4556/ Requested Signal/Noise Ratio = 200.000 at wavelength 7000.00 (per resolution element) gives: Time = 145.2628 seconds gives: Time to Saturation (for a single exposure) = 503.31 seconds V=12.7 https://etc.stsci.edu/etc/results/STIS.sp.152 4555/ Requested Signal/Noise Ratio = 200.000 at wavelength 7000.00 (per resolution element) gives: Time = 110.1575 seconds gives: Time to Saturation (for a single exposure) = 381.84 seconds ------------------------------------------------------------------------------------------------------------------------------------ 7 WAVE STIS/CCD ACCUM 52X0.1 G750L 7751 1 DEF (0 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 NONE STIS/CCD ACCUM 0.3X0.09 G750L 7751 LAMP=TUNGSTEN, GAIN=4 2 120 S (240 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 WAVE STIS/NUV ACCUM 31X0.05ND G230L 2376 1 DEF (0 S) -MAMA C ------------------------------------------------------------------------------------------------------------------------------------ 10 2MASS-J0521 STIS/NUV TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=680, WAVECAL=NO 1 2790 S 5658+435922 -MAMA G (2790 S) 0 Comments: For STIS/MAMA we used the GALEX NUV =21.5ABmag in the ETC for normalization if all of the GALEX NUV flux is from the red giant: https://etc.stsci.edu/etc/results/STIS.sp.152 4275/ if it were from a companion with a B5V-like SED: https://etc.stsci.edu/etc/results/STIS.sp.152 4276/ ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 10] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 2MASS-J0521 WFC3/UVI ACCUM UVIS2-C1K F606W FLASH=12 1 0.5 S (1 PATTERN 1 11-15 5658+435922 S 1C-SUB S) 0 Comments: F606W : V=13 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524029/ Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0384 seconds gives: Time to Saturation (for a single exposure) = 1.75 seconds gives: Optimum SNR = 89.7245 V=12.7 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524030/ Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0291 seconds gives: Time to Saturation (for a single exposure) = 1.33 seconds gives: Optimum SNR = 89.7244 WARNING MESSAGE: Result of the calculation 0.0291425 is less than the minimum exposure time for this detector (0.5) WARNING MESSAGE: "Electrons per pixel due to background (0.0016) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in Section 6.9 of the WFC3 Instrument Handbook. Updates are provided on the WFC3 webpages." AUGUST 10 2021 : checking BCKG with exposure time=0.5sec: https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532208/ for V=12.7 Exposure time (seconds) = 0.5000 gives: SNR = 347.0119 gives: Time to Saturation (for a single exposure) = 1.33 seconds gives: Optimum SNR = 375.2628 WARNING MESSAGE: "Electrons per pixel due to background (0.028) is less than the recommended threshold of 20 electrons 16654( 7) - 08-Nov-2021 21:12:24 - [ 11] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 12 2MASS-J0521 WFC3/UVI ACCUM UVIS2-C1K F475W FLASH=12 1 0.7 S (1.4 5658+435922 S 1C-SUB S) 0 Comments: F606W : V=13 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524029/ Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0384 seconds gives: Time to Saturation (for a single exposure) = 1.75 seconds gives: Optimum SNR = 89.7245 V=12.7 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524030/ Requested Signal/Noise Ratio = 80.000 gives: Time = 0.0291 seconds gives: Time to Saturation (for a single exposure) = 1.33 seconds gives: Optimum SNR = 89.7244 WARNING MESSAGE: Result of the calculation 0.0291425 is less than the minimum exposure time for this detector (0.5) WARNING MESSAGE: "Electrons per pixel due to background (0.0016) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in Section 6.9 of the WFC3 Instrument Handbook. Updates are provided on the WFC3 webpages." AUGUST 10 2021: for exp.time =0.7, V=12.7 : https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532209/ Exposure time (seconds) = 0.7000 gives: SNR = 218.1151 gives: Time to Saturation (for a single exposure) = 4.44 seconds gives: Optimum SNR = 236.8344 WARNING MESSAGE: "Electrons per pixel due to background (0.02) is less than the recommended threshold of 20 electrons ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 12] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 2MASS-J0521 WFC3/UVI ACCUM UVIS2-C1K F336W