Science Keywords: Select from 2 to 5 items. Science Keywords is a required field. 0 Assigned ID: 1302 ----- Attempting Submission 1 (Fri Nov 18 16:38:13 GMT 2016) ----- Joint NRAO This is my first time using the Phase II APT and I am not 100% sure that I have tuned everything for the SHADOW constraint, so I would appreciate feedback if there are ways in which the observations can be optimized. I have not had any contact with the VLA schedulers about arrangements for a simultaneous observation. 102477998 ----- Attempting Submission 1 (Tue Dec 13 19:49:09 GMT 2016) ----- Radio studies show that, despite their low temperatures, very low-mass stars and brown dwarfs can generate strong magnetic fields and accelerate ~MeV electrons. Strikingly, the resulting phenomenology resembles that of a scaled- up planet more than a scaled-down star, with aurorae and radiation belts thousands of times brighter than those of Jupiter. In both Jupiter and the "ultracool dwarfs," radio emission traces energetic magnetospheric electrons. In Jupiter, many of these electrons eventually crash into the upper atmosphere, their energy driving haze production and vertical mixing. We do not know how efficiently magnetic energy is deposited in ultracool dwarf atmospheres, or the chemistry that this drives. This deposition leads to FUV emission, however, and we have recently calculated that the most radio-active ultracool dwarf, NLTT33370B, should produce enough FUV to be detectable with Hubble. We propose a 4-hour simultaneous VLA/HST observation to measure the impact of this deposition process. Using a novel VLA sub-arraying tactic, we will leverage well-vetted planetary radiation belt models to obtain an unprecendently detailed view of how electrons migrate through this dwarfs's inner magnetosphere. Hubble will probe their ultimate fate. We propose an HST UV imaging observation aiming to achieve S/N = 5 in our fiducial model of the auroral UV emission of NLTT 33370 B (described in the VLA proposal text). This observation is to be conducted simultaneously with a Very Large Array observation. The Solar Blind Channel of the ACS provides the highest raw sensitivity. Using a realistic model of the auroral emission spectrum (Gustin+, 2013JMoSp.291..108G), we find that observations with the SHADOW constraint provide the most efficient use of HST time. Given the system's known NUV emission (see Williams+, 2015ApJ...799..192W), we propose dithered exposures in both the F115LP and F165LP filters to allow "red leak" subtraction. Using the ACS instrument handbook and the HST exposure time calculator, we find that the desired S/N can be achieved in 2 orbits, with 2470 s (226 s) of on-target exposure in the F115LP (F165LP) filters, after accounting for overheads; the achieved S/N is 6.1 (6.2). [NOTE: these numbers have not been updated to match the precise values derived from use of the orbit planner.] We have checked that the proposed observations do not exceed ACS/SBC count limits, and both the HST Bright Object Tool and GALEX catalogs confirm that there are no sources in a 70'' diameter that threaten instrument safety. The SHADOW constraint means that NLTT 33370 B is visible to HST for a relatively brief window, from 2017 Apr 9 to 2017 Jul 5 with some gaps. This window overlaps a VLA configuration change (D -> C; 2017 May 15--25), but the configuration change fortuitously mostly overlaps a gap in HST visit schedulability. Stellar Physics 12 false false false false false false SUPPORTED STAR M V-IV NO This object was generated by the targetselector and retrieved from the SIMBAD database. Astrometry has been updated from Dupuy et al 2016. LSPM-J1314+1320 2MASS-J13142039+1320011 J2000 J2000 spectral type M7, GALEX NUV magnitude 21.0 +- 0.2, not detected in GALEX FUV ACS/SBC Imaging No No F115LP POS-TARG DITHER 0.472 LINE false false 2 44.4 ACS-SBC-DITHER-LINE 2 false 1481572786062 /home/peter/zorra/apt/OP-cache/phase2-v01.xml The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. This visit is to be conducted simultaneously with an observation on the Very Large Array. It also has a SHADOW constraint which constrains the time of its execution to a few-month window. (Tic-Visit :proposal-id 14897 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "12-Dec-2016 14:59:45.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "28" :si-bright-earth-limb-angle 20.0 :data-volume 148112 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14897 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14897 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 1918 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1918 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14897 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 1918 :al-overhead-at-end 0 :internal-dur-at-end 198 :dark-offset 0 :dark-utilization 1918 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 2 0