! File: 4348C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:22:49:08 coverpage: title_1: LONG PERIOD VARIABLES OF M81: CYCLE3MEDIUM sci_cat: GALAXIES & CLUSTERS sci_subcat: STELLAR POPULATIONS proposal_for: GO longterm: 2 pi_fname: SHAUN pi_mi: M pi_lname: HUGHES pi_inst: PALOMAR OBSERVATORY pi_country: USA hours_pri: 6.00 num_pri: 2 wf_pc: Y funds_length: 3 off_fname: EARL off_mi: J off_lname: FREISE off_title: DIRECTOR OF RESEARCH off_inst: CALTECH off_addr_1: CALTECH off_addr_2: MS 213-6 off_city: PASADENA off_state: CA off_zip: 91125 off_country: USA off_phone: 818 356 6357 ! end of coverpage abstract: line_1: This is part of a very long term project to identify Long-Period line_2: Variables (LPVs) in external galaxies. Most LPVs are members of the line_3: Asymptotic Giant Branch (AGB), and hence one of the main reasons for line_4: studying the LPVs will be to understand the AGB, and how it varies in line_5: nearby galaxies. So far the only AGB LPVs to be identified in external line_6: galaxies are those in the Magellanic Clouds. Ground based programs are line_7: currently underway to identify the AGB LPVs in M31, and using HST to line_8: identify the LPVs in a galaxy beyond the local group will tell us how line_9: important a part galactic environment plays in the formation of AGB line_10: progenitor stars (ie initial main sequence masses of between ~0.8 and line_11: 9 solar masses). An important bonus of studying LPVs is that line_12: they possess a precise PL relation, which will be a very useful check line_13: against the distance derived from Cepheids in the H_0 key project line_14: (Program No. 2227). ! ! end of abstract general_form_proposers: lname: HUGHES fname: SHAUN title: PI mi: M inst: PALOMAR OBSERVATORY country: USA ! lname: MOULD fname: JEREMY mi: R inst: PALOMAR OBSERVATORY country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: Cycle 2: 1 epoch of 25.9m I May 1993 M81 disk field line_2: : 1 epoch of 25.9m I May 1993 M81 V30 field line_3: Cycle 3: 2 epochs of 25.9m I July 1993 M81 disk field line_4: : 2 epochs of 25.9m I July 1993 M81 V30 field line_5: : 2 epochs of 25.9m I Nov 1993 M81 disk field line_6: : 2 epochs of 25.9m I Nov 1993 M81 V30 field line_7: : 1 epoch of 25.9m I Jan 1994 M81 disk field line_8: : 1 epoch of 25.9m I Jan 1994 M81 V30 field line_10: Cycle 1 Primary Hours: Parallel Hours: Exposures: line_11: Cycle 2 Primary Hours: 0.9 Parallel Hours: 0 Exposures: 2 line_12: Cycle 3 Primary Hours: 4.3 Parallel Hours: 0 Exposures: 10 line_13: Cycle 4 Primary Hours: 1.0 Parallel Hours: 0 Exposures: 12 ! question: 4 section: 1 line_1: So far the only AGB LPVs to be identified in external galaxies are those line_2: in the Magellanic Clouds. Ground based programs are currently underway to line_3: identify the AGB LPVs in M31, which is at the limit of current ground-based line_4: observations. Using HST to identify the LPVs in a galaxy beyond the local line_5: group will tell us how important a part galactic environment plays line_6: in the formation of AGB progenitor stars (ie initial main sequence masses of line_7: between ~0.8 and 9 solar masses). An important bonus of studying LPVs is that line_8: they possess a precise P-L relation, which will be a very useful check line_9: against the distance derived from Cepheids in the H_0 key project line_10: (Program No. 2227). line_11: In order to obtain accurate periods, we shall need 18 epochs. line_12: As part of Program No. 2227, there already exists four F785LP exposures in line_13: each of the two fields from cycle 1, and an additional two exposures will be line_14: taken in each field in cycle 2. The Cepheid surveys have established that a line_15: cycle 3 HST can reliably reach magnitudes of 23.5 in I in 1800 sec. Due line_16: to spacecraft overheads, the amount of spacecraft time allocated in cycle 3 line_17: phase I is sufficient for 12 exposures (6 epochs) of 1610 sec, a reduction of line_18: 0.12 mag, which should not reduce the numbers of recovered LPVs too severely. line_19: In