9587( 3) - 04/18/02 14:26 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9587 Version: 3 Check-in Date: 18-Apr-2002 14:26:27 1.Proposal Title: HST Imaging Polarimetry of the Light Echo around V838 Monocerotis ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO/DD 10 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Sumner Starrfield Arizona State University CoI: Howard E. Bond Space Telescope Science Institute Y 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. ------------------------------------------------------------------------------------ 9587( 3) - 04/18/02 14:26 - [ 2] Observations Description ------------------------ 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. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9587( 3) - 04/18/02 14:26 - [ 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 = 10.0+/-0.5 -03D 50' 50.2" +/- 0.1" Coordinate Source: OTHER_SOURCE 9587( 3) - 04/18/02 14:26 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BEFORE 04-May-2002 On Hold Comments: Additional Comments: This visit should be done as soon as practicable, since the light echo is fading rapidly. 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 POL0UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 20 V838-MON ACS/WF ACCUM WFC POL60UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 30 V838-MON ACS/WF ACCUM WFC POL120UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 9587( 3) - 04/18/02 14:26 - [ 5] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 20-MAY-2002 AND 26-MAY-2002 ORIENT -5D to 5D FROM 1 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. 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 POL0UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 20 V838-MON ACS/WF ACCUM WFC POL60UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 30 V838-MON ACS/WF ACCUM WFC POL120UV, 1 506 S C F435W ------------------------------------------------------------------------------------------------------------------------------------ 9587( 3) - 04/18/02 14:26 - [ 6] Summary Form for Proposal 9587 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/DD ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 04-May-2002 BETWEEN 20-MAY-2002 AND 26-MAY-2002 ORIENT -5D to 5D FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements POL0UV,F435W POL60UV,F435W POL120UV,F435W ------------------------------------------------------------------------------------------------------------------------------------ Target Names V838-MON ------------------------------------------------------------------------------------------------------------------------------------