12610( 3) - 04-Jan-2012 13:33:59 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12610 Version: 3 Check-in Time: 04-Jan-2012 13:33:59 STScI Edit Number: 0 Title Convection and mass loss through the chromosphere of Betelgeuse ------------------------------------------------------------------------------------ Type Cycle GO 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Stephen T. Ridgway National Optical Astronomy Observatory, AURA CoI: Dr. Pierre Kervella Observatoire de Paris Y CoI: Dr. Andrea Chiavassa Universite Libre de Bruxelles N CoI: Dr. Xavier Haubois Universidade de Sao Paulo N CoI: Dr. Guy Perrin Observatoire de Paris N CoI: Mr. Miguel Montarges Observatoire de Paris N ------------------------------------------------------------------------------------ Abstract Betelgeuse is well suited for detailed study of the mass loss process in a massive red supergiant. We have engaged in a multi-scale, multi-color study to trace the ejected material from the photosphere to the interstellar medium, and understand its chemical evolution (formation of molecules and dust). Infrared interferometry already gave us a detailed image of the photosphere, compatible with large convective cells. Adaptive optics spectro-imaging (1.0-2.2 microns) allowed us to detect the presence of the CN molecule and mass loss plume structures up to at least 6 R*. At larger distances, we observed silicate-rich dust in thermal IR (8-20 microns). From the surface to 100 R*, we therefore have a continuous coverage with multicolor imagery. The chromosphere lies at a key location, between the photosphere and the molecular envelope. As shown by STIS spatially resolved spectroscopy (Lobel & Dupree 2001), it contains rising and falling gases. Such structure is supported by our 3D modeling of the convection. In order to probe the dynamics of the envelope and its relation to photospheric spots and mass loss plumes, we propose to obtain UV imaging with STIS at 3 epochs to complement our coordinated ground-based effort as well as the earlier HST UV snapshots. We will use this imagery to correlate structures at different radii and temperatures, and to explore the time-scales of evolution. With the support of our 3D models, this information will answer specific questions including deciding between convective and polar explanations for bright spots and plumes. Our infrared imaging observations will be repeated contemporaneously with the requested HST/STIS images. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe Betelgeuse: - at two epochs with STIS-MAMA in three filters (FUV-F25LYA, FUV-F25NDQ1, NUV-F25ND5), - at one epoch with STIS-MAMA in two filters (FUV-F25NDQ1, NUV-F25ND5) We will also observe a PSF calibrator, HD 38393, at one epoch, in three filters (FUV-F25LYA, FUV-F25NDQ1, NUV-F25ND5). 12610( 3) - 04-Jan-2012 13:33:59 - [ 2] The observations of Betelgeuse and the PSF calibrator in the F25NDQ1 and F25ND5 filters will be dithered with 1.5-pixel steps to obtain a better PSF sampling. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12610( 3) - 04-Jan-2012 13:33:59 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 BETELGEUSE STAR, CIRCUMSTELLAR RA=05H55M10.3053S +/- 0.1", J2000 V = V = 0.7 +/- 0.5 magU = 4.38, magB = MATTER, HOTSPOT, M DEC=+07D24'25.43" +/- 0.1" 21.91 2.27, E(B-V)=0.4699 III-I Reference Frame: ICRS Comments: Betelgeuse is an irregular, moderately variable star. Its current (Dec 2011) V band magnitude according to the AAVSO, is mV=0.45, i.e. slightly above its average brightness over the last 10 years (mV ~0.5, with an evolution range between 0.3 and 1.0). Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0018514498381218894 0.011300000000000001 0.00655 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD38393 CALIBRATION, RA=05H44M27.7909S +/- 0.1", J2000 V = -9.7 V = 3.6 magU=4.08, magB=4.07 PHOTOMETRIC, POINT DEC=-22D26'54.18" +/- 0.1" SPREAD FUNCTION Reference Frame: ICRS Comments: This star (Gamma Lep) is a PSF calibrator. