16451( 3) - 17-Dec-2020 20:39:03 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16451 Version: 3 Check-in Time: 17-Dec-2020 20:39:03 STScI Edit Number: 0 Title A STIS view of ASASSN-14ko: uncovering the nature of the recently discovered periodic nuclear transient ------------------------------------------------------------------------------------ Type Cycle GO 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Benjamin John Shappee University of Hawaii Y CoI: Anna Payne University of Hawaii N CoI: Dr. Chris S. Kochanek The Ohio State University N CoI: Dr. Katie Auchettl Dark Cosmology Centre, Niels Bohr N Institute CoI: Dr. Thomas Holoien Carnegie Institution of Washington N CoI: Dr. Krzysztof Z. Stanek The Ohio State University N ------------------------------------------------------------------------------------ Abstract ASASSN-14ko is a recently discovered, periodically flaring, nuclear transient within known AGN ESO 253-G003. The flares have a mean period of ~114 days and a nonzero, negative period derivative. The exact origin of these UV/optical flares is currently unknown. Here we propose a four epoch STIS UV set of observations of the next predicted flare in December 2020. The prior 6+ years of seventeen observed flares seen in ASAS-SN tightly constrains the predicted times of pre-flare quiescence, rise, peak, and decline. These observations will be part of a much larger followup effort but the UV spectroscopy is pivotal. We will measure the evolution of UV absorption and emission lines from elements (e.g., C, N, Si) and ionization states/potentials not seen in optical spectra, which will directly help distinguish whether or not these flares are caused by a partial TDE, AGN disk accretion, or another high energy phenomenon. ------------------------------------------------------------------------------------ Observations Description ------------------------ The impact of reduced-gyro operations on this project are uncertain, but, given that the epochs of these observations are highly constrained it is likely that the effect will be to further constrain or eliminate some of the epochs. ------------------------------------------------------------------------------------ 16451( 3) - 17-Dec-2020 20:39:03 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ASASSN-14KO GALAXY, ACCRETION DISK, RA=05H25M18.1170S +/- 0.10", J2000 Z = V = 14.5 +/- 0.2 at peak: MULTIPLE NUCLEI, DEC=-46D00'20.23" +/- 0.10" 0.042489 W1=15.69(0.04), M2=15.66(0.07), and NUCLEUS, QUASAR W2=15.64(0.04) Reference Frame: ICRS Comments: Note, this is the nucleaus of a galaxy, but, it is a complex galaxy. Please see submission notes. 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 ------------------------------------------------------------------------------------------------------------------------------------ 16451( 3) - 17-Dec-2020 20:39:03 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.3829 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.3829 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16451( 3) - 17-Dec-2020 20:39:03 - [ 4] Visit: 01 (Epoch 1 (Quiescence)) Visit Requirements: BETWEEN 05-MAR-2021:00:00:00 AND 20-MAR-2021:00:00:00 On Hold Comments: Additional Comments: Quiescence before ASASSN-14ko Dec 2020 outburst 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 ASASSN-14KO STIS/CCD ACQ 50CCD MIRROR 1 5 S (5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ASASSN-14KO STIS/NUV ACCUM 52X0.2 G230L 2376 2 150 S PATTERN 2 2 -MAMA see below (1242 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ASASSN-14KO STIS/FUV ACCUM 52X0.2 G140L 1425 2 500 S PATTERN 2 3 -MAMA see below (3004 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 | ------------------------------------------------------------------------------------------------------------------------------------ ASASSN-14KO 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 2 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 2 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 2 none 1 207.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 1 none 1 502.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 2 none 2 N/A -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 1 none 2 N/A -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 2 none 2 N/A -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 1 none 2 501.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 2 none 2 501.0 S -MAMA 16451( 3) - 17-Dec-2020 20:39:03 - [ 5] Visit: 02 (Epoch 2 (Rise)) Visit Requirements: SCHED 90%; BETWEEN 17-DEC-2020:00:00:00 AND 19-DEC-2020:00:00:00 On Hold Comments: Additional Comments: Rise of ASASSN-14ko Dec 2020 outburst 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 ASASSN-14KO STIS/CCD ACQ 50CCD MIRROR 1 5 S (5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ASASSN-14KO STIS/NUV ACCUM 52X0.2 G230L 2376 2 200 S PATTERN 2 2 -MAMA see below (1010 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ASASSN-14KO STIS/FUV ACCUM 52X0.2 G140L 1425 2 500 S PATTERN 2 3 -MAMA see below (2835 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 | ------------------------------------------------------------------------------------------------------------------------------------ ASASSN-14KO 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 1 none 1 168.