9588( 3) - 05/07/02 09:33 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9588 Version: 3 Check-in Date: 07-May-2002 09:32:57 1.Proposal Title: HST Imaging Polarimetry of the Light Echo around V838 Monocerotis. Part II. ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO/DD 10 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Howard E. Bond Space Telescope Science Institute CoI: Sumner Starrfield Arizona State University N CoI: Nino Panagia Space Telescope Science Institute N CoI: William Sparks Space Telescope Science Institute N CoI: Mark Wagner University of Arizona N ------------------------------------------------------------------------------------ 5. Abstract V838 Mon is a completely unanticipated new kind of object: although it has undergone an outburst somewhat similar to that of an extremely slow nova, its spectrum is unique and totally unlike that of any type of nova. Knowledge of its distance and luminosity is crucial in understanding its nature and origin. Remarkably, a rapidly evolving light echo around V838 Mon has been detected from the ground in recent weeks. HST polarimetric imaging over the next few months, as the light echo expands and fades, will provide a direct geometrical distance to this object (because polarization allows us to selectively identify material with a scattering angle of 90 deg, lying in the plane of the sky at the same distance as the star). The outburst of V838 Mon thus provides a magnificent, unique, and unexpected testbed for the method proposed by Sparks for measuring extragalactic distances using supernova light echoes, which was the primary justification for adding polarimetric capabilities to the Advanced Camera for Surveys. Since the only previous Galactic nova light echoes occurred in 1901 and 1936, this extraordinary combination of circumstances is unlikely to recur during the HST mission. ------------------------------------------------------------------------------------ 9588( 3) - 05/07/02 09:33 - [ 2] Observations Description ------------------------ In GO/DD-9587, we will obtain imaging polarimetry of V838 Mon at two epochs. At each epoch, we will image in the Johnson B filter (F435W) combined with each of the 3 UV polarizers. In this augmentation program, we will additionally devote one more orbit to obtaining polarimetric images in Broad V, and a single unpolarized image in I. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9588( 3) - 05/07/02 09:33 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V838-MON STAR, NOVA-LIKE RA=07H 04M 04.79S +/- 0.1", DEC= J2000 V = 16.0+/-0.5 -03D 50' 50.2" +/- 0.1" Coordinate Source: OTHER_SOURCE 9588( 3) - 05/07/02 09:33 - [ 4] Visit: 03 Visit Priority: Visit Requirements: BETWEEN 17-MAY-2002 AND 26-MAY-2002 ORIENT 109D TO 115D On Hold Comments: Additional Comments: This visit to be done just before target goes into solar avoidance zone. ORIENT should be as close as possible to that of Visit 1 of GO-9587, i.e., 112D. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 V838-MON ACS/WF ACCUM WFC POL0V, 1 362 S C F606W ------------------------------------------------------------------------------------------------------------------------------------ 20 V838-MON ACS/WF ACCUM WFC POL60V, 1 362 S C F606W ------------------------------------------------------------------------------------------------------------------------------------ 30 V838-MON ACS/WF ACCUM WFC POL120V, 1 362 S C F606W Comments: ACS ETC suggests exposure ratios of B:V:I = 500:36:5 ------------------------------------------------------------------------------------------------------------------------------------ 40 V838-MON ACS/WF ACCUM WFC1-FI F814W CR-SPLIT=NO 1 30 S POS TARG 50.64, 4.48 C X Comments: The purpose of the POS TARG is to place the target at the same location as for exposures 10-30, according to our understanding of where polarimetry targets are placed with respect to the center of WFC1. There should NOT be a SAM before this exposure ------------------------------------------------------------------------------------------------------------------------------------ 9588( 3) - 05/07/02 09:33 - [ 5] Summary Form for Proposal 9588 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC WFC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/DD ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 17-MAY-2002 AND 26-MAY-2002 ORIENT 109D TO 115D POS TARG 50.64, 4.48 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements POL0V,F606W POL60V,F606W POL120V,F606W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names V838-MON ------------------------------------------------------------------------------------------------------------------------------------