17451( 4) - 08-Aug-2024 16:34:47 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17451 Version: 4 Check-in Time: 08-Aug-2024 16:34:47 STScI Edit Number: 1 Title UV Spectroscopy of the D-type Symbiotic, R Aquarii: Revealing the Energetics of the Inner Nebula ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Ravi Sankrit Space Telescope Science Institute Y CoI: Dr. Thomas B. Ake Space Telescope Science Institute N CoI: Dr. Manuel Bautista NASA Headquarters N CoI: Dr. Steven Goldman Space Telescope Science Institute N CoI: Dr. Uma Gorti SETI Institute N CoI: Prof. Shazrene S. Mohamed The University of Virginia N CoI: Mr. Eric Omelian Space Science Institute Y ------------------------------------------------------------------------------------ Abstract The much anticipated eclipse of R Aquarii (R Aqr) in its 44 year binary orbit is underway. The hot White Dwarf (WD) and accretion disk have moved in front of the cool, dusty mass losing AGB companion giving us a direct view of the accretion flow. The system has just passed periastron, and is in a high state of binary activity, with material being injected near the base of the bipolar jet into a fast collimated flow. Fast shocks with speeds of up to, perhaps, 250 km/s are being driven into the surrounding photoionized nebula and into the pre-existing jet material. These shocks will raise the ionization levels of the gas and produce bright high-ionization emission lines in the ultraviolet (UV). We propose to use COS to obtain UV spectra (spanning 1135-3200 Ang.) of the region immediately surrounding the binary, and use the emission lines to identify and measure the various processes energizing the inner nebula during this extremely active phase. We will study the evolution of the UV emission and their causes by comparing our data with IUE spectra obtained over half an orbital period ago. During this critical phase in its binary orbit, R Aqr is being intensively monitored from the ground, and has been observed at all wavelengths from the radio to the X-ray except that no UV spectra have been obtained. This eclipse will end in a few years time, and there is an urgent imperative that COS spectra be obtained to unravel key physical processes underlying the accretion and jet formation in this nearby object. The insights gained will have wide applicability, in many astronomical systems where accretion and jets are present. ------------------------------------------------------------------------------------ Observations Description ------------------------ The program consists of one 3-orbit visit with a single pointing centered on the R Aqr symbiotic binary. The source spectrum consists of a relatively weak continuum and a number of emission lines of varying strength as detected in several IUE observations, e.g. Kafatos et al. 1986 ApJ Supp. 62, 853; Meier and Kafatos 1995 ApJ 451, 359 (MK95). It is expected that the continuum is dominated by the central source comprising the AGB, WD and accretion disk, while the emission lines arise in an extended, yet compact, nebula surrounding 17451( 4) - 08-Aug-2024 16:34:47 - [ 2] the binary. Our proposed visit starts with an NUV ACQ/IM exposure. The co-ordinates are well known, and since the NUV bandpass will be dominated by the continuum we expect the target to be well centered. Following the acquisition are a series of spectroscopic exposures listed below. NUV: G185M/1913, G225M/2325, G230L/2635, G230L/2950 FUV: G130M/1291, G160M/1611 Each NUV mode will be observed at the two extreme FP-POS (1, 4) for wavelength coverage. The G160M/1611 exposures should be obtained at LP4 in order to maximize S/N without the large overheads for split wavecals. (This was requested in our Phase I proposal.) The ETC calculations used for both Phase I and Phase II use IUE fluxes reported in MK95. For Phase I, we mainly used fluxes of the weaker lines in order to estimate the required exposure times. Here, we instead use the highest observed fluxes. In Phase II calculations we have used a continuum surface brightness of 5E-14 cgs, which is five times the value used in Phase I. This is primarily to show that the count-rates are well below the bright object limits, and secondarily to estimate suitable BUFFER TIME values. In most cases the BUFFER TIMES have been chosen for maximizing efficiency. ------------------------------------------------------------------------------------ 17451( 4) - 08-Aug-2024 16:34:47 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V-R-AQR STAR, SYMBIOTIC STAR RA=23H43M49.4634S +/- 0.01", J2000 V = 8.8 DEC=-15D17'4.18" +/- 0.01" Reference Frame: ICRS Extended: YES Comments: Co-ordinates and propermotions obtained from SIMBAD, which uses Gaia DR3. