14501( 5) - 04-May-2016 15:50:52 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14501 Version: 5 Check-in Time: 04-May-2016 15:50:52 STScI Edit Number: 0 Title Confirming the wide binary companion of IRC+10216 ------------------------------------------------------------------------------------ Type Cycle GO/DD 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Hyosun Kim Academia Sinica, Institute of Astronomy Y and Astrophysics CoI: Prof. You-Hua Chu Academia Sinica, Institute of Astronomy N and Astrophysics CoI: Dr. Ho-Gyu Lee Korea Astronomy and Space Science N Institute (KASI) CoI: Dr. Ji Hoon Kim National Astronomical Obs of Japan (NAOJ), N Subaru Telescope CoI: Dr. Youichi Ohyama Academia Sinica, Institute of Astronomy N and Astrophysics CoI: Dr. Toshiya Ueta University of Denver N CoI: Dr. Nicolas Mauron Laboratoire Univers et Particules de N Montpellier CoI: Dr. Peter Scicluna Academia Sinica, Institute of Astronomy N and Astrophysics ------------------------------------------------------------------------------------ Abstract The latest HST optical images of the nearest carbon-rich asymptotic giant branch (AGB) star IRC+10216 revealed two point-like sources at the center of its circumstellar envelope (CSE). A plausible interpretation is that the dense inner envelope is clearing, and hence revealing the central binary stars and the associated structures. Since IRC+10216 has changed so dramatically in 10 years, more frequent monitoring is necessary. A similar dramatic change is also found in the near-infrared (NIR). The clumps detected over two decades have disappeared in a ground-based observation in Feb. 2016, leaving a single peak in H and K and two peaks in J. The second peak in J has a different color from that of the primary peak and its CSE, implying a different origin and thus supporting the identification as a companion star. In particular, its spectral peak is likely at a wavelength slightly shorter than J band, consistent with an M-type main-sequence star. However, its correspondance with the optical source is not conclusive because of the small field of view of the ground-based NIR observations, traded with the high resolution using the adaptive optics. In order to confirm/refute the identication of the AGB star IRC+10216 and its companion and to monitor the evolution of its CSE, we propose for WFC3 snapshots in two UVIS bands and one IR band to simultaneously achieve (1) high resolution and (2) large field of view for astrometry. This would be the first confirmation of a "main-sequence companion" consisting a "wide binary" with an AGB star, which is the major category of missing companions of evolved stars. This observation is optimized near the light curve minimum, which is now. ------------------------------------------------------------------------------------ Observations Description ------------------------ 14501( 5) - 04-May-2016 15:50:52 - [ 2] The proposed observations are to take WFC3 images of IRC+10216 in two UVIS bands (F606W and F814W) and one IR band (F098M). The F606W and F814W observations are the repeats of the previous PID 12205 observations (June 4, 2011) but for shorter integration times. It will also be observed with the F098M filter, which will bridge the F606W and F814W images to our newly observed GEMINI/NIFS data in J band. The 2011 HST F606W and F814W images consist of one bright point-like source (tentatively identified as a carbon star; IRC+10216 A) connected by bright North-South blobs with a ~0.4 arcsec extension and one weaker point-like source (tentatively identified as a companion, M-type main-sequence star; IRC+10216 B) at ~0.5 arcsec east of the bright source. There were several diffuse clumps surrounding these point-like sources. See Figure 1(c) in the proposal pdf file. As the nature of a carbon star, it has an extended component with FWHM > 1 arcsec over ~100 arcsec (Figure 1(e)). The carbon star (and thus the extended halo component) light is currently in the increasing phase (see Figure 2, dark gray), and the F098M observation would enter nonlinear (or saturation) regime after May 5-10. EARLIER EXECUTION IS DESIRED, and a careful treatment is required after this date. IRC+10216 is not visible in the HST orbit after June 24. With the on-source time ~700 sec, ~60 sec, and ~15 sec for F606W, F814W, and F098M, the companion (0.3-0.5 arcsec east of the peak) would have S/N>100. We do not expect any saturation issue for the two UVIS bands. The IR band (F098M) could have saturation issue, therefore we will set the individual exposure time to be the minimum (~2.9 sec). We expect the peak pixel of F098M image to remain in a linear regime before ~May 5 (no later than May 10) and to enter non-linear regime but not to be saturated before ~June 24. The observations with all 3 filters will be completed in one orbit. To bridge the gap between the UVIS chips for F606W and F814W, we will use a 2-point dither following the WFC3-UVIS-GAP-LINE pattern. For the NIR imaging, we will use a 2-point dither applying the WFC3-IR-DITHER-BLOB pattern to mitigate the effects of blobs and other artifacts. ------------------------------------------------------------------------------------ 