5981( 0) - 07/18/95 19:03 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5981 Version: ********** Check-in Date: ********** 1.Proposal Title: Calibration of Nearby Type Ia Supernovae as Standard Candles: NGC 4639 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Galaxies & Clusters GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Allan Sandage Observatories of the Carnegie Institution of Washington CoI: Gustav Tammann Universitat Basel N CoI: Lukas Labhardt Universitat Basel N CoI: Duccio Macchetto Space Telescope Science Institute N CoI: Nino Panagia Space Telescope Science Institute N CoI: Abhijit Saha Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract We propose to continue our calibration experiment for M(max) of type Ia supernovae (SNe Ia) by determining Cepheid distances to their parent galaxies. To date we have completed the calibration for 3 SNe Ia (SN 1937C in IC 4182 from Cycle 1, and SN 1895B and SN 1972E in NGC 5253 from Cycle 3), and are at the beginning of the calibration of SN 1960F in NGC 4496 and SN 1981B in NGC 4536 from Cycle 4 data being received just now. The experiment is designed to determine how stable M(max) is for SNe Ia, and how large the dispersion is about this mean. To adequately do this we need the calibration of about 10 such SNe Ia. We propose for 84 orbits to observe 2 more parent galaxies of SNe Ia. We now know from the success of the Cycle 4 data that NGC 5055, parent of SN 1971I, and NGC 4414, parent of SN 1974G, are within the capabilities of the present HST. If NGC 4414 is unavailable, being protected for another project, we request that the second galaxy for the proposed Cycle 5 program be NGC 4639, parent of SN 1990N. ------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 2] Observations Description ------------------------ Observations will be carried out with the WFPC2. Properly time spaced observations spanning a period of about 2 months in the V band will be required. A special timing scheme has been specified, which provides maximum detection completeness and phase coverage for Cepheids with periods form 15 to 70 days, and minimizes aliassing problems with period determination. This makes a total of 12 epochs or visits to each galaxy. THIS IS AN EXTREMELY MINIMALIST approach: reducing the number of epochs from this level or altering the timing scheme significantly will introduce aliassing, and incur the risk of obtaining incorrect periods. Each epoch in V (or I) is a pair of back to back orbits, utilizing the orbit duration to the fullest, which results in effective exposure times of 4000s or a little more. The limiting magnitude is thus 28 in V (F555W), and Cepheids with mean magnitudes V < 27.5 can be detected. These numbers are empirical determinations from Cycle 4 data. This means that Cepheids with periods longer than 10 days can be detected at distance moduli up to 31.6, and those with P > 20 days can be found to distance moduli of 32.2. Real Time Justification ----------------------- 1) Timing - Observations need to be conducted at the planned time intervals to ensure adequate coverage of the Cepheids' light curves. 2) Orientation - it is highly desirable (but not essential) to keep the field orientation the same over most of the observing period. The natural telescope roll angle for a given target changes with observation epoch. Hence the time of year for observations should be chosen to provide the maximum range for off-nominal roll angles so that the field orientation is kept the same over the maximum permissible span of dates. Such accomodation has been possible in previous cycles. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 GALAXY, SPIRAL RA=12H 42M 52.6S +/- 0.5S , DEC 2000.0 V = 27.0 = 13D 15' 42.0" +/- 5.0" Surf-BKG(V)=24.0 Comments: repeated visits to find Cepheids Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1990.0 0 0 0.0 5981( 0) - 07/18/95 19:03 - [ 4] Visit: 01 Visit Requirements: ORIENT 111.5D to 112.5D; BETWEEN 22-APR-95 AND 8-MAY-95 On Hold Comments: Additional Comments: this 1st epoch visit must happen within specified dates and at specified roll angle for sequence to work Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 5] Visit: 02 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 8.3D TO 8.7D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 6] Visit: 03 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 15.4D TO 15.8D On Hold Comments: Additional Comments: Same position as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 7] Visit: 04 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 21.3D TO 21.7D On Hold Comments: Additional Comments: Same pointing position as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4639 WFPC2 IMAGE WFALL- F814W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4639 WFPC2 IMAGE WFALL- F814W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4639 WFPC2 IMAGE WFALL- F814W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 8] Visit: 05 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 26.1D TO 26.5D On Hold Comments: Additional Comments: Same pointing position as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 9] Visit: 06 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 31.4D TO 31.8D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 10] Visit: 07 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 35.3D TO 35.9D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 11] Visit: 08 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 39.3D TO 39.9D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4639 WFPC2 IMAGE WFALL- F814W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4639 WFPC2 IMAGE WFALL- F814W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 12] Visit: 09 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 45.0D TO 45.6D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 13] Visit: 10 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 51.4D TO 52.0D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 14] Visit: 11 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 59.3D TO 59.9D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 15] Visit: 12 Visit Requirements: SAME ORIENT as 1; AFTER 1 BY 68.7D TO 69.3D On Hold Comments: Additional Comments: Same pointing as 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2000S EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE WFALL- F555W ATD-GAIN = 7, 1 2500S SAME POS AS 1; EXPAND; END ORBIT FIX CR-SPLIT = NO Comments: Exposure should fill the orbit visibility ------------------------------------------------------------------------------------------------------------------------------------ 5981( 0) - 07/18/95 19:03 - [ 16] Summary Form for Proposal 5981 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN = 7 CR-SPLIT = NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Galaxies & Clusters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 111.5D to 112.5D; BETWEEN 22-APR-95 AND 8-MAY-95 EXPAND; END ORBIT SAME POS AS 1; EXPAND; END ORBIT SAME ORIENT as 1; AFTER 1 BY 8.3D TO 8.7D SAME ORIENT as 1; AFTER 1 BY 15.4D TO 15.8D SAME ORIENT as 1; AFTER 1 BY 21.3D TO 21.7D SAME ORIENT as 1; AFTER 1 BY 26.1D TO 26.5D SAME ORIENT as 1; AFTER 1 BY 31.4D TO 31.8D SAME ORIENT as 1; AFTER 1 BY 35.3D TO 35.9D SAME ORIENT as 1; AFTER 1 BY 39.3D TO 39.9D SAME ORIENT as 1; AFTER 1 BY 45.0D TO 45.6D SAME ORIENT as 1; AFTER 1 BY 51.4D TO 52.0D SAME ORIENT as 1; AFTER 1 BY 59.3D TO 59.9D SAME ORIENT as 1; AFTER 1 BY 68.7D TO 69.3D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4639 ------------------------------------------------------------------------------------------------------------------------------------