Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5340 Report Date: 18-Jul-95:17:12 Version: ********** Check-in Date: ********** 1.Proposal Title: LINE ABSORPTION DUE TO EJECTED NEBULA OF AN OLD NOVA ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID INTERSTELLAR MEDIUM GO Sub Category NOVAE ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Michael Friedjung INSTITUT D'ASTROPHYSIQUE, PA FRANCE 33 1 43 20 14 ------------------------------------------------------------------------------------ 7. Abstract We plan to use the GHRS to observe ultra violet absorption lines with lower level excitation potentials at zero electron volts, produced by the nebula ejected by the old nova V603 Aql (1918). This old nova is very bright, while the line of sight to the central remnant seems to pass through or near the density maximum of the nebula, which is called a "polar cap". Following the repair of the HST it will be possible to obtain good line profiles. Analysis of them will give information about the velocity field of the nebula along the line of sight to the central remnant and from this about the nebular thickness. Limits to the column densities of different ions will be obtainable and when combined with ground based and IUE fluxes as well as with ionization calculations, will give conditions about relative element abundances. In addition we shall also be able to determine characteristics of a possible wind from an accretion disk, if present around the white dwarf component of the binary system. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 3.00 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5340 PI: Michael Friedjung Proposal Title: LINE ABSORPTION DUE TO EJECTED NEBULA OF AN OLD NOVA ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Michael Friedjung 5436 FRANCE X Antonio Bianchini 6470 ITALY X Angelo Cassatella 6406 ITALY X Pierluigi Selvelli 6440 ITALY X ------------------------------------------------------------------------------------ 3. Description of proposed observations. The proposal involves GHRS observations of the old nova V603 Aql in 3 spectral regions, using the G160 grating and the small science aperture. The spectral regions are centred near 1540 A (CIV), 1390 A (Si IV) and 1240 A (NV), the aim being to observe absorption components produced by the ejected envelope of the nova. The ejected nebula is much larger than either aperture (diameter of the order of 2 minutes arc), but the small science aperture will help to eliminate traces of it as much as possible, as well as providing better line profiles. We wish to have a signal to noise ratio of the order of 20/1, so as to be able to detect and measure weak features and obtain good line profiles. Onboard acquisition in the ACCUMULATION mode is very suitable. The exposure of each region has been broken down into short subexposures, so as to minimize long exposure problems. In view of the time alocated, we shall especially concentrate on obtaining this signal to noise ratio for the C IV region, as there is a very good chance of at least seeing the C IV doublet in absorption. Estimates of exposure times needed are based on IUE fluxes, combined with table 7.4.1 of the GHRS post COSTAR handbook large aperture sensitivities, multiplied by 2/3. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The proposed observations are in the ultraviolet spectral domain, which is unaccesible from the ground. Though V603 Aql is the only old classical nova to have been observed at high spectral resolution with IUE, the signal to noise ratio was too low to do what is proposed. Note that the presence of CIV absorption was inspite of this suspected by one of us (P.L. Selvelli) in the IUE results. In addition the resolution of IUE is lower than that obtainable with the proposed grating of the GHRS. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. No special requirements. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. None. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. We intend to organize ourselves the acquisition of ground based observations of images of the nebula and spectra of the central object. These do not need to be exactly simultanious, as changes of the nebula should be slow. Page 3 ------------------------------------------------------------------------------------ 9. Description of previous HST work. All present investigators were involved in a previous version of this proposal with a slightly different title, having the same PI, made for cycle 1 "Absorption lines due to ejected nebula of an old nova (no. 2345). Cycle 1 proposal no. 2345 was accepted with supplemental priority in 1989. Following the discovery of spherical aberration it was re- examined in 1991 and still only given supplemental priority. The repair of the HST should enable this similar programme to be carried out correctly. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Funds are supplied by the french "Institut National des Sciences de l'Univers". ------------------------------------------------------------------------------------ 11. Address Information Name: MICHAEL FRIEDJUNG Category: PI Institution: 5436 Address: INSTITUT D'ASTROPHYSIQUE (CNRS) 98 BIS BOULEVARD ARAGO City: PARIS State: Zip Code: 75014 Country: FRANCE Telephone: 33 1 43 20 14 25 Telex (or e-mail): INTERNET FRIEDJUNG@IAP.FR FAX 33 1 43 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5340 [ 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 HD174107 A,150,161,926 PLATE-ID = 050T, 2000 V = -23 1 V=11.7 +/- 0.2 V603-AQL RA = 18H 48M 54.611S +/- 2 B-V=0.0 +/- 0.1 GSC448-423 0.2", 3 E(B-V)=0.1 DEC = +00D 35' 2.95" +/-0.2" 4 F-CONT(1541)= 6 +/-2 E-13 5 F-CONT(1235)= 6 +/-2 E-13 6 F-CONT(1391)= 7 +/-2 E-13 7 F-CONT(2500)= 2.0 +/-0.5 E-13 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5340 [ 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 HD174107 HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=3 1 3.6S 1 1 CYCLE 4 BRIGHT=RETURN 2 ONBOARD ACQ FOR 2 LOCATE=YES 3 7 Comments: ONBOARD ACQUISITION OF FAIRLY BRIGHT STAR WITH NORMAL 3X3 SEARCH. STEP-TIME IS 0.4SEC COUNT RATE IS 50000 CNTS/SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD174107 HRS ACQ/ 0.25 MIRROR-N2 SEARCH-SIZE=5 1 10.0S 1 CYCLE 4 PEAKUP ONBOARD ACQ FOR 3- 5 Comments: PEAKUP IN SSA FOR LINES 3-5 STEP-TIME IS 0.4SEC ------------------------------------------------------------------------------------------------------------------------------------ 3 HD174107 HRS ACCUM 0.25 G160M 1541 FP-SPLIT=FOUR 1 44M 20 4 1 CYCLE 4 COMB=FOUR 44M STEP-PATT=5 DOPPLER=ON Comments: OBTAIN 4 FP-SPLIT SPECTRA WITH A TOTAL S/N NEAR 20 ------------------------------------------------------------------------------------------------------------------------------------ 4 HD174107 HRS ACCUM 0.25 G160M 1235 FP-SPLIT=FOUR 1 42M 20 5 2 CYCLE 4 COMB=FOUR 42M STEP-PATT=5 DOPPLER=ON Comments: OBTAIN 4 FP-SPLIT SPECTRA WITH A TOTAL S/N OF ORDER OF 20 ------------------------------------------------------------------------------------------------------------------------------------ 5 HD174107 HRS ACCUM 0.25 G160M 1391 FP-SPLIT=FOUR 1 32M 20 6 3 CYCLE 4 COMB=FOUR 32M STEP-PATT=5 DOPPLER=ON Comments: OBTAIN 4 FP-SPLIT SPECTRA WITH A TOTAL S/N OF ORDER OF 20 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5340 [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=3 BRIGHT=RETURN LOCATE=YES SEARCH-SIZE=5 FP-SPLIT=FOUR COMB=FOUR STEP-PATT=5 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 3.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category NOVAE ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4; ONBOARD ACQ FOR 2 ONBOARD ACQ FOR 3-5 CYCLE 4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD174107 V603-AQL GSC448-423 ------------------------------------------------------------------------------------------------------------------------------------