0 Assigned ID: 2579 ----- Attempting Submission 1 (Wed Sep 29 21:56:54 GMT 2021) ----- HST Phase I Proposal 2579 successfully submitted. Receipt: # 2579-1 COS ETC runs have been updated for each exposure. The ETCs use the brightest AE Aqr spectrum taken by FOS and scaled to the distance of J0240 (36 times further away). Each ETC run matches the exposure time for the subexposures and uses the 1105 wavelength. -1566478383 ----- Attempting Submission 1 (Sun Dec 12 20:58:35 GMT 2021) ----- HST Phase II Proposal 16881 successfully submitted. Receipt: # 16881-1 ----- Attempting Submission 2 (Tue Dec 21 21:17:35 GMT 2021) ----- Recently, LAMOST-J0240 was identified as a likely second propeller in a cataclysmic variable (CV) system with optical properties that are very similar to the original propeller: AE Aqr. Only after the Cycle 29 proposal deadline was the white dwarf (WD) rotation in LAMOST-J0240 detected with a period of just 25s, making it the fastest spinning WD in a CV binary. We propose ultraviolet spectroscopy of this newly confirmed propeller to tests two theories of magnetic CV evolution. First, we will use the CIV and NV emission line ratio, observable only in the FUV, to test the thermal time-scale mass transfer model as the way to spin-up WDs. Peculiar CNO abundance ratios are a signature of unstable mass transfer that can reach down to the companion star's core. Inverted NV/CIV ratios are seen in CV systems with WD spin periods between 30s and 40s. Second, we will test the crystallization theory for generating magnetic fields in WDs by precisely measuring the WD surface temperature. In an analogy with convective planetary magnetic field generation, only fast-spinning WDs that have cooled to the point of core crystallization form significant fields. Being a propeller, LAMOST-J0240 clearly has a fast rotating, magnetic WD, and the model predicts that its surface temperature should be half of the ground-based limit of 25000K. Further, the data will establish a baseline for estimating the spin-down age of the WD to constrain the time since the unstable mass transfer event. LAMOST-J0240 is an intermediate polar (IP) that has a rapidly spinning, magnetic white dwarf (WD). Gas donated from the secondary gets accelerated by the rotating magnetosphere and is ejected from the system. The scenario is thought to be similar to AE Aquarii, except in J0240 we view the system nearly edge-on, so that eclipses and the ejected gas is visible in optical spectra. Here, we plan to observed J0240 in the FUV with COS using the G140L grating and Time-tag mode. We plan to cover an entire binary orbit of 7.3 hours. This period is nearly identical to 5 Hubble orbits, so observing over 5 consecutive orbits is ideal. If this is not schedulable, we can divide the observations up into two visits (3+2) with a constraint to allow the second visit to complete the binary orbital phase coverage. COS ETC calculations are based on the brightest FOS spectrum of AE Aqr scaled to the distance of J0240 (36 times fainter). The team assembled for this project consists of experts in the fields of cataclysmic variable stars and observational astrophysics. All members of the team have contributed to publications that have advanced our understanding of the LAMOST-J0240 propeller system. Szkody, Thorstensen, Wagner, Littlefield and Garanvich are experts on the observational aspects of cataclysmic variable stars and magnetic accretion on to white dwarf stars. They all have extensive experience with analysis and interpretation of ground and space based telescope observations and several members of the team have obtained and analyzed HST/COS spectra from previous HST proposals and the archive. Stellar Physics and Stellar Types 3 false false true false false false true false SUPPORTED STAR EJECTA EMISSION LINE STAR INTERMEDIATE POLAR NO Variable in the optical with an amplitude of 1 magnitude J2000 J2000 Between 1e-16 and 12e-16 erg/cm2/s/Ang at 2200 Ang from Swift COS/FUV Spectroscopic No No G140L 1105 1640119781479 /private/var/folders/j1/730l_tzs09jdnw98498x_l080000gr/T/OPVisit4636304221287371209.xml The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16881 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "21-Dec-2021 15:49:41.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 182880 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16881 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16881 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2763 :al-overhead-at-end 0 :internal-dur-at-end 57 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16881 :visit-id "01" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 67 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16881 :visit-id "01" :orbit-number 3 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 67 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16881 :visit-id "01" :orbit-number 4 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 48 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16881 :visit-id "01" :orbit-number 5 :pcs-time 392 :si-vis-utilization 2764 :al-overhead-at-end 0 :internal-dur-at-end 363 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3156 :pcs-gap 0 ) true 5 0 Swift UVOT provide a flux of 1e-16 erg/cm2/s/A at 2200 Ang. The imaging acquire ETC shows a S/N=20 in a 20s exposure of NUV, Mirror A, and the PSA. To be safe, we have increased the exposure to 30s.