Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4593c Report Date: 09-May-96:19:43 Version: ********** Check-in Date: ********** 1.Proposal Title: POSITIONING OF THE GEMINGA OPTICAL COUNTERPART ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID HOT STARS GO/DD Sub Category NEUTRON STARS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Giovanni F. Bignami CNR INSTITUTO DI FISICA COSM ITALY ------------------------------------------------------------------------------------ 7. Abstract The status of our understanding of Geminga (1E0630+178) has recently much improved with the ROSAT/GRO discovery of a common periodicity in the X and gamma-ray source. The timing data require the object to be a rotating neutron star, at a distance very likely less than 100 pc. If so, a proper motion of the supposed optical counterpart (G") should be detectable with a PC exposure. This is all we need both for comparison with ground based images (taken as early as 1984), and as a reference for future HST data. This appears as the only feasible method of at last deciding on the optical counterpart of Geminga since if G" is indeed the counterpart it could have a detectable proper motion. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.39 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4593c PI: Giovanni F. Bignami Proposal Title: POSITIONING OF THE GEMINGA OPTICAL COUNTERPART ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Giovanni F. Bignami CNR INSTITUTO DI FISICA COSMICA, ITALY X MILANO Patrizia A. Caraveo CNR INSTITUTO DI FISICA COSMICA, ITALY X MILANO Sandro Mereghetti CNR INSTITUTO DI FISICA COSMICA, ITALY X MILANO ------------------------------------------------------------------------------------ 2. Scientific Justification. a. Provide a short description of the proposed observations, by cycle if a long- term project. If this is an Archival Research proposal, provide a list of the number of exposures requested, or provide a generic description if appropriate. For the proposed scientifc objectives we need a PC8 image with a V filter. We simply want to image the Geminga field once to be able to position, with PC accuracy, the best available optical candidate, G". We have chosen the combination of the PC and V filter(F555W) because in this color we are sure of the object's magnitude and thus of its detectability in the requested time. ------------------------------------------------------------------------------------ 3. Description of proposed observations. Ground based astronomy has been exploited in full for Geminga. One exposure (split in 2 parts to allow cleaning for the CR hits) with the PC on HST, even with its reduced capability, will yield the one single crucial observation,i.e. the accurate subarcsec positioning of G", which could settle the optical side of the Geminga story. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The observing time requested for this program has been kept to a minimum, in the spirit of the reassessment of our original proposal (ID2525), approved for cycle 1. In particular, we only need to be able to detect G" with the PC8 through the single V filter (F555W) and, following synphot, this can be obtained with S/N=10 in 2500 sec. In order to perform cosmic ray cleaning we request two 2500 sec exposures for a total of 5000 sec. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. The proposers have significant experience with ground based optical astronomy data analysis. At our Institute in Milano we have directly available IRAF (with STSDAS), MIDAS on SUN WS and VAX. We plan, however, to make full use of the ECF facility in Garching, and also to interact strongly with STScI Personnel. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. 2525 SEARCHING FOR THE GEMINGA OPTICAL COUNTERPART WITH MULTI COLOR PHOTOMETRY related 3432 CIR-X1 REVISITED: SPECTROSCOPY THROUGHOUT THE 16.6 DAY CYCLE OF THE REAL OPTICAL CANDIDATE not related b. Summarize the main results obtained from previous related programs. No results yet. ------------------------------------------------------------------------------------ 9. Description of previous HST work. The Istituto di Fisica Cosmica has VAX nad SUN WS equipped with MIDAS and IRAF (with STSDAS). Students from the Istituto di Fisica of the Milano University normally take active part in the data analysis. Funds will be provided by the Agenzia Spaziale Italian and by the CNR Page 3 ------------------------------------------------------------------------------------ 11. Address Information Name: GIOVANNI F. BIGNAMI Category: PI Institution: CNR Instituto di Fisica Cosmica, Address: City: State: Zip Code: Country: ITALY Telephone: 39-2-2367587 Telex (or e-mail): 313839 MUACNR ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 4593c [ 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 STAR- A,160 RA = 06H 33M 53.98S +/- J2000 1 V= 25.3 +/- 0.2 0633+1746 0.5", GEMINGA DEC = 17D 46' 11.20" +/-0.5" 1E0630+178 Comments: LINE 1 REFERES TO THE FAINTEST OBJECT KNOWN IN THE FIELD. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4593c [ 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 STAR- PC IMAGE PC6 F555W CR-SPLIT=NO 1 1400S 10 1 1 SEQ 1-3 NO GAP 0633+1746 CYCLE 2 / 1-3 Comments: EXPOSURE TIME HAS BEEN REDUCED BY -20% TO FIT IN AN ALIGNMENT. ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR- PC IMAGE PC6 F555W CR-SPLIT=NO 1 2000S 10 1 1 0633+1746 Comments: EXPOSURE TIME HAS BEEN REDUCED 20% TO FIT IN AN ALIGNMENT. ------------------------------------------------------------------------------------------------------------------------------------ 3 STAR- PC IMAGE PC6 F555W CR-SPLIT=NO 1 2000S 10 1 1 0633+1746 Comments: EXPOSURE TIME HAS BEEN REDUCED 20% TO FIT IN AN ALIGNMENT. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4593c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations PC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO/DD ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.39 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category NEUTRON STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1-3 NO GAP; CYCLE 2 / 1-3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names STAR-0633+1746 GEMINGA 1E0630+178 ------------------------------------------------------------------------------------------------------------------------------------