Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2345c Report Date: 09-May-96:17:03 Version: ********** Check-in Date: ********** 1.Proposal Title: ABSORPTION LINES DUE TO EJECTED NEBULA OF AN OLD NOVA. ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS GO Sub Category NOVAE ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Michael Friedjung INSTITUT D'ASTROPHYSIQUE (CN FRANCE 33 1 43201425 CHARGE DE RECHERCHE ------------------------------------------------------------------------------------ 7. Abstract We plan to use the HRS to observe ultraviolet absorption lines with lower level excitation potentials at or near zero electron volts, produced by the nebula of the old nova V 603 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 ejected nebula associated with a "polar cap". Analysis of lines due to the ions C IV, NV and Si IV will give information about the velocity field of the nebula on the line of sight to the central remnant and from this on the nebular thickness, as well as on nebular ionization and perhaps on the abundances. Information about the wind expected from the accretion disk around the white dwarf component of the central binary will also be obtainable. ------------------------------------------------------------------------------------ 8. Scientific Key Words: ABSORPTION LINE, ABUNDANCE, NEBULA, NOVA, PROFILE UV, WIND ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.60 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2345c PI: Dr. Michael Friedjung Proposal Title: ABSORPTION LINES DUE TO EJECTED NEBULA OF AN OLD NOVA. ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr Michael Friedjung INSTITUT D'ASTROPHYSIQUE-PARIS FRANCE X Dr. Antonio Bianchini OSSERVATORIO ASTRONOMICO PADOVA ITALY X Dr. Angelo Cassatella IUE OBSERVATORY VILSPA- SPAIN X Dr. Pierluigi Selvelli CNR-OSSERVATORIO ASTRONOMICO DI ITALY X TRIESTE Dr. Robert E. Williams CTIO - LA SERENA CHILE Dr. Robert Gehrz UNIVERSITY OF MINNESOTA - USA MINNEAPOLIS Dr. Steven N. Shore NEW MEXICO INSTITUTE OF MINING USA TECHNOLOGY Dr. Sumner G. Starrfield ARIZONA STATE UNIVERSITY - TEMPE USA Dr. R. M. Wagner LOWELL OBSERVATORY- FLAGSTAFF, USA ARIZONA ------------------------------------------------------------------------------------ 3. Description of proposed observations. This proposal involves HRS observations of the old nova V603 Aql in 3 spectral regions, using the G160M grating with an 0.25 arcsec aperture. The spectral regions are centered, in oredr of priority at 1541 A (corresponding to violet- shifted absorption lines of CIV), 1235 A (corresponding to absorption lines of NV) and 1391 A (lines of SiIV). The small aperture is to eliminate as many traces as possible of weak nebular emission. We aim to have signal to noise ratios in the continuum spectrum of at least 20. Estimates are based on IUE fluxes published by Krautter et al. ( Astron. Astrophys. 102, 337, 1981). ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The proposed observations are in the UV, inaccessible from the ground. Though V603 Aql is the only old classical nova to have been observed at high resolution with IUE, the signal to noise ratio was too low to do what is now proposed. In addition, the resolution of IUE is lower. It should also be emphasized that the present type of study cannot be carried out during outbursts when novae are much brighter, as the then optically very thick absorption lines due to the expanding envelope, are partly filled in by line emission. At some stages this filling in can dominate. Some of us have been involved in the study of UV spectra with IUE of both old novae and novae during outburst. Two of us (Friedjung and Starrfield) have written reviews of UV obser- vations ("The Classical Novae", Bode and Evans eds., 1988 J. Wiley Publ. Comp.; "Exploring the Universe with the IUE Satellite", Y. Kondo ed., 1987, Reidel Publ. Comp.). Starrfield, Truran and Williams have been particularly concerned with the measurement and interpretation of element abundances in novae. Most of us have studied novae for many years. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The exposure times were calculated using the published IUE fluxes (Krautter et al., Astron. Astrophys. 102, 337, 1981) and the HRS sensitivity Table ( number 4- 9b) for grating G160M and the small 0.25 Aperture as given in the "Hubble Space Telescope Goddard High Resolution Spectrograph Instrument Book", version 2.0 May 1989. The aim was to obtain a signal to noise ratio of at least 20. Page 3 ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data reduction can be performed at the ST-ECF in Garching. However, we also plan to make copies of the data since most of us have access in their own institutes to a VAX computer on which the data reduction software is available. We aim to obtain line profiles. These will be analysed and compared to obtain the velocity distribution in the line of sight and information on column densities for the nebular absorption lines. Absorption line profiles due to a possible weak continuing wind will be compared with models. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Most of the institutes in which we work as well as national organisations will provide the necessary computing and financial facilities. ------------------------------------------------------------------------------------ 11. Address Information Name: MICHAEL FRIEDJUNG Category: PI Institution: INSTITUT D'ASTROPHYSIQUE Address: 98/BIS BOULEVARD ARAGO City: PARIS State: Zip Code: 75014 Country: FRANCE Telephone: 33-1-43201425 Telex (or e-mail): 270070 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2345c [ 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 V603-AQL OLD-NOVA PLATE-ID = 050T, 2000 1 V=11.8 +/- 0.2 , E(B-V)=0.1 NOVA-AQL- RA=18H 48M 54.611S +/- 0.2", 2 F-CONT(1541)= 7 +/- 1 E-13 1918 GSC448- DEC=+00D 35' 2.95" +/- 0.2" 3 F-CONT(1235)= 9 +/- 1 E-13 423 4 F-CONT(1391)= 8 +/- 1 E-13 Comments: FLUX VALUES REFER TO THE CONTINUUM AT CENTRAL WAVELENGTHS CORRESPONDING TO THE THREE SELECTED SPECTRAL REGIONS. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2345c [ 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 V603-AQL HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=3 1 1.8S 2 1 ONBOARD ACQ FOR 2- BRIGHT=60000 3 4.1 FAINT=3000 4 ------------------------------------------------------------------------------------------------------------------------------------ 2 V603-AQL HRS ACCUM 0.25 G160M 1541 1 15M 22 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2.1 V603-AQL HRS ACCUM 0.25 G160M 1541 1 10M 22 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 V603-AQL HRS ACCUM 0.25 G160M 1235 1 15M 20 3 2 ------------------------------------------------------------------------------------------------------------------------------------ 3.1 V603-AQL HRS ACCUM 0.25 G160M 1235 1 10M 20 3 2 ------------------------------------------------------------------------------------------------------------------------------------ 4 V603-AQL HRS ACCUM 0.25 G160M 1391 1 15M 21 4 3 ------------------------------------------------------------------------------------------------------------------------------------ 4.1 V603-AQL HRS ACCUM 0.25 G160M 1391 1 10M 21 4 3 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2345c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=3 BRIGHT=60000 FAINT=3000 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.60 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category NOVAE ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2-4.1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names V603-AQL NOVA-AQL-1918 GSC448-423 ------------------------------------------------------------------------------------------------------------------------------------