! Proposal 6651, submission 1 ! PI: James K. McCarthy ! Received Wed Feb 7 23:46:08 EST 1996 ! From: jkm@astro.caltech.edu ! ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6651,v 3.1 1996/02/08 23:51:43 pepsa Exp $ ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Ray Lucas ! Phone: 410-338-4716, E-mail: lucas@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0683.mccarthy.prop ! Date generated: Fri Dec 22 16:36:45 EST 1995 ! Proposal_Information Title: WLR Distances from Accurate Multi-Color WFPC2 Photometry of A & B Supergiants in M31 and M33 Proposal_Category: GO Scientific_Category: HOT STARS Cycle: 6 Investigators PI_name: James K. McCarthy PI_Institution: California Institute of Technology CoI_Name: Artemio Herrero CoI_Institution: Instituto de Astrofisca de Canarias Contact: N CoI_Name: Rolf Kudritzki CoI_Institution: Universitaet Sternwarte Muenchen Contact: N CoI_Name: Danny Lennon CoI_Institution: Universitaet Sternwarte Muenchen Contact: N CoI_Name: Barry Madore CoI_Institution: Infrared Processing and Analysis Center Contact: N CoI_Name: Joachim Puls CoI_Institution: Universitaet Sternwarte Muenchen Contact: N CoI_Name: Kim Venn CoI_Institution: Universitaet Sternwarte Muenchen Contact: N Abstract: We propose to acquire WFPC2 multi-color photometry of A and B supergiant stars in M31 and M33 with a precision far exceeding that of existing ground-based estimates. The resulting WFPC2 magnitudes and colors will be used to determine distances to the hot stars using the Wind-momentum Luminosity Relationship (WLR), in conjunction with existing moderate- and high- resolution spectra from 4-m class telescopes and the 10-m Keck-I telescope, respectively. The radiation-driven stellar wind momenta and metallicities derived from our high S/N spectra translate via the WLR into the intrinsic stellar luminosities; HST photometry is now crucial for distance determination. First, accurate distance moduli require accurate apparent magnitudes, which in the crowded fields of the M31 and M33 spiral arms demand the high spatial resolution of HST. Second, our model atmosphere analyses of the stellar spectra permit us to determine the extinction to each object by comparing the expected and observed (reddened) colors, where again the accuracy afforded by HST is critical. Third, implicit to the WLR method is the assumption that the objects are single highly luminous stars as opposed to tight associations (unresolved from the ground), an assumption we seek to test with WFPC2 imagery. The resulting WLR distances to M31 and M33 will be compared to the distances from Cepheids (where metallicity and extinction influences are less tractable), as a basis for extending the WLR method to larger distances. Questions Observing_Description: We require multi-color photometry in the standard U,B,V,I passbands F336W, F439W, F569W, and F814W, respectively. We omit R (F675W) because strong H-alpha emission is expected in the stars, as well as spatially variable H-alpha emission from HII recombination in the OB Associations of which our target stars are a part. In addition, we intend to obtain images in F170W to detect visually-faint hot companions, if present, which could influence the U-B colors we shall use for reddening. All exposures will be cosmic-ray split, giving us an overhead per target of 7.5 min for G.S. Acq. plus 25 minutes of WFPC2 CCD readout overhead (5 pairs of cosmic-ray split exposures, one pair per filter, at five minutes each). We do not require target acquisition, only that the A,B supergiant target is positioned on the PC chip for maximum spatial resolution and sampling of the PSF. We shall use the 14 e-/ADU gain setting throughout, since in the high S/N regime of interest to us, quantization noise is not a significant factor. Integration times to reach S/N > 100 for our faintest target (V=17.55; Sp. A0I; E(B-V)~0.1) will be very short in U,B,V,I (i.e., 7, 2, 0.5, and 1 min). We intend to adjust the science integration time spent on F170W to use all of the remaining time in each orbit: for the faintest star example, this allows >10min with F170W, yielding S/N=20 based on the exposure time calculator for WFPC2 on the WWW. Note that we will have I-band exposures with which to gauge the red leak contamination expected through F170W, and so we prefer the higher UV throughput of F170W over F160WB. Real_Time_Justification: Calibration_Justification: Additional_Comments: Fixed_Targets Target_Number: 1 Target_Name: NGC598-117-A Alternate_Names: M33-117-A Description: EXT-STAR,A0-A3 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 00.18S +/- 0.3", DEC=+30D 23' 23.8" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.34 +/- 0.3 B-V=0.18 TYPE=A0Ia Comments: Target_Number: 2 Target_Name: NGC598-B-133 Alternate_Names: M33-B-133,NGC598-OB31-0515 Description: EXT-STAR,B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 29.08S +/- 0.3", DEC=+30D 47' 44.3" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.5 +/- 0.3 B-V=0.0 U-B=-0.70 TYPE=B2.5Ia Comments: Target_Number: 3 Target_Name: NGC598-110-C