Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3336c Report Date: 09-May-96:18:28 Version: ********** Check-in Date: ********** 1.Proposal Title: CENTRAL STARS OF PLANETARY NEBULAE - CYCLE 3 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS AUG/FOC 3747 Sub Category SUBLUMINOUS STARS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Ir. T. M Kamperman SRON SPACE RESEARCH UTRECHT NETHERLAND 3130535715 PROGRAM COORDINATOR ------------------------------------------------------------------------------------ 7. Abstract It has proved impossible to detect the very hot exciting stars of some planetary neblae from the ground. This is probably because these stars emit a great many ionizing photons for each visible quantum. The ionized nebula is therefore so extensive that the nebular emission, both line and continuum, completely dominate the visual continuum emission of the central star, which becomes lost in the noise. Observing above the atmosphere increases the possibility of detection of these central star by a factor of at least 400. A factor ~ 100 because the light of the central star is within an image of. 1" instead of the ~ 1" ground seeing limitation allowing better discrimination of the star against the diffuse nebular continuum and a further factor ~ 4 occurs because the star is that much brighter, relative to the nebula, in the ultraviolet than it is in the visible. With the spherical abberation of HST, the above mentioned factor of 100 is reduced to about 15, but as the UV adventage remains, detectability is still several magnitudes beyond groundobservations. ------------------------------------------------------------------------------------ 8. Scientific Key Words: PLANETARY NEBULAE, HOT CENTRAL STARS. ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 5.30 par: 0 10. Num targs pri: 5 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3336c PI: Ir. T. M Kamperman Proposal Title: CENTRAL STARS OF PLANETARY NEBULAE - CYCLE 3 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Prof. S. R Pottasch GRONINGEN, UNIVERSITY OF NETHERLANDS X Dr. A. A Zijlstra GRONINGEN, UNIVERSITY OF NETHERLANDS X Dr. N. Walton UNIVERSITY COLLEGE LONDON ENGLAND X T. M Kamperman SRON SPACE RESEARCH UTRECHT NETHERLANDS X ------------------------------------------------------------------------------------ 3. Description of proposed observations. For each object 3 exposure images will be taken through different narrow band U.V. filters. The filters are chosen so that we avoid areas of the spectrum with strong emission lines, and seperated by a reasonable wavelength interval. This serves two purposes. a) We will be able to discriminate between low temperature field stars and the true central star by measuring their colour temperature, b) If there is an enhancement in the nebular continuum surrounding the central star, we will be able to seperate the contributions from the nebular and stellar continuum surrounding the central star, we will be able to seperate the contributions from the nebular and stellar continuum by their different gradients. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The combination of ultraviolet sensitivity and the sharp central peak in HST's PSF will result in a much higher detectability of central stars. Where the detectability ratio HST/ground was originally at least 400, the ratio is still about 70 in the same observation time. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. No special scheduling requests. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. All proposers have access to state-of-the-art data analysis facilities at their home institutions. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. All objects have been GASP-ed at the STSCI. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. In CYCLE 1 NGC7027 was observed in a very small field. Maybe due to a mispointing the star observed was not the wanted central star. This is still under imvestigation. ------------------------------------------------------------------------------------ 9. Description of previous HST work. All three institutes have sufficient resources to support this project ------------------------------------------------------------------------------------ 11. Address Information Page 3 Name: T. M KAMPERMAN Category: PI Institution: SRON SPACE RESEARCH UTRECHT Address: SORBONNELAAN 2 3584 CA City: UTRECHT State: Zip Code: Country: NETHERLANDS Telephone: 3130535715 Telex (or e-mail): NL 47224 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3336c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6741 A,184 RA=19H02M37S+/-.5S, J2000 V=40 EXT 1 V=10.2+/-.2 DEC=-00D26'58"+/-2", 2 SURF(V)=13.8+/-1. 3 F(4861)=4.1+/-0.5E-12 4 SURF(1500)=4.5+/-1.E-17 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC2440 A,184 RA=07H41M55.4S+/-.5S, J2000 V=45 EXT 1 V=9.0+/-.2 DEC=-18D12'33.0"+/-2", 2 SURF(V)=16.9+/-3. 3 F(4861)=2.9+/-2.E-11 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6886 A,184 RA=20H12M43S+/-.5S, J2000 V=35 EXT 1 V=10.2+/-.2 DEC=19D58'37"+/-2", 2 SURF(V)=13.8+/-1. 3 F(4861)=4.9+/-0.5E-12 4 SURF(1500)=5.4+/-1.E-17 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6537 A,184 RA=18H05M13.3S+/-.5S, J2000 V=-4 EXT 1 V=9.6+/-.2 DEC=-19D50'14.0"+/-2", 2 SURF(V)=15.8+/-1. 3 F(4861)=9.5+/-1.E-12 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6445 A,184 RA=17H49M15.2S+/-.5S, J2000 V=29 EXT 1 V=9.5+/-.2 DEC=-20D00'34.0"+/-2", 2 SURF(V)=19.6+/-1. 3 F(4861)=1.6+/-1.E-11 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3336c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE # FOC/96 IMAGE 512X512 F130M 1 8M 3 # SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE # FOC/96 IMAGE 512X512 F210M 1 8M 3 # SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 3 DEFINE # FOC/96 IMAGE 512X512 F278M 1 8M 3 # SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 4 USE NGC6741 1 CYCLE 3 SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 5 USE NGC2440 1 CYCLE 3 SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 6 USE NGC6886 1 CYCLE 3 SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 7 USE NGC6537 1 CYCLE 3 SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ 8 USE NGC6445 1 CYCLE 3 SIZE512 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3336c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOC/96 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Proposal for AUG/FOC ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 5.30 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category SUBLUMINOUS STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F130M F210M F278M ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC6741 NGC2440 NGC6886 NGC6537 NGC6445 ------------------------------------------------------------------------------------------------------------------------------------