CR-SPLIT=2, FLASH=12 1 10. S (20 5658+435922 S 1C-SUB S) 0 Comments: V=13 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524036/ Requested Signal/Noise Ratio = 80.000 gives: Time = 7.6590 seconds gives: Time to Saturation (for a single exposure) = 350.52 seconds gives: Optimum SNR = 91.1004 V=12.7 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524037/ BCKG countrate =0.397 c/s Total counts= 2.31 w/o flash (circle with radius 0.2 arcsec) Requested Signal/Noise Ratio = 80.000 gives: Time = 5.8094 seconds gives: Time to Saturation (for a single exposure) = 265.90 seconds gives: Optimum SNR = 91.0974 Exposure time calculation HAD WARNINGS. WARNING MESSAGE: "Electrons per pixel due to background (0.029) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies ... AUGUST 10 2021: V=12.7 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532210/ Exposure time (seconds) = 10.0000 gives: SNR = 107.0793 gives: Time to Saturation (for a single exposure) = 265.90 seconds gives: Optimum SNR = 120.0181 WARNING MESSAGE: "Electrons per pixel due to background (0.049) is less than the recommended threshold of 20 electrons ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 13] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 14 2MASS-J0521 WFC3/UVI ACCUM UVIS2-C1K F218W CR-SPLIT=3, FLASH=12 1 264. S 5658+435922 S 1C-SUB (528 S) 0 Comments: using GALEX NUV=21.5 ABmag : For 2790sec exposure (orbit 2): if the GALEX NUV flux is from the red giant: https://etc.stsci.edu/etc/results/STIS.sp.152 4275/ G230L https://etc.stsci.edu/etc/results/STIS.sp.152 4366/ prism if it were from a companion with a B5V-like SED: https://etc.stsci.edu/etc/results/STIS.sp.152 4276/ G230L https://etc.stsci.edu/etc/plot_page/STIS.sp.1 524364/ prism AUGUST 10 2021: V=12.7 for 300sec (I must set CRsplit=3) Exposure time (seconds) = 300.0000 gives: SNR = 18.1840 gives: Time to Saturation (for a single exposure) = 129, 773.03 seconds gives: Optimum SNR = 25.9562 WARNING MESSAGE: "Electrons per pixel due to background (0.87) is less than the recommended threshold of 20 electrons for exp. time 360sec https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532211/ Exposure time (seconds) = 360.0000 gives: SNR = 20.7758 gives: Time to Saturation (for a single exposure) = 129, 773.03 seconds (so I used CRsplit=3 of 360sec) gives: Optimum SNR = 28.8298 WARNING MESSAGE: "Electrons per pixel due to background (1) is less than the recommended threshold of 20 electrons to avoid AUG.10 2021: V=12.7 exp=264 https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532216/ I used CRSPIT=3 to be safe Exposure time (seconds) = 267.0000 gives: SNR = 16.6632 gives: Time to Saturation (for a single exposure) = 129, 773.03 seconds gives: Optimum SNR = 24.2429 WARNING MESSAGE: "Electrons per pixel due to background (0.78) is less than the recommended threshold of 20 electrons to... 16654( 7) - 08-Nov-2021 21:12:24 - [ 14] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 16654( 7) - 08-Nov-2021 21:12:24 - [ 15] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 2MASS-J0521 WFC3/UVI ACCUM UVIS2-C1K F275W FLASH=12, CR-SPLIT=2 1 230. S 5658+435922 S 1C-SUB (460 S) 0 Comments: using GALEX NUV=21.5 ABmag : for the red giant (input: Castelli-Kurucz Models K0III 4750 2.0) : https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524122/ Requested Signal/Noise Ratio = 80.000 - BCKG total counts=21.3 , countrate = 0.341 w/o postflash gives: Time = 61.9197 seconds gives: Time to Saturation (for a single exposure) = 2, 882.74 seconds gives: Optimum SNR = 91.5070 Exposure time calculation HAD WARNINGS. WARNING MESSAGE: "Electrons per pixel due to background (0.26) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in Section 6.9 of the WFC3 Instrument Handbook. Updates are provided on the WFC3 webpages." WARNING MESSAGE: This observation has a significant filter leak where 6.6 percent of the signal comes from outside the prescribed filter bandpass. If the NUV-emitting companion were a B5V (Teff=15kK) : https://etc.stsci.edu/etc/results/WFC3UVIS.im .1524124/ Requested Signal/Noise Ratio = 80.000 gives: Time = 375.9904 seconds gives: Time to Saturation (for a single exposure) = 18, 391.47 seconds gives: Optimum SNR = 92.8594 If the NUV-emitting companion were a B1V (Teff=30kK) - like spectrum Requested Signal/Noise Ratio = 80.000 gives: Time = 428.7019 seconds gives: Time to Saturation (for a single exposure) = 20, 982.11 seconds gives: Optimum SNR = 92.9710 AUG 10 2021: for the RG V=12.7 exp.