14501( 5) - 04-May-2016 15:50:52 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IRC+10216 EXT-STAR, AGB STAR, RA=09H47M59.5500S, J2000 V = 10.96 CARBON STAR, DEC=+13D16'45.00" CIRCUMSTELLAR MATTER, M V-IV, SPIRAL ARM Reference Frame: Other: SIMBAD 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) 2006 0.0023974348510231217 0.012 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 IRC+10216-UV EXT-STAR, AGB STAR, RA=09H47M59.5193S, J2000 V = 10.96 IS CARBON STAR, DEC=+13D16'59.12" CIRCUMSTELLAR MATTER, M V-IV, SPIRAL ARM Reference Frame: Other: SIMBAD ------------------------------------------------------------------------------------------------------------------------------------ 3 IRC+10216-IR EXT-STAR, AGB STAR, RA=09H47M59.6487S, J2000 V = 10.96 CARBON STAR, DEC=+13D16'47.42" CIRCUMSTELLAR MATTER, M V-IV, SPIRAL ARM Reference Frame: Other: SIMBAD ------------------------------------------------------------------------------------------------------------------------------------ 14501( 5) - 04-May-2016 15:50:52 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 2.414 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.759 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BLOB Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 5.183 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.859 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 14501( 5) - 04-May-2016 15:50:52 - [ 5] Visit: 02 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 IRC+10216-I WFC3/IR MULTIAC IR F098M NSAMP=1, SAMP-SEQ=RAPID 6 DEF PATTERN 2 1 R CUM (35.187 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 IRC+10216-U WFC3/UVI ACCUM UVIS F606W 1 350 S (700 PATTERN 1 2 VIS S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 IRC+10216-U WFC3/UVI ACCUM UVIS F814W FLASH=4 1 350 S (700 PATTERN 1 3 VIS S 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 | ------------------------------------------------------------------------------------------------------------------------------------ IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 1 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 2 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 3 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 4 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 5 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 1 none 6 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 1 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 2 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 3 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 4 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 5 none 1 N/A CUM IRC+10216-IR 1 WFC3/IR MULTIAC IR F098M 2 none 6 none 1 N/A CUM IRC+10216-UVIS 2 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 N/A S 14501( 5) - 04-May-2016 15:50:52 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ IRC+10216-UVIS 2 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 N/A S IRC+10216-UVIS 3 WFC3/UVI ACCUM UVIS F814W 1 none none none 1 N/A S IRC+10216-UVIS 3 WFC3/UVI ACCUM UVIS F814W 2 none none none 1 N/A S 14501( 5) - 04-May-2016 15:50:52 - [ 7] Visit: 03 (Alternate observation Single Target) Visit Requirements: ORIENT 90D TO 130 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IRC+10216 WFC3/IR MULTIAC IR F098M NSAMP=1, SAMP-SEQ=RAPID 6 DEF PATTERN 2 1 CUM (35.187 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 IRC+10216 WFC3/UVI ACCUM UVIS F606W 1 350 S (700 PATTERN 1 2 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 IRC+10216 WFC3/UVI ACCUM UVIS F814W FLASH=4 1 350 S (700 PATTERN 1 3 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 1 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 2 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 3 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 4 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 5 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 1 none 6 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 1 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 2 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 3 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 4 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 5 none 1 N/A CUM IRC+10216 1 WFC3/IR MULTIAC IR F098M 2 none 6 none 1 N/A CUM IRC+10216 2 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 N/A S 14501( 5) - 04-May-2016 15:50:52 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ IRC+10216 2 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 N/A S IRC+10216 3 WFC3/UVI ACCUM UVIS F814W 1 none none none 1 N/A S IRC+10216 3 WFC3/UVI ACCUM UVIS F814W 2 none none none 1 N/A S 14501( 5) - 04-May-2016 15:50:52 - [ 9] Summary Form for Proposal 14501 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=4, NSAMP=1, SAMP-SEQ=RAPID ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 90D TO 130 D, PATTERN 1 2, PATTERN 1 3, PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F098M, F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names IRC+10216, IRC+10216-IR, IRC+10216-UVIS ------------------------------------------------------------------------------------------------------------------------------------