6744( 3) - 02/05/96 12:13 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6744 Version: 3 Check-in Date: 05-Feb-1996 11:51:54 1.Proposal Title: Fundamental properties of the pulsar/white-dwarf binary PSR B1855+09 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle HOT STARS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: M. H. van Kerkwijk California Institute of Technology CoI: V. M. Kaspi IPAC/Caltech/JPL N CoI: S. R. Kulkarni California Institute of Technology N CoI: J. F. Bell Jodrell Bank N CoI: A. R. Klemola Lick Observatory N ------------------------------------------------------------------------------------ 6. Abstract We propose to obtain a broad-band image of the field of the millisecond pulsar B1855+09, to identify the white-dwarf companion. The PSR B1855+09 system is unique. It is the only one for which Shapiro delay of the pulsed signal has yielded an accurate mass determination of the white dwarf (M_WD=0.258^+0.028_-0.016 Msun), and it is the only pulsar for which a parallax has been measured. If the temperature of the white dwarf were known as well, then the system would offer an unprecedented opportunity for quantitative comparisons between the theoretical and observational properties of a low-mass helium white dwarf, which would allow one to constrain the interior structure and atmosphere of the white dwarf, to determine the cooling age of the white dwarf, and to constrain the age of the pulsar. At its low Galactic latitude, the companion has eluded detection until the appearance of the Keck telescope, with which we have found a candidate counterpart. We hope to confirm the identification with this HST observation. ------------------------------------------------------------------------------------ 6744( 3) - 02/05/96 12:13 - [ 2] Observations Description ------------------------ We plan to observe the field of PSR B1855+09 in the Planetary Camera for 1 orbit in the F555W filter, obtaining three integrations of 800 seconds. Following the technique described by Freudling (1995) (see also ST-ECF News Letter 22), the three integrations will be taken at dithered positions, in order to limit systematic effects in the photometry, while allowing for the efficient rejection of cosmic ray hits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6744( 3) - 02/05/96 12:13 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR- STAR, PULSAR, BINARY RA=18H 57M 36.393S +/- 0.001S, 2000 R = 25.1+/-0.2 185736+09431 PULSAR DEC=+09D 43' 17.32" +/- 0.01" V-R = 0.5+/-0.5 7 Comments: Only R is known; color is best estimate 6744( 3) - 02/05/96 12:13 - [ 4] Visit: 01 Visit Requirements: 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 STAR- WFPC2 IMAGE PC1 F555W CR- 1 700S 185736+0943 SPLIT=NO,CLOCKS 17 =YES,DITHER- TYPE=LINE,DITHE R-LINE- Comments: STEPS=3,DITHER- LINE- SPACING=0.1928 ------------------------------------------------------------------------------------------------------------------------------------ 6744( 3) - 02/05/96 12:13 - [ 5] Summary Form for Proposal 6744 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO CLOCKS=YES DITHER-TYPE=LINE DITHER-LINE-STEPS=3 DITHER-LINE-SPACING=0.1928 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names STAR-185736+094317 ------------------------------------------------------------------------------------------------------------------------------------