0 Assigned ID: 1413 ----- Attempting Submission 1 (Fri Mar 26 14:35:31 GMT 2021) ----- HST Phase I Proposal 1413 successfully submitted. Receipt: # 1413-1 It would be good to have a sanity check of the coords/proper motions and acquistion -- the coords/proper motions were imported from simbad, but since it then reports it for a non-standard epoch, it is tough to double check the #s -- the proper motions seem fine. The ACQ image is very short even with a neutral density filter. We have checked the timing of the in eclipse observations a whole bunch of times...... -1319401934 ----- Attempting Submission 1 (Wed Jul 21 21:44:48 GMT 2021) ----- Testing the Existence of a 3 Solar Mass Dark Companion to V723 Mon The bright, nearby star V723 Mon has a 3 Solar mass dark companion, most easily explained as a mass gap black hole. There is no optical spectral evidence for a stellar companion, nor are there continuum eclipses, but there is evidence of a non-stellar, blue "veiling'' light and eclipses of the Balmer lines. Extraordinary claims require extraordinary evidence, and so it is important to better characterize the excess UV emission. Because all but one (UVM2) of the Swift UV filters have red leaks, the shape of the UV spectral energy distribution (SED) cannot be measured with Swift in the presence of V723 Mon. A rising UV SED would strongly suggest the presence of a hot stellar companion. More generally, the UV emission is not dominated by the red giant and so is the best place to search for spectral features from any stellar companion. If it is not stellar emission, the UV is also an important probe of the origin of the claimed "veiling'' light source. These questions are easily addressed with two one orbit STIS/CCD/G230LB spectra, one in eclipse and one out of eclipse. The goal is a UV spectrum when the companion is in eclipse, and one when it is not. The in eclipse observation is pretty tightly constrained. The eclipse is estimated to last 5 days, and the observations are constrained to be in the three days centered on opposition. The out of eclipse observation is pretty lightly constrained to be any time from quadrature to quadrature. Since there is no need to do the observations in the same orbit, this means that the out of eclipse observations are not highly constrained even though the in eclipse observations are.The visit planner still reports that both observations can be scheduled, although the in eclipse observations have only two full windows and then one fractional window. The target star is a very bright red giant (V~8.3), so the acquisition image is very short (2 sec). Even with the 10^(-3) neutral density filter, the expected signal-to-noise ratio of the image is very high. We have supplied the ETC run code, and it would probably be good to have a sanity check. With the 0.2 arcsec slit, the plan is to use only a acquisition image and not the additional slit image mode. The target position and proper motion was imported from SIMBAD -- this is the first time I have dealt with a source with a proper motion -- it all looks OK to me. The spectra are taken in 6 equal time observations at 3 along slit dithers each with 2 CR-split images. We have Swift UV observations (unfortunately only in one filter since the others have red leaks) and so we know the UV flux. Based on this flux, and the U band flux of the giant, we should not have any problems with saturation in the spectra. The 0.5 arcsec dither spacing exceeds the width of the spectral extraction width (although it is surprising that the manuals only give a "make it bigger than this" rather than "we recommend a dither of X for point sources"). This is a proposal by the team that discovered that V723 Mon has a dark companion. Team members have extensive experience observing with HST. The most recent similar observations were STIS/MAMA UV spectra of a series of tidal disruption events (GO-15312, 14781), with the most recent results published in Neustadt et al. (2020, MNRAS, 494, 2538). The PI is also involved in the HST/COS UV spectroscopic reverberation mapping programs led by B. Peterson (GO-13330, 16196). Stellar Physics and Stellar Types 6 false false false false false false false SUPPORTED STAR G III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 B 9.2 Vega, Swift UVM2 14.1 AB STIS/CCD Spectroscopic No No G230LB 2375 STIS/CCD Spectroscopic No No G230LB 2375 POS-TARG DITHER 0.50 LINE false false 3 90.0 STIS-ALONG-SLIT 1 false The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. Observation of V723 Mon with the companion out of eclipse - observe any time between quadratures 1639140935000 325.0 (Tic-Visit :proposal-id 16708 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "19-Jul-2021 15:04:07.0" :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 129232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16708 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16708 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2749 :al-overhead-at-end 0 :internal-dur-at-end 439 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. observation of V723 Mon when the companion is in eclipse -- observations are 3 day windows centered on the estimated 5 day eclipse period 1642251480000 35.43687030579861 (Tic-Visit :proposal-id 16708 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "19-Jul-2021 15:04:08.0" :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 129232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16708 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16708 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2749 :al-overhead-at-end 0 :internal-dur-at-end 439 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 1 0 observation of V723 Mon when the companion is in eclipse -- observations are 3 day windows centered on the estimated 5 day eclipse period (Tic-Visit :proposal-id 16708 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "19-Jul-2021 15:04:08.0" :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 129232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16708 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16708 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2749 :al-overhead-at-end 0 :internal-dur-at-end 439 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) false 1 0