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.02103891325723694 -0.36897 0.11202 ------------------------------------------------------------------------------------------------------------------------------------ 12610( 3) - 04-Jan-2012 13:33:59 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-MAMA-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.0369 Line_Spacing 0.0369 Coordinate_Frame POS-TARG Pattern_Orient 26.6 Angle_Between_Sides 143.130102 Center_Pattern NO Pattern_Comments: This pattern is intended to improve the sampling of the STIS-MAMA PSF by combining four exposures with offsets of 1.5 pixel (1 pixel = 0.0246"). It will be used for following filter configurations: FUV-F25NDQ1 and NUV-F25ND5. ------------------------------------------------------------------------------------------------------------------------------------ 12610( 3) - 04-Jan-2012 13:33:59 - [ 5] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: This is a three-filter exposure on Betelgeuse (FUV-F25LYA, FUV-F25NDQ2, NUV-F25ND5), spread over 2 orbits. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 BETELGEUSE STIS/FUV TIME-TA F25LYA MIRROR BUFFER-TIME=400 1 2800 S -MAMA G see below Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is similar to a STIS-MAMA F25LYA exposure in TIME-TAG mode (EXPTIME=2300s) obtained on 2000-03-14 on Betelgeuse with STIS in the same configuration (exposure id: o55001d7q), that gave a maximum flux of 200 counts/s on the star, and a total flux of 1450 counts/s on the MAMA array. This figure is comparable to out result using the STIS imaging ETC (1870 counts/s). The corresponding BUFFER-TIME parameter is therefore 2e6/1870 = 1070 s. With a further safety margin of 20%, we obtain a BUFFER-TIME value of 855 s. ------------------------------------------------------------------------------------------------------------------------------------ 2 BETELGEUSE STIS/FUV ACCUM F25NDQ2 MIRROR 1 120 S PATTERN 1 2 -MAMA Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 3 BETELGEUSE STIS/NUV ACCUM F25ND5 MIRROR 1 500 S PATTERN 1 3 -MAMA see below Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 12610( 3) - 04-Jan-2012 13:33:59 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETELGEUSE 1 STIS/FUV TIME-TA F25LYA MIRROR none none none none 1 2751.0 S -MAMA G BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 1 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 2 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 3 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 4 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 1 none none none 2 479.0 S -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 2 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 3 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 4 none none none 2 N/A -MAMA 12610( 3) - 04-Jan-2012 13:33:59 - [ 7] Visit: 02 Visit Requirements: AFTER 01 BY 15 D TO 45 D On Hold Comments: Additional Comments: Two-filter exposure on Betelgeuse, over a 1 orbit visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 BETELGEUSE STIS/FUV ACCUM F25NDQ2 MIRROR 1 110 S PATTERN 1 1 -MAMA Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 2 BETELGEUSE STIS/NUV ACCUM F25ND5 MIRROR 1 430 S PATTERN 1 2 -MAMA Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETELGEUSE 1 STIS/FUV ACCUM F25NDQ2 MIRROR 1 none none none 1 N/A -MAMA BETELGEUSE 1 STIS/FUV ACCUM F25NDQ2 MIRROR 2 none none none 1 N/A -MAMA BETELGEUSE 1 STIS/FUV ACCUM F25NDQ2 MIRROR 3 none none none 1 N/A -MAMA BETELGEUSE 1 STIS/FUV ACCUM F25NDQ2 MIRROR 4 none none none 1 N/A -MAMA BETELGEUSE 2 STIS/NUV ACCUM F25ND5 MIRROR 1 none none none 1 N/A -MAMA BETELGEUSE 2 STIS/NUV ACCUM F25ND5 MIRROR 2 none none none 1 N/A -MAMA BETELGEUSE 2 STIS/NUV ACCUM F25ND5 MIRROR 3 none none none 1 N/A -MAMA BETELGEUSE 2 STIS/NUV ACCUM F25ND5 MIRROR 4 none none none 1 169.0 S -MAMA 12610( 3) - 04-Jan-2012 13:33:59 - [ 8] Visit: 03 Visit Requirements: AFTER 01 BY 300 D TO 430 D On Hold Comments: Additional Comments: This is a three-filter exposure on Betelgeuse (FUV-F25LYA, FUV-F25NDQ2, NUV-F25ND5), spread over 2 orbits. