0 Assigned ID: 1034 ----- Attempting Submission 1 (Fri Apr 07 22:47:02 GMT 2017) ----- Hi Shelly, here is a first draft of the phase 2. aim is to use a mosaic of 5 parallel slits (width 0.1 arcsec), aligned E-W, with a grid spacing of 0.1 arcsec each, please have a look and let me know if its OK. thanks raghvendra 576636600 ----- Attempting Submission 1 (Thu Jul 13 22:40:39 GMT 2017) ----- The carbon star V Hya is experiencing heavy mass loss as it undergoes the transition from an AGB star to a planetary nebula (PN). This is possibly the earliest object known in this brief phase, which is so short that few nearby stars are likely to be caught in the act. Molecular observations reveal that a bipolar nebula has been established even at this early stage. Using STIS, we obtained high spatial-resolution long-slit optical spectra of V Hya spanning 3 epochs spaced apart by a year during each of two periods (2002-2004, 2011-2013). These data reveal high-velocity emission in [SII] lines from compact blobs located both on- and off-source, with the ejection axis executing a flip-flop, both in, and perpendicular to, the sky-plane. We have proposed a detailed model in which V Hya ejects high-speed (200-250 km/s) bullets once every 8.5 yr associated with periastron passage of a binary companion in an eccentric orbit with an 8.5 yr period. We suggest that the jet driver is an accretion disk (produced by gravitational capture of material from the primary) that is warped and precessing. Our model predicts the locations of previously ejected bullets in V Hya and future epochs at which new bullets will emerge. We now propose new STIS observations of these remarkable bullet ejections over two new epochs well separated from previous ones, to robustly test our model. The proposed observations will provide us with an unprecedented opportunity to look on as V Hya's circumstellar envelope is sculpted by these bullets. Our study will help solve the long-standing puzzle of how the spherical mass-loss envelopes of AGB stars evolve into bipolar and multipolar PNe. We will utilise an observing set-up that uses a mosaic of 5 parallel slits aligned E-W to probe the spatio-kinematic structure of the emission-line blobs in the [SII]$\lambda\lambda\,4069.7,4077.5$ doublet. STIS will be used with G430M (tilt setting of 4194) and the $52{''}\times$0\farcs1 slit to obtain spectra in the $\lambda\lambda$4051-4337{\AA} range. From our previous data, the [SII]$\lambda$4066{\AA} line has a peak intensity that is about4$\times10^{-13}$ erg s$^{-1}$ cm$^{-2}$ {\AA}$^{-1}$ arcsec$^{-2}$ and a FWHM of about 1\AA. We will use exposure times ($\sim$1100\,s per dither position), and CR-SPLIT=2, which gives us a S/N$\gsim$40--80 at the peak of the [SII]$\lambda$4066{\AA} line, and a S/N$\gsim$15 in the continuum (which is roughly a factor 4 weaker in the offset slit, where the high-velocity bullet emission is strongest). This high S/N ratio is necessary because it allows us to measure the spatial offset of the peak from the source continuum with sub-pixel accuracy, which is important since the proper motion is about 0\farcs07 per year (and may decrease with time). In addition, we want to continue to be able to detect important fainter lines ([FeII]$\lambda$4241 \& 4285{\AA}) which we have detected previously, and which provide additional probes of the physical conditions in the bullet. The G430M observations will require 4 orbits per epochs. The available windows for observing V Hya given our STIS slit ORIENT constraints (we require an ORIENT within $\pm$4\arcdeg~of those used in the previous epochs) occur twice each calendar year, i.e., (1) in June/Aug, and (2) in Dec. Stellar Physics 6 false false false false false 0.0 0.0 false SUPPORTED STAR CARBON STAR DISK EMISSION LINE NEBULA PULSATING VARIABLE WIND YES J2000 J2000 B=12.7 STIS/CCD Spectroscopic No No G430M 4194 STIS/CCD Spectroscopic No No G430M 4194 POS-TARG MOSAIC DITHER 3 0.1 pattern should produce a mosaic of 5 slits, spaced apart by 0.1 arcsec, with a 3-point dither along the slit for each slit position STIS-ALONG-SLIT false true 0.22851 5 0.0 POS-TARG STIS-PERP-TO-SLIT 90.0 1 true The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. /tmp/OPVisit3435188682617532822.xml 1499985604407 (Tic-Visit :proposal-id 15209 :visit-id "01" :proposal-version -1 :trans-version "20170613" :date "13-Jul-2017 15:40:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 645072 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15209 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15209 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2882 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3217 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15209 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2992 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3217 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15209 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2994 :al-overhead-at-end 72 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3217 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15209 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2989 :al-overhead-at-end 0 :internal-dur-at-end 399 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3217 :pcs-gap 0 ) true 4 0 15 exposures to produce a mosaic of 5 slits, spaced apart by 0.1 arcsec, with a 3-point dither along the slit for each slit position