8322( 5) - 02/07/00 12:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8322 Version: 5 Check-in Date: 07-Feb-2000 12:57:54 1.Proposal Title: The Distance to NGC 2841: Improving the TF Calibration and Definitively Testing MOND ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Gregory Bothun University of Oregon CoI: Dr. Wendy Freedman Carnegie Observatories N ------------------------------------------------------------------------------------ 5. Abstract This proposal aims to measure a distance to the spiral galaxy NGC 2841 using Cepheid variables. NGC 2841 provides a unique opportunity to simultaneously probe three separate phenomenon in extragalactic astronomy: 1) It will provide the highest rotational velocity data point for the Cepheid based calibration of the I-band Tully -Fisher relation and thus will firmly determine if this relation experiences curvature or remains linear all the way out to high rotational velocities. 2) It has hosted two SN Ia events; both of which have good photometry (1957A and 1972R)- this significantly adds to the number of calibrators for the SN Ia distance scale; 3) If its distance can be shown to be significantly less than 19.5 MPC, then MOND can be definitively ruled out because NGC 2841 will require a value of a_o substantially in excess of the empirically determined "universal" value. The current estimated distances for NGC 2841 range from 9--20 Mpc. An accurate determination of this distance, based on HST detection and measurements of its Cepheids, will therefore have an important and distinctive impact in these three areas. ------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 2] Observations Description ------------------------ The aim of the proposal is to discover and determine the periods and luminosities of Cepheids in NGC 2841. We will adopt the successful search methodology (Madore and Freedman 1995 AJ 109, 1654) used by the Key Project team and other groups searching for Cepheids to measure extragalactic distances. Because we will use these data as a calibration of the Cepheid P-L relation, it is important that we obtain a well-populated P-L relation with a range of periods. Therefore, we request 12 epochs of V and I data distributed within a single window of approximately 60 days duration (chosen to preserve the spacecraft roll angle.) We will follow an optimally scheduled pattern of observations within that window so as to maximize the uniformity of phase coverage for all Cepheids with periods in the range of 10-60 days regardless of their individual periods and particular phasing. We will also revisit the same field approximately one year later to minimize aliasing effects for the longest -period Cepheids. At each of these 12 epochs, we will obtain V and I images. Both bands are needed for a true distance modulus and reddening solution. Based on our extensive previous experience with HST studies of Cepheid distances, exposures amounting to 2 orbits in V and 2 orbits in I are sufficient for determining accurate photometry for Cepheids with periods as in the range of 10 - 60 days for galaxies at distances of ~10 Mpc and 60 for galaxies at distances 20 Mpc. Hence, we will be successful at finding Cepheids in this galaxy, whether it is at the closer distance that we expect from other considerations, or if MOND is correct and the galaxy is farther away. Discovery of the variables, determination of periods, phases and total light curves will be made in the V band; colors will be derived from the I-band data giving reddening corrections to the apparent Cepheid moduli. Real Time Justification ----------------------- The observations are not time-critical. However, once they have begun, we request that our program scheduled according to the optimal sampling strategy detailed in the previous section. Such a sampling strategy is critical for obtaining the most uniform phase coverage for the target Cepheids. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2841 galaxy RA=09H 22M 12.0S +/- 5S, 2000 V = 714 SURF(V) = 24 DEC=+50D 56' 16" +/- 5" 8322( 5) - 02/07/00 12:58 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENTation 125D TO 148D SCHEDulability 100% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC2841 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 5] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 1.5D TO 2.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 6] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 3.6D TO 4.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 7] Visit: 04 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 5.9D TO 6.5D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC2841 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 8] Visit: 05 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 8.6D TO 9.2D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 9] Visit: 06 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 11.9D TO 12.5D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 10] Visit: 07 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 15.6D TO 16.4D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC2841 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 11] Visit: 08 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 20.2D TO 21.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 12] Visit: 09 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 25.5D TO 26.5D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC2841 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 13] Visit: 10 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 32.0D TO 33.2D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 14] Visit: 11 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 39.6D TO 41.2D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC2841 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 15] Visit: 12 Visit Priority: Visit Requirements: SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 49.1D TO 50.9D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC2841 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=0.5 ,CR-TOLERANCE=0.1 1 2300 S ------------------------------------------------------------------------------------------------------------------------------------ 8322( 5) - 02/07/00 12:58 - [ 16] Summary Form for Proposal 8322 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENTation 125D TO 148D SCHEDulability 100% SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 1.5D TO 2.0D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 3.6D TO 4.0D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 5.9D TO 6.5D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 8.6D TO 9.2D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 11.9D TO 12.5D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 15.6D TO 16.4D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 20.2D TO 21.0D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 25.5D TO 26.5D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 32.0D TO 33.2D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 39.6D TO 41.2D SAME ORIENTation AS 1 SCHEDulability 100% AFTER 1 BY 49.1D TO 50.9D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC2841 ------------------------------------------------------------------------------------------------------------------------------------