order to obtain near-continuous light curves (see below) one epoch is line_20: requested for the end of cycle 2, and five epochs in cycle 3. The line_21: remaining six epochs required to finish the project will be requested in line_22: cycle 4, for which the WFPC2 refurbishment should mean that we can line_23: reduce the required exposure times by a factor of 6. ! question: 5 section: 1 line_1: Time-critical observations: Because the periods of some LPVs change from line_2: cycle to cycle, and in order to avoid severe period aliases, we will line_3: need to obtain well-sampled continuous light curves. The existing data are line_4: concentrated over a period of 42 days (4 epochs) in cycle 1, with 2 epochs in line_5: cycle 2. Hence it is important to obtain one epoch at the end of cycle 2, to line_6: light-curve continuity, with the remaining epochs well-spread over the rest of line_7: maintain the sampling time. However, because the pulsation periods are so long line_8: (100-1000 days), we can tolerate a reasonably large scatter (+/- 5 days) about line_9: the ideal sampling times listed below. line_11: Special orientation: because of undersampling, and to ensure good phase coverage line_12: for the maximum number of stars, it is very important to expose on the same line_13: area for each observation in a sequence. This means the position and line_14: orientation (+/- Nx90 deg) must be kept fixed for the maximum number of line_15: exposures. We have obtained output from the RUN-ORIENT program to determine line_16: the allowable dates for the correct orientation for each exposure. line_17: This gives us 4 windows per year (one for each orientation), two of which line_18: last 60 days, and the other two lasting only 10 days. line_21: Future Cycles: Although we have been allocated only 1.5 hours of spacecraft line_22: time in `Future Cycles', enough for only 3x5 min exposures plus overheads, line_23: we hope to be allocated more time when cycle 4 proposals are solicited. ! question: 6 section: 1 line_1: ! question: 7 section: 1 line_1: A preliminary calibration of the HST Program No. 2227 data (Cepheids in M81) line_2: shows that the ALLFRAME photometry package (based on DAOPHOT) is well able to line_3: produce accurate photometry (to I ~ 23.5) from the Science Images produced by line_4: the standard STSDAS pipeline. We shall therefore be using the same package on line_5: the LPV data. The added advantage of using ALLFRAME is that it also provides line_6: the light curve of every detected image in the frame, and so it is a relatively line_7: easy matter of analysing each light curve to search for variability and line_8: periodicity, in a similar manner to Hughes (1989 AJ 97, 1634), which will also line_9: enable completeness estimates to be made, and which can be applied to the final line_10: results to obtain reasonable LPV luminosity functions and period distributions. line_12: Ground-based (Palomar 200-inch) photometry of the brightest stars already line_13: exists and will be used to calibrate the data onto the Cousins I system. ! question: 8 section: 1 line_1: It would be highly desirable for the data to be reserved for our exclusive use line_2: until one year after the cycle 4 data have been acquired, as a premature line_3: analysis of a partial light curve sample will only produce misleading results. ! question: 9 section: 1 line_1: 2227GO: The Extragalactic Distance Scale I. M81. line_2: 3905GO: The Extragalactic Distance Scale II. M81 & M101. line_3: These programs are aimed at finding Cepheids in galaxies beyond the local group, line_4: and eventually out to the Virgo group. The first and nearest galaxy to be line_5: observed is M81, and in cycle 1, 12 and 4 epochs were obtained in F555W and line_6: F785LP, in two fields of M81, while in cycle 2 a further 6 and 2 epochs will be line_7: obtained. The F785LP frames will be used as part of the data for this LPV line_8: proposal. line_9: From the cycle 1 data, 37 Cepheid candidates have been identified. line_10: More epochs being