16649( 3) - 07-Oct-2021 15:07:21 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16649 Version: 3 Check-in Time: 07-Oct-2021 15:07:21 STScI Edit Number: 0 Title The final word on SN 2009ip: is it dead? ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Nathan Smith University of Arizona Y CoI: Dr. Jon Mauerhan The Aerospace Corporation N CoI: Prof. Alex V. Filippenko University of California - Berkeley N CoI: Dr. Schuyler D. Van Dyk California Institute of Technology N CoI: Dr. Jennifer Andrews NOIRLab - Gemini North (HI) N CoI: Dr. Ori Dosovitz Fox Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract We propose 10 yr post-explosion UV/optical imaging of the remarkable transient SN 2009ip, in order to determine its ultimate fate. This object was discovered in a non-terminal eruption in 2009, and then appeared to explode in a much more extreme supernova (SN)-like event in 2012. A very massive (80 Msun) quiescent progenitor was identified in an archival HST image, and the star had several luminous blue variable (LBV)-like eruptions before 2012. Many SNe IIn are inferred to have LBV progenitors to make their dense circumstellar material (CSM), but SN2009ip is an extraordinary case where the LBV-like progenitor was detected directly, and where spectra of numerous pre-SN eruptions were obtained. No other SN has this treasure trove of detailed information about the progenitor (not even SN1987A). This was one of the most important transient events of the past decade, because if it was a true core-collapse (CC) SN, then it is the first definitive case of a very massive star above 30 Msun that went SN and didn't collapse to a black hole. However, the interpretation of SN2009ip as a true CCSN is controversial for 2 reasons: (1) its lightcurve could also be explained by shell collisions from non-terminal explosive transients, and (2) the tell-tale signs of nucleosynthetic products, if present, were largely masked by CSM interaction. As with all SN progenitor candidates, proof that the star is dead requires that it disappear in late time data. Five years ago the source was only marginally fainter than the progenitor and apparently still fading. Cycle 29 will be 10 years since explosion. Our proposed observations will determine once and for all if the progenitor is gone. ------------------------------------------------------------------------------------ Observations Description ------------------------ The goal of these observations is to measure the UV/optical/IR spectral energy distrbution (SED) and H-alpha emission line strength of the source at SN 2009ip's position at a time of roughly 10 years after its 2012 explosion. If the source at SN 2009ip's position has faded beyond detectability, these observations will place deep-enough upper limits on a late-time source to confirm that the progenitor star is gone. If a detectable source remains, the observations are designed to be able to distinguish between three competing possibilities: (1) A massive luminous blue variable (LBV) progenitor star that survived, possibly obscured by dust that was ejected in the event or returning 16649( 3) - 07-Oct-2021 15:07:21 - [ 2] to a hot state, (2) A SN explosion where the late-time source is dominated by ongoing late-time circumstellar material (CSM) interaction, or (3) A companion star or star cluster that is coincident with the SN position. Of course, the late time source may be due to a combination of these sources, and the UV/optical/IR SED plus H-alpha emission will be able to distinguish them. It is impossible to rule out or distinguish between these possibilities with only optical/IR continuum filters; both the UV flux and the H-alpha emission are essential as well. Although we have organized the observations into separate visits, they should be executed as close together in time as possible. Whether the lingering source is a SN powered by late-time CSM interaction or a surviving LBV star, it is likely to be variable. LBVs can vary on short (few days) timescales, and late-time CSM interaction luminosity can change quickly if the CSM is clumpy or has shell structure. In order to produce a useful SED to test the various hypotheses, the full continuum broad-band set of filters from UV to IR must be obtained close together in time. Most importantly, the narrow F657N filter (tracing H-alpha emission) should be obtained as close to quasi-simultaneously with the F555W, F606W, and F814W filter images as possible. The F657N filter will be used to measure the equivalent width of H-alpha emission - but to do this, we need to know the off-line optical continuum emission level measured by the F555W, F606W, and F814W filters at the same time. Both the continuum luminosity and H-alpha emission can be variable (and they may be independently variable). It is impossible to complete the science goals of this program without comparably deep optical continuum filters to subtract from the Halpha filter. Also, it will greatly improve the archival value of the images if the F657N and broad continuum filters (at least F555W and F814W) are obtained at nearly the same time, with the SN located at the same position on the detector, and with the same roll angle. This is because well-aligned and simultaneous continuum images are needed to make a continuum-subtracted image of the H-alpha emission. We do not strictly need this spatial alignment to complete the goal of measuring the H-alpha equivalent width from SN 2009ip (we could do this even