0 Assigned ID: 1213 ----- Attempting Submission 1 (Thu Feb 28 14:04:23 GMT 2013) ----- The specification of the slit for CCD-FLAT was corrected to read 0.3X0.09, as per IHB Table 11.1 -944605591 ----- Attempting Submission 1 (Tue Jun 25 17:39:03 GMT 2013) ----- HST Phase II Proposal 13373 (phase2_final.apt) successfully submitted. ----- Attempting Submission 2 (Tue Jun 25 19:50:22 GMT 2013) ----- HST Phase II Proposal 13373 (phase2_final.apt) successfully submitted. ----- Attempting Submission 3 (Sun Oct 20 14:46:01 GMT 2013) ----- HD 5980 is an extraordinary system of massive stars that is located in the Small Magellanic Cloud. It contains an eclipsing binary (P=19.3 d) consisting of a luminous blue variable (LBV) and its Wolf-Rayet (WR) companion. The LBV underwent a major eruptive event in 1994 during which its bolometric luminosity increased by a factor of ~5 and it is currently approaching its minimum state of activity. The primary objective of this proposal is to determine the wind velocity and mass-loss rate of the LBV in its current state. With these observations and our earlier observations and analyses, HD 5980 offers the unprecedented opportunity of deriving all the fundamental parameters of an LBV system throughout its activity cycle, parameters which are required in order to constrain the sources of the instabilities that lead to the eruptive phenomena. To accomplish these goals, we request 2 HST orbits to observe HD 5980 with STIS in order to obtain one set of FUV MAMA and CCD spectra at the eclipse, when the LBV occults its WR companion. The study of HD 5980 and the UV spectrum that we propose to acquire are relevant to a broad range of problems including wind-wind collision phenomena, the formation of circumstellar structures powered by stellar winds and the evolution of supernova progenitors. We plan to observe HD 5980 in the 1170--1730 A spectral interval with STIS using the FUV- MAMA detector, the E140M grating and the 0.2x0.2 slit. To calculate the exposure time we used the STIS spectrum obtained on 2009 Sept 9. The Exposure Time Calculator (516777) indicates that with a 4678s exposure time we will attain S/N= 47 per resolution element at 1500 A, allowing a very good measurement of the edge and saturated portions of the P Cygni profiles. We will obtain the first part of this observation with a 2608s exposure in the first orbit and then a 2070s exposure in the second orbit. We will also obtain exposures using the CCD detector and the G230LB, G430L and G750L gratings and 52x0.2 aperture. These will provide a full spectral energy distribution for the CMFGEN model fits. Using the CCD spectra obtained by STIS in the year 2000, we find that S/N>100 is attained with exposure times of 300s, 60s and 60 , respectively. The total exposure time+overheads for the CCD spectra is less than 25 min. The first orbit will contain the target acquisition and the first FUV-MAMA exposure. The second orbit will contain the second FUV-MAMA exposure and the CCD spectra. The mixture of MAMA and CCD observations in the same orbit is justified by the short exposure time required for the CCD spectra (HST Primer sec. 6.2.2). A CCD-FLAT will be acquired during occultation after the G750L exposure in order to correct for the fringing in this spectral region. The visit is to be carried out when the binary system is at orbital phase 0.00+/-0.01. This is the eclipse of Star B (=WR) by Star A (=LBV). The orbital period and initial epoch are P=19.2654 d (Breysacher & Sterken 1997) and T0=HJD 2443158.873 (Koenigsberger et al. 2013). Within the time slots given by the Visit Planner, windows of opportunity in 2013 for phase=0.00 for this visit are on: HJD 2456509.795, 2456567.592, 2456586.856 and 2456625.388. HOT STARS 3 false false 0.0 0.0 false false false SUPPORTED STAR INTERACTING BINARY LUMINOUS BLUE VARIABLE WOLF RAYET - WN This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 1.0e-11erg/cm^2-s-A @ NV 1240; 1.7e-11 erg/cm^2-s-A @ HeII 1640 STIS/FUV-MAMA Spectroscopic No No E140M 1425 STIS/CCD Spectroscopic No No G230LB 2375 STIS/CCD Spectroscopic No No G430L 4300 STIS/CCD Spectroscopic No No G750L 7751 1382279908125 /private/var/folders/mr/fh1dvk_x3jdfxj7fx_k0rk580000gv/T/OPVisit7401358654277678268.xml The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13373 :visit-id "01" :proposal-version -1 :trans-version "20130919" :date "20-Oct-2013 09:38:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 376864 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13373 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13373 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3302 :al-overhead-at-end 194 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3635 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13373 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3413 :al-overhead-at-end 0 :internal-dur-at-end 707 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3635 :pcs-gap 0 ) true 2 0