0 Assigned ID: 430 ----- Attempting Submission 1 (Fri Apr 08 09:39:51 GMT 2016) ----- HST Phase I Proposal 430 (one.apt) successfully submitted. Receipt: # 430-1 ----- Attempting Submission 2 (Fri Apr 08 16:49:54 GMT 2016) ----- Hi Amber, I updated the target acquisition to use MIRRORB, as discussed with Paule. Boris 2039239267 ----- Attempting Submission 1 (Mon Jun 27 15:54:22 GMT 2016) ----- Your proposal could not be saved. Submission aborted. ----- Attempting Submission 2 (Fri Sep 30 10:24:08 GMT 2016) ----- ----- Attempting Submission 3 (Thu Dec 22 22:09:38 GMT 2016) ----- SDSS 1240+6710: a partially burnt supernova remnant We have recently (Kepler et al. 2016, Science 352, 6281, April 1 issue) identified SDSSJ124043.01+671034.68 as a white dwarf with most peculiar characterstics. Instead of the usual hydrogen or helium, its atmosphere is composed almost purely of oxygen, the only other trace elements detected are neon, magnesium, and silicon; and it has a large transverse velocity of ~340km/s. The relatively low mass, 0.6Msun, and the non-detection of carbon strongly argue against SDSSJ1240+6710 being a canonical oxygen-neon core formed from the evolution of a single progenitor star with a mass of ~6.5-10Msun. The detection of silicon suggests that the progenitor of this white dwarf may have initiated oxygen-burning, and we argue that SDSSJ1240+6710 is the partially burnt remnant of an unusual thermonuclear supernova, of which a variety have been discovered by the ongoing large transient surveys. We propose to obtain COS ultraviolet spectroscopy of SDSSJ1240+6710 to measure (1) the abundances of phosphorus and sulfur, two other products of oxygen-burning, (2) significantly improve the upper limits on hydrogen (from Ly alpha) and carbon (1330/1335A resonance lines), (3) probe for traces of other nuclear burning, including nitrogen, iron, and nickel, and (4) accurately measure its effective temperature and mass. SDSSJ1240+6710 provides so far the unique opportunity to test the predictions of the rapidly growing number of theoretical stellar explosion models producing gravitationally bound remnants. The purpose of this program is to obtain a S/N~20 spectrum of the white dwarf SDSS1240+6710 to improve on the photospheric abundances of O, Si, and Mg, and to search for absorption lines of S, P, and C. The target is located in the continiuous viewing zone (requested in Phase I), which allows to efficiently pack the required exposure time into four orbits. The star has GALEX FUV and NUV fluxes, and we carried out the ETC simulations with a model spectrum computed based on the abundances measured from optical spectroscopy. The star will be acquired with NUV imaging, after which G140L spectroscopy will be obtained using all four FP-POS settings. Stellar Physics 12 false true false false false false SUPPORTED STAR DZ NO 2016/09/29: updated the proper motions from Gould et al. 2004ApJS..152..103G J2000 J2000 GALEX FUV=17.92 GALEX NUV=17.5 COS/FUV Spectroscopic No No G140L 1105 The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. /tmp/OPVisit6692496048387990657.xml 2016-12-22: Updated target acquisition to use MIRRORB to avoid BOP violation. (Tic-Visit :proposal-id 14600 :visit-id "02" :proposal-version -1 :trans-version "20160601" :date "22-Dec-2016 22:07:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 1617856 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14600 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :cvz T :proposal-id 14600 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 22216 :al-overhead-at-end 0 :internal-dur-at-end 331 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 0 :low-sky "N" :pcs-visibility 0 :pcs-gap 0 ) true 4 0 Updated to use MIRRORB