6809( 3) - 02/26/96 11:11 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6809 Version: 3 Check-in Date: 26-Feb-1996 11:09:21 1.Proposal Title: An Optical Counterpart to the X-Ray Point Source in the Puppis A Supernova Remnant? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle HOT STARS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: P. Frank Winkler Middlebury College CoI: Robert Petre Goddard Space Flight Center N CoI: Chris M. Becker Massachusetts Institute of Technology N CoI: Dale A. Frail National Radio Astronomy Observatory -- N Very Large Array ------------------------------------------------------------------------------------ 6. Abstract Recent ROSAT observations of the supernova remnant Puppis A have identified an X-ray point source near its center. No X- ray or radio pulsations have been detected from this source, though the present limits are not stringent. All the data are consistent with the source being a hot neutron star formed at the time of the supernova which produced Puppis A, some 4000 years ago. We propose to search for an optical counterpart to the X-ray source, using the power of HST and the WFPC2 to reach significantly deeper than can be achieved from the ground. If the hot neutron star interpretation is correct, we would expect it to be well beyond the limits of detectability even from HST.\ \ But the limits achievable from HST should enable us to rule out virtually all known alternative compact sources on the basis of an unreasonably high X-ray/optical flux ratio. ------------------------------------------------------------------------------------ 6809( 3) - 02/26/96 11:11 - [ 2] Observations Description ------------------------ We propose to observe the source with one of the WFC chips for one full orbit in each of two filters: F606W (Wide V) provides the best match with the chip response and should give the highest sensitivity for all but the most highly reddened sources (or intrinsically very red objects). For a source in Puppis A itself, for which E(B-V) ~ 0.5, this filter should give the best sensitivity. F814W (Wide I) will have a higher sensitivity for very highly reddened sources, such as a background extragalactic object, and will give color information to help classify any object bright enough to be detected through both filters. These observations should give a 3Sigma\\\\ detection for any source with f_opt/f_X >~ 10^-5\\\\ in either V or I band, an increase in sensitivity by a factor of 20 or more over the existing ground-based data. Observations through each filter will be done in 3 exposures of ~800\\\\ s each, in order to eliminate almost entirely the chance of cosmic-ray contamination while maintaining sky-limited conditions. Real Time Justification ----------------------- None. Calibration Justification ------------------------- None. Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address*P. Frank Winkler*Department of Physics*Middlebury College*Middlebury, VT*05753 Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6809( 3) - 02/26/96 11:11 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-082158- STAR,NEUTRON RA=08H 21M 57.50S +/- 0.5S,DEC=- 2000. V = 24.+/-1. 430016 STAR,SUPERNOVA,ISM,SNR 43D 00' 15.8" +/- 5" Comments: FLUX IS UPPER LIMIT ONLY. 6809( 3) - 02/26/96 11:11 - [ 4] Visit: 01 Visit Requirements: ORIENT 60D TO 90D SCHED 40% On Hold Comments: Additional Comments: Orientation to avoid bright stars Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 STAR-082158 WFPC2 IMAGE WF3 F814W DITHER- 1 1000S -430016 TYPE=LINE Comments: Pair-Dither-Pair. ------------------------------------------------------------------------------------------------------------------------------------ 20 STAR-082158 WFPC2 IMAGE WF3 F606W DITHER- 1 1100S -430016 TYPE=LINE Comments: Pair-Dither-Pair ------------------------------------------------------------------------------------------------------------------------------------ 6809( 3) - 02/26/96 11:11 - [ 5] Summary Form for Proposal 6809 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DITHER-TYPE=LINE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 60D TO 90D SCHED 40% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names STAR-082158-430016 ------------------------------------------------------------------------------------------------------------------------------------