11977( 4) - 27-Jan-2009 13:30:36 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11977 Version: 4 Check-in Time: 27-Jan-2009 13:30:36 STScI Edit Number: 2 Title WFPC2 12-Year Proper Motions of Two Galactic Analogs of the SN1987A Rings ------------------------------------------------------------------------------------ Type Cycle GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Nathan Smith University of California - Berkeley CoI: Dr. Robert D. Gehrz University of Minnesota - Twin Cities N CoI: Dr. Alex V. Filippenko University of California - Berkeley N ------------------------------------------------------------------------------------ Abstract This special call in Cycle 16 is a unique opportunity to measure fine-scale proper motions with the same WFPC2 camera after more than a decade has elapsed, and is the last time such an opportunity is likely to be available. We aim to apply this powerful tool to the ring nebulae around two hot supergiants: the set of ionized double-rings around the massive eclipsing binary RY Scuti, and the equatorial ring and bipolar lobes around Sher 25. These are the only two Galactic analogs of SN1987A for which this proper motion measurement is possible (others lack a first-epoch image with HST, and SN1987A is too distant). In the case of RY Scuti, the expected motions are small because the compact ring nebula is only 1-arcsec in diameter. For Sher 25 the expected motions are small because the object is thought to be at d=6 kpc. The 10-12 years that have elapsed since earlier imaging epochs for these sources make it possible to accurately measure their expected sub-pixel proper motion, and hence, their ages and distances. We can discriminate between specific proposed models for the formation of these ring nebulae by measuring the relative ages of these ionized equatorial rings compared to outer structures: the bipolar lobes in the case of Sher 25, and an outer dust shell in the case of RY Scuti. These will provide the first quantitative tests of binary merger vs. rapidly rotating single star models for the shaping of SN1987A and related ring nebulae around massive stars, which until now have relied upon qualitative comparisons to structues seen in single-epoch images. The expected expansion is less than 0.1 arcsec, so there is no hope of making either measurement from the ground, and increased systematic errors associated with switching to new instruments (with different pixel scales and distortion corrections) will make this measurement more difficult even for HST after SM4. ------------------------------------------------------------------------------------ Observations Description ------------------------ The purpose of these observations is to obtain H-alpha F656N and [N II] F658N images of two targets, RY Scuti and Sher 25. These images will duplicate previous observations made about 10 years ago in order to measure proper motion expansion of the circumstellar nebular rings around these stars. Both targets are centered on the PC chip. Real Time Justification ----------------------- 11977( 4) - 27-Jan-2009 13:30:36 - [ 2] Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11977( 4) - 27-Jan-2009 13:30:36 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V-RY-SCT STAR, CIRCUMSTELLAR RA=18H25M31.4785S +/- 0.1", J2000 V = 9.14 MATTER, EMISSION LINE DEC=-12D41'24.19" +/- 0.1" NEBULA, INTERACTING BINARY, SUPERGIANT O, WOLF RAYET Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 2 SHER-25 STAR, B0-B2 III-I, RA=11H15M7.6000S +/- 0.3", J2000 V = 12.3 CIRCUMSTELLAR MATTER, DEC=-61D15'14.00" +/- 0.3" EMISSION LINE NEBULA, RING Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 11977( 4) - 27-Jan-2009 13:30:36 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V-RY-SCT WFPC2 IMAGE PC1-FIX F658N 1 18 S ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RY-SCT WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 350 S see below ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RY-SCT WFPC2 IMAGE PC1-FIX F656N 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 4 V-RY-SCT WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 260 S see below ------------------------------------------------------------------------------------------------------------------------------------ 5 V-RY-SCT WFPC2 IMAGE PC1-FIX F658N 1 18 S POS TARG 0.11375, 0.11375 ------------------------------------------------------------------------------------------------------------------------------------ 6 V-RY-SCT WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 350 S SAME POS AS 5 see below ------------------------------------------------------------------------------------------------------------------------------------ 7 V-RY-SCT WFPC2 IMAGE PC1-FIX F656N 1 10 S SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ 8 V-RY-SCT WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 260 S SAME POS AS 5 see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ V-RY-SCT 1 WFPC2 IMAGE PC1-FIX F658N none none none none 1 N/A V-RY-SCT 2 WFPC2 IMAGE PC1-FIX F658N none none none none 1 350.0 S V-RY-SCT 3 WFPC2 IMAGE PC1-FIX F656N none none none none 1 N/A V-RY-SCT 4 WFPC2 IMAGE PC1-FIX F656N none none none none 1 260.0 S V-RY-SCT 5 WFPC2 IMAGE PC1-FIX F658N none none none none 1 N/A V-RY-SCT 6 WFPC2 IMAGE PC1-FIX F658N none none none none 1 350.0 S V-RY-SCT 7 WFPC2 IMAGE PC1-FIX F656N none none none none 1 N/A V-RY-SCT 8 WFPC2 IMAGE PC1-FIX F656N none none none none 1 260.0 S 11977( 4) - 27-Jan-2009 13:30:36 - [ 5] Visit: 02 Visit Requirements: ORIENT 340D TO 20 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SHER-25 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 2 SHER-25 WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 600 S ------------------------------------------------------------------------------------------------------------------------------------ 3 SHER-25 WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 600 S ------------------------------------------------------------------------------------------------------------------------------------ 4 SHER-25 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 5 SHER-25 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 300 S POS TARG 0.11375, 0.11375 ------------------------------------------------------------------------------------------------------------------------------------ 6 SHER-25 WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 600 S SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ 7 SHER-25 WFPC2 IMAGE PC1-FIX F658N CR-SPLIT=DEF 1 600 S SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ 8 SHER-25 WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=DEF 1 300 S SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SHER-25 1 WFPC2 IMAGE PC1-FIX F656N none none none none 1 N/A SHER-25 2 WFPC2 IMAGE PC1-FIX F658N none none none none 1 N/A SHER-25 3 WFPC2 IMAGE PC1-FIX F658N none none none none 1 N/A SHER-25 4 WFPC2 IMAGE PC1-FIX F656N none none none none 1 N/A SHER-25 5 WFPC2 IMAGE PC1-FIX F656N none none none none 2 N/A SHER-25 6 WFPC2 IMAGE PC1-FIX F658N none none none none 2 N/A SHER-25 7 WFPC2 IMAGE PC1-FIX F658N none none none none 2 N/A SHER-25 8 WFPC2 IMAGE PC1-FIX F656N none none none none 2 N/A 11977( 4) - 27-Jan-2009 13:30:36 - [ 6] Summary Form for Proposal 11977 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 340D TO 20 D, POS TARG 0.11375, 0.11375, SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F656N, F658N ------------------------------------------------------------------------------------------------------------------------------------ Target Names SHER-25, V-RY-SCT ------------------------------------------------------------------------------------------------------------------------------------