Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2590c Report Date: 09-May-96:17:14 Version: ********** Check-in Date: ********** 1.Proposal Title: DEEP IMAGING OF THE SITE OF SN 1961V, A POSSIBLE EXTRAGALACTIC ETA CARINAE ANALOGUE ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS GO Sub Category MASSIVE STARS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. Alexei V. Filippenko CALIFORNIA, UNIVERSITY OF, B USA 415-642-1813 ASSOCIATE PROFESSOR ------------------------------------------------------------------------------------ 7. Abstract Analysis of new and old ground-based observations leads us to hypothesize that the unique "Type V Supernova" 1961V in NGC1058 was not a SN (the explosion of a massive star at the end of its life). Rather, it was the super-outburst of a luminous blue variable --- an exaggerated eta Car-type outburst of a very massive, evolved star near the end of core hydrogen burning. The long plateau in the light curve following outburst, at nearly the same brightness as the pre-outburst star, suggests that the progenitor survived the outburst; it later faded only because of the formation of optically thick dust in the ejecta. The underlying star should be a hot Of/WN star. Our observations suggest a circumstellar extinction of Av=5mag, if the surviving star resembles eta Car. The present brightness of the star should be near V=27, but perhaps as bright as V=23. We will determine whether the star is present by imaging the site of SN1961V with the WFC. The faint star cannot be seen from the ground because of contamination by the underlying HII regions. ------------------------------------------------------------------------------------ 8. Scientific Key Words: EXT-STAR; SN; LBV; HOST=NGC1058 IMAGING ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.00 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2590c PI: Prof. Alexei V. Filippenko Proposal Title: DEEP IMAGING OF THE SITE OF SN 1961V, A POSSIBLE EXTRAGALACTIC ETA CARINAE ANALOGUE ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Prof. Alexei V. Filippenko CALIFORNIA, UNIVERSITY OF, USA BERKELEY Robert W. Goodrich CALIFORNIA INSTITUTE OF USA TECHNOLOGY Guy S. Stringfellow MOUNT STROMLO OBSERVATORY AUSTRALIA Alain C. Porter KPNO, NOAO USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. We will obtain WFC images of the site of SN 1961V through wide-band filters (corresponding to V, R, and I), to attempt to locate the star which we believe produced the SN 1961V outburst. If our hypothesis is correct, the star should still exist; it was not a true supernova. The object may, however, be severely reddened; hence, exposures at several different wavelengths are desired. These exposures should help in the identification of the star, if several candidates are visible in a small region, since we will have color information. The wide- band filters we have chosen are F555W, F702W, and F785LP. This combination maximizes the wavelength range over which observations will be made. CR-split will be used, and we will not pre-flash the exposures. The chosen set of wide- band filters differs in detail from the one originally proposed, because the original WFPC handbook did not make it clear which filters correspond most closely with the Johnson filters. ------------------------------------------------------------------------------------ 11. Address Information Name: ALEXEI V. FILIPPENKO Category: PI Institution: UNIVERSITY OF CALIFORNIA Address: DEPARTMENT OF ASTRONOMY City: BERKELEY State: CA Zip Code: 94720 Country: USA Telephone: 415-642-1813 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2590c [ 3] ------------------------------------------------------------------------------------------------------------------------------------ 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 SN1961V EXT-STAR; SN; LBV; RA = 2H 40M 29.70S +/- 4", 1950.0 Z = 1 V = 26.0 +/- 1.0 HOST=NGC1058 DEC = +37D 8' 1.6" +/- 4", 0.0017 2 B-V = 0.3 +/- 1.0 REGION Comments: STELLAR OBJECT AT SITE OF SN1961V HAS NEVER BEEN DETECTED; WE ARE TESTING A THEORETICAL PREDICTION. THUS MAGNITUDE AND COLOR ESTIMATES ARE HIGHLY UNCERTAIN. IF SUITABLE GUIDE STARS NOT FOUND, CAN POINT HST UP TO 30" FROM ABOVE POSITION. IN WORST CASE, CENTER IN W2,3, OR 4 INSTEAD OF W1. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2590c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 SN1961V WFC IMAGE W1 F702W PRE-FLASH=NO 1 1500S 6 1 1 CYCLE 1 CR-SPLIT=NO 2 SEQ 1-3 NO GAP Comments: IF THERE IS EXTRA TIME BEFORE EARTH OCCULTATION, IT CAN BE ADDED TO THE EXPOSURE TIME TO INCREASE S/N. QUOTED S/N IS SUM OF TWO 30M EXP. WANT DATA FROM ALL 4 CCDS. ------------------------------------------------------------------------------------------------------------------------------------ 1.5 SN1961V WFC IMAGE W1 F702W PRE-FLASH=NO 1 40M 6 1 1 CYCLE 1 CR-SPLIT=NO 2 Comments: IF THERE IS EXTRA TIME BEFORE EARTH OCCULTATION, IT CAN BE ADDED TO THE EXPOSURE TIME TO INCREASE S/N. QUOTED S/N IS SUM OF TWO 30M EXP. WANT DATA FROM ALL 4 CCDS. ------------------------------------------------------------------------------------------------------------------------------------ 2 SN1961V WFC IMAGE W1 F785LP PRE-FLASH=NO 3 40M 4 1 2 CYCLE 1 CR-SPLIT=NO 2 Comments: IF THERE IS EXTRA TIME BEFORE EARTH OCCULTATION, IT CAN BE ADDED TO THE EXPOSURE TIME TO INCREASE S/N. QUOTED S/N IS SUM OF TWO 47.5M EXP. WANT DATA FROM ALL 4 CCDS. ------------------------------------------------------------------------------------------------------------------------------------ 3 SN1961V WFC IMAGE W1 F555W PRE-FLASH=NO 2 40M 6 1 3 CYCLE 1 CR-SPLIT=NO 2 Comments: IF THERE IS EXTRA TIME BEFORE EARTH OCCULTATION, IT CAN BE ADDED TO THE EXPOSURE TIME TO INCREASE S/N. QUOTED S/N IS SUM OF TWO 30-M EXP. WANT DATA FROM ALL 4 CCDS. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2590c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PRE-FLASH=NO CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category MASSIVE STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 1; SEQ 1-3 NO GAP CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F702W F785LP F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN1961V ------------------------------------------------------------------------------------------------------------------------------------