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 BETELGEUSE STIS/FUV TIME-TA F25LYA MIRROR BUFFER-TIME=400 1 2800 S -MAMA G see below Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is similar to a STIS-MAMA F25LYA exposure in TIME-TAG mode (EXPTIME=2300s) obtained on 2000-03-14 on Betelgeuse with STIS in the same configuration (exposure id: o55001d7q), that gave a maximum flux of 200 counts/s on the star, and a total flux of 1450 counts/s on the MAMA array. This figure is comparable to out result using the STIS imaging ETC (1870 counts/s). The corresponding BUFFER-TIME parameter is therefore 2e6/1870 = 1070 s. With a further safety margin of 20%, we obtain a BUFFER-TIME value of 855 s. ------------------------------------------------------------------------------------------------------------------------------------ 2 BETELGEUSE STIS/FUV ACCUM F25NDQ2 MIRROR 1 120 S PATTERN 1 2 -MAMA Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 3 BETELGEUSE STIS/NUV ACCUM F25ND5 MIRROR 1 500 S PATTERN 1 3 -MAMA see below Comments: For the ETC computation, we assembled a spectrum of Betelgeuse from past STIS observations using the E140M and E230M settings. This exposure is split in four sub-exposures to allow dithering with an amplitude of 1.5 pixels. ------------------------------------------------------------------------------------------------------------------------------------ 12610( 3) - 04-Jan-2012 13:33:59 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETELGEUSE 1 STIS/FUV TIME-TA F25LYA MIRROR none none none none 1 2751.0 S -MAMA G BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 1 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 2 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 3 none none none 2 N/A -MAMA BETELGEUSE 2 STIS/FUV ACCUM F25NDQ2 MIRROR 4 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 1 none none none 2 479.0 S -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 2 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 3 none none none 2 N/A -MAMA BETELGEUSE 3 STIS/NUV ACCUM F25ND5 MIRROR 4 none none none 2 N/A -MAMA 12610( 3) - 04-Jan-2012 13:33:59 - [ 10] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Three-filter exposure on the PSF calibrator HD 38393, 1 orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD38393 STIS/FUV TIME-TA F25LYA MIRROR BUFFER-TIME=400 1 200 S -MAMA G see below Comments: This exposure is similar to a STIS-MAMA F25LYA exposure in TIME-TAG mode (EXPTIME=2300s) obtained on 2000-03-14 on HD38393 with STIS in the same configuration (exposure id: o55003dhq), that gave a maximum flux of 1867 counts in central pixel on the star. For the ETC computation, we assembled a flux-calibrated spectrum of HD38393 from archival IUE spectra. The STIS ETC gives a total count rate on the detector of 1990 counts/s, which is comparable to the observed total count rate of 1960 counts/s in the o55003dhq exposure. We rely on this 2000 counts/s figure, with a safety margin of 20% to estimate the corresponding BUFFER-TIME parameter a being 800 s. ------------------------------------------------------------------------------------------------------------------------------------ 2 HD38393 STIS/FUV ACCUM F25NDQ2 MIRROR 1 40 S PATTERN 1 2 -MAMA Comments: For the ETC computation, we assembled a flux-calibrated spectrum of HD38393 from archival IUE spectra. ------------------------------------------------------------------------------------------------------------------------------------ 3 HD38393 STIS/NUV ACCUM F25ND5 MIRROR 1 110 S PATTERN 1 3 -MAMA Comments: For the ETC computation, we assembled a flux-calibrated spectrum of HD38393 from archival IUE spectra. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD38393 1 STIS/FUV TIME-TA F25LYA MIRROR none none none none 1 894.0 S -MAMA G 12610( 3) - 04-Jan-2012 13:33:59 - [ 11] 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD38393 2 STIS/FUV ACCUM F25NDQ2 MIRROR 1 none none none 1 N/A -MAMA HD38393 2 STIS/FUV ACCUM F25NDQ2 MIRROR 2 none none none 1 N/A -MAMA HD38393 2 STIS/FUV ACCUM F25NDQ2 MIRROR 3 none none none 1 N/A -MAMA HD38393 2 STIS/FUV ACCUM F25NDQ2 MIRROR 4 none none none 1 N/A -MAMA HD38393 3 STIS/NUV ACCUM F25ND5 MIRROR 1 none none none 1 N/A -MAMA HD38393 3 STIS/NUV ACCUM F25ND5 MIRROR 2 none none none 1 N/A -MAMA HD38393 3 STIS/NUV ACCUM F25ND5 MIRROR 3 none none none 1 N/A -MAMA HD38393 3 STIS/NUV ACCUM F25ND5 MIRROR 4 none none none 1 133.0 S -MAMA 12610( 3) - 04-Jan-2012 13:33:59 - [ 12] Summary Form for Proposal 12610 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25LYA, F25ND5, F25NDQ2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=400 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 15 D TO 45 D, AFTER 01 BY 300 D TO 430 D, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names BETELGEUSE, HD38393 ------------------------------------------------------------------------------------------------------------------------------------