0 Assigned ID: 5785 ----- Attempting Submission 1 (Tue Mar 26 22:55:46 GMT 2024) ----- I run an ETC calculation for the COS exposures incuding the brightest line emission that we can expect. 210542830 ----- Attempting Submission 1 (Wed Aug 14 07:31:36 GMT 2024) ----- HST Phase II Proposal 17720 successfully submitted. Receipt: # 17720-1 ----- Attempting Submission 2 (Sat Sep 28 12:38:14 GMT 2024) ----- ----- Attempting Submission 3 (Thu Oct 24 09:27:06 GMT 2024) ----- Confirming the first strongly asynchronous polar We have discovered a new exotic binary system containing an accreting highly magnetized white dwarf. The peculiar variability in the hydrogen emission lines and the high magnetic field of the white dwarf hint to a very exciting explanation for the current observations: we might have caught the system in a rare evolutionary stage, in which the highly magnetized white dwarf has only recently started accreting from the companion and therefore its rotation period is not yet synchronized with the orbital period of the binary. We here propose a joint HST-XMM program to confirm the nature of this system as a strongly asynchronous polar, to constrain the magnetic field strength and temperature of the white dwarf, and to measure the accretion rate of the system. If confirmed, this system promises to become a keystone for our understanding of the evolution of cataclysmic variables and of binary evolution in general. The purpose of this program is to study the SED and lightcurve of the white dwarf ZTF J2008+4449 in the UV. ZTF J12008+449 is a new exotic binary system containing an accreting highly magnetized white dwarf, which could be the first highly asynchronous polar observed. If confirmed, this system promises to become a keystone for our understanding of the evolution of cataclysmic variables. The proposed HST observations will allow us to constrain the magnetic field strength and temperature of the white dwarf, and possibly detect cyclotron emission humps. We ask for 5 orbits of COS spectroscopy and 4 orbits of STIS spectroscopy in the time-tag mode, so that we will obtain high signal-to-noise phase resolved spectra and UV lightcurves. For the COS observations, we ask for a different FP-POS in each orbit. There are no time constraints on the observations, and the visits can be scheduled separately. Dr. Ilaria Caiazzo is an Assistant Professor at the Institute of Science and Technology Austria. She is an expert on high-energy astrophysics and the physics of white dwarfs, as well as in the analysis of white dwarf spectroscopy and photometry. Dr. Tim Cunningham is a Hubble Fellow at Harvard. He is an expert in X-ray observations of white dwarfs. Dr Boris Gaensicke is a Professor at the University of Warwick. He is a world expert in white dwarf studies and has led several HST proposals. Dr. Paula SZkody is a Professor at the University of Washington. She is a world expert in studies of accreting white dwarfs. Mr. Antonio Rodriguez is a Graduate student at Caltech. He is an expert in X-ray studies of accreting magnetized white dwarfs. Dr. Thomas Prince is a Professor at Caltech. He is the co-PI of the Zwicky Transient Facility and he's an expert in compact binaries. Mr. Andrei Cristea is a Graduate Student at the Institute of Science and Technology Austria. He is an expert in compact objects and high-energy astrophysics. Dr. Kevin Burdge is a Pappalardo Fellow at MIT. He is an expert in variable white dwarfs and compact binaries. Stellar Physics and Stellar Types 6 false true false false false false false true PRIMARY 50 true SUPPORTED STAR POLAR NO J2000 J2000 Galex FUV 17.9 COS/FUV Spectroscopic No No G140L 800 STIS/NUV-MAMA Spectroscopic No No G230L 2376 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1739051802000 337.7779739616866 (Tic-Visit :proposal-id 17720 :visit-id "01" :proposal-version -1 :trans-version "20240604" :date "14-Aug-2024 09:25:38.0" :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 165424 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17720 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17720 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2669 :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 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "01" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2669 :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 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "01" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2669 :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 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "01" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2669 :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 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "01" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) true 5 0 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939816 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939816 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939817 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939815 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939815 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939815 As there could be some cyclotron emission in the FUV, the emission itself could be up to a magnitude brighter. We therefore run the ETC with the normalization magnitude smaller by 1 to check that the local cout rate is ok. Also, we included the brightest emission lines that we can expect from previous COS observations of polars. ETC number: 1939815 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1747724664000 238.6155939039461 (Tic-Visit :proposal-id 17720 :visit-id "02" :proposal-version -1 :trans-version "20240604" :date "14-Aug-2024 09:25:42.0" :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 835344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17720 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17720 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "02" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "02" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17720 :visit-id "02" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) true 4 0