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0018576403129046334 -0.030411 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17451( 4) - 08-Aug-2024 16:34:47 - [ 4] Visit: 01 (RAqr) 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 V-R-AQR COS/NUV ACQ/IMA BOA MIRRORA 1 52 S (52 GE S) Comments: Used December 1991 IUE spectrum to estimate exposure time. Increased the exposure time from the calculation result by a factor of 4 in order to get a higher S/N image of the field, and also to guard against the flux having decreased. ------------------------------------------------------------------------------------------------------------------------------------ 2 V-R-AQR COS/NUV TIME-TA PSA G185M 1913 BUFFER-TIME=340, FP-POS=1 1 450 S G see below (382 S) Comments: The C III] line is described as saturated in MK95; we use twice their reported flux in our calculation and show it is still safe. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-R-AQR COS/NUV TIME-TA PSA G185M 1913 BUFFER-TIME=340, FP-POS=4 1 450 S G see below (382 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 V-R-AQR COS/NUV TIME-TA PSA G225M 2325 BUFFER-TIME=377, FP-POS=1 1 477 S G see below (409 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 V-R-AQR COS/NUV TIME-TA PSA G225M 2325 BUFFER-TIME=377, FP-POS=4 1 477 S G see below (409 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 V-R-AQR COS/NUV TIME-TA PSA G230L 2635 BUFFER-TIME=170, FP-POS=1 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 V-R-AQR COS/NUV TIME-TA PSA G230L 2635 BUFFER-TIME=170, FP-POS=4 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 V-R-AQR COS/NUV TIME-TA PSA G230L 2950 BUFFER-TIME=170, FP-POS=1 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 17451( 4) - 08-Aug-2024 16:34:47 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 9 V-R-AQR COS/NUV TIME-TA PSA G230L 2950 BUFFER-TIME=170, FP-POS=4 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=228, 1 228 S G LIFETIME-POS=LP5 see below (156 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=172, 1 172 S G LIFETIME-POS=LP5 see below (119 S) ------------------------------------------------------------------------------------------------------------------------------------ 12 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=145, 1 400 S G LIFETIME-POS=LP5 see below (347 S) ------------------------------------------------------------------------------------------------------------------------------------ 13 V-R-AQR COS/FUV TIME-TA PSA G160M 1611 FP-POS=ALL, BUFFER-TIME=186, 1 296 S G LIFETIME-POS=LP4 see below (972 S) Comments: The ETC run includes the total CIV 1548, 1552 doublet flux as a single line, and both OIII] 1663 and NIII] 1750. Calculation COS.sp.1888995 includes the CIV lines separately and the OIII]. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-R-AQR 1 COS/NUV ACQ/IMA BOA MIRRORA none none none none 1 N/A GE V-R-AQR 2 COS/NUV TIME-TA PSA G185M 1913 none none none none 1 382.0 S G V-R-AQR 3 COS/NUV TIME-TA PSA G185M 1913 none none none none 1 382.0 S G V-R-AQR 4 COS/NUV TIME-TA PSA G225M 2325 none none none none 1 409.0 S G V-R-AQR 5 COS/NUV TIME-TA PSA G225M 2325 none none none none 1 409.0 S G V-R-AQR 6 COS/NUV TIME-TA PSA G230L 2635 none none none none 2 378.0 S G V-R-AQR 7 COS/NUV TIME-TA PSA G230L 2635 none none none none 2 378.0 S G V-R-AQR 8 COS/NUV TIME-TA PSA G230L 2950 none none none none 2 378.0 S G 17451( 4) - 08-Aug-2024 16:34:47 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-R-AQR 9 COS/NUV TIME-TA PSA G230L 2950 none none none none 2 378.0 S G V-R-AQR 10 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 156.0 S G V-R-AQR 11 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 119.0 S G V-R-AQR 12 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 347.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 1 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 2 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 3 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 4 3 243.0 S G 17451( 4) - 08-Aug-2024 16:34:47 - [ 7] Visit: 51 (RAqr) Visit Requirements: On Hold Comments: Additional Comments: Repeat of failed visit 01. 