obtained in cycle 2 will be used to obtain accurate periods. line_11: The entire data set is now being calibrated against ground-based photometry line_12: (Palomar 200-inch) of the brightest stars in each of the fields. The Cepheid line_13: colors will then be used to estimate internal extinction, and when combined line_14: with the re-calibrated data will provide an accurate distance to M81, the line_15: first step in measuring H_0 to better than 10%. line_16: Cepheids in Nearby Galaxies, Freedman, W. in IAU Colloquium 139, in press, 1992 line_17: Faint Stellar Photometry with HST, Hughes, S., in IAU Coll. 136, in press, 1992 line_18: Stellar Populations in Neighboring Galaxies, Mould, J., in line_19: Science with the Hubble Space Telescope, in press, 1992. ! question: 10 section: 1 line_1: A computer workstation will be used to reduce and analyse the data. ! !end of general form text general_form_address: lname: HUGHES fname: SHAUN mi: M category: PI inst: Palomar Observatory addr_1: CALTECH addr_2: MS 105-24 city: PASADENA state: CA zip: 91125 country: USA phone: 818 356 4023 telex: 675425 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC3031-FIELD descr_1: E,301 pos_1: RA=09H 51M 02.6S +/- 2", pos_2: DEC=+69D 23' 15" +/- 2" equinox: 1950 pm_or_par: N rv_or_z: V=80 comment_1: DISK FIELD fluxnum_1: 1 fluxval_1: SURF(V)=25 fluxnum_2: 2 fluxval_2: SURF(I)=25 ! targnum: 2 name_1: NGC3031-V30 descr_1: E,301 pos_1: RA=09H 52M 03.0S +/- 2", pos_2: DEC=+69D 21' 18" +/- 2" equinox: 1950 pm_or_par: N rv_or_z: V=80 comment_1: V30 FIELD fluxnum_1: 1 fluxval_1: SURF(V)=25 fluxnum_2: 2 fluxval_2: SURF(I)=25 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 23.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 1 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: BEFORE 35 BY 260.0D +/- 15.0D; req_2: ORIENT 270D +/- 2.00D FROM 35; req_3: CYCLE 2 / 23; req_4: PCS MODE C /23-35; comment_1: THIS IS AN EXACTLY 270 DEG ROTATED comment_2: EXPOSURE. I.E. -90 DEGREES FROM 35 ! linenum: 31.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 2 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: BEFORE 35 BY 179.0D +/- 15.0D; req_2: ORIENT 180D +/- 2.00D FROM 35; req_3: CYCLE 3 / 31; comment_1: THIS IS AN EXACTLY INVERTED EXPOSURE comment_2: I.E. 180 DEGREES FROM 35 ! linenum: 32.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 1 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: BEFORE 35 BY 97.0D +/- 5.0D; req_2: ORIENT 90D +/- 2.00D FROM 35; req_3: CYCLE 3 / 32; comment_1: THIS IS AN EXACTLY 90 DEG ROTATED comment_2: EXPOSURE. I.E. +90 DEGREES FROM 35 ! linenum: 33.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 1 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: BEFORE 35 BY 74.0D +/- 5.0D; req_2: SAME POS FOR 33 AS 32; req_3: SAME ORIENT FOR 33 AS 32; req_4: CYCLE 3 / 33; comment_1: SAME GUIDE STARS FOR 33 AS 32 comment_2: (RETURNING TO THE SAME POSITION comment_3: AND SAME ORIENTATION IS CRUCIAL) comment_4: EXPOSURE +90 DEGREES FROM 35 ! linenum: 34.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 1 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: BEFORE 35 BY 51.0D +/- 5.0D; req_2: SAME POS FOR 34 AS 32; req_3: SAME ORIENT FOR 34 AS 32; req_4: CYCLE 3 / 34; comment_1: SAME GUIDE STARS FOR 34 AS 32 comment_2: (RETURNING TO THE SAME POSITION comment_3: AND SAME ORIENTATION IS CRUCIAL) comment_4: EXPOSURE +90 DEGREES FROM 35 ! linenum: 35.000 sequence_1: DEFINE sequence_2: ILONG targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 1 time_per_exp: 1600S s_to_n: 10 fluxnum_1: 1 priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: AT 19-JAN-94 +/- 4D; req_2: CYCLE 3 / 35; comment_1: THIS POSITION PUTS TARGET ON APEX ! linenum: 301.000 sequence_1: USE sequence_2: ILONG targname: NGC3031-FIELD priority: 1 req_1: CYCLE 2 / 23; req_2: CYCLE 3 / 31 - 35; ! linenum: 302.000 sequence_1: USE sequence_2: ILONG targname: NGC3031-V30 priority: 2 req_1: CYCLE 2 / 23; req_2: CYCLE 3 / 31 - 35; ! ! end of exposure logsheet ! No scan data records found