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 2 none 1 168.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 1 none 1 168.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 2 none 1 168.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 1 none 1 169.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 2 none 1 169.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 1 none 1 422.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 2 none 2 460.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 1 none 2 460.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 2 none 2 460.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 1 none 2 460.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 2 none 2 573.0 S -MAMA 16451( 3) - 17-Dec-2020 20:39:03 - [ 6] Visit: 03 (Epoch 3 (Peak)) Visit Requirements: SCHED 70%; BETWEEN 21-DEC-2020:00:00:00 AND 23-DEC-2020:00:00:00 On Hold Comments: Additional Comments: Peak of the ASASSN-14ko Dec 2020 outburst 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 ASASSN-14KO STIS/CCD ACQ 50CCD MIRROR 1 5 S (5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ASASSN-14KO STIS/FUV ACCUM 52X0.2 G140L 1425 2 100 S PATTERN 1 2 -MAMA see below (440 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ASASSN-14KO STIS/NUV ACCUM 52X0.2 G230L 2376 2 100 S PATTERN 1 3 -MAMA see below (965 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 | ------------------------------------------------------------------------------------------------------------------------------------ ASASSN-14KO 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A ASASSN-14KO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 1 none 1 100.0 S -MAMA ASASSN-14KO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 2 none 1 100.0 S -MAMA ASASSN-14KO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 1 none 1 120.0 S -MAMA ASASSN-14KO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 2 none 1 120.0 S -MAMA ASASSN-14KO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 1 none 1 241.0 S -MAMA ASASSN-14KO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 2 none 1 241.0 S -MAMA ASASSN-14KO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 1 none 1 241.0 S -MAMA ASASSN-14KO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 2 none 1 242.0 S -MAMA 16451( 3) - 17-Dec-2020 20:39:03 - [ 7] Visit: 04 (Epoch 4 (Decline)) Visit Requirements: BETWEEN 28-DEC-2020:00:00:00 AND 03-JAN-2021:00:00:00 On Hold Comments: Additional Comments: Decline of the ASASSN-14ko Dec 2020 outburst 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 ASASSN-14KO STIS/CCD ACQ 50CCD MIRROR 1 5 S (5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ASASSN-14KO STIS/NUV ACCUM 52X0.2 G230L 2376 2 300 S PATTERN 2 2 -MAMA see below (1242 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ASASSN-14KO STIS/FUV ACCUM 52X0.2 G140L 1425 2 300 S PATTERN 2 3 -MAMA see below (3004 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 | ------------------------------------------------------------------------------------------------------------------------------------ ASASSN-14KO 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none 2 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none 2 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 1 none 1 207.0 S -MAMA ASASSN-14KO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none 2 none 1 207.0 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 1 none 1 502 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none 2 none 2 500 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 1 none 2 500 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none 2 none 2 500 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 1 none 2 500 S -MAMA ASASSN-14KO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none 2 none 2 502.0 S -MAMA 16451( 3) - 17-Dec-2020 20:39:03 - [ 8] Summary Form for Proposal 16451 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 50CCD, 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 05-MAR-2021:00:00:00 AND 20-MAR-2021:00:00:00, BETWEEN 17-DEC-2020:00:00:00 AND 19-DEC-2020:00:00:00, BETWEEN 21-DEC-2020:00:00:00 AND 23-DEC-2020:00:00:00, BETWEEN 28-DEC-2020:00:00:00 AND 03-JAN-2021:00:00:00, PATTERN 1 2, PATTERN 1 3, PATTERN 2 2, PATTERN 2 3, SCHED 70%, SCHED 90% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names ASASSN-14KO ------------------------------------------------------------------------------------------------------------------------------------