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 V-R-AQR COS/NUV ACQ/IMA BOA MIRRORA 1 52 S (52 GE S) Comments: Used December 1991 IUE spectrum to estimate exposure time. Increased the exposure time from the calculation result by a factor of 4 in order to get a higher S/N image of the field, and also to guard against the flux having decreased. ------------------------------------------------------------------------------------------------------------------------------------ 2 V-R-AQR COS/NUV TIME-TA PSA G185M 1913 BUFFER-TIME=340, FP-POS=1 1 450 S G see below (382 S) Comments: The C III] line is described as saturated in MK95; we use twice their reported flux in our calculation and show it is still safe. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-R-AQR COS/NUV TIME-TA PSA G185M 1913 BUFFER-TIME=340, FP-POS=4 1 450 S G see below (382 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 V-R-AQR COS/NUV TIME-TA PSA G225M 2325 BUFFER-TIME=377, FP-POS=1 1 477 S G see below (409 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 V-R-AQR COS/NUV TIME-TA PSA G225M 2325 BUFFER-TIME=377, FP-POS=4 1 477 S G see below (409 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 V-R-AQR COS/NUV TIME-TA PSA G230L 2635 BUFFER-TIME=170, FP-POS=1 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 V-R-AQR COS/NUV TIME-TA PSA G230L 2635 BUFFER-TIME=170, FP-POS=4 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 V-R-AQR COS/NUV TIME-TA PSA G230L 2950 BUFFER-TIME=170, FP-POS=1 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 17451( 4) - 08-Aug-2024 16:34:47 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 9 V-R-AQR COS/NUV TIME-TA PSA G230L 2950 BUFFER-TIME=170, FP-POS=4 1 450 S G see below (378 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=228, 1 228 S G LIFETIME-POS=LP5 see below (156 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=172, 1 172 S G LIFETIME-POS=LP5 see below (119 S) ------------------------------------------------------------------------------------------------------------------------------------ 12 V-R-AQR COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, BUFFER-TIME=145, 1 400 S G LIFETIME-POS=LP5 see below (347 S) ------------------------------------------------------------------------------------------------------------------------------------ 13 V-R-AQR COS/FUV TIME-TA PSA G160M 1611 FP-POS=ALL, BUFFER-TIME=186, 1 296 S G LIFETIME-POS=LP4 see below (972 S) Comments: The ETC run includes the total CIV 1548, 1552 doublet flux as a single line, and both OIII] 1663 and NIII] 1750. Calculation COS.sp.1888995 includes the CIV lines separately and the OIII]. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-R-AQR 1 COS/NUV ACQ/IMA BOA MIRRORA none none none none 1 N/A GE V-R-AQR 2 COS/NUV TIME-TA PSA G185M 1913 none none none none 1 382.0 S G V-R-AQR 3 COS/NUV TIME-TA PSA G185M 1913 none none none none 1 382.0 S G V-R-AQR 4 COS/NUV TIME-TA PSA G225M 2325 none none none none 1 409.0 S G V-R-AQR 5 COS/NUV TIME-TA PSA G225M 2325 none none none none 1 409.0 S G V-R-AQR 6 COS/NUV TIME-TA PSA G230L 2635 none none none none 2 378.0 S G V-R-AQR 7 COS/NUV TIME-TA PSA G230L 2635 none none none none 2 378.0 S G V-R-AQR 8 COS/NUV TIME-TA PSA G230L 2950 none none none none 2 378.0 S G 17451( 4) - 08-Aug-2024 16:34:47 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-R-AQR 9 COS/NUV TIME-TA PSA G230L 2950 none none none none 2 378.0 S G V-R-AQR 10 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 156.0 S G V-R-AQR 11 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 119.0 S G V-R-AQR 12 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 347.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 1 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 2 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 3 3 243.0 S G V-R-AQR 13 COS/FUV TIME-TA PSA G160M 1611 none none none 4 3 243.0 S G 17451( 4) - 08-Aug-2024 16:34:47 - [ 10] Summary Form for Proposal 17451 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures BOA, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=145, BUFFER-TIME=170, BUFFER-TIME=172, BUFFER-TIME=186, BUFFER-TIME=228, BUFFER-TIME=340, BUFFER-TIME=377, FP-POS=1, FP-POS=3, FP-POS=4, FP-POS=ALL, LIFETIME-POS=LP4, LIFETIME-POS=LP5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G160M, G185M, G225M, G230L, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names V-R-AQR ------------------------------------------------------------------------------------------------------------------------------------