=230sec https://etc.stsci.edu/etc/results/WFC3UVIS.im .1532213/ Exposure time (seconds) = 230.0000 gives: SNR = 87.1431 gives: Time to Saturation (for a single exposure) = 9, 095.19 seconds gives: Optimum SNR = 99.3563 WARNING MESSAGE: "Electrons per pixel due to background (0.97) is less than the recommended threshold of 20 electrons to... 16654( 7) - 08-Nov-2021 21:12:24 - [ 16] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASS-J05215658+435 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 9220 WAVE 2 STIS/NUV ACCUM 31X0.05N G230L 2376 none none none none 1 N/A -MAMA DC 2MASS-J05215658+435 3 STIS/NUV ACCUM 52X0.5 G230L 2376 none none none none 1 N/A 9220 -MAMA 2MASS-J05215658+435 4 STIS/CCD ACCUM 52X0.5 G430L 4300 none none none 1 1 N/A 9220 2MASS-J05215658+435 4 STIS/CCD ACCUM 52X0.5 G430L 4300 none none none 2 1 N/A 9220 2MASS-J05215658+435 4 STIS/CCD ACCUM 52X0.5 G430L 4300 none none none 3 1 N/A 9220 WAVE 5 STIS/CCD ACCUM 52X0.1 G430L 4300 none none none none 1 N/A 2MASS-J05215658+435 6 STIS/CCD ACCUM 52X0.5 G750L 7751 none none none 1 1 N/A 9220 2MASS-J05215658+435 6 STIS/CCD ACCUM 52X0.5 G750L 7751 none none none 2 1 N/A 9220 2MASS-J05215658+435 6 STIS/CCD ACCUM 52X0.5 G750L 7751 none none none 3 1 N/A 9220 WAVE 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none none none 1 N/A NONE 8 STIS/CCD ACCUM 0.3X0.09 G750L 7751 none none 1 none 1 N/A NONE 8 STIS/CCD ACCUM 0.3X0.09 G750L 7751 none none 2 none 1 N/A WAVE 9 STIS/NUV ACCUM 31X0.05N G230L 2376 none none none none 1 N/A -MAMA DC 2MASS-J05215658+435 10 STIS/NUV TIME-TA 52X0.5 G230L 2376 none none none none 2 N/A 9220 -MAMA G 2MASS-J05215658+435 11 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none none none 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 11 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none none none 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 12 WFC3/UVI ACCUM UVIS2-C1 F475W 1 none none none 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 12 WFC3/UVI ACCUM UVIS2-C1 F475W 2 none none none 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 13 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none 1 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 13 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none 2 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 13 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none 1 3 N/A 9220 S K1C-SUB 16654( 7) - 08-Nov-2021 21:12:24 - [ 17] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASS-J05215658+435 13 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none 2 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 1 none none 1 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 1 none none 2 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 1 none none 3 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 2 none none 1 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 2 none none 2 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 14 WFC3/UVI ACCUM UVIS2-C1 F218W 2 none none 3 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 15 WFC3/UVI ACCUM UVIS2-C1 F275W 1 none none 1 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 15 WFC3/UVI ACCUM UVIS2-C1 F275W 1 none none 2 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 15 WFC3/UVI ACCUM UVIS2-C1 F275W 2 none none 1 3 N/A 9220 S K1C-SUB 2MASS-J05215658+435 15 WFC3/UVI ACCUM UVIS2-C1 F275W 2 none none 2 3 N/A 9220 S K1C-SUB 16654( 7) - 08-Nov-2021 21:12:24 - [ 18] Summary Form for Proposal 16654 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 0.3X0.09, 31X0.05NDC, 52X0.1, 52X0.5, F28X50LP, UVIS2-C1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/NUV-MAMA, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=680, CR-SPLIT=2, CR-SPLIT=3, FLASH=12, GAIN=4, LAMP=TUNGSTEN, WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 11-15 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F218W, F275W, F336W, F475W, F606W, G230L, G430L, G750L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2MASS-J05215658+4359220, NONE, WAVE ------------------------------------------------------------------------------------------------------------------------------------