if the target were at a slightly different position on the detector, as long as the observations were close in time). However this alignment is needed in order to make a continuum-subtracted H-alpha emission map of the surrounding environment in the host galaxy in order to study star forming HII regions or search for emission line stars, for example. It would significantly decrease the archival value if the F657N and broad-band filters were not obtained with the same target positon on the detector and a very close roll angle. This is because the differences in distortion correction and pixel resampling are minimized or eliminated when the roll angle and field of view aer the same, and obviously, the overlapping area on the sky in the F657N and continuum filters is optimum if they are spatially aligned. If it turns out that there is a source remaining at SN2009ip's position and that source is consistent with a star cluster contributing to the observed light, the UV/optical/IR SED will be used to contrain the age of that cluster with comparison to population synthesis models. If the remaining light is a combination of a star cluster (presumabl not variable) and late-time CSM interaction (variable) then the SED would be corrupted if images in different 16649( 3) - 07-Oct-2021 15:07:21 - [ 3] filters are obtained at significantly different times. ------------------------------------------------------------------------------------ 16649( 3) - 07-Oct-2021 15:07:21 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2009IP STAR, EMISSION LINE RA=22H23M8.2600S +/- 0.5", J2000 V = 22 STAR, LUMINOUS BLUE DEC=-28D56'52.40" +/- 0.5" VARIABLE, SUPERNOVA TYPE II Reference Frame: Other: SIMBAD Extended: NO Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 16649( 3) - 07-Oct-2021 15:07:21 - [ 5] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.636 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16649( 3) - 07-Oct-2021 15:07:21 - [ 6] Visit: 01 (SN2009ip UV) Visit Requirements: GROUP 01, 02, 03 WITHIN 1D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2009IP WFC3/UVI ACCUM UVIS2-C1K F275W FLASH=20, CR-SPLIT=2 1 900 S GS ACQ SCENARIO BASE1B3; S 1C-SUB see below PATTERN 2 1 (2480 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F275W 1 none none 1 1 620.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F275W 1 none none 2 1 620.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F275W 2 none none 1 1 620.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F275W 2 none none 2 1 620.0 S S K1C-SUB 16649( 3) - 07-Oct-2021 15:07:21 - [ 7] Visit: 02 (SN2009ip Ha) Visit Requirements: SAME ORIENT AS 01 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2009IP WFC3/UVI ACCUM UVIS2-C1K F657N FLASH=20, CR-SPLIT=2 1 2540 S GS ACQ SCENARIO BASE1B3; S 1C-SUB see below PATTERN 2 1 (5344 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F657N 1 none none 1 1 1338.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F657N 1 none none 2 1 1338.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F657N 2 none none 1 2 1334.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F657N 2 none none 2 2 1334.0 S S K1C-SUB 16649( 3) - 07-Oct-2021 15:07:21 - [ 8] Visit: 03 (SN2009ip VRI) Visit Requirements: SAME ORIENT AS 01 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2009IP WFC3/UVI ACCUM UVIS2-C1K F814W CR-SPLIT=2, FLASH=5 1 600 S GS ACQ SCENARIO BASE1B3 S 1C-SUB see below (634 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2009IP WFC3/UVI ACCUM UVIS2-C1K F555W CR-SPLIT=2 1 1000 S S 1C-SUB see below (1034 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2009IP WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=2 1 600 S S 1C-SUB see below (634 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F814W none none none 1 1 317.0 S S K1C-SUB SN2009IP 1 WFC3/UVI ACCUM UVIS2-C1 F814W none none none 2 1 317.0 S S K1C-SUB SN2009IP 2 WFC3/UVI ACCUM UVIS2-C1 F555W none none none 1 1 517.0 S S K1C-SUB SN2009IP 2 WFC3/UVI ACCUM UVIS2-C1 F555W none none none 2 1 517.0 S S K1C-SUB SN2009IP 3 WFC3/UVI ACCUM UVIS2-C1 F606W none none none 1 1 317.0 S S K1C-SUB SN2009IP 3 WFC3/UVI ACCUM UVIS2-C1 F606W none none none 2 1 317.0 S S K1C-SUB 16649( 3) - 07-Oct-2021 15:07:21 - [ 9] Visit: 04 (SN2009IP IR) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2009IP WFC3/IR MULTIAC IR F125W NSAMP=12, SAMP-SEQ=STEP100 1 DEF PATTERN 1 1-2 CUM (1198.465 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2009IP WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=STEP100 1 DEF CUM (1398.465 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2009IP 1 WFC3/IR MULTIAC IR F125W 1 none none none 1 N/A CUM SN2009IP 1 WFC3/IR MULTIAC IR F125W 2 none none none 1 N/A CUM SN2009IP 2 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM SN2009IP 2 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM 16649( 3) - 07-Oct-2021 15:07:21 - [ 10] Summary Form for Proposal 16649 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS2-C1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2, FLASH=20, FLASH=5, NSAMP=12, NSAMP=13, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 01, 02, 03 WITHIN 1D, GS ACQ SCENARIO BASE1B3, PATTERN 1 1-2, PATTERN 2 1, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F125W, F160W, F275W, F555W, F606W, F657N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2009IP ------------------------------------------------------------------------------------------------------------------------------------