Alternate_Names: M33-110-C Description: EXT-STAR,F0-F2,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 36.62S +/- 0.3", DEC=+30D 22' 06.7" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.8 +/- 0.3 TYPE=F0Ia Comments: Verify that PA avoids bright star 1h33m37.08s +30d23'21.8" Target_Number: 4 Target_Name: NGC598-110-A Alternate_Names: M33-110-A,NGC598-OB110-0785 Description: EXT-STAR,B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 41.22S +/- 0.3", DEC=+30D 22' 37.3" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.10 +/- 0.3 B-V=0.10 U-B=-0.90 TYPE=B1Ia+ Comments: Verify that PA avoids bright star 1h33m37.08s +30d23'21.8" Target_Number: 5 Target_Name: NGC598-OB142-1054 Alternate_Names: M33-OB142-1054 Description: EXT-STAR,B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 50.77S +/- 0.3", DEC=+30D 38' 34.5" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.6 +/- 0.3 B-V=-0.40 TYPE=B2Ib Comments: Target_Number: 6 Target_Name: NGC598-B-324 Alternate_Names: M33-B-324 Description: EXT-STAR,F0-F2,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 55.91S +/- 0.3", DEC=+30D 45' 30.3" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=15.2 +/- 0.3 B-V=0.31 TYPE=A7Ia++ Comments: Target_Number: 7 Target_Name: NGC598-OB109-1330-1345 Alternate_Names: M33-OB109-1330,M33-OB109-1345 Description: EXT-STAR,B6-B9.5 III-I,A0-A3 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 33M 59.73S +/- 0.3", DEC=+30D 23' 02.9" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.6 +/- 0.3 B-V=0.20 U-B=-0.50 TYPE=A0Ia+ Comments: #1330: 1h33m59.68s +30d23'04.3" #1345: 1h33m59.77s +30d23'01.5" Target_Number: 8 Target_Name: NGC598-B-526 Alternate_Names: M33-B-526,NGC598-OB101-1733 Description: EXT-STAR,B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=1H 34M 16.06S +/- 0.3", DEC=+30D 33' 43.8" +/- 0.3", PLATE-ID=00DV Equinox: J2000.0 RV_or_Z: Flux: V=16.7 +/- 0.3 B-V=0.00 U-B=-0.90 TYPE=B2.5Ia++ Comments: Target_Number: 9 Target_Name: NGC224-IV-A207 Alternate_Names: M31-IV-A207 Description: EXT-STAR,B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 37M 45.06S +/- 0.3", DEC=+39D 58' 20.6" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=17.1 +/- 0.3 B-V=0.43 U-B=-0.03 TYPE=F5Ia Comments: Target_Number: 10 Target_Name: NGC224-40-1939 Alternate_Names: M31-41-1939,NGC206-277 Description: EXT-STAR, B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 40M 30.26S +/- 0.3", DEC=+40D 42' 31.5" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.18 +/- 0.3 B-V=0.29 TYPE=B1Ia Comments: Target_Number: 11 Target_Name: NGC224-40-2028 Alternate_Names: M31-40-2028,NGC206-478 Description: EXT-STAR, B0-B2 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 40M 32.79S +/- 0.3", DEC=+40D 45' 08.0" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=17.5 +/- 0.3 B-V=0.12 U-B=-1.24 TYPE=B0.5Ia+ Comments: Target_Number: 12 Target_Name: NGC224-41-2368 Alternate_Names: M31-41-2368 Description: EXT-STAR,A4-A9 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 44M 16.59S +/- 0.3", DEC=+41D 21' 02.5" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.3 +/- 0.3 B-V=-0.15 U-B=-0.63 TYPE=A8Ia Comments: Target_Number: 13 Target_Name: NGC224-41-2553 Alternate_Names: M31-41-2553 Description: EXT-STAR,B6-B9.5 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 44M 25.52S +/- 0.3", DEC=+41D 21' 00.2" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.9 +/- 0.3 B-V=-0.03 U-B=-0.69 TYPE=B8Ia Comments: Target_Number: 14 Target_Name: NGC224-41-3654 Alternate_Names: M31-41-3654,NGC224-OB48-123 Description: EXT-STAR,A0-A3 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 45M 07.80S +/- 0.3", DEC=+41D 37' 41.8" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.5 +/- 0.3 B-V=0.29 U-B=-0.70 TYPE=A2Ia Comments: Target_Number: 15 Target_Name: NGC224-41-3712 Alternate_Names: M31-41-3712,NGC224-OB48-203 Description: EXT-STAR,A0-A3 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 45M 10.24S +/- 0.3", DEC=+41D 36' 58.9" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.2 +/- 0.3 B-V=0.29 U-B=-0.89 TYPE=A3Ia Comments: Target_Number: 16 Target_Name: NGC224-41-3860 Alternate_Names: M31-41-3860,NGC224-OB48-505 Description: EXT-STAR,A0-A3 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 45M 17.35S +/- 0.3", DEC=+41D 38' 59.7" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=17.55 +/- 0.3 B-V=-0.11 U-B=-0.63 TYPE=A0I Comments: Target_Number: 17 Target_Name: NGC224-41-4918 Alternate_Names: M31-41-4918 Description: EXT-STAR,B6-B9.5 III-I,EXT-CLUSTER,OB ASSOCIATION Position: RA=0H 46M 31.99S +/- 0.3", DEC=+42D 05' 09.2" +/- 0.3", PLATE-ID=06PI Equinox: J2000.0 RV_or_Z: Flux: V=16.6 +/- 0.3 B-V=0.44 U-B=-1.15 TYPE=B8Ia Comments: Solar_System_Targets Generic_Targets Scan_Data Visits !============================================================================== Visit_Number: 1 Visit_Requirements: PCS MODE FINE ! GUIDing TOLerance ! DROP TO GYRO IF NECESSARY [NO REACQuisition] ